diff options
Diffstat (limited to 'libtommath/pre_gen')
| -rw-r--r-- | libtommath/pre_gen/mpi.c | 8819 |
1 files changed, 8819 insertions, 0 deletions
diff --git a/libtommath/pre_gen/mpi.c b/libtommath/pre_gen/mpi.c new file mode 100644 index 0000000..7d832e7 --- /dev/null +++ b/libtommath/pre_gen/mpi.c @@ -0,0 +1,8819 @@ +/* Start: bn_error.c */ +#include <tommath.h> +#ifdef BN_ERROR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +static const struct { + int code; + char *msg; +} msgs[] = { + { MP_OKAY, "Successful" }, + { MP_MEM, "Out of heap" }, + { MP_VAL, "Value out of range" } +}; + +/* return a char * string for a given code */ +char *mp_error_to_string(int code) +{ + int x; + + /* scan the lookup table for the given message */ + for (x = 0; x < (int)(sizeof(msgs) / sizeof(msgs[0])); x++) { + if (msgs[x].code == code) { + return msgs[x].msg; + } + } + + /* generic reply for invalid code */ + return "Invalid error code"; +} + +#endif + +/* End: bn_error.c */ + +/* Start: bn_fast_mp_invmod.c */ +#include <tommath.h> +#ifdef BN_FAST_MP_INVMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes the modular inverse via binary extended euclidean algorithm, + * that is c = 1/a mod b + * + * Based on slow invmod except this is optimized for the case where b is + * odd as per HAC Note 14.64 on pp. 610 + */ +int +fast_mp_invmod (mp_int * a, mp_int * b, mp_int * c) +{ + mp_int x, y, u, v, B, D; + int res, neg; + + /* 2. [modified] b must be odd */ + if (mp_iseven (b) == 1) { + return MP_VAL; + } + + /* init all our temps */ + if ((res = mp_init_multi(&x, &y, &u, &v, &B, &D, NULL)) != MP_OKAY) { + return res; + } + + /* x == modulus, y == value to invert */ + if ((res = mp_copy (b, &x)) != MP_OKAY) { + goto LBL_ERR; + } + + /* we need y = |a| */ + if ((res = mp_abs (a, &y)) != MP_OKAY) { + goto LBL_ERR; + } + + /* 3. u=x, v=y, A=1, B=0, C=0,D=1 */ + if ((res = mp_copy (&x, &u)) != MP_OKAY) { + goto LBL_ERR; + } + if ((res = mp_copy (&y, &v)) != MP_OKAY) { + goto LBL_ERR; + } + mp_set (&D, 1); + +top: + /* 4. while u is even do */ + while (mp_iseven (&u) == 1) { + /* 4.1 u = u/2 */ + if ((res = mp_div_2 (&u, &u)) != MP_OKAY) { + goto LBL_ERR; + } + /* 4.2 if B is odd then */ + if (mp_isodd (&B) == 1) { + if ((res = mp_sub (&B, &x, &B)) != MP_OKAY) { + goto LBL_ERR; + } + } + /* B = B/2 */ + if ((res = mp_div_2 (&B, &B)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* 5. while v is even do */ + while (mp_iseven (&v) == 1) { + /* 5.1 v = v/2 */ + if ((res = mp_div_2 (&v, &v)) != MP_OKAY) { + goto LBL_ERR; + } + /* 5.2 if D is odd then */ + if (mp_isodd (&D) == 1) { + /* D = (D-x)/2 */ + if ((res = mp_sub (&D, &x, &D)) != MP_OKAY) { + goto LBL_ERR; + } + } + /* D = D/2 */ + if ((res = mp_div_2 (&D, &D)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* 6. if u >= v then */ + if (mp_cmp (&u, &v) != MP_LT) { + /* u = u - v, B = B - D */ + if ((res = mp_sub (&u, &v, &u)) != MP_OKAY) { + goto LBL_ERR; + } + + if ((res = mp_sub (&B, &D, &B)) != MP_OKAY) { + goto LBL_ERR; + } + } else { + /* v - v - u, D = D - B */ + if ((res = mp_sub (&v, &u, &v)) != MP_OKAY) { + goto LBL_ERR; + } + + if ((res = mp_sub (&D, &B, &D)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* if not zero goto step 4 */ + if (mp_iszero (&u) == 0) { + goto top; + } + + /* now a = C, b = D, gcd == g*v */ + + /* if v != 1 then there is no inverse */ + if (mp_cmp_d (&v, 1) != MP_EQ) { + res = MP_VAL; + goto LBL_ERR; + } + + /* b is now the inverse */ + neg = a->sign; + while (D.sign == MP_NEG) { + if ((res = mp_add (&D, b, &D)) != MP_OKAY) { + goto LBL_ERR; + } + } + mp_exch (&D, c); + c->sign = neg; + res = MP_OKAY; + +LBL_ERR:mp_clear_multi (&x, &y, &u, &v, &B, &D, NULL); + return res; +} +#endif + +/* End: bn_fast_mp_invmod.c */ + +/* Start: bn_fast_mp_montgomery_reduce.c */ +#include <tommath.h> +#ifdef BN_FAST_MP_MONTGOMERY_REDUCE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes xR**-1 == x (mod N) via Montgomery Reduction + * + * This is an optimized implementation of montgomery_reduce + * which uses the comba method to quickly calculate the columns of the + * reduction. + * + * Based on Algorithm 14.32 on pp.601 of HAC. +*/ +int +fast_mp_montgomery_reduce (mp_int * x, mp_int * n, mp_digit rho) +{ + int ix, res, olduse; + mp_word W[MP_WARRAY]; + + /* get old used count */ + olduse = x->used; + + /* grow a as required */ + if (x->alloc < n->used + 1) { + if ((res = mp_grow (x, n->used + 1)) != MP_OKAY) { + return res; + } + } + + /* first we have to get the digits of the input into + * an array of double precision words W[...] + */ + { + register mp_word *_W; + register mp_digit *tmpx; + + /* alias for the W[] array */ + _W = W; + + /* alias for the digits of x*/ + tmpx = x->dp; + + /* copy the digits of a into W[0..a->used-1] */ + for (ix = 0; ix < x->used; ix++) { + *_W++ = *tmpx++; + } + + /* zero the high words of W[a->used..m->used*2] */ + for (; ix < n->used * 2 + 1; ix++) { + *_W++ = 0; + } + } + + /* now we proceed to zero successive digits + * from the least significant upwards + */ + for (ix = 0; ix < n->used; ix++) { + /* mu = ai * m' mod b + * + * We avoid a double precision multiplication (which isn't required) + * by casting the value down to a mp_digit. Note this requires + * that W[ix-1] have the carry cleared (see after the inner loop) + */ + register mp_digit mu; + mu = (mp_digit) (((W[ix] & MP_MASK) * rho) & MP_MASK); + + /* a = a + mu * m * b**i + * + * This is computed in place and on the fly. The multiplication + * by b**i is handled by offseting which columns the results + * are added to. + * + * Note the comba method normally doesn't handle carries in the + * inner loop In this case we fix the carry from the previous + * column since the Montgomery reduction requires digits of the + * result (so far) [see above] to work. This is + * handled by fixing up one carry after the inner loop. The + * carry fixups are done in order so after these loops the + * first m->used words of W[] have the carries fixed + */ + { + register int iy; + register mp_digit *tmpn; + register mp_word *_W; + + /* alias for the digits of the modulus */ + tmpn = n->dp; + + /* Alias for the columns set by an offset of ix */ + _W = W + ix; + + /* inner loop */ + for (iy = 0; iy < n->used; iy++) { + *_W++ += ((mp_word)mu) * ((mp_word)*tmpn++); + } + } + + /* now fix carry for next digit, W[ix+1] */ + W[ix + 1] += W[ix] >> ((mp_word) DIGIT_BIT); + } + + /* now we have to propagate the carries and + * shift the words downward [all those least + * significant digits we zeroed]. + */ + { + register mp_digit *tmpx; + register mp_word *_W, *_W1; + + /* nox fix rest of carries */ + + /* alias for current word */ + _W1 = W + ix; + + /* alias for next word, where the carry goes */ + _W = W + ++ix; + + for (; ix <= n->used * 2 + 1; ix++) { + *_W++ += *_W1++ >> ((mp_word) DIGIT_BIT); + } + + /* copy out, A = A/b**n + * + * The result is A/b**n but instead of converting from an + * array of mp_word to mp_digit than calling mp_rshd + * we just copy them in the right order + */ + + /* alias for destination word */ + tmpx = x->dp; + + /* alias for shifted double precision result */ + _W = W + n->used; + + for (ix = 0; ix < n->used + 1; ix++) { + *tmpx++ = (mp_digit)(*_W++ & ((mp_word) MP_MASK)); + } + + /* zero oldused digits, if the input a was larger than + * m->used+1 we'll have to clear the digits + */ + for (; ix < olduse; ix++) { + *tmpx++ = 0; + } + } + + /* set the max used and clamp */ + x->used = n->used + 1; + mp_clamp (x); + + /* if A >= m then A = A - m */ + if (mp_cmp_mag (x, n) != MP_LT) { + return s_mp_sub (x, n, x); + } + return MP_OKAY; +} +#endif + +/* End: bn_fast_mp_montgomery_reduce.c */ + +/* Start: bn_fast_s_mp_mul_digs.c */ +#include <tommath.h> +#ifdef BN_FAST_S_MP_MUL_DIGS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* Fast (comba) multiplier + * + * This is the fast column-array [comba] multiplier. It is + * designed to compute the columns of the product first + * then handle the carries afterwards. This has the effect + * of making the nested loops that compute the columns very + * simple and schedulable on super-scalar processors. + * + * This has been modified to produce a variable number of + * digits of output so if say only a half-product is required + * you don't have to compute the upper half (a feature + * required for fast Barrett reduction). + * + * Based on Algorithm 14.12 on pp.595 of HAC. + * + */ +int +fast_s_mp_mul_digs (mp_int * a, mp_int * b, mp_int * c, int digs) +{ + int olduse, res, pa, ix, iz; + mp_digit W[MP_WARRAY]; + register mp_word _W; + + /* grow the destination as required */ + if (c->alloc < digs) { + if ((res = mp_grow (c, digs)) != MP_OKAY) { + return res; + } + } + + /* number of output digits to produce */ + pa = MIN(digs, a->used + b->used); + + /* clear the carry */ + _W = 0; + for (ix = 0; ix < pa; ix++) { + int tx, ty; + int iy; + mp_digit *tmpx, *tmpy; + + /* get offsets into the two bignums */ + ty = MIN(b->used-1, ix); + tx = ix - ty; + + /* setup temp aliases */ + tmpx = a->dp + tx; + tmpy = b->dp + ty; + + /* this is the number of times the loop will iterrate, essentially its + while (tx++ < a->used && ty-- >= 0) { ... } + */ + iy = MIN(a->used-tx, ty+1); + + /* execute loop */ + for (iz = 0; iz < iy; ++iz) { + _W += ((mp_word)*tmpx++)*((mp_word)*tmpy--); + } + + /* store term */ + W[ix] = ((mp_digit)_W) & MP_MASK; + + /* make next carry */ + _W = _W >> ((mp_word)DIGIT_BIT); + } + + /* store final carry */ + W[ix] = _W; + + /* setup dest */ + olduse = c->used; + c->used = digs; + + { + register mp_digit *tmpc; + tmpc = c->dp; + for (ix = 0; ix < digs; ix++) { + /* now extract the previous digit [below the carry] */ + *tmpc++ = W[ix]; + } + + /* clear unused digits [that existed in the old copy of c] */ + for (; ix < olduse; ix++) { + *tmpc++ = 0; + } + } + mp_clamp (c); + return MP_OKAY; +} +#endif + +/* End: bn_fast_s_mp_mul_digs.c */ + +/* Start: bn_fast_s_mp_mul_high_digs.c */ +#include <tommath.h> +#ifdef BN_FAST_S_MP_MUL_HIGH_DIGS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* this is a modified version of fast_s_mul_digs that only produces + * output digits *above* digs. See the comments for fast_s_mul_digs + * to see how it works. + * + * This is used in the Barrett reduction since for one of the multiplications + * only the higher digits were needed. This essentially halves the work. + * + * Based on Algorithm 14.12 on pp.595 of HAC. + */ +int +fast_s_mp_mul_high_digs (mp_int * a, mp_int * b, mp_int * c, int digs) +{ + int olduse, res, pa, ix, iz; + mp_digit W[MP_WARRAY]; + mp_word _W; + + /* grow the destination as required */ + pa = a->used + b->used; + if (c->alloc < pa) { + if ((res = mp_grow (c, pa)) != MP_OKAY) { + return res; + } + } + + /* number of output digits to produce */ + pa = a->used + b->used; + _W = 0; + for (ix = digs; ix < pa; ix++) { + int tx, ty, iy; + mp_digit *tmpx, *tmpy; + + /* get offsets into the two bignums */ + ty = MIN(b->used-1, ix); + tx = ix - ty; + + /* setup temp aliases */ + tmpx = a->dp + tx; + tmpy = b->dp + ty; + + /* this is the number of times the loop will iterrate, essentially its + while (tx++ < a->used && ty-- >= 0) { ... } + */ + iy = MIN(a->used-tx, ty+1); + + /* execute loop */ + for (iz = 0; iz < iy; iz++) { + _W += ((mp_word)*tmpx++)*((mp_word)*tmpy--); + } + + /* store term */ + W[ix] = ((mp_digit)_W) & MP_MASK; + + /* make next carry */ + _W = _W >> ((mp_word)DIGIT_BIT); + } + + /* store final carry */ + W[ix] = _W; + + /* setup dest */ + olduse = c->used; + c->used = pa; + + { + register mp_digit *tmpc; + + tmpc = c->dp + digs; + for (ix = digs; ix <= pa; ix++) { + /* now extract the previous digit [below the carry] */ + *tmpc++ = W[ix]; + } + + /* clear unused digits [that existed in the old copy of c] */ + for (; ix < olduse; ix++) { + *tmpc++ = 0; + } + } + mp_clamp (c); + return MP_OKAY; +} +#endif + +/* End: bn_fast_s_mp_mul_high_digs.c */ + +/* Start: bn_fast_s_mp_sqr.c */ +#include <tommath.h> +#ifdef BN_FAST_S_MP_SQR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* fast squaring + * + * This is the comba method where the columns of the product + * are computed first then the carries are computed. This + * has the effect of making a very simple inner loop that + * is executed the most + * + * W2 represents the outer products and W the inner. + * + * A further optimizations is made because the inner + * products are of the form "A * B * 2". The *2 part does + * not need to be computed until the end which is good + * because 64-bit shifts are slow! + * + * Based on Algorithm 14.16 on pp.597 of HAC. + * + */ +/* the jist of squaring... + +you do like mult except the offset of the tmpx [one that starts closer to zero] +can't equal the offset of tmpy. So basically you set up iy like before then you min it with +(ty-tx) so that it never happens. You double all those you add in the inner loop + +After that loop you do the squares and add them in. + +Remove W2 and don't memset W + +*/ + +int fast_s_mp_sqr (mp_int * a, mp_int * b) +{ + int olduse, res, pa, ix, iz; + mp_digit W[MP_WARRAY], *tmpx; + mp_word W1; + + /* grow the destination as required */ + pa = a->used + a->used; + if (b->alloc < pa) { + if ((res = mp_grow (b, pa)) != MP_OKAY) { + return res; + } + } + + /* number of output digits to produce */ + W1 = 0; + for (ix = 0; ix < pa; ix++) { + int tx, ty, iy; + mp_word _W; + mp_digit *tmpy; + + /* clear counter */ + _W = 0; + + /* get offsets into the two bignums */ + ty = MIN(a->used-1, ix); + tx = ix - ty; + + /* setup temp aliases */ + tmpx = a->dp + tx; + tmpy = a->dp + ty; + + /* this is the number of times the loop will iterrate, essentially its + while (tx++ < a->used && ty-- >= 0) { ... } + */ + iy = MIN(a->used-tx, ty+1); + + /* now for squaring tx can never equal ty + * we halve the distance since they approach at a rate of 2x + * and we have to round because odd cases need to be executed + */ + iy = MIN(iy, (ty-tx+1)>>1); + + /* execute loop */ + for (iz = 0; iz < iy; iz++) { + _W += ((mp_word)*tmpx++)*((mp_word)*tmpy--); + } + + /* double the inner product and add carry */ + _W = _W + _W + W1; + + /* even columns have the square term in them */ + if ((ix&1) == 0) { + _W += ((mp_word)a->dp[ix>>1])*((mp_word)a->dp[ix>>1]); + } + + /* store it */ + W[ix] = _W; + + /* make next carry */ + W1 = _W >> ((mp_word)DIGIT_BIT); + } + + /* setup dest */ + olduse = b->used; + b->used = a->used+a->used; + + { + mp_digit *tmpb; + tmpb = b->dp; + for (ix = 0; ix < pa; ix++) { + *tmpb++ = W[ix] & MP_MASK; + } + + /* clear unused digits [that existed in the old copy of c] */ + for (; ix < olduse; ix++) { + *tmpb++ = 0; + } + } + mp_clamp (b); + return MP_OKAY; +} +#endif + +/* End: bn_fast_s_mp_sqr.c */ + +/* Start: bn_mp_2expt.c */ +#include <tommath.h> +#ifdef BN_MP_2EXPT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes a = 2**b + * + * Simple algorithm which zeroes the int, grows it then just sets one bit + * as required. + */ +int +mp_2expt (mp_int * a, int b) +{ + int res; + + /* zero a as per default */ + mp_zero (a); + + /* grow a to accomodate the single bit */ + if ((res = mp_grow (a, b / DIGIT_BIT + 1)) != MP_OKAY) { + return res; + } + + /* set the used count of where the bit will go */ + a->used = b / DIGIT_BIT + 1; + + /* put the single bit in its place */ + a->dp[b / DIGIT_BIT] = ((mp_digit)1) << (b % DIGIT_BIT); + + return MP_OKAY; +} +#endif + +/* End: bn_mp_2expt.c */ + +/* Start: bn_mp_abs.c */ +#include <tommath.h> +#ifdef BN_MP_ABS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* b = |a| + * + * Simple function copies the input and fixes the sign to positive + */ +int +mp_abs (mp_int * a, mp_int * b) +{ + int res; + + /* copy a to b */ + if (a != b) { + if ((res = mp_copy (a, b)) != MP_OKAY) { + return res; + } + } + + /* force the sign of b to positive */ + b->sign = MP_ZPOS; + + return MP_OKAY; +} +#endif + +/* End: bn_mp_abs.c */ + +/* Start: bn_mp_add.c */ +#include <tommath.h> +#ifdef BN_MP_ADD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* high level addition (handles signs) */ +int mp_add (mp_int * a, mp_int * b, mp_int * c) +{ + int sa, sb, res; + + /* get sign of both inputs */ + sa = a->sign; + sb = b->sign; + + /* handle two cases, not four */ + if (sa == sb) { + /* both positive or both negative */ + /* add their magnitudes, copy the sign */ + c->sign = sa; + res = s_mp_add (a, b, c); + } else { + /* one positive, the other negative */ + /* subtract the one with the greater magnitude from */ + /* the one of the lesser magnitude. The result gets */ + /* the sign of the one with the greater magnitude. */ + if (mp_cmp_mag (a, b) == MP_LT) { + c->sign = sb; + res = s_mp_sub (b, a, c); + } else { + c->sign = sa; + res = s_mp_sub (a, b, c); + } + } + return res; +} + +#endif + +/* End: bn_mp_add.c */ + +/* Start: bn_mp_add_d.c */ +#include <tommath.h> +#ifdef BN_MP_ADD_D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* single digit addition */ +int +mp_add_d (mp_int * a, mp_digit b, mp_int * c) +{ + int res, ix, oldused; + mp_digit *tmpa, *tmpc, mu; + + /* grow c as required */ + if (c->alloc < a->used + 1) { + if ((res = mp_grow(c, a->used + 1)) != MP_OKAY) { + return res; + } + } + + /* if a is negative and |a| >= b, call c = |a| - b */ + if (a->sign == MP_NEG && (a->used > 1 || a->dp[0] >= b)) { + /* temporarily fix sign of a */ + a->sign = MP_ZPOS; + + /* c = |a| - b */ + res = mp_sub_d(a, b, c); + + /* fix sign */ + a->sign = c->sign = MP_NEG; + + return res; + } + + /* old number of used digits in c */ + oldused = c->used; + + /* sign always positive */ + c->sign = MP_ZPOS; + + /* source alias */ + tmpa = a->dp; + + /* destination alias */ + tmpc = c->dp; + + /* if a is positive */ + if (a->sign == MP_ZPOS) { + /* add digit, after this we're propagating + * the carry. + */ + *tmpc = *tmpa++ + b; + mu = *tmpc >> DIGIT_BIT; + *tmpc++ &= MP_MASK; + + /* now handle rest of the digits */ + for (ix = 1; ix < a->used; ix++) { + *tmpc = *tmpa++ + mu; + mu = *tmpc >> DIGIT_BIT; + *tmpc++ &= MP_MASK; + } + /* set final carry */ + ix++; + *tmpc++ = mu; + + /* setup size */ + c->used = a->used + 1; + } else { + /* a was negative and |a| < b */ + c->used = 1; + + /* the result is a single digit */ + if (a->used == 1) { + *tmpc++ = b - a->dp[0]; + } else { + *tmpc++ = b; + } + + /* setup count so the clearing of oldused + * can fall through correctly + */ + ix = 1; + } + + /* now zero to oldused */ + while (ix++ < oldused) { + *tmpc++ = 0; + } + mp_clamp(c); + + return MP_OKAY; +} + +#endif + +/* End: bn_mp_add_d.c */ + +/* Start: bn_mp_addmod.c */ +#include <tommath.h> +#ifdef BN_MP_ADDMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* d = a + b (mod c) */ +int +mp_addmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d) +{ + int res; + mp_int t; + + if ((res = mp_init (&t)) != MP_OKAY) { + return res; + } + + if ((res = mp_add (a, b, &t)) != MP_OKAY) { + mp_clear (&t); + return res; + } + res = mp_mod (&t, c, d); + mp_clear (&t); + return res; +} +#endif + +/* End: bn_mp_addmod.c */ + +/* Start: bn_mp_and.c */ +#include <tommath.h> +#ifdef BN_MP_AND_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* AND two ints together */ +int +mp_and (mp_int * a, mp_int * b, mp_int * c) +{ + int res, ix, px; + mp_int t, *x; + + if (a->used > b->used) { + if ((res = mp_init_copy (&t, a)) != MP_OKAY) { + return res; + } + px = b->used; + x = b; + } else { + if ((res = mp_init_copy (&t, b)) != MP_OKAY) { + return res; + } + px = a->used; + x = a; + } + + for (ix = 0; ix < px; ix++) { + t.dp[ix] &= x->dp[ix]; + } + + /* zero digits above the last from the smallest mp_int */ + for (; ix < t.used; ix++) { + t.dp[ix] = 0; + } + + mp_clamp (&t); + mp_exch (c, &t); + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_mp_and.c */ + +/* Start: bn_mp_clamp.c */ +#include <tommath.h> +#ifdef BN_MP_CLAMP_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* trim unused digits + * + * This is used to ensure that leading zero digits are + * trimed and the leading "used" digit will be non-zero + * Typically very fast. Also fixes the sign if there + * are no more leading digits + */ +void +mp_clamp (mp_int * a) +{ + /* decrease used while the most significant digit is + * zero. + */ + while (a->used > 0 && a->dp[a->used - 1] == 0) { + --(a->used); + } + + /* reset the sign flag if used == 0 */ + if (a->used == 0) { + a->sign = MP_ZPOS; + } +} +#endif + +/* End: bn_mp_clamp.c */ + +/* Start: bn_mp_clear.c */ +#include <tommath.h> +#ifdef BN_MP_CLEAR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* clear one (frees) */ +void +mp_clear (mp_int * a) +{ + int i; + + /* only do anything if a hasn't been freed previously */ + if (a->dp != NULL) { + /* first zero the digits */ + for (i = 0; i < a->used; i++) { + a->dp[i] = 0; + } + + /* free ram */ + XFREE(a->dp); + + /* reset members to make debugging easier */ + a->dp = NULL; + a->alloc = a->used = 0; + a->sign = MP_ZPOS; + } +} +#endif + +/* End: bn_mp_clear.c */ + +/* Start: bn_mp_clear_multi.c */ +#include <tommath.h> +#ifdef BN_MP_CLEAR_MULTI_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ +#include <stdarg.h> + +void mp_clear_multi(mp_int *mp, ...) +{ + mp_int* next_mp = mp; + va_list args; + va_start(args, mp); + while (next_mp != NULL) { + mp_clear(next_mp); + next_mp = va_arg(args, mp_int*); + } + va_end(args); +} +#endif + +/* End: bn_mp_clear_multi.c */ + +/* Start: bn_mp_cmp.c */ +#include <tommath.h> +#ifdef BN_MP_CMP_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* compare two ints (signed)*/ +int +mp_cmp (mp_int * a, mp_int * b) +{ + /* compare based on sign */ + if (a->sign != b->sign) { + if (a->sign == MP_NEG) { + return MP_LT; + } else { + return MP_GT; + } + } + + /* compare digits */ + if (a->sign == MP_NEG) { + /* if negative compare opposite direction */ + return mp_cmp_mag(b, a); + } else { + return mp_cmp_mag(a, b); + } +} +#endif + +/* End: bn_mp_cmp.c */ + +/* Start: bn_mp_cmp_d.c */ +#include <tommath.h> +#ifdef BN_MP_CMP_D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* compare a digit */ +int mp_cmp_d(mp_int * a, mp_digit b) +{ + /* compare based on sign */ + if (a->sign == MP_NEG) { + return MP_LT; + } + + /* compare based on magnitude */ + if (a->used > 1) { + return MP_GT; + } + + /* compare the only digit of a to b */ + if (a->dp[0] > b) { + return MP_GT; + } else if (a->dp[0] < b) { + return MP_LT; + } else { + return MP_EQ; + } +} +#endif + +/* End: bn_mp_cmp_d.c */ + +/* Start: bn_mp_cmp_mag.c */ +#include <tommath.h> +#ifdef BN_MP_CMP_MAG_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* compare maginitude of two ints (unsigned) */ +int mp_cmp_mag (mp_int * a, mp_int * b) +{ + int n; + mp_digit *tmpa, *tmpb; + + /* compare based on # of non-zero digits */ + if (a->used > b->used) { + return MP_GT; + } + + if (a->used < b->used) { + return MP_LT; + } + + /* alias for a */ + tmpa = a->dp + (a->used - 1); + + /* alias for b */ + tmpb = b->dp + (a->used - 1); + + /* compare based on digits */ + for (n = 0; n < a->used; ++n, --tmpa, --tmpb) { + if (*tmpa > *tmpb) { + return MP_GT; + } + + if (*tmpa < *tmpb) { + return MP_LT; + } + } + return MP_EQ; +} +#endif + +/* End: bn_mp_cmp_mag.c */ + +/* Start: bn_mp_cnt_lsb.c */ +#include <tommath.h> +#ifdef BN_MP_CNT_LSB_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +static const int lnz[16] = { + 4, 0, 1, 0, 2, 0, 1, 0, 3, 0, 1, 0, 2, 0, 1, 0 +}; + +/* Counts the number of lsbs which are zero before the first zero bit */ +int mp_cnt_lsb(mp_int *a) +{ + int x; + mp_digit q, qq; + + /* easy out */ + if (mp_iszero(a) == 1) { + return 0; + } + + /* scan lower digits until non-zero */ + for (x = 0; x < a->used && a->dp[x] == 0; x++); + q = a->dp[x]; + x *= DIGIT_BIT; + + /* now scan this digit until a 1 is found */ + if ((q & 1) == 0) { + do { + qq = q & 15; + x += lnz[qq]; + q >>= 4; + } while (qq == 0); + } + return x; +} + +#endif + +/* End: bn_mp_cnt_lsb.c */ + +/* Start: bn_mp_copy.c */ +#include <tommath.h> +#ifdef BN_MP_COPY_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* copy, b = a */ +int +mp_copy (mp_int * a, mp_int * b) +{ + int res, n; + + /* if dst == src do nothing */ + if (a == b) { + return MP_OKAY; + } + + /* grow dest */ + if (b->alloc < a->used) { + if ((res = mp_grow (b, a->used)) != MP_OKAY) { + return res; + } + } + + /* zero b and copy the parameters over */ + { + register mp_digit *tmpa, *tmpb; + + /* pointer aliases */ + + /* source */ + tmpa = a->dp; + + /* destination */ + tmpb = b->dp; + + /* copy all the digits */ + for (n = 0; n < a->used; n++) { + *tmpb++ = *tmpa++; + } + + /* clear high digits */ + for (; n < b->used; n++) { + *tmpb++ = 0; + } + } + + /* copy used count and sign */ + b->used = a->used; + b->sign = a->sign; + return MP_OKAY; +} +#endif + +/* End: bn_mp_copy.c */ + +/* Start: bn_mp_count_bits.c */ +#include <tommath.h> +#ifdef BN_MP_COUNT_BITS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* returns the number of bits in an int */ +int +mp_count_bits (mp_int * a) +{ + int r; + mp_digit q; + + /* shortcut */ + if (a->used == 0) { + return 0; + } + + /* get number of digits and add that */ + r = (a->used - 1) * DIGIT_BIT; + + /* take the last digit and count the bits in it */ + q = a->dp[a->used - 1]; + while (q > ((mp_digit) 0)) { + ++r; + q >>= ((mp_digit) 1); + } + return r; +} +#endif + +/* End: bn_mp_count_bits.c */ + +/* Start: bn_mp_div.c */ +#include <tommath.h> +#ifdef BN_MP_DIV_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +#ifdef BN_MP_DIV_SMALL + +/* slower bit-bang division... also smaller */ +int mp_div(mp_int * a, mp_int * b, mp_int * c, mp_int * d) +{ + mp_int ta, tb, tq, q; + int res, n, n2; + + /* is divisor zero ? */ + if (mp_iszero (b) == 1) { + return MP_VAL; + } + + /* if a < b then q=0, r = a */ + if (mp_cmp_mag (a, b) == MP_LT) { + if (d != NULL) { + res = mp_copy (a, d); + } else { + res = MP_OKAY; + } + if (c != NULL) { + mp_zero (c); + } + return res; + } + + /* init our temps */ + if ((res = mp_init_multi(&ta, &tb, &tq, &q, NULL) != MP_OKAY)) { + return res; + } + + + mp_set(&tq, 1); + n = mp_count_bits(a) - mp_count_bits(b); + if (((res = mp_abs(a, &ta)) != MP_OKAY) || + ((res = mp_abs(b, &tb)) != MP_OKAY) || + ((res = mp_mul_2d(&tb, n, &tb)) != MP_OKAY) || + ((res = mp_mul_2d(&tq, n, &tq)) != MP_OKAY)) { + goto LBL_ERR; + } + + while (n-- >= 0) { + if (mp_cmp(&tb, &ta) != MP_GT) { + if (((res = mp_sub(&ta, &tb, &ta)) != MP_OKAY) || + ((res = mp_add(&q, &tq, &q)) != MP_OKAY)) { + goto LBL_ERR; + } + } + if (((res = mp_div_2d(&tb, 1, &tb, NULL)) != MP_OKAY) || + ((res = mp_div_2d(&tq, 1, &tq, NULL)) != MP_OKAY)) { + goto LBL_ERR; + } + } + + /* now q == quotient and ta == remainder */ + n = a->sign; + n2 = (a->sign == b->sign ? MP_ZPOS : MP_NEG); + if (c != NULL) { + mp_exch(c, &q); + c->sign = (mp_iszero(c) == MP_YES) ? MP_ZPOS : n2; + } + if (d != NULL) { + mp_exch(d, &ta); + d->sign = (mp_iszero(d) == MP_YES) ? MP_ZPOS : n; + } +LBL_ERR: + mp_clear_multi(&ta, &tb, &tq, &q, NULL); + return res; +} + +#else + +/* integer signed division. + * c*b + d == a [e.g. a/b, c=quotient, d=remainder] + * HAC pp.598 Algorithm 14.20 + * + * Note that the description in HAC is horribly + * incomplete. For example, it doesn't consider + * the case where digits are removed from 'x' in + * the inner loop. It also doesn't consider the + * case that y has fewer than three digits, etc.. + * + * The overall algorithm is as described as + * 14.20 from HAC but fixed to treat these cases. +*/ +int mp_div (mp_int * a, mp_int * b, mp_int * c, mp_int * d) +{ + mp_int q, x, y, t1, t2; + int res, n, t, i, norm, neg; + + /* is divisor zero ? */ + if (mp_iszero (b) == 1) { + return MP_VAL; + } + + /* if a < b then q=0, r = a */ + if (mp_cmp_mag (a, b) == MP_LT) { + if (d != NULL) { + res = mp_copy (a, d); + } else { + res = MP_OKAY; + } + if (c != NULL) { + mp_zero (c); + } + return res; + } + + if ((res = mp_init_size (&q, a->used + 2)) != MP_OKAY) { + return res; + } + q.used = a->used + 2; + + if ((res = mp_init (&t1)) != MP_OKAY) { + goto LBL_Q; + } + + if ((res = mp_init (&t2)) != MP_OKAY) { + goto LBL_T1; + } + + if ((res = mp_init_copy (&x, a)) != MP_OKAY) { + goto LBL_T2; + } + + if ((res = mp_init_copy (&y, b)) != MP_OKAY) { + goto LBL_X; + } + + /* fix the sign */ + neg = (a->sign == b->sign) ? MP_ZPOS : MP_NEG; + x.sign = y.sign = MP_ZPOS; + + /* normalize both x and y, ensure that y >= b/2, [b == 2**DIGIT_BIT] */ + norm = mp_count_bits(&y) % DIGIT_BIT; + if (norm < (int)(DIGIT_BIT-1)) { + norm = (DIGIT_BIT-1) - norm; + if ((res = mp_mul_2d (&x, norm, &x)) != MP_OKAY) { + goto LBL_Y; + } + if ((res = mp_mul_2d (&y, norm, &y)) != MP_OKAY) { + goto LBL_Y; + } + } else { + norm = 0; + } + + /* note hac does 0 based, so if used==5 then its 0,1,2,3,4, e.g. use 4 */ + n = x.used - 1; + t = y.used - 1; + + /* while (x >= y*b**n-t) do { q[n-t] += 1; x -= y*b**{n-t} } */ + if ((res = mp_lshd (&y, n - t)) != MP_OKAY) { /* y = y*b**{n-t} */ + goto LBL_Y; + } + + while (mp_cmp (&x, &y) != MP_LT) { + ++(q.dp[n - t]); + if ((res = mp_sub (&x, &y, &x)) != MP_OKAY) { + goto LBL_Y; + } + } + + /* reset y by shifting it back down */ + mp_rshd (&y, n - t); + + /* step 3. for i from n down to (t + 1) */ + for (i = n; i >= (t + 1); i--) { + if (i > x.used) { + continue; + } + + /* step 3.1 if xi == yt then set q{i-t-1} to b-1, + * otherwise set q{i-t-1} to (xi*b + x{i-1})/yt */ + if (x.dp[i] == y.dp[t]) { + q.dp[i - t - 1] = ((((mp_digit)1) << DIGIT_BIT) - 1); + } else { + mp_word tmp; + tmp = ((mp_word) x.dp[i]) << ((mp_word) DIGIT_BIT); + tmp |= ((mp_word) x.dp[i - 1]); + tmp /= ((mp_word) y.dp[t]); + if (tmp > (mp_word) MP_MASK) + tmp = MP_MASK; + q.dp[i - t - 1] = (mp_digit) (tmp & (mp_word) (MP_MASK)); + } + + /* while (q{i-t-1} * (yt * b + y{t-1})) > + xi * b**2 + xi-1 * b + xi-2 + + do q{i-t-1} -= 1; + */ + q.dp[i - t - 1] = (q.dp[i - t - 1] + 1) & MP_MASK; + do { + q.dp[i - t - 1] = (q.dp[i - t - 1] - 1) & MP_MASK; + + /* find left hand */ + mp_zero (&t1); + t1.dp[0] = (t - 1 < 0) ? 0 : y.dp[t - 1]; + t1.dp[1] = y.dp[t]; + t1.used = 2; + if ((res = mp_mul_d (&t1, q.dp[i - t - 1], &t1)) != MP_OKAY) { + goto LBL_Y; + } + + /* find right hand */ + t2.dp[0] = (i - 2 < 0) ? 0 : x.dp[i - 2]; + t2.dp[1] = (i - 1 < 0) ? 0 : x.dp[i - 1]; + t2.dp[2] = x.dp[i]; + t2.used = 3; + } while (mp_cmp_mag(&t1, &t2) == MP_GT); + + /* step 3.3 x = x - q{i-t-1} * y * b**{i-t-1} */ + if ((res = mp_mul_d (&y, q.dp[i - t - 1], &t1)) != MP_OKAY) { + goto LBL_Y; + } + + if ((res = mp_lshd (&t1, i - t - 1)) != MP_OKAY) { + goto LBL_Y; + } + + if ((res = mp_sub (&x, &t1, &x)) != MP_OKAY) { + goto LBL_Y; + } + + /* if x < 0 then { x = x + y*b**{i-t-1}; q{i-t-1} -= 1; } */ + if (x.sign == MP_NEG) { + if ((res = mp_copy (&y, &t1)) != MP_OKAY) { + goto LBL_Y; + } + if ((res = mp_lshd (&t1, i - t - 1)) != MP_OKAY) { + goto LBL_Y; + } + if ((res = mp_add (&x, &t1, &x)) != MP_OKAY) { + goto LBL_Y; + } + + q.dp[i - t - 1] = (q.dp[i - t - 1] - 1UL) & MP_MASK; + } + } + + /* now q is the quotient and x is the remainder + * [which we have to normalize] + */ + + /* get sign before writing to c */ + x.sign = x.used == 0 ? MP_ZPOS : a->sign; + + if (c != NULL) { + mp_clamp (&q); + mp_exch (&q, c); + c->sign = neg; + } + + if (d != NULL) { + mp_div_2d (&x, norm, &x, NULL); + mp_exch (&x, d); + } + + res = MP_OKAY; + +LBL_Y:mp_clear (&y); +LBL_X:mp_clear (&x); +LBL_T2:mp_clear (&t2); +LBL_T1:mp_clear (&t1); +LBL_Q:mp_clear (&q); + return res; +} + +#endif + +#endif + +/* End: bn_mp_div.c */ + +/* Start: bn_mp_div_2.c */ +#include <tommath.h> +#ifdef BN_MP_DIV_2_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* b = a/2 */ +int mp_div_2(mp_int * a, mp_int * b) +{ + int x, res, oldused; + + /* copy */ + if (b->alloc < a->used) { + if ((res = mp_grow (b, a->used)) != MP_OKAY) { + return res; + } + } + + oldused = b->used; + b->used = a->used; + { + register mp_digit r, rr, *tmpa, *tmpb; + + /* source alias */ + tmpa = a->dp + b->used - 1; + + /* dest alias */ + tmpb = b->dp + b->used - 1; + + /* carry */ + r = 0; + for (x = b->used - 1; x >= 0; x--) { + /* get the carry for the next iteration */ + rr = *tmpa & 1; + + /* shift the current digit, add in carry and store */ + *tmpb-- = (*tmpa-- >> 1) | (r << (DIGIT_BIT - 1)); + + /* forward carry to next iteration */ + r = rr; + } + + /* zero excess digits */ + tmpb = b->dp + b->used; + for (x = b->used; x < oldused; x++) { + *tmpb++ = 0; + } + } + b->sign = a->sign; + mp_clamp (b); + return MP_OKAY; +} +#endif + +/* End: bn_mp_div_2.c */ + +/* Start: bn_mp_div_2d.c */ +#include <tommath.h> +#ifdef BN_MP_DIV_2D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* shift right by a certain bit count (store quotient in c, optional remainder in d) */ +int mp_div_2d (mp_int * a, int b, mp_int * c, mp_int * d) +{ + mp_digit D, r, rr; + int x, res; + mp_int t; + + + /* if the shift count is <= 0 then we do no work */ + if (b <= 0) { + res = mp_copy (a, c); + if (d != NULL) { + mp_zero (d); + } + return res; + } + + if ((res = mp_init (&t)) != MP_OKAY) { + return res; + } + + /* get the remainder */ + if (d != NULL) { + if ((res = mp_mod_2d (a, b, &t)) != MP_OKAY) { + mp_clear (&t); + return res; + } + } + + /* copy */ + if ((res = mp_copy (a, c)) != MP_OKAY) { + mp_clear (&t); + return res; + } + + /* shift by as many digits in the bit count */ + if (b >= (int)DIGIT_BIT) { + mp_rshd (c, b / DIGIT_BIT); + } + + /* shift any bit count < DIGIT_BIT */ + D = (mp_digit) (b % DIGIT_BIT); + if (D != 0) { + register mp_digit *tmpc, mask, shift; + + /* mask */ + mask = (((mp_digit)1) << D) - 1; + + /* shift for lsb */ + shift = DIGIT_BIT - D; + + /* alias */ + tmpc = c->dp + (c->used - 1); + + /* carry */ + r = 0; + for (x = c->used - 1; x >= 0; x--) { + /* get the lower bits of this word in a temp */ + rr = *tmpc & mask; + + /* shift the current word and mix in the carry bits from the previous word */ + *tmpc = (*tmpc >> D) | (r << shift); + --tmpc; + + /* set the carry to the carry bits of the current word found above */ + r = rr; + } + } + mp_clamp (c); + if (d != NULL) { + mp_exch (&t, d); + } + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_mp_div_2d.c */ + +/* Start: bn_mp_div_3.c */ +#include <tommath.h> +#ifdef BN_MP_DIV_3_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* divide by three (based on routine from MPI and the GMP manual) */ +int +mp_div_3 (mp_int * a, mp_int *c, mp_digit * d) +{ + mp_int q; + mp_word w, t; + mp_digit b; + int res, ix; + + /* b = 2**DIGIT_BIT / 3 */ + b = (((mp_word)1) << ((mp_word)DIGIT_BIT)) / ((mp_word)3); + + if ((res = mp_init_size(&q, a->used)) != MP_OKAY) { + return res; + } + + q.used = a->used; + q.sign = a->sign; + w = 0; + for (ix = a->used - 1; ix >= 0; ix--) { + w = (w << ((mp_word)DIGIT_BIT)) | ((mp_word)a->dp[ix]); + + if (w >= 3) { + /* multiply w by [1/3] */ + t = (w * ((mp_word)b)) >> ((mp_word)DIGIT_BIT); + + /* now subtract 3 * [w/3] from w, to get the remainder */ + w -= t+t+t; + + /* fixup the remainder as required since + * the optimization is not exact. + */ + while (w >= 3) { + t += 1; + w -= 3; + } + } else { + t = 0; + } + q.dp[ix] = (mp_digit)t; + } + + /* [optional] store the remainder */ + if (d != NULL) { + *d = (mp_digit)w; + } + + /* [optional] store the quotient */ + if (c != NULL) { + mp_clamp(&q); + mp_exch(&q, c); + } + mp_clear(&q); + + return res; +} + +#endif + +/* End: bn_mp_div_3.c */ + +/* Start: bn_mp_div_d.c */ +#include <tommath.h> +#ifdef BN_MP_DIV_D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +static int s_is_power_of_two(mp_digit b, int *p) +{ + int x; + + for (x = 1; x < DIGIT_BIT; x++) { + if (b == (((mp_digit)1)<<x)) { + *p = x; + return 1; + } + } + return 0; +} + +/* single digit division (based on routine from MPI) */ +int mp_div_d (mp_int * a, mp_digit b, mp_int * c, mp_digit * d) +{ + mp_int q; + mp_word w; + mp_digit t; + int res, ix; + + /* cannot divide by zero */ + if (b == 0) { + return MP_VAL; + } + + /* quick outs */ + if (b == 1 || mp_iszero(a) == 1) { + if (d != NULL) { + *d = 0; + } + if (c != NULL) { + return mp_copy(a, c); + } + return MP_OKAY; + } + + /* power of two ? */ + if (s_is_power_of_two(b, &ix) == 1) { + if (d != NULL) { + *d = a->dp[0] & ((((mp_digit)1)<<ix) - 1); + } + if (c != NULL) { + return mp_div_2d(a, ix, c, NULL); + } + return MP_OKAY; + } + +#ifdef BN_MP_DIV_3_C + /* three? */ + if (b == 3) { + return mp_div_3(a, c, d); + } +#endif + + /* no easy answer [c'est la vie]. Just division */ + if ((res = mp_init_size(&q, a->used)) != MP_OKAY) { + return res; + } + + q.used = a->used; + q.sign = a->sign; + w = 0; + for (ix = a->used - 1; ix >= 0; ix--) { + w = (w << ((mp_word)DIGIT_BIT)) | ((mp_word)a->dp[ix]); + + if (w >= b) { + t = (mp_digit)(w / b); + w -= ((mp_word)t) * ((mp_word)b); + } else { + t = 0; + } + q.dp[ix] = (mp_digit)t; + } + + if (d != NULL) { + *d = (mp_digit)w; + } + + if (c != NULL) { + mp_clamp(&q); + mp_exch(&q, c); + } + mp_clear(&q); + + return res; +} + +#endif + +/* End: bn_mp_div_d.c */ + +/* Start: bn_mp_dr_is_modulus.c */ +#include <tommath.h> +#ifdef BN_MP_DR_IS_MODULUS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* determines if a number is a valid DR modulus */ +int mp_dr_is_modulus(mp_int *a) +{ + int ix; + + /* must be at least two digits */ + if (a->used < 2) { + return 0; + } + + /* must be of the form b**k - a [a <= b] so all + * but the first digit must be equal to -1 (mod b). + */ + for (ix = 1; ix < a->used; ix++) { + if (a->dp[ix] != MP_MASK) { + return 0; + } + } + return 1; +} + +#endif + +/* End: bn_mp_dr_is_modulus.c */ + +/* Start: bn_mp_dr_reduce.c */ +#include <tommath.h> +#ifdef BN_MP_DR_REDUCE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* reduce "x" in place modulo "n" using the Diminished Radix algorithm. + * + * Based on algorithm from the paper + * + * "Generating Efficient Primes for Discrete Log Cryptosystems" + * Chae Hoon Lim, Pil Joong Lee, + * POSTECH Information Research Laboratories + * + * The modulus must be of a special format [see manual] + * + * Has been modified to use algorithm 7.10 from the LTM book instead + * + * Input x must be in the range 0 <= x <= (n-1)**2 + */ +int +mp_dr_reduce (mp_int * x, mp_int * n, mp_digit k) +{ + int err, i, m; + mp_word r; + mp_digit mu, *tmpx1, *tmpx2; + + /* m = digits in modulus */ + m = n->used; + + /* ensure that "x" has at least 2m digits */ + if (x->alloc < m + m) { + if ((err = mp_grow (x, m + m)) != MP_OKAY) { + return err; + } + } + +/* top of loop, this is where the code resumes if + * another reduction pass is required. + */ +top: + /* aliases for digits */ + /* alias for lower half of x */ + tmpx1 = x->dp; + + /* alias for upper half of x, or x/B**m */ + tmpx2 = x->dp + m; + + /* set carry to zero */ + mu = 0; + + /* compute (x mod B**m) + k * [x/B**m] inline and inplace */ + for (i = 0; i < m; i++) { + r = ((mp_word)*tmpx2++) * ((mp_word)k) + *tmpx1 + mu; + *tmpx1++ = (mp_digit)(r & MP_MASK); + mu = (mp_digit)(r >> ((mp_word)DIGIT_BIT)); + } + + /* set final carry */ + *tmpx1++ = mu; + + /* zero words above m */ + for (i = m + 1; i < x->used; i++) { + *tmpx1++ = 0; + } + + /* clamp, sub and return */ + mp_clamp (x); + + /* if x >= n then subtract and reduce again + * Each successive "recursion" makes the input smaller and smaller. + */ + if (mp_cmp_mag (x, n) != MP_LT) { + s_mp_sub(x, n, x); + goto top; + } + return MP_OKAY; +} +#endif + +/* End: bn_mp_dr_reduce.c */ + +/* Start: bn_mp_dr_setup.c */ +#include <tommath.h> +#ifdef BN_MP_DR_SETUP_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* determines the setup value */ +void mp_dr_setup(mp_int *a, mp_digit *d) +{ + /* the casts are required if DIGIT_BIT is one less than + * the number of bits in a mp_digit [e.g. DIGIT_BIT==31] + */ + *d = (mp_digit)((((mp_word)1) << ((mp_word)DIGIT_BIT)) - + ((mp_word)a->dp[0])); +} + +#endif + +/* End: bn_mp_dr_setup.c */ + +/* Start: bn_mp_exch.c */ +#include <tommath.h> +#ifdef BN_MP_EXCH_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* swap the elements of two integers, for cases where you can't simply swap the + * mp_int pointers around + */ +void +mp_exch (mp_int * a, mp_int * b) +{ + mp_int t; + + t = *a; + *a = *b; + *b = t; +} +#endif + +/* End: bn_mp_exch.c */ + +/* Start: bn_mp_expt_d.c */ +#include <tommath.h> +#ifdef BN_MP_EXPT_D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* calculate c = a**b using a square-multiply algorithm */ +int mp_expt_d (mp_int * a, mp_digit b, mp_int * c) +{ + int res, x; + mp_int g; + + if ((res = mp_init_copy (&g, a)) != MP_OKAY) { + return res; + } + + /* set initial result */ + mp_set (c, 1); + + for (x = 0; x < (int) DIGIT_BIT; x++) { + /* square */ + if ((res = mp_sqr (c, c)) != MP_OKAY) { + mp_clear (&g); + return res; + } + + /* if the bit is set multiply */ + if ((b & (mp_digit) (((mp_digit)1) << (DIGIT_BIT - 1))) != 0) { + if ((res = mp_mul (c, &g, c)) != MP_OKAY) { + mp_clear (&g); + return res; + } + } + + /* shift to next bit */ + b <<= 1; + } + + mp_clear (&g); + return MP_OKAY; +} +#endif + +/* End: bn_mp_expt_d.c */ + +/* Start: bn_mp_exptmod.c */ +#include <tommath.h> +#ifdef BN_MP_EXPTMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + + +/* this is a shell function that calls either the normal or Montgomery + * exptmod functions. Originally the call to the montgomery code was + * embedded in the normal function but that wasted alot of stack space + * for nothing (since 99% of the time the Montgomery code would be called) + */ +int mp_exptmod (mp_int * G, mp_int * X, mp_int * P, mp_int * Y) +{ + int dr; + + /* modulus P must be positive */ + if (P->sign == MP_NEG) { + return MP_VAL; + } + + /* if exponent X is negative we have to recurse */ + if (X->sign == MP_NEG) { +#ifdef BN_MP_INVMOD_C + mp_int tmpG, tmpX; + int err; + + /* first compute 1/G mod P */ + if ((err = mp_init(&tmpG)) != MP_OKAY) { + return err; + } + if ((err = mp_invmod(G, P, &tmpG)) != MP_OKAY) { + mp_clear(&tmpG); + return err; + } + + /* now get |X| */ + if ((err = mp_init(&tmpX)) != MP_OKAY) { + mp_clear(&tmpG); + return err; + } + if ((err = mp_abs(X, &tmpX)) != MP_OKAY) { + mp_clear_multi(&tmpG, &tmpX, NULL); + return err; + } + + /* and now compute (1/G)**|X| instead of G**X [X < 0] */ + err = mp_exptmod(&tmpG, &tmpX, P, Y); + mp_clear_multi(&tmpG, &tmpX, NULL); + return err; +#else + /* no invmod */ + return MP_VAL; +#endif + } + +#ifdef BN_MP_DR_IS_MODULUS_C + /* is it a DR modulus? */ + dr = mp_dr_is_modulus(P); +#else + dr = 0; +#endif + +#ifdef BN_MP_REDUCE_IS_2K_C + /* if not, is it a uDR modulus? */ + if (dr == 0) { + dr = mp_reduce_is_2k(P) << 1; + } +#endif + + /* if the modulus is odd or dr != 0 use the fast method */ +#ifdef BN_MP_EXPTMOD_FAST_C + if (mp_isodd (P) == 1 || dr != 0) { + return mp_exptmod_fast (G, X, P, Y, dr); + } else { +#endif +#ifdef BN_S_MP_EXPTMOD_C + /* otherwise use the generic Barrett reduction technique */ + return s_mp_exptmod (G, X, P, Y); +#else + /* no exptmod for evens */ + return MP_VAL; +#endif +#ifdef BN_MP_EXPTMOD_FAST_C + } +#endif +} + +#endif + +/* End: bn_mp_exptmod.c */ + +/* Start: bn_mp_exptmod_fast.c */ +#include <tommath.h> +#ifdef BN_MP_EXPTMOD_FAST_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes Y == G**X mod P, HAC pp.616, Algorithm 14.85 + * + * Uses a left-to-right k-ary sliding window to compute the modular exponentiation. + * The value of k changes based on the size of the exponent. + * + * Uses Montgomery or Diminished Radix reduction [whichever appropriate] + */ + +#ifdef MP_LOW_MEM + #define TAB_SIZE 32 +#else + #define TAB_SIZE 256 +#endif + +int +mp_exptmod_fast (mp_int * G, mp_int * X, mp_int * P, mp_int * Y, int redmode) +{ + mp_int M[TAB_SIZE], res; + mp_digit buf, mp; + int err, bitbuf, bitcpy, bitcnt, mode, digidx, x, y, winsize; + + /* use a pointer to the reduction algorithm. This allows us to use + * one of many reduction algorithms without modding the guts of + * the code with if statements everywhere. + */ + int (*redux)(mp_int*,mp_int*,mp_digit); + + /* find window size */ + x = mp_count_bits (X); + if (x <= 7) { + winsize = 2; + } else if (x <= 36) { + winsize = 3; + } else if (x <= 140) { + winsize = 4; + } else if (x <= 450) { + winsize = 5; + } else if (x <= 1303) { + winsize = 6; + } else if (x <= 3529) { + winsize = 7; + } else { + winsize = 8; + } + +#ifdef MP_LOW_MEM + if (winsize > 5) { + winsize = 5; + } +#endif + + /* init M array */ + /* init first cell */ + if ((err = mp_init(&M[1])) != MP_OKAY) { + return err; + } + + /* now init the second half of the array */ + for (x = 1<<(winsize-1); x < (1 << winsize); x++) { + if ((err = mp_init(&M[x])) != MP_OKAY) { + for (y = 1<<(winsize-1); y < x; y++) { + mp_clear (&M[y]); + } + mp_clear(&M[1]); + return err; + } + } + + /* determine and setup reduction code */ + if (redmode == 0) { +#ifdef BN_MP_MONTGOMERY_SETUP_C + /* now setup montgomery */ + if ((err = mp_montgomery_setup (P, &mp)) != MP_OKAY) { + goto LBL_M; + } +#else + err = MP_VAL; + goto LBL_M; +#endif + + /* automatically pick the comba one if available (saves quite a few calls/ifs) */ +#ifdef BN_FAST_MP_MONTGOMERY_REDUCE_C + if (((P->used * 2 + 1) < MP_WARRAY) && + P->used < (1 << ((CHAR_BIT * sizeof (mp_word)) - (2 * DIGIT_BIT)))) { + redux = fast_mp_montgomery_reduce; + } else +#endif + { +#ifdef BN_MP_MONTGOMERY_REDUCE_C + /* use slower baseline Montgomery method */ + redux = mp_montgomery_reduce; +#else + err = MP_VAL; + goto LBL_M; +#endif + } + } else if (redmode == 1) { +#if defined(BN_MP_DR_SETUP_C) && defined(BN_MP_DR_REDUCE_C) + /* setup DR reduction for moduli of the form B**k - b */ + mp_dr_setup(P, &mp); + redux = mp_dr_reduce; +#else + err = MP_VAL; + goto LBL_M; +#endif + } else { +#if defined(BN_MP_REDUCE_2K_SETUP_C) && defined(BN_MP_REDUCE_2K_C) + /* setup DR reduction for moduli of the form 2**k - b */ + if ((err = mp_reduce_2k_setup(P, &mp)) != MP_OKAY) { + goto LBL_M; + } + redux = mp_reduce_2k; +#else + err = MP_VAL; + goto LBL_M; +#endif + } + + /* setup result */ + if ((err = mp_init (&res)) != MP_OKAY) { + goto LBL_M; + } + + /* create M table + * + + * + * The first half of the table is not computed though accept for M[0] and M[1] + */ + + if (redmode == 0) { +#ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C + /* now we need R mod m */ + if ((err = mp_montgomery_calc_normalization (&res, P)) != MP_OKAY) { + goto LBL_RES; + } +#else + err = MP_VAL; + goto LBL_RES; +#endif + + /* now set M[1] to G * R mod m */ + if ((err = mp_mulmod (G, &res, P, &M[1])) != MP_OKAY) { + goto LBL_RES; + } + } else { + mp_set(&res, 1); + if ((err = mp_mod(G, P, &M[1])) != MP_OKAY) { + goto LBL_RES; + } + } + + /* compute the value at M[1<<(winsize-1)] by squaring M[1] (winsize-1) times */ + if ((err = mp_copy (&M[1], &M[1 << (winsize - 1)])) != MP_OKAY) { + goto LBL_RES; + } + + for (x = 0; x < (winsize - 1); x++) { + if ((err = mp_sqr (&M[1 << (winsize - 1)], &M[1 << (winsize - 1)])) != MP_OKAY) { + goto LBL_RES; + } + if ((err = redux (&M[1 << (winsize - 1)], P, mp)) != MP_OKAY) { + goto LBL_RES; + } + } + + /* create upper table */ + for (x = (1 << (winsize - 1)) + 1; x < (1 << winsize); x++) { + if ((err = mp_mul (&M[x - 1], &M[1], &M[x])) != MP_OKAY) { + goto LBL_RES; + } + if ((err = redux (&M[x], P, mp)) != MP_OKAY) { + goto LBL_RES; + } + } + + /* set initial mode and bit cnt */ + mode = 0; + bitcnt = 1; + buf = 0; + digidx = X->used - 1; + bitcpy = 0; + bitbuf = 0; + + for (;;) { + /* grab next digit as required */ + if (--bitcnt == 0) { + /* if digidx == -1 we are out of digits so break */ + if (digidx == -1) { + break; + } + /* read next digit and reset bitcnt */ + buf = X->dp[digidx--]; + bitcnt = (int)DIGIT_BIT; + } + + /* grab the next msb from the exponent */ + y = (mp_digit)(buf >> (DIGIT_BIT - 1)) & 1; + buf <<= (mp_digit)1; + + /* if the bit is zero and mode == 0 then we ignore it + * These represent the leading zero bits before the first 1 bit + * in the exponent. Technically this opt is not required but it + * does lower the # of trivial squaring/reductions used + */ + if (mode == 0 && y == 0) { + continue; + } + + /* if the bit is zero and mode == 1 then we square */ + if (mode == 1 && y == 0) { + if ((err = mp_sqr (&res, &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = redux (&res, P, mp)) != MP_OKAY) { + goto LBL_RES; + } + continue; + } + + /* else we add it to the window */ + bitbuf |= (y << (winsize - ++bitcpy)); + mode = 2; + + if (bitcpy == winsize) { + /* ok window is filled so square as required and multiply */ + /* square first */ + for (x = 0; x < winsize; x++) { + if ((err = mp_sqr (&res, &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = redux (&res, P, mp)) != MP_OKAY) { + goto LBL_RES; + } + } + + /* then multiply */ + if ((err = mp_mul (&res, &M[bitbuf], &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = redux (&res, P, mp)) != MP_OKAY) { + goto LBL_RES; + } + + /* empty window and reset */ + bitcpy = 0; + bitbuf = 0; + mode = 1; + } + } + + /* if bits remain then square/multiply */ + if (mode == 2 && bitcpy > 0) { + /* square then multiply if the bit is set */ + for (x = 0; x < bitcpy; x++) { + if ((err = mp_sqr (&res, &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = redux (&res, P, mp)) != MP_OKAY) { + goto LBL_RES; + } + + /* get next bit of the window */ + bitbuf <<= 1; + if ((bitbuf & (1 << winsize)) != 0) { + /* then multiply */ + if ((err = mp_mul (&res, &M[1], &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = redux (&res, P, mp)) != MP_OKAY) { + goto LBL_RES; + } + } + } + } + + if (redmode == 0) { + /* fixup result if Montgomery reduction is used + * recall that any value in a Montgomery system is + * actually multiplied by R mod n. So we have + * to reduce one more time to cancel out the factor + * of R. + */ + if ((err = redux(&res, P, mp)) != MP_OKAY) { + goto LBL_RES; + } + } + + /* swap res with Y */ + mp_exch (&res, Y); + err = MP_OKAY; +LBL_RES:mp_clear (&res); +LBL_M: + mp_clear(&M[1]); + for (x = 1<<(winsize-1); x < (1 << winsize); x++) { + mp_clear (&M[x]); + } + return err; +} +#endif + + +/* End: bn_mp_exptmod_fast.c */ + +/* Start: bn_mp_exteuclid.c */ +#include <tommath.h> +#ifdef BN_MP_EXTEUCLID_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* Extended euclidean algorithm of (a, b) produces + a*u1 + b*u2 = u3 + */ +int mp_exteuclid(mp_int *a, mp_int *b, mp_int *U1, mp_int *U2, mp_int *U3) +{ + mp_int u1,u2,u3,v1,v2,v3,t1,t2,t3,q,tmp; + int err; + + if ((err = mp_init_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL)) != MP_OKAY) { + return err; + } + + /* initialize, (u1,u2,u3) = (1,0,a) */ + mp_set(&u1, 1); + if ((err = mp_copy(a, &u3)) != MP_OKAY) { goto _ERR; } + + /* initialize, (v1,v2,v3) = (0,1,b) */ + mp_set(&v2, 1); + if ((err = mp_copy(b, &v3)) != MP_OKAY) { goto _ERR; } + + /* loop while v3 != 0 */ + while (mp_iszero(&v3) == MP_NO) { + /* q = u3/v3 */ + if ((err = mp_div(&u3, &v3, &q, NULL)) != MP_OKAY) { goto _ERR; } + + /* (t1,t2,t3) = (u1,u2,u3) - (v1,v2,v3)q */ + if ((err = mp_mul(&v1, &q, &tmp)) != MP_OKAY) { goto _ERR; } + if ((err = mp_sub(&u1, &tmp, &t1)) != MP_OKAY) { goto _ERR; } + if ((err = mp_mul(&v2, &q, &tmp)) != MP_OKAY) { goto _ERR; } + if ((err = mp_sub(&u2, &tmp, &t2)) != MP_OKAY) { goto _ERR; } + if ((err = mp_mul(&v3, &q, &tmp)) != MP_OKAY) { goto _ERR; } + if ((err = mp_sub(&u3, &tmp, &t3)) != MP_OKAY) { goto _ERR; } + + /* (u1,u2,u3) = (v1,v2,v3) */ + if ((err = mp_copy(&v1, &u1)) != MP_OKAY) { goto _ERR; } + if ((err = mp_copy(&v2, &u2)) != MP_OKAY) { goto _ERR; } + if ((err = mp_copy(&v3, &u3)) != MP_OKAY) { goto _ERR; } + + /* (v1,v2,v3) = (t1,t2,t3) */ + if ((err = mp_copy(&t1, &v1)) != MP_OKAY) { goto _ERR; } + if ((err = mp_copy(&t2, &v2)) != MP_OKAY) { goto _ERR; } + if ((err = mp_copy(&t3, &v3)) != MP_OKAY) { goto _ERR; } + } + + /* copy result out */ + if (U1 != NULL) { mp_exch(U1, &u1); } + if (U2 != NULL) { mp_exch(U2, &u2); } + if (U3 != NULL) { mp_exch(U3, &u3); } + + err = MP_OKAY; +_ERR: mp_clear_multi(&u1, &u2, &u3, &v1, &v2, &v3, &t1, &t2, &t3, &q, &tmp, NULL); + return err; +} +#endif + +/* End: bn_mp_exteuclid.c */ + +/* Start: bn_mp_fread.c */ +#include <tommath.h> +#ifdef BN_MP_FREAD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* read a bigint from a file stream in ASCII */ +int mp_fread(mp_int *a, int radix, FILE *stream) +{ + int err, ch, neg, y; + + /* clear a */ + mp_zero(a); + + /* if first digit is - then set negative */ + ch = fgetc(stream); + if (ch == '-') { + neg = MP_NEG; + ch = fgetc(stream); + } else { + neg = MP_ZPOS; + } + + for (;;) { + /* find y in the radix map */ + for (y = 0; y < radix; y++) { + if (mp_s_rmap[y] == ch) { + break; + } + } + if (y == radix) { + break; + } + + /* shift up and add */ + if ((err = mp_mul_d(a, radix, a)) != MP_OKAY) { + return err; + } + if ((err = mp_add_d(a, y, a)) != MP_OKAY) { + return err; + } + + ch = fgetc(stream); + } + if (mp_cmp_d(a, 0) != MP_EQ) { + a->sign = neg; + } + + return MP_OKAY; +} + +#endif + +/* End: bn_mp_fread.c */ + +/* Start: bn_mp_fwrite.c */ +#include <tommath.h> +#ifdef BN_MP_FWRITE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +int mp_fwrite(mp_int *a, int radix, FILE *stream) +{ + char *buf; + int err, len, x; + + if ((err = mp_radix_size(a, radix, &len)) != MP_OKAY) { + return err; + } + + buf = OPT_CAST(char) XMALLOC (len); + if (buf == NULL) { + return MP_MEM; + } + + if ((err = mp_toradix(a, buf, radix)) != MP_OKAY) { + XFREE (buf); + return err; + } + + for (x = 0; x < len; x++) { + if (fputc(buf[x], stream) == EOF) { + XFREE (buf); + return MP_VAL; + } + } + + XFREE (buf); + return MP_OKAY; +} + +#endif + +/* End: bn_mp_fwrite.c */ + +/* Start: bn_mp_gcd.c */ +#include <tommath.h> +#ifdef BN_MP_GCD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* Greatest Common Divisor using the binary method */ +int mp_gcd (mp_int * a, mp_int * b, mp_int * c) +{ + mp_int u, v; + int k, u_lsb, v_lsb, res; + + /* either zero than gcd is the largest */ + if (mp_iszero (a) == 1 && mp_iszero (b) == 0) { + return mp_abs (b, c); + } + if (mp_iszero (a) == 0 && mp_iszero (b) == 1) { + return mp_abs (a, c); + } + + /* optimized. At this point if a == 0 then + * b must equal zero too + */ + if (mp_iszero (a) == 1) { + mp_zero(c); + return MP_OKAY; + } + + /* get copies of a and b we can modify */ + if ((res = mp_init_copy (&u, a)) != MP_OKAY) { + return res; + } + + if ((res = mp_init_copy (&v, b)) != MP_OKAY) { + goto LBL_U; + } + + /* must be positive for the remainder of the algorithm */ + u.sign = v.sign = MP_ZPOS; + + /* B1. Find the common power of two for u and v */ + u_lsb = mp_cnt_lsb(&u); + v_lsb = mp_cnt_lsb(&v); + k = MIN(u_lsb, v_lsb); + + if (k > 0) { + /* divide the power of two out */ + if ((res = mp_div_2d(&u, k, &u, NULL)) != MP_OKAY) { + goto LBL_V; + } + + if ((res = mp_div_2d(&v, k, &v, NULL)) != MP_OKAY) { + goto LBL_V; + } + } + + /* divide any remaining factors of two out */ + if (u_lsb != k) { + if ((res = mp_div_2d(&u, u_lsb - k, &u, NULL)) != MP_OKAY) { + goto LBL_V; + } + } + + if (v_lsb != k) { + if ((res = mp_div_2d(&v, v_lsb - k, &v, NULL)) != MP_OKAY) { + goto LBL_V; + } + } + + while (mp_iszero(&v) == 0) { + /* make sure v is the largest */ + if (mp_cmp_mag(&u, &v) == MP_GT) { + /* swap u and v to make sure v is >= u */ + mp_exch(&u, &v); + } + + /* subtract smallest from largest */ + if ((res = s_mp_sub(&v, &u, &v)) != MP_OKAY) { + goto LBL_V; + } + + /* Divide out all factors of two */ + if ((res = mp_div_2d(&v, mp_cnt_lsb(&v), &v, NULL)) != MP_OKAY) { + goto LBL_V; + } + } + + /* multiply by 2**k which we divided out at the beginning */ + if ((res = mp_mul_2d (&u, k, c)) != MP_OKAY) { + goto LBL_V; + } + c->sign = MP_ZPOS; + res = MP_OKAY; +LBL_V:mp_clear (&u); +LBL_U:mp_clear (&v); + return res; +} +#endif + +/* End: bn_mp_gcd.c */ + +/* Start: bn_mp_get_int.c */ +#include <tommath.h> +#ifdef BN_MP_GET_INT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* get the lower 32-bits of an mp_int */ +unsigned long mp_get_int(mp_int * a) +{ + int i; + unsigned long res; + + if (a->used == 0) { + return 0; + } + + /* get number of digits of the lsb we have to read */ + i = MIN(a->used,(int)((sizeof(unsigned long)*CHAR_BIT+DIGIT_BIT-1)/DIGIT_BIT))-1; + + /* get most significant digit of result */ + res = DIGIT(a,i); + + while (--i >= 0) { + res = (res << DIGIT_BIT) | DIGIT(a,i); + } + + /* force result to 32-bits always so it is consistent on non 32-bit platforms */ + return res & 0xFFFFFFFFUL; +} +#endif + +/* End: bn_mp_get_int.c */ + +/* Start: bn_mp_grow.c */ +#include <tommath.h> +#ifdef BN_MP_GROW_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* grow as required */ +int mp_grow (mp_int * a, int size) +{ + int i; + mp_digit *tmp; + + /* if the alloc size is smaller alloc more ram */ + if (a->alloc < size) { + /* ensure there are always at least MP_PREC digits extra on top */ + size += (MP_PREC * 2) - (size % MP_PREC); + + /* reallocate the array a->dp + * + * We store the return in a temporary variable + * in case the operation failed we don't want + * to overwrite the dp member of a. + */ + tmp = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * size); + if (tmp == NULL) { + /* reallocation failed but "a" is still valid [can be freed] */ + return MP_MEM; + } + + /* reallocation succeeded so set a->dp */ + a->dp = tmp; + + /* zero excess digits */ + i = a->alloc; + a->alloc = size; + for (; i < a->alloc; i++) { + a->dp[i] = 0; + } + } + return MP_OKAY; +} +#endif + +/* End: bn_mp_grow.c */ + +/* Start: bn_mp_init.c */ +#include <tommath.h> +#ifdef BN_MP_INIT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* init a new mp_int */ +int mp_init (mp_int * a) +{ + int i; + + /* allocate memory required and clear it */ + a->dp = OPT_CAST(mp_digit) XMALLOC (sizeof (mp_digit) * MP_PREC); + if (a->dp == NULL) { + return MP_MEM; + } + + /* set the digits to zero */ + for (i = 0; i < MP_PREC; i++) { + a->dp[i] = 0; + } + + /* set the used to zero, allocated digits to the default precision + * and sign to positive */ + a->used = 0; + a->alloc = MP_PREC; + a->sign = MP_ZPOS; + + return MP_OKAY; +} +#endif + +/* End: bn_mp_init.c */ + +/* Start: bn_mp_init_copy.c */ +#include <tommath.h> +#ifdef BN_MP_INIT_COPY_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* creates "a" then copies b into it */ +int mp_init_copy (mp_int * a, mp_int * b) +{ + int res; + + if ((res = mp_init (a)) != MP_OKAY) { + return res; + } + return mp_copy (b, a); +} +#endif + +/* End: bn_mp_init_copy.c */ + +/* Start: bn_mp_init_multi.c */ +#include <tommath.h> +#ifdef BN_MP_INIT_MULTI_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ +#include <stdarg.h> + +int mp_init_multi(mp_int *mp, ...) +{ + mp_err res = MP_OKAY; /* Assume ok until proven otherwise */ + int n = 0; /* Number of ok inits */ + mp_int* cur_arg = mp; + va_list args; + + va_start(args, mp); /* init args to next argument from caller */ + while (cur_arg != NULL) { + if (mp_init(cur_arg) != MP_OKAY) { + /* Oops - error! Back-track and mp_clear what we already + succeeded in init-ing, then return error. + */ + va_list clean_args; + + /* end the current list */ + va_end(args); + + /* now start cleaning up */ + cur_arg = mp; + va_start(clean_args, mp); + while (n--) { + mp_clear(cur_arg); + cur_arg = va_arg(clean_args, mp_int*); + } + va_end(clean_args); + res = MP_MEM; + break; + } + n++; + cur_arg = va_arg(args, mp_int*); + } + va_end(args); + return res; /* Assumed ok, if error flagged above. */ +} + +#endif + +/* End: bn_mp_init_multi.c */ + +/* Start: bn_mp_init_set.c */ +#include <tommath.h> +#ifdef BN_MP_INIT_SET_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* initialize and set a digit */ +int mp_init_set (mp_int * a, mp_digit b) +{ + int err; + if ((err = mp_init(a)) != MP_OKAY) { + return err; + } + mp_set(a, b); + return err; +} +#endif + +/* End: bn_mp_init_set.c */ + +/* Start: bn_mp_init_set_int.c */ +#include <tommath.h> +#ifdef BN_MP_INIT_SET_INT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* initialize and set a digit */ +int mp_init_set_int (mp_int * a, unsigned long b) +{ + int err; + if ((err = mp_init(a)) != MP_OKAY) { + return err; + } + return mp_set_int(a, b); +} +#endif + +/* End: bn_mp_init_set_int.c */ + +/* Start: bn_mp_init_size.c */ +#include <tommath.h> +#ifdef BN_MP_INIT_SIZE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* init an mp_init for a given size */ +int mp_init_size (mp_int * a, int size) +{ + int x; + + /* pad size so there are always extra digits */ + size += (MP_PREC * 2) - (size % MP_PREC); + + /* alloc mem */ + a->dp = OPT_CAST(mp_digit) XMALLOC (sizeof (mp_digit) * size); + if (a->dp == NULL) { + return MP_MEM; + } + + /* set the members */ + a->used = 0; + a->alloc = size; + a->sign = MP_ZPOS; + + /* zero the digits */ + for (x = 0; x < size; x++) { + a->dp[x] = 0; + } + + return MP_OKAY; +} +#endif + +/* End: bn_mp_init_size.c */ + +/* Start: bn_mp_invmod.c */ +#include <tommath.h> +#ifdef BN_MP_INVMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* hac 14.61, pp608 */ +int mp_invmod (mp_int * a, mp_int * b, mp_int * c) +{ + /* b cannot be negative */ + if (b->sign == MP_NEG || mp_iszero(b) == 1) { + return MP_VAL; + } + +#ifdef BN_FAST_MP_INVMOD_C + /* if the modulus is odd we can use a faster routine instead */ + if (mp_isodd (b) == 1) { + return fast_mp_invmod (a, b, c); + } +#endif + +#ifdef BN_MP_INVMOD_SLOW_C + return mp_invmod_slow(a, b, c); +#endif + + return MP_VAL; +} +#endif + +/* End: bn_mp_invmod.c */ + +/* Start: bn_mp_invmod_slow.c */ +#include <tommath.h> +#ifdef BN_MP_INVMOD_SLOW_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* hac 14.61, pp608 */ +int mp_invmod_slow (mp_int * a, mp_int * b, mp_int * c) +{ + mp_int x, y, u, v, A, B, C, D; + int res; + + /* b cannot be negative */ + if (b->sign == MP_NEG || mp_iszero(b) == 1) { + return MP_VAL; + } + + /* init temps */ + if ((res = mp_init_multi(&x, &y, &u, &v, + &A, &B, &C, &D, NULL)) != MP_OKAY) { + return res; + } + + /* x = a, y = b */ + if ((res = mp_copy (a, &x)) != MP_OKAY) { + goto LBL_ERR; + } + if ((res = mp_copy (b, &y)) != MP_OKAY) { + goto LBL_ERR; + } + + /* 2. [modified] if x,y are both even then return an error! */ + if (mp_iseven (&x) == 1 && mp_iseven (&y) == 1) { + res = MP_VAL; + goto LBL_ERR; + } + + /* 3. u=x, v=y, A=1, B=0, C=0,D=1 */ + if ((res = mp_copy (&x, &u)) != MP_OKAY) { + goto LBL_ERR; + } + if ((res = mp_copy (&y, &v)) != MP_OKAY) { + goto LBL_ERR; + } + mp_set (&A, 1); + mp_set (&D, 1); + +top: + /* 4. while u is even do */ + while (mp_iseven (&u) == 1) { + /* 4.1 u = u/2 */ + if ((res = mp_div_2 (&u, &u)) != MP_OKAY) { + goto LBL_ERR; + } + /* 4.2 if A or B is odd then */ + if (mp_isodd (&A) == 1 || mp_isodd (&B) == 1) { + /* A = (A+y)/2, B = (B-x)/2 */ + if ((res = mp_add (&A, &y, &A)) != MP_OKAY) { + goto LBL_ERR; + } + if ((res = mp_sub (&B, &x, &B)) != MP_OKAY) { + goto LBL_ERR; + } + } + /* A = A/2, B = B/2 */ + if ((res = mp_div_2 (&A, &A)) != MP_OKAY) { + goto LBL_ERR; + } + if ((res = mp_div_2 (&B, &B)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* 5. while v is even do */ + while (mp_iseven (&v) == 1) { + /* 5.1 v = v/2 */ + if ((res = mp_div_2 (&v, &v)) != MP_OKAY) { + goto LBL_ERR; + } + /* 5.2 if C or D is odd then */ + if (mp_isodd (&C) == 1 || mp_isodd (&D) == 1) { + /* C = (C+y)/2, D = (D-x)/2 */ + if ((res = mp_add (&C, &y, &C)) != MP_OKAY) { + goto LBL_ERR; + } + if ((res = mp_sub (&D, &x, &D)) != MP_OKAY) { + goto LBL_ERR; + } + } + /* C = C/2, D = D/2 */ + if ((res = mp_div_2 (&C, &C)) != MP_OKAY) { + goto LBL_ERR; + } + if ((res = mp_div_2 (&D, &D)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* 6. if u >= v then */ + if (mp_cmp (&u, &v) != MP_LT) { + /* u = u - v, A = A - C, B = B - D */ + if ((res = mp_sub (&u, &v, &u)) != MP_OKAY) { + goto LBL_ERR; + } + + if ((res = mp_sub (&A, &C, &A)) != MP_OKAY) { + goto LBL_ERR; + } + + if ((res = mp_sub (&B, &D, &B)) != MP_OKAY) { + goto LBL_ERR; + } + } else { + /* v - v - u, C = C - A, D = D - B */ + if ((res = mp_sub (&v, &u, &v)) != MP_OKAY) { + goto LBL_ERR; + } + + if ((res = mp_sub (&C, &A, &C)) != MP_OKAY) { + goto LBL_ERR; + } + + if ((res = mp_sub (&D, &B, &D)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* if not zero goto step 4 */ + if (mp_iszero (&u) == 0) + goto top; + + /* now a = C, b = D, gcd == g*v */ + + /* if v != 1 then there is no inverse */ + if (mp_cmp_d (&v, 1) != MP_EQ) { + res = MP_VAL; + goto LBL_ERR; + } + + /* if its too low */ + while (mp_cmp_d(&C, 0) == MP_LT) { + if ((res = mp_add(&C, b, &C)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* too big */ + while (mp_cmp_mag(&C, b) != MP_LT) { + if ((res = mp_sub(&C, b, &C)) != MP_OKAY) { + goto LBL_ERR; + } + } + + /* C is now the inverse */ + mp_exch (&C, c); + res = MP_OKAY; +LBL_ERR:mp_clear_multi (&x, &y, &u, &v, &A, &B, &C, &D, NULL); + return res; +} +#endif + +/* End: bn_mp_invmod_slow.c */ + +/* Start: bn_mp_is_square.c */ +#include <tommath.h> +#ifdef BN_MP_IS_SQUARE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* Check if remainders are possible squares - fast exclude non-squares */ +static const char rem_128[128] = { + 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, + 0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, + 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, + 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, + 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, + 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, + 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, + 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1 +}; + +static const char rem_105[105] = { + 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, + 0, 0, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, + 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, + 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, + 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, + 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, + 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1 +}; + +/* Store non-zero to ret if arg is square, and zero if not */ +int mp_is_square(mp_int *arg,int *ret) +{ + int res; + mp_digit c; + mp_int t; + unsigned long r; + + /* Default to Non-square :) */ + *ret = MP_NO; + + if (arg->sign == MP_NEG) { + return MP_VAL; + } + + /* digits used? (TSD) */ + if (arg->used == 0) { + return MP_OKAY; + } + + /* First check mod 128 (suppose that DIGIT_BIT is at least 7) */ + if (rem_128[127 & DIGIT(arg,0)] == 1) { + return MP_OKAY; + } + + /* Next check mod 105 (3*5*7) */ + if ((res = mp_mod_d(arg,105,&c)) != MP_OKAY) { + return res; + } + if (rem_105[c] == 1) { + return MP_OKAY; + } + + + if ((res = mp_init_set_int(&t,11L*13L*17L*19L*23L*29L*31L)) != MP_OKAY) { + return res; + } + if ((res = mp_mod(arg,&t,&t)) != MP_OKAY) { + goto ERR; + } + r = mp_get_int(&t); + /* Check for other prime modules, note it's not an ERROR but we must + * free "t" so the easiest way is to goto ERR. We know that res + * is already equal to MP_OKAY from the mp_mod call + */ + if ( (1L<<(r%11)) & 0x5C4L ) goto ERR; + if ( (1L<<(r%13)) & 0x9E4L ) goto ERR; + if ( (1L<<(r%17)) & 0x5CE8L ) goto ERR; + if ( (1L<<(r%19)) & 0x4F50CL ) goto ERR; + if ( (1L<<(r%23)) & 0x7ACCA0L ) goto ERR; + if ( (1L<<(r%29)) & 0xC2EDD0CL ) goto ERR; + if ( (1L<<(r%31)) & 0x6DE2B848L ) goto ERR; + + /* Final check - is sqr(sqrt(arg)) == arg ? */ + if ((res = mp_sqrt(arg,&t)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sqr(&t,&t)) != MP_OKAY) { + goto ERR; + } + + *ret = (mp_cmp_mag(&t,arg) == MP_EQ) ? MP_YES : MP_NO; +ERR:mp_clear(&t); + return res; +} +#endif + +/* End: bn_mp_is_square.c */ + +/* Start: bn_mp_jacobi.c */ +#include <tommath.h> +#ifdef BN_MP_JACOBI_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes the jacobi c = (a | n) (or Legendre if n is prime) + * HAC pp. 73 Algorithm 2.149 + */ +int mp_jacobi (mp_int * a, mp_int * p, int *c) +{ + mp_int a1, p1; + int k, s, r, res; + mp_digit residue; + + /* if p <= 0 return MP_VAL */ + if (mp_cmp_d(p, 0) != MP_GT) { + return MP_VAL; + } + + /* step 1. if a == 0, return 0 */ + if (mp_iszero (a) == 1) { + *c = 0; + return MP_OKAY; + } + + /* step 2. if a == 1, return 1 */ + if (mp_cmp_d (a, 1) == MP_EQ) { + *c = 1; + return MP_OKAY; + } + + /* default */ + s = 0; + + /* step 3. write a = a1 * 2**k */ + if ((res = mp_init_copy (&a1, a)) != MP_OKAY) { + return res; + } + + if ((res = mp_init (&p1)) != MP_OKAY) { + goto LBL_A1; + } + + /* divide out larger power of two */ + k = mp_cnt_lsb(&a1); + if ((res = mp_div_2d(&a1, k, &a1, NULL)) != MP_OKAY) { + goto LBL_P1; + } + + /* step 4. if e is even set s=1 */ + if ((k & 1) == 0) { + s = 1; + } else { + /* else set s=1 if p = 1/7 (mod 8) or s=-1 if p = 3/5 (mod 8) */ + residue = p->dp[0] & 7; + + if (residue == 1 || residue == 7) { + s = 1; + } else if (residue == 3 || residue == 5) { + s = -1; + } + } + + /* step 5. if p == 3 (mod 4) *and* a1 == 3 (mod 4) then s = -s */ + if ( ((p->dp[0] & 3) == 3) && ((a1.dp[0] & 3) == 3)) { + s = -s; + } + + /* if a1 == 1 we're done */ + if (mp_cmp_d (&a1, 1) == MP_EQ) { + *c = s; + } else { + /* n1 = n mod a1 */ + if ((res = mp_mod (p, &a1, &p1)) != MP_OKAY) { + goto LBL_P1; + } + if ((res = mp_jacobi (&p1, &a1, &r)) != MP_OKAY) { + goto LBL_P1; + } + *c = s * r; + } + + /* done */ + res = MP_OKAY; +LBL_P1:mp_clear (&p1); +LBL_A1:mp_clear (&a1); + return res; +} +#endif + +/* End: bn_mp_jacobi.c */ + +/* Start: bn_mp_karatsuba_mul.c */ +#include <tommath.h> +#ifdef BN_MP_KARATSUBA_MUL_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* c = |a| * |b| using Karatsuba Multiplication using + * three half size multiplications + * + * Let B represent the radix [e.g. 2**DIGIT_BIT] and + * let n represent half of the number of digits in + * the min(a,b) + * + * a = a1 * B**n + a0 + * b = b1 * B**n + b0 + * + * Then, a * b => + a1b1 * B**2n + ((a1 - a0)(b1 - b0) + a0b0 + a1b1) * B + a0b0 + * + * Note that a1b1 and a0b0 are used twice and only need to be + * computed once. So in total three half size (half # of + * digit) multiplications are performed, a0b0, a1b1 and + * (a1-b1)(a0-b0) + * + * Note that a multiplication of half the digits requires + * 1/4th the number of single precision multiplications so in + * total after one call 25% of the single precision multiplications + * are saved. Note also that the call to mp_mul can end up back + * in this function if the a0, a1, b0, or b1 are above the threshold. + * This is known as divide-and-conquer and leads to the famous + * O(N**lg(3)) or O(N**1.584) work which is asymptopically lower than + * the standard O(N**2) that the baseline/comba methods use. + * Generally though the overhead of this method doesn't pay off + * until a certain size (N ~ 80) is reached. + */ +int mp_karatsuba_mul (mp_int * a, mp_int * b, mp_int * c) +{ + mp_int x0, x1, y0, y1, t1, x0y0, x1y1; + int B, err; + + /* default the return code to an error */ + err = MP_MEM; + + /* min # of digits */ + B = MIN (a->used, b->used); + + /* now divide in two */ + B = B >> 1; + + /* init copy all the temps */ + if (mp_init_size (&x0, B) != MP_OKAY) + goto ERR; + if (mp_init_size (&x1, a->used - B) != MP_OKAY) + goto X0; + if (mp_init_size (&y0, B) != MP_OKAY) + goto X1; + if (mp_init_size (&y1, b->used - B) != MP_OKAY) + goto Y0; + + /* init temps */ + if (mp_init_size (&t1, B * 2) != MP_OKAY) + goto Y1; + if (mp_init_size (&x0y0, B * 2) != MP_OKAY) + goto T1; + if (mp_init_size (&x1y1, B * 2) != MP_OKAY) + goto X0Y0; + + /* now shift the digits */ + x0.used = y0.used = B; + x1.used = a->used - B; + y1.used = b->used - B; + + { + register int x; + register mp_digit *tmpa, *tmpb, *tmpx, *tmpy; + + /* we copy the digits directly instead of using higher level functions + * since we also need to shift the digits + */ + tmpa = a->dp; + tmpb = b->dp; + + tmpx = x0.dp; + tmpy = y0.dp; + for (x = 0; x < B; x++) { + *tmpx++ = *tmpa++; + *tmpy++ = *tmpb++; + } + + tmpx = x1.dp; + for (x = B; x < a->used; x++) { + *tmpx++ = *tmpa++; + } + + tmpy = y1.dp; + for (x = B; x < b->used; x++) { + *tmpy++ = *tmpb++; + } + } + + /* only need to clamp the lower words since by definition the + * upper words x1/y1 must have a known number of digits + */ + mp_clamp (&x0); + mp_clamp (&y0); + + /* now calc the products x0y0 and x1y1 */ + /* after this x0 is no longer required, free temp [x0==t2]! */ + if (mp_mul (&x0, &y0, &x0y0) != MP_OKAY) + goto X1Y1; /* x0y0 = x0*y0 */ + if (mp_mul (&x1, &y1, &x1y1) != MP_OKAY) + goto X1Y1; /* x1y1 = x1*y1 */ + + /* now calc x1-x0 and y1-y0 */ + if (mp_sub (&x1, &x0, &t1) != MP_OKAY) + goto X1Y1; /* t1 = x1 - x0 */ + if (mp_sub (&y1, &y0, &x0) != MP_OKAY) + goto X1Y1; /* t2 = y1 - y0 */ + if (mp_mul (&t1, &x0, &t1) != MP_OKAY) + goto X1Y1; /* t1 = (x1 - x0) * (y1 - y0) */ + + /* add x0y0 */ + if (mp_add (&x0y0, &x1y1, &x0) != MP_OKAY) + goto X1Y1; /* t2 = x0y0 + x1y1 */ + if (mp_sub (&x0, &t1, &t1) != MP_OKAY) + goto X1Y1; /* t1 = x0y0 + x1y1 - (x1-x0)*(y1-y0) */ + + /* shift by B */ + if (mp_lshd (&t1, B) != MP_OKAY) + goto X1Y1; /* t1 = (x0y0 + x1y1 - (x1-x0)*(y1-y0))<<B */ + if (mp_lshd (&x1y1, B * 2) != MP_OKAY) + goto X1Y1; /* x1y1 = x1y1 << 2*B */ + + if (mp_add (&x0y0, &t1, &t1) != MP_OKAY) + goto X1Y1; /* t1 = x0y0 + t1 */ + if (mp_add (&t1, &x1y1, c) != MP_OKAY) + goto X1Y1; /* t1 = x0y0 + t1 + x1y1 */ + + /* Algorithm succeeded set the return code to MP_OKAY */ + err = MP_OKAY; + +X1Y1:mp_clear (&x1y1); +X0Y0:mp_clear (&x0y0); +T1:mp_clear (&t1); +Y1:mp_clear (&y1); +Y0:mp_clear (&y0); +X1:mp_clear (&x1); +X0:mp_clear (&x0); +ERR: + return err; +} +#endif + +/* End: bn_mp_karatsuba_mul.c */ + +/* Start: bn_mp_karatsuba_sqr.c */ +#include <tommath.h> +#ifdef BN_MP_KARATSUBA_SQR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* Karatsuba squaring, computes b = a*a using three + * half size squarings + * + * See comments of karatsuba_mul for details. It + * is essentially the same algorithm but merely + * tuned to perform recursive squarings. + */ +int mp_karatsuba_sqr (mp_int * a, mp_int * b) +{ + mp_int x0, x1, t1, t2, x0x0, x1x1; + int B, err; + + err = MP_MEM; + + /* min # of digits */ + B = a->used; + + /* now divide in two */ + B = B >> 1; + + /* init copy all the temps */ + if (mp_init_size (&x0, B) != MP_OKAY) + goto ERR; + if (mp_init_size (&x1, a->used - B) != MP_OKAY) + goto X0; + + /* init temps */ + if (mp_init_size (&t1, a->used * 2) != MP_OKAY) + goto X1; + if (mp_init_size (&t2, a->used * 2) != MP_OKAY) + goto T1; + if (mp_init_size (&x0x0, B * 2) != MP_OKAY) + goto T2; + if (mp_init_size (&x1x1, (a->used - B) * 2) != MP_OKAY) + goto X0X0; + + { + register int x; + register mp_digit *dst, *src; + + src = a->dp; + + /* now shift the digits */ + dst = x0.dp; + for (x = 0; x < B; x++) { + *dst++ = *src++; + } + + dst = x1.dp; + for (x = B; x < a->used; x++) { + *dst++ = *src++; + } + } + + x0.used = B; + x1.used = a->used - B; + + mp_clamp (&x0); + + /* now calc the products x0*x0 and x1*x1 */ + if (mp_sqr (&x0, &x0x0) != MP_OKAY) + goto X1X1; /* x0x0 = x0*x0 */ + if (mp_sqr (&x1, &x1x1) != MP_OKAY) + goto X1X1; /* x1x1 = x1*x1 */ + + /* now calc (x1-x0)**2 */ + if (mp_sub (&x1, &x0, &t1) != MP_OKAY) + goto X1X1; /* t1 = x1 - x0 */ + if (mp_sqr (&t1, &t1) != MP_OKAY) + goto X1X1; /* t1 = (x1 - x0) * (x1 - x0) */ + + /* add x0y0 */ + if (s_mp_add (&x0x0, &x1x1, &t2) != MP_OKAY) + goto X1X1; /* t2 = x0x0 + x1x1 */ + if (mp_sub (&t2, &t1, &t1) != MP_OKAY) + goto X1X1; /* t1 = x0x0 + x1x1 - (x1-x0)*(x1-x0) */ + + /* shift by B */ + if (mp_lshd (&t1, B) != MP_OKAY) + goto X1X1; /* t1 = (x0x0 + x1x1 - (x1-x0)*(x1-x0))<<B */ + if (mp_lshd (&x1x1, B * 2) != MP_OKAY) + goto X1X1; /* x1x1 = x1x1 << 2*B */ + + if (mp_add (&x0x0, &t1, &t1) != MP_OKAY) + goto X1X1; /* t1 = x0x0 + t1 */ + if (mp_add (&t1, &x1x1, b) != MP_OKAY) + goto X1X1; /* t1 = x0x0 + t1 + x1x1 */ + + err = MP_OKAY; + +X1X1:mp_clear (&x1x1); +X0X0:mp_clear (&x0x0); +T2:mp_clear (&t2); +T1:mp_clear (&t1); +X1:mp_clear (&x1); +X0:mp_clear (&x0); +ERR: + return err; +} +#endif + +/* End: bn_mp_karatsuba_sqr.c */ + +/* Start: bn_mp_lcm.c */ +#include <tommath.h> +#ifdef BN_MP_LCM_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes least common multiple as |a*b|/(a, b) */ +int mp_lcm (mp_int * a, mp_int * b, mp_int * c) +{ + int res; + mp_int t1, t2; + + + if ((res = mp_init_multi (&t1, &t2, NULL)) != MP_OKAY) { + return res; + } + + /* t1 = get the GCD of the two inputs */ + if ((res = mp_gcd (a, b, &t1)) != MP_OKAY) { + goto LBL_T; + } + + /* divide the smallest by the GCD */ + if (mp_cmp_mag(a, b) == MP_LT) { + /* store quotient in t2 such that t2 * b is the LCM */ + if ((res = mp_div(a, &t1, &t2, NULL)) != MP_OKAY) { + goto LBL_T; + } + res = mp_mul(b, &t2, c); + } else { + /* store quotient in t2 such that t2 * a is the LCM */ + if ((res = mp_div(b, &t1, &t2, NULL)) != MP_OKAY) { + goto LBL_T; + } + res = mp_mul(a, &t2, c); + } + + /* fix the sign to positive */ + c->sign = MP_ZPOS; + +LBL_T: + mp_clear_multi (&t1, &t2, NULL); + return res; +} +#endif + +/* End: bn_mp_lcm.c */ + +/* Start: bn_mp_lshd.c */ +#include <tommath.h> +#ifdef BN_MP_LSHD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* shift left a certain amount of digits */ +int mp_lshd (mp_int * a, int b) +{ + int x, res; + + /* if its less than zero return */ + if (b <= 0) { + return MP_OKAY; + } + + /* grow to fit the new digits */ + if (a->alloc < a->used + b) { + if ((res = mp_grow (a, a->used + b)) != MP_OKAY) { + return res; + } + } + + { + register mp_digit *top, *bottom; + + /* increment the used by the shift amount then copy upwards */ + a->used += b; + + /* top */ + top = a->dp + a->used - 1; + + /* base */ + bottom = a->dp + a->used - 1 - b; + + /* much like mp_rshd this is implemented using a sliding window + * except the window goes the otherway around. Copying from + * the bottom to the top. see bn_mp_rshd.c for more info. + */ + for (x = a->used - 1; x >= b; x--) { + *top-- = *bottom--; + } + + /* zero the lower digits */ + top = a->dp; + for (x = 0; x < b; x++) { + *top++ = 0; + } + } + return MP_OKAY; +} +#endif + +/* End: bn_mp_lshd.c */ + +/* Start: bn_mp_mod.c */ +#include <tommath.h> +#ifdef BN_MP_MOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* c = a mod b, 0 <= c < b */ +int +mp_mod (mp_int * a, mp_int * b, mp_int * c) +{ + mp_int t; + int res; + + if ((res = mp_init (&t)) != MP_OKAY) { + return res; + } + + if ((res = mp_div (a, b, NULL, &t)) != MP_OKAY) { + mp_clear (&t); + return res; + } + + if (t.sign != b->sign) { + res = mp_add (b, &t, c); + } else { + res = MP_OKAY; + mp_exch (&t, c); + } + + mp_clear (&t); + return res; +} +#endif + +/* End: bn_mp_mod.c */ + +/* Start: bn_mp_mod_2d.c */ +#include <tommath.h> +#ifdef BN_MP_MOD_2D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* calc a value mod 2**b */ +int +mp_mod_2d (mp_int * a, int b, mp_int * c) +{ + int x, res; + + /* if b is <= 0 then zero the int */ + if (b <= 0) { + mp_zero (c); + return MP_OKAY; + } + + /* if the modulus is larger than the value than return */ + if (b >= (int) (a->used * DIGIT_BIT)) { + res = mp_copy (a, c); + return res; + } + + /* copy */ + if ((res = mp_copy (a, c)) != MP_OKAY) { + return res; + } + + /* zero digits above the last digit of the modulus */ + for (x = (b / DIGIT_BIT) + ((b % DIGIT_BIT) == 0 ? 0 : 1); x < c->used; x++) { + c->dp[x] = 0; + } + /* clear the digit that is not completely outside/inside the modulus */ + c->dp[b / DIGIT_BIT] &= + (mp_digit) ((((mp_digit) 1) << (((mp_digit) b) % DIGIT_BIT)) - ((mp_digit) 1)); + mp_clamp (c); + return MP_OKAY; +} +#endif + +/* End: bn_mp_mod_2d.c */ + +/* Start: bn_mp_mod_d.c */ +#include <tommath.h> +#ifdef BN_MP_MOD_D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +int +mp_mod_d (mp_int * a, mp_digit b, mp_digit * c) +{ + return mp_div_d(a, b, NULL, c); +} +#endif + +/* End: bn_mp_mod_d.c */ + +/* Start: bn_mp_montgomery_calc_normalization.c */ +#include <tommath.h> +#ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* + * shifts with subtractions when the result is greater than b. + * + * The method is slightly modified to shift B unconditionally upto just under + * the leading bit of b. This saves alot of multiple precision shifting. + */ +int mp_montgomery_calc_normalization (mp_int * a, mp_int * b) +{ + int x, bits, res; + + /* how many bits of last digit does b use */ + bits = mp_count_bits (b) % DIGIT_BIT; + + + if (b->used > 1) { + if ((res = mp_2expt (a, (b->used - 1) * DIGIT_BIT + bits - 1)) != MP_OKAY) { + return res; + } + } else { + mp_set(a, 1); + bits = 1; + } + + + /* now compute C = A * B mod b */ + for (x = bits - 1; x < (int)DIGIT_BIT; x++) { + if ((res = mp_mul_2 (a, a)) != MP_OKAY) { + return res; + } + if (mp_cmp_mag (a, b) != MP_LT) { + if ((res = s_mp_sub (a, b, a)) != MP_OKAY) { + return res; + } + } + } + + return MP_OKAY; +} +#endif + +/* End: bn_mp_montgomery_calc_normalization.c */ + +/* Start: bn_mp_montgomery_reduce.c */ +#include <tommath.h> +#ifdef BN_MP_MONTGOMERY_REDUCE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes xR**-1 == x (mod N) via Montgomery Reduction */ +int +mp_montgomery_reduce (mp_int * x, mp_int * n, mp_digit rho) +{ + int ix, res, digs; + mp_digit mu; + + /* can the fast reduction [comba] method be used? + * + * Note that unlike in mul you're safely allowed *less* + * than the available columns [255 per default] since carries + * are fixed up in the inner loop. + */ + digs = n->used * 2 + 1; + if ((digs < MP_WARRAY) && + n->used < + (1 << ((CHAR_BIT * sizeof (mp_word)) - (2 * DIGIT_BIT)))) { + return fast_mp_montgomery_reduce (x, n, rho); + } + + /* grow the input as required */ + if (x->alloc < digs) { + if ((res = mp_grow (x, digs)) != MP_OKAY) { + return res; + } + } + x->used = digs; + + for (ix = 0; ix < n->used; ix++) { + /* mu = ai * rho mod b + * + * The value of rho must be precalculated via + * montgomery_setup() such that + * it equals -1/n0 mod b this allows the + * following inner loop to reduce the + * input one digit at a time + */ + mu = (mp_digit) (((mp_word)x->dp[ix]) * ((mp_word)rho) & MP_MASK); + + /* a = a + mu * m * b**i */ + { + register int iy; + register mp_digit *tmpn, *tmpx, u; + register mp_word r; + + /* alias for digits of the modulus */ + tmpn = n->dp; + + /* alias for the digits of x [the input] */ + tmpx = x->dp + ix; + + /* set the carry to zero */ + u = 0; + + /* Multiply and add in place */ + for (iy = 0; iy < n->used; iy++) { + /* compute product and sum */ + r = ((mp_word)mu) * ((mp_word)*tmpn++) + + ((mp_word) u) + ((mp_word) * tmpx); + + /* get carry */ + u = (mp_digit)(r >> ((mp_word) DIGIT_BIT)); + + /* fix digit */ + *tmpx++ = (mp_digit)(r & ((mp_word) MP_MASK)); + } + /* At this point the ix'th digit of x should be zero */ + + + /* propagate carries upwards as required*/ + while (u) { + *tmpx += u; + u = *tmpx >> DIGIT_BIT; + *tmpx++ &= MP_MASK; + } + } + } + + /* at this point the n.used'th least + * significant digits of x are all zero + * which means we can shift x to the + * right by n.used digits and the + * residue is unchanged. + */ + + /* x = x/b**n.used */ + mp_clamp(x); + mp_rshd (x, n->used); + + /* if x >= n then x = x - n */ + if (mp_cmp_mag (x, n) != MP_LT) { + return s_mp_sub (x, n, x); + } + + return MP_OKAY; +} +#endif + +/* End: bn_mp_montgomery_reduce.c */ + +/* Start: bn_mp_montgomery_setup.c */ +#include <tommath.h> +#ifdef BN_MP_MONTGOMERY_SETUP_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* setups the montgomery reduction stuff */ +int +mp_montgomery_setup (mp_int * n, mp_digit * rho) +{ + mp_digit x, b; + +/* fast inversion mod 2**k + * + * Based on the fact that + * + * XA = 1 (mod 2**n) => (X(2-XA)) A = 1 (mod 2**2n) + * => 2*X*A - X*X*A*A = 1 + * => 2*(1) - (1) = 1 + */ + b = n->dp[0]; + + if ((b & 1) == 0) { + return MP_VAL; + } + + x = (((b + 2) & 4) << 1) + b; /* here x*a==1 mod 2**4 */ + x *= 2 - b * x; /* here x*a==1 mod 2**8 */ +#if !defined(MP_8BIT) + x *= 2 - b * x; /* here x*a==1 mod 2**16 */ +#endif +#if defined(MP_64BIT) || !(defined(MP_8BIT) || defined(MP_16BIT)) + x *= 2 - b * x; /* here x*a==1 mod 2**32 */ +#endif +#ifdef MP_64BIT + x *= 2 - b * x; /* here x*a==1 mod 2**64 */ +#endif + + /* rho = -1/m mod b */ + *rho = (((mp_word)1 << ((mp_word) DIGIT_BIT)) - x) & MP_MASK; + + return MP_OKAY; +} +#endif + +/* End: bn_mp_montgomery_setup.c */ + +/* Start: bn_mp_mul.c */ +#include <tommath.h> +#ifdef BN_MP_MUL_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* high level multiplication (handles sign) */ +int mp_mul (mp_int * a, mp_int * b, mp_int * c) +{ + int res, neg; + neg = (a->sign == b->sign) ? MP_ZPOS : MP_NEG; + + /* use Toom-Cook? */ +#ifdef BN_MP_TOOM_MUL_C + if (MIN (a->used, b->used) >= TOOM_MUL_CUTOFF) { + res = mp_toom_mul(a, b, c); + } else +#endif +#ifdef BN_MP_KARATSUBA_MUL_C + /* use Karatsuba? */ + if (MIN (a->used, b->used) >= KARATSUBA_MUL_CUTOFF) { + res = mp_karatsuba_mul (a, b, c); + } else +#endif + { + /* can we use the fast multiplier? + * + * The fast multiplier can be used if the output will + * have less than MP_WARRAY digits and the number of + * digits won't affect carry propagation + */ + int digs = a->used + b->used + 1; + +#ifdef BN_FAST_S_MP_MUL_DIGS_C + if ((digs < MP_WARRAY) && + MIN(a->used, b->used) <= + (1 << ((CHAR_BIT * sizeof (mp_word)) - (2 * DIGIT_BIT)))) { + res = fast_s_mp_mul_digs (a, b, c, digs); + } else +#endif +#ifdef BN_S_MP_MUL_DIGS_C + res = s_mp_mul (a, b, c); /* uses s_mp_mul_digs */ +#else + res = MP_VAL; +#endif + + } + c->sign = (c->used > 0) ? neg : MP_ZPOS; + return res; +} +#endif + +/* End: bn_mp_mul.c */ + +/* Start: bn_mp_mul_2.c */ +#include <tommath.h> +#ifdef BN_MP_MUL_2_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* b = a*2 */ +int mp_mul_2(mp_int * a, mp_int * b) +{ + int x, res, oldused; + + /* grow to accomodate result */ + if (b->alloc < a->used + 1) { + if ((res = mp_grow (b, a->used + 1)) != MP_OKAY) { + return res; + } + } + + oldused = b->used; + b->used = a->used; + + { + register mp_digit r, rr, *tmpa, *tmpb; + + /* alias for source */ + tmpa = a->dp; + + /* alias for dest */ + tmpb = b->dp; + + /* carry */ + r = 0; + for (x = 0; x < a->used; x++) { + + /* get what will be the *next* carry bit from the + * MSB of the current digit + */ + rr = *tmpa >> ((mp_digit)(DIGIT_BIT - 1)); + + /* now shift up this digit, add in the carry [from the previous] */ + *tmpb++ = ((*tmpa++ << ((mp_digit)1)) | r) & MP_MASK; + + /* copy the carry that would be from the source + * digit into the next iteration + */ + r = rr; + } + + /* new leading digit? */ + if (r != 0) { + /* add a MSB which is always 1 at this point */ + *tmpb = 1; + ++(b->used); + } + + /* now zero any excess digits on the destination + * that we didn't write to + */ + tmpb = b->dp + b->used; + for (x = b->used; x < oldused; x++) { + *tmpb++ = 0; + } + } + b->sign = a->sign; + return MP_OKAY; +} +#endif + +/* End: bn_mp_mul_2.c */ + +/* Start: bn_mp_mul_2d.c */ +#include <tommath.h> +#ifdef BN_MP_MUL_2D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* shift left by a certain bit count */ +int mp_mul_2d (mp_int * a, int b, mp_int * c) +{ + mp_digit d; + int res; + + /* copy */ + if (a != c) { + if ((res = mp_copy (a, c)) != MP_OKAY) { + return res; + } + } + + if (c->alloc < (int)(c->used + b/DIGIT_BIT + 1)) { + if ((res = mp_grow (c, c->used + b / DIGIT_BIT + 1)) != MP_OKAY) { + return res; + } + } + + /* shift by as many digits in the bit count */ + if (b >= (int)DIGIT_BIT) { + if ((res = mp_lshd (c, b / DIGIT_BIT)) != MP_OKAY) { + return res; + } + } + + /* shift any bit count < DIGIT_BIT */ + d = (mp_digit) (b % DIGIT_BIT); + if (d != 0) { + register mp_digit *tmpc, shift, mask, r, rr; + register int x; + + /* bitmask for carries */ + mask = (((mp_digit)1) << d) - 1; + + /* shift for msbs */ + shift = DIGIT_BIT - d; + + /* alias */ + tmpc = c->dp; + + /* carry */ + r = 0; + for (x = 0; x < c->used; x++) { + /* get the higher bits of the current word */ + rr = (*tmpc >> shift) & mask; + + /* shift the current word and OR in the carry */ + *tmpc = ((*tmpc << d) | r) & MP_MASK; + ++tmpc; + + /* set the carry to the carry bits of the current word */ + r = rr; + } + + /* set final carry */ + if (r != 0) { + c->dp[(c->used)++] = r; + } + } + mp_clamp (c); + return MP_OKAY; +} +#endif + +/* End: bn_mp_mul_2d.c */ + +/* Start: bn_mp_mul_d.c */ +#include <tommath.h> +#ifdef BN_MP_MUL_D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* multiply by a digit */ +int +mp_mul_d (mp_int * a, mp_digit b, mp_int * c) +{ + mp_digit u, *tmpa, *tmpc; + mp_word r; + int ix, res, olduse; + + /* make sure c is big enough to hold a*b */ + if (c->alloc < a->used + 1) { + if ((res = mp_grow (c, a->used + 1)) != MP_OKAY) { + return res; + } + } + + /* get the original destinations used count */ + olduse = c->used; + + /* set the sign */ + c->sign = a->sign; + + /* alias for a->dp [source] */ + tmpa = a->dp; + + /* alias for c->dp [dest] */ + tmpc = c->dp; + + /* zero carry */ + u = 0; + + /* compute columns */ + for (ix = 0; ix < a->used; ix++) { + /* compute product and carry sum for this term */ + r = ((mp_word) u) + ((mp_word)*tmpa++) * ((mp_word)b); + + /* mask off higher bits to get a single digit */ + *tmpc++ = (mp_digit) (r & ((mp_word) MP_MASK)); + + /* send carry into next iteration */ + u = (mp_digit) (r >> ((mp_word) DIGIT_BIT)); + } + + /* store final carry [if any] */ + *tmpc++ = u; + + /* now zero digits above the top */ + while (ix++ < olduse) { + *tmpc++ = 0; + } + + /* set used count */ + c->used = a->used + 1; + mp_clamp(c); + + return MP_OKAY; +} +#endif + +/* End: bn_mp_mul_d.c */ + +/* Start: bn_mp_mulmod.c */ +#include <tommath.h> +#ifdef BN_MP_MULMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* d = a * b (mod c) */ +int +mp_mulmod (mp_int * a, mp_int * b, mp_int * c, mp_int * d) +{ + int res; + mp_int t; + + if ((res = mp_init (&t)) != MP_OKAY) { + return res; + } + + if ((res = mp_mul (a, b, &t)) != MP_OKAY) { + mp_clear (&t); + return res; + } + res = mp_mod (&t, c, d); + mp_clear (&t); + return res; +} +#endif + +/* End: bn_mp_mulmod.c */ + +/* Start: bn_mp_n_root.c */ +#include <tommath.h> +#ifdef BN_MP_N_ROOT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* find the n'th root of an integer + * + * Result found such that (c)**b <= a and (c+1)**b > a + * + * This algorithm uses Newton's approximation + * x[i+1] = x[i] - f(x[i])/f'(x[i]) + * which will find the root in log(N) time where + * each step involves a fair bit. This is not meant to + * find huge roots [square and cube, etc]. + */ +int mp_n_root (mp_int * a, mp_digit b, mp_int * c) +{ + mp_int t1, t2, t3; + int res, neg; + + /* input must be positive if b is even */ + if ((b & 1) == 0 && a->sign == MP_NEG) { + return MP_VAL; + } + + if ((res = mp_init (&t1)) != MP_OKAY) { + return res; + } + + if ((res = mp_init (&t2)) != MP_OKAY) { + goto LBL_T1; + } + + if ((res = mp_init (&t3)) != MP_OKAY) { + goto LBL_T2; + } + + /* if a is negative fudge the sign but keep track */ + neg = a->sign; + a->sign = MP_ZPOS; + + /* t2 = 2 */ + mp_set (&t2, 2); + + do { + /* t1 = t2 */ + if ((res = mp_copy (&t2, &t1)) != MP_OKAY) { + goto LBL_T3; + } + + /* t2 = t1 - ((t1**b - a) / (b * t1**(b-1))) */ + + /* t3 = t1**(b-1) */ + if ((res = mp_expt_d (&t1, b - 1, &t3)) != MP_OKAY) { + goto LBL_T3; + } + + /* numerator */ + /* t2 = t1**b */ + if ((res = mp_mul (&t3, &t1, &t2)) != MP_OKAY) { + goto LBL_T3; + } + + /* t2 = t1**b - a */ + if ((res = mp_sub (&t2, a, &t2)) != MP_OKAY) { + goto LBL_T3; + } + + /* denominator */ + /* t3 = t1**(b-1) * b */ + if ((res = mp_mul_d (&t3, b, &t3)) != MP_OKAY) { + goto LBL_T3; + } + + /* t3 = (t1**b - a)/(b * t1**(b-1)) */ + if ((res = mp_div (&t2, &t3, &t3, NULL)) != MP_OKAY) { + goto LBL_T3; + } + + if ((res = mp_sub (&t1, &t3, &t2)) != MP_OKAY) { + goto LBL_T3; + } + } while (mp_cmp (&t1, &t2) != MP_EQ); + + /* result can be off by a few so check */ + for (;;) { + if ((res = mp_expt_d (&t1, b, &t2)) != MP_OKAY) { + goto LBL_T3; + } + + if (mp_cmp (&t2, a) == MP_GT) { + if ((res = mp_sub_d (&t1, 1, &t1)) != MP_OKAY) { + goto LBL_T3; + } + } else { + break; + } + } + + /* reset the sign of a first */ + a->sign = neg; + + /* set the result */ + mp_exch (&t1, c); + + /* set the sign of the result */ + c->sign = neg; + + res = MP_OKAY; + +LBL_T3:mp_clear (&t3); +LBL_T2:mp_clear (&t2); +LBL_T1:mp_clear (&t1); + return res; +} +#endif + +/* End: bn_mp_n_root.c */ + +/* Start: bn_mp_neg.c */ +#include <tommath.h> +#ifdef BN_MP_NEG_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* b = -a */ +int mp_neg (mp_int * a, mp_int * b) +{ + int res; + if ((res = mp_copy (a, b)) != MP_OKAY) { + return res; + } + if (mp_iszero(b) != MP_YES) { + b->sign = (a->sign == MP_ZPOS) ? MP_NEG : MP_ZPOS; + } + return MP_OKAY; +} +#endif + +/* End: bn_mp_neg.c */ + +/* Start: bn_mp_or.c */ +#include <tommath.h> +#ifdef BN_MP_OR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* OR two ints together */ +int mp_or (mp_int * a, mp_int * b, mp_int * c) +{ + int res, ix, px; + mp_int t, *x; + + if (a->used > b->used) { + if ((res = mp_init_copy (&t, a)) != MP_OKAY) { + return res; + } + px = b->used; + x = b; + } else { + if ((res = mp_init_copy (&t, b)) != MP_OKAY) { + return res; + } + px = a->used; + x = a; + } + + for (ix = 0; ix < px; ix++) { + t.dp[ix] |= x->dp[ix]; + } + mp_clamp (&t); + mp_exch (c, &t); + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_mp_or.c */ + +/* Start: bn_mp_prime_fermat.c */ +#include <tommath.h> +#ifdef BN_MP_PRIME_FERMAT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* performs one Fermat test. + * + * If "a" were prime then b**a == b (mod a) since the order of + * the multiplicative sub-group would be phi(a) = a-1. That means + * it would be the same as b**(a mod (a-1)) == b**1 == b (mod a). + * + * Sets result to 1 if the congruence holds, or zero otherwise. + */ +int mp_prime_fermat (mp_int * a, mp_int * b, int *result) +{ + mp_int t; + int err; + + /* default to composite */ + *result = MP_NO; + + /* ensure b > 1 */ + if (mp_cmp_d(b, 1) != MP_GT) { + return MP_VAL; + } + + /* init t */ + if ((err = mp_init (&t)) != MP_OKAY) { + return err; + } + + /* compute t = b**a mod a */ + if ((err = mp_exptmod (b, a, a, &t)) != MP_OKAY) { + goto LBL_T; + } + + /* is it equal to b? */ + if (mp_cmp (&t, b) == MP_EQ) { + *result = MP_YES; + } + + err = MP_OKAY; +LBL_T:mp_clear (&t); + return err; +} +#endif + +/* End: bn_mp_prime_fermat.c */ + +/* Start: bn_mp_prime_is_divisible.c */ +#include <tommath.h> +#ifdef BN_MP_PRIME_IS_DIVISIBLE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* determines if an integers is divisible by one + * of the first PRIME_SIZE primes or not + * + * sets result to 0 if not, 1 if yes + */ +int mp_prime_is_divisible (mp_int * a, int *result) +{ + int err, ix; + mp_digit res; + + /* default to not */ + *result = MP_NO; + + for (ix = 0; ix < PRIME_SIZE; ix++) { + /* what is a mod LBL_prime_tab[ix] */ + if ((err = mp_mod_d (a, ltm_prime_tab[ix], &res)) != MP_OKAY) { + return err; + } + + /* is the residue zero? */ + if (res == 0) { + *result = MP_YES; + return MP_OKAY; + } + } + + return MP_OKAY; +} +#endif + +/* End: bn_mp_prime_is_divisible.c */ + +/* Start: bn_mp_prime_is_prime.c */ +#include <tommath.h> +#ifdef BN_MP_PRIME_IS_PRIME_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* performs a variable number of rounds of Miller-Rabin + * + * Probability of error after t rounds is no more than + + * + * Sets result to 1 if probably prime, 0 otherwise + */ +int mp_prime_is_prime (mp_int * a, int t, int *result) +{ + mp_int b; + int ix, err, res; + + /* default to no */ + *result = MP_NO; + + /* valid value of t? */ + if (t <= 0 || t > PRIME_SIZE) { + return MP_VAL; + } + + /* is the input equal to one of the primes in the table? */ + for (ix = 0; ix < PRIME_SIZE; ix++) { + if (mp_cmp_d(a, ltm_prime_tab[ix]) == MP_EQ) { + *result = 1; + return MP_OKAY; + } + } + + /* first perform trial division */ + if ((err = mp_prime_is_divisible (a, &res)) != MP_OKAY) { + return err; + } + + /* return if it was trivially divisible */ + if (res == MP_YES) { + return MP_OKAY; + } + + /* now perform the miller-rabin rounds */ + if ((err = mp_init (&b)) != MP_OKAY) { + return err; + } + + for (ix = 0; ix < t; ix++) { + /* set the prime */ + mp_set (&b, ltm_prime_tab[ix]); + + if ((err = mp_prime_miller_rabin (a, &b, &res)) != MP_OKAY) { + goto LBL_B; + } + + if (res == MP_NO) { + goto LBL_B; + } + } + + /* passed the test */ + *result = MP_YES; +LBL_B:mp_clear (&b); + return err; +} +#endif + +/* End: bn_mp_prime_is_prime.c */ + +/* Start: bn_mp_prime_miller_rabin.c */ +#include <tommath.h> +#ifdef BN_MP_PRIME_MILLER_RABIN_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* Miller-Rabin test of "a" to the base of "b" as described in + * HAC pp. 139 Algorithm 4.24 + * + * Sets result to 0 if definitely composite or 1 if probably prime. + * Randomly the chance of error is no more than 1/4 and often + * very much lower. + */ +int mp_prime_miller_rabin (mp_int * a, mp_int * b, int *result) +{ + mp_int n1, y, r; + int s, j, err; + + /* default */ + *result = MP_NO; + + /* ensure b > 1 */ + if (mp_cmp_d(b, 1) != MP_GT) { + return MP_VAL; + } + + /* get n1 = a - 1 */ + if ((err = mp_init_copy (&n1, a)) != MP_OKAY) { + return err; + } + if ((err = mp_sub_d (&n1, 1, &n1)) != MP_OKAY) { + goto LBL_N1; + } + + /* set 2**s * r = n1 */ + if ((err = mp_init_copy (&r, &n1)) != MP_OKAY) { + goto LBL_N1; + } + + /* count the number of least significant bits + * which are zero + */ + s = mp_cnt_lsb(&r); + + /* now divide n - 1 by 2**s */ + if ((err = mp_div_2d (&r, s, &r, NULL)) != MP_OKAY) { + goto LBL_R; + } + + /* compute y = b**r mod a */ + if ((err = mp_init (&y)) != MP_OKAY) { + goto LBL_R; + } + if ((err = mp_exptmod (b, &r, a, &y)) != MP_OKAY) { + goto LBL_Y; + } + + /* if y != 1 and y != n1 do */ + if (mp_cmp_d (&y, 1) != MP_EQ && mp_cmp (&y, &n1) != MP_EQ) { + j = 1; + /* while j <= s-1 and y != n1 */ + while ((j <= (s - 1)) && mp_cmp (&y, &n1) != MP_EQ) { + if ((err = mp_sqrmod (&y, a, &y)) != MP_OKAY) { + goto LBL_Y; + } + + /* if y == 1 then composite */ + if (mp_cmp_d (&y, 1) == MP_EQ) { + goto LBL_Y; + } + + ++j; + } + + /* if y != n1 then composite */ + if (mp_cmp (&y, &n1) != MP_EQ) { + goto LBL_Y; + } + } + + /* probably prime now */ + *result = MP_YES; +LBL_Y:mp_clear (&y); +LBL_R:mp_clear (&r); +LBL_N1:mp_clear (&n1); + return err; +} +#endif + +/* End: bn_mp_prime_miller_rabin.c */ + +/* Start: bn_mp_prime_next_prime.c */ +#include <tommath.h> +#ifdef BN_MP_PRIME_NEXT_PRIME_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* finds the next prime after the number "a" using "t" trials + * of Miller-Rabin. + * + * bbs_style = 1 means the prime must be congruent to 3 mod 4 + */ +int mp_prime_next_prime(mp_int *a, int t, int bbs_style) +{ + int err, res, x, y; + mp_digit res_tab[PRIME_SIZE], step, kstep; + mp_int b; + + /* ensure t is valid */ + if (t <= 0 || t > PRIME_SIZE) { + return MP_VAL; + } + + /* force positive */ + a->sign = MP_ZPOS; + + /* simple algo if a is less than the largest prime in the table */ + if (mp_cmp_d(a, ltm_prime_tab[PRIME_SIZE-1]) == MP_LT) { + /* find which prime it is bigger than */ + for (x = PRIME_SIZE - 2; x >= 0; x--) { + if (mp_cmp_d(a, ltm_prime_tab[x]) != MP_LT) { + if (bbs_style == 1) { + /* ok we found a prime smaller or + * equal [so the next is larger] + * + * however, the prime must be + * congruent to 3 mod 4 + */ + if ((ltm_prime_tab[x + 1] & 3) != 3) { + /* scan upwards for a prime congruent to 3 mod 4 */ + for (y = x + 1; y < PRIME_SIZE; y++) { + if ((ltm_prime_tab[y] & 3) == 3) { + mp_set(a, ltm_prime_tab[y]); + return MP_OKAY; + } + } + } + } else { + mp_set(a, ltm_prime_tab[x + 1]); + return MP_OKAY; + } + } + } + /* at this point a maybe 1 */ + if (mp_cmp_d(a, 1) == MP_EQ) { + mp_set(a, 2); + return MP_OKAY; + } + /* fall through to the sieve */ + } + + /* generate a prime congruent to 3 mod 4 or 1/3 mod 4? */ + if (bbs_style == 1) { + kstep = 4; + } else { + kstep = 2; + } + + /* at this point we will use a combination of a sieve and Miller-Rabin */ + + if (bbs_style == 1) { + /* if a mod 4 != 3 subtract the correct value to make it so */ + if ((a->dp[0] & 3) != 3) { + if ((err = mp_sub_d(a, (a->dp[0] & 3) + 1, a)) != MP_OKAY) { return err; }; + } + } else { + if (mp_iseven(a) == 1) { + /* force odd */ + if ((err = mp_sub_d(a, 1, a)) != MP_OKAY) { + return err; + } + } + } + + /* generate the restable */ + for (x = 1; x < PRIME_SIZE; x++) { + if ((err = mp_mod_d(a, ltm_prime_tab[x], res_tab + x)) != MP_OKAY) { + return err; + } + } + + /* init temp used for Miller-Rabin Testing */ + if ((err = mp_init(&b)) != MP_OKAY) { + return err; + } + + for (;;) { + /* skip to the next non-trivially divisible candidate */ + step = 0; + do { + /* y == 1 if any residue was zero [e.g. cannot be prime] */ + y = 0; + + /* increase step to next candidate */ + step += kstep; + + /* compute the new residue without using division */ + for (x = 1; x < PRIME_SIZE; x++) { + /* add the step to each residue */ + res_tab[x] += kstep; + + /* subtract the modulus [instead of using division] */ + if (res_tab[x] >= ltm_prime_tab[x]) { + res_tab[x] -= ltm_prime_tab[x]; + } + + /* set flag if zero */ + if (res_tab[x] == 0) { + y = 1; + } + } + } while (y == 1 && step < ((((mp_digit)1)<<DIGIT_BIT) - kstep)); + + /* add the step */ + if ((err = mp_add_d(a, step, a)) != MP_OKAY) { + goto LBL_ERR; + } + + /* if didn't pass sieve and step == MAX then skip test */ + if (y == 1 && step >= ((((mp_digit)1)<<DIGIT_BIT) - kstep)) { + continue; + } + + /* is this prime? */ + for (x = 0; x < t; x++) { + mp_set(&b, ltm_prime_tab[t]); + if ((err = mp_prime_miller_rabin(a, &b, &res)) != MP_OKAY) { + goto LBL_ERR; + } + if (res == MP_NO) { + break; + } + } + + if (res == MP_YES) { + break; + } + } + + err = MP_OKAY; +LBL_ERR: + mp_clear(&b); + return err; +} + +#endif + +/* End: bn_mp_prime_next_prime.c */ + +/* Start: bn_mp_prime_rabin_miller_trials.c */ +#include <tommath.h> +#ifdef BN_MP_PRIME_RABIN_MILLER_TRIALS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + + +static const struct { + int k, t; +} sizes[] = { +{ 128, 28 }, +{ 256, 16 }, +{ 384, 10 }, +{ 512, 7 }, +{ 640, 6 }, +{ 768, 5 }, +{ 896, 4 }, +{ 1024, 4 } +}; + +/* returns # of RM trials required for a given bit size */ +int mp_prime_rabin_miller_trials(int size) +{ + int x; + + for (x = 0; x < (int)(sizeof(sizes)/(sizeof(sizes[0]))); x++) { + if (sizes[x].k == size) { + return sizes[x].t; + } else if (sizes[x].k > size) { + return (x == 0) ? sizes[0].t : sizes[x - 1].t; + } + } + return sizes[x-1].t + 1; +} + + +#endif + +/* End: bn_mp_prime_rabin_miller_trials.c */ + +/* Start: bn_mp_prime_random_ex.c */ +#include <tommath.h> +#ifdef BN_MP_PRIME_RANDOM_EX_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* makes a truly random prime of a given size (bits), + * + * Flags are as follows: + * + * LTM_PRIME_BBS - make prime congruent to 3 mod 4 + * LTM_PRIME_SAFE - make sure (p-1)/2 is prime as well (implies LTM_PRIME_BBS) + * LTM_PRIME_2MSB_OFF - make the 2nd highest bit zero + * LTM_PRIME_2MSB_ON - make the 2nd highest bit one + * + * You have to supply a callback which fills in a buffer with random bytes. "dat" is a parameter you can + * have passed to the callback (e.g. a state or something). This function doesn't use "dat" itself + * so it can be NULL + * + */ + +/* This is possibly the mother of all prime generation functions, muahahahahaha! */ +int mp_prime_random_ex(mp_int *a, int t, int size, int flags, ltm_prime_callback cb, void *dat) +{ + unsigned char *tmp, maskAND, maskOR_msb, maskOR_lsb; + int res, err, bsize, maskOR_msb_offset; + + /* sanity check the input */ + if (size <= 1 || t <= 0) { + return MP_VAL; + } + + /* LTM_PRIME_SAFE implies LTM_PRIME_BBS */ + if (flags & LTM_PRIME_SAFE) { + flags |= LTM_PRIME_BBS; + } + + /* calc the byte size */ + bsize = (size>>3) + ((size&7)?1:0); + + /* we need a buffer of bsize bytes */ + tmp = OPT_CAST(unsigned char) XMALLOC(bsize); + if (tmp == NULL) { + return MP_MEM; + } + + /* calc the maskAND value for the MSbyte*/ + maskAND = ((size&7) == 0) ? 0xFF : (0xFF >> (8 - (size & 7))); + + /* calc the maskOR_msb */ + maskOR_msb = 0; + maskOR_msb_offset = (size - 2) >> 3; + if (flags & LTM_PRIME_2MSB_ON) { + maskOR_msb |= 1 << ((size - 2) & 7); + } else if (flags & LTM_PRIME_2MSB_OFF) { + maskAND &= ~(1 << ((size - 2) & 7)); + } + + /* get the maskOR_lsb */ + maskOR_lsb = 0; + if (flags & LTM_PRIME_BBS) { + maskOR_lsb |= 3; + } + + do { + /* read the bytes */ + if (cb(tmp, bsize, dat) != bsize) { + err = MP_VAL; + goto error; + } + + /* work over the MSbyte */ + tmp[0] &= maskAND; + tmp[0] |= 1 << ((size - 1) & 7); + + /* mix in the maskORs */ + tmp[maskOR_msb_offset] |= maskOR_msb; + tmp[bsize-1] |= maskOR_lsb; + + /* read it in */ + if ((err = mp_read_unsigned_bin(a, tmp, bsize)) != MP_OKAY) { goto error; } + + /* is it prime? */ + if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { goto error; } + if (res == MP_NO) { + continue; + } + + if (flags & LTM_PRIME_SAFE) { + /* see if (a-1)/2 is prime */ + if ((err = mp_sub_d(a, 1, a)) != MP_OKAY) { goto error; } + if ((err = mp_div_2(a, a)) != MP_OKAY) { goto error; } + + /* is it prime? */ + if ((err = mp_prime_is_prime(a, t, &res)) != MP_OKAY) { goto error; } + } + } while (res == MP_NO); + + if (flags & LTM_PRIME_SAFE) { + /* restore a to the original value */ + if ((err = mp_mul_2(a, a)) != MP_OKAY) { goto error; } + if ((err = mp_add_d(a, 1, a)) != MP_OKAY) { goto error; } + } + + err = MP_OKAY; +error: + XFREE(tmp); + return err; +} + + +#endif + +/* End: bn_mp_prime_random_ex.c */ + +/* Start: bn_mp_radix_size.c */ +#include <tommath.h> +#ifdef BN_MP_RADIX_SIZE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* returns size of ASCII reprensentation */ +int mp_radix_size (mp_int * a, int radix, int *size) +{ + int res, digs; + mp_int t; + mp_digit d; + + *size = 0; + + /* special case for binary */ + if (radix == 2) { + *size = mp_count_bits (a) + (a->sign == MP_NEG ? 1 : 0) + 1; + return MP_OKAY; + } + + /* make sure the radix is in range */ + if (radix < 2 || radix > 64) { + return MP_VAL; + } + + /* init a copy of the input */ + if ((res = mp_init_copy (&t, a)) != MP_OKAY) { + return res; + } + + /* digs is the digit count */ + digs = 0; + + /* if it's negative add one for the sign */ + if (t.sign == MP_NEG) { + ++digs; + t.sign = MP_ZPOS; + } + + /* fetch out all of the digits */ + while (mp_iszero (&t) == 0) { + if ((res = mp_div_d (&t, (mp_digit) radix, &t, &d)) != MP_OKAY) { + mp_clear (&t); + return res; + } + ++digs; + } + mp_clear (&t); + + /* return digs + 1, the 1 is for the NULL byte that would be required. */ + *size = digs + 1; + return MP_OKAY; +} + +#endif + +/* End: bn_mp_radix_size.c */ + +/* Start: bn_mp_radix_smap.c */ +#include <tommath.h> +#ifdef BN_MP_RADIX_SMAP_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* chars used in radix conversions */ +const char *mp_s_rmap = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz+/"; +#endif + +/* End: bn_mp_radix_smap.c */ + +/* Start: bn_mp_rand.c */ +#include <tommath.h> +#ifdef BN_MP_RAND_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* makes a pseudo-random int of a given size */ +int +mp_rand (mp_int * a, int digits) +{ + int res; + mp_digit d; + + mp_zero (a); + if (digits <= 0) { + return MP_OKAY; + } + + /* first place a random non-zero digit */ + do { + d = ((mp_digit) abs (rand ())); + } while (d == 0); + + if ((res = mp_add_d (a, d, a)) != MP_OKAY) { + return res; + } + + while (digits-- > 0) { + if ((res = mp_lshd (a, 1)) != MP_OKAY) { + return res; + } + + if ((res = mp_add_d (a, ((mp_digit) abs (rand ())), a)) != MP_OKAY) { + return res; + } + } + + return MP_OKAY; +} +#endif + +/* End: bn_mp_rand.c */ + +/* Start: bn_mp_read_radix.c */ +#include <tommath.h> +#ifdef BN_MP_READ_RADIX_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* read a string [ASCII] in a given radix */ +int mp_read_radix (mp_int * a, char *str, int radix) +{ + int y, res, neg; + char ch; + + /* make sure the radix is ok */ + if (radix < 2 || radix > 64) { + return MP_VAL; + } + + /* if the leading digit is a + * minus set the sign to negative. + */ + if (*str == '-') { + ++str; + neg = MP_NEG; + } else { + neg = MP_ZPOS; + } + + /* set the integer to the default of zero */ + mp_zero (a); + + /* process each digit of the string */ + while (*str) { + /* if the radix < 36 the conversion is case insensitive + * this allows numbers like 1AB and 1ab to represent the same value + * [e.g. in hex] + */ + ch = (char) ((radix < 36) ? toupper (*str) : *str); + for (y = 0; y < 64; y++) { + if (ch == mp_s_rmap[y]) { + break; + } + } + + /* if the char was found in the map + * and is less than the given radix add it + * to the number, otherwise exit the loop. + */ + if (y < radix) { + if ((res = mp_mul_d (a, (mp_digit) radix, a)) != MP_OKAY) { + return res; + } + if ((res = mp_add_d (a, (mp_digit) y, a)) != MP_OKAY) { + return res; + } + } else { + break; + } + ++str; + } + + /* set the sign only if a != 0 */ + if (mp_iszero(a) != 1) { + a->sign = neg; + } + return MP_OKAY; +} +#endif + +/* End: bn_mp_read_radix.c */ + +/* Start: bn_mp_read_signed_bin.c */ +#include <tommath.h> +#ifdef BN_MP_READ_SIGNED_BIN_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* read signed bin, big endian, first byte is 0==positive or 1==negative */ +int +mp_read_signed_bin (mp_int * a, unsigned char *b, int c) +{ + int res; + + /* read magnitude */ + if ((res = mp_read_unsigned_bin (a, b + 1, c - 1)) != MP_OKAY) { + return res; + } + + /* first byte is 0 for positive, non-zero for negative */ + if (b[0] == 0) { + a->sign = MP_ZPOS; + } else { + a->sign = MP_NEG; + } + + return MP_OKAY; +} +#endif + +/* End: bn_mp_read_signed_bin.c */ + +/* Start: bn_mp_read_unsigned_bin.c */ +#include <tommath.h> +#ifdef BN_MP_READ_UNSIGNED_BIN_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* reads a unsigned char array, assumes the msb is stored first [big endian] */ +int +mp_read_unsigned_bin (mp_int * a, unsigned char *b, int c) +{ + int res; + + /* make sure there are at least two digits */ + if (a->alloc < 2) { + if ((res = mp_grow(a, 2)) != MP_OKAY) { + return res; + } + } + + /* zero the int */ + mp_zero (a); + + /* read the bytes in */ + while (c-- > 0) { + if ((res = mp_mul_2d (a, 8, a)) != MP_OKAY) { + return res; + } + +#ifndef MP_8BIT + a->dp[0] |= *b++; + a->used += 1; +#else + a->dp[0] = (*b & MP_MASK); + a->dp[1] |= ((*b++ >> 7U) & 1); + a->used += 2; +#endif + } + mp_clamp (a); + return MP_OKAY; +} +#endif + +/* End: bn_mp_read_unsigned_bin.c */ + +/* Start: bn_mp_reduce.c */ +#include <tommath.h> +#ifdef BN_MP_REDUCE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* reduces x mod m, assumes 0 < x < m**2, mu is + * precomputed via mp_reduce_setup. + * From HAC pp.604 Algorithm 14.42 + */ +int +mp_reduce (mp_int * x, mp_int * m, mp_int * mu) +{ + mp_int q; + int res, um = m->used; + + /* q = x */ + if ((res = mp_init_copy (&q, x)) != MP_OKAY) { + return res; + } + + /* q1 = x / b**(k-1) */ + mp_rshd (&q, um - 1); + + /* according to HAC this optimization is ok */ + if (((unsigned long) um) > (((mp_digit)1) << (DIGIT_BIT - 1))) { + if ((res = mp_mul (&q, mu, &q)) != MP_OKAY) { + goto CLEANUP; + } + } else { +#ifdef BN_S_MP_MUL_HIGH_DIGS_C + if ((res = s_mp_mul_high_digs (&q, mu, &q, um - 1)) != MP_OKAY) { + goto CLEANUP; + } +#elif defined(BN_FAST_S_MP_MUL_HIGH_DIGS_C) + if ((res = fast_s_mp_mul_high_digs (&q, mu, &q, um - 1)) != MP_OKAY) { + goto CLEANUP; + } +#else + { + res = MP_VAL; + goto CLEANUP; + } +#endif + } + + /* q3 = q2 / b**(k+1) */ + mp_rshd (&q, um + 1); + + /* x = x mod b**(k+1), quick (no division) */ + if ((res = mp_mod_2d (x, DIGIT_BIT * (um + 1), x)) != MP_OKAY) { + goto CLEANUP; + } + + /* q = q * m mod b**(k+1), quick (no division) */ + if ((res = s_mp_mul_digs (&q, m, &q, um + 1)) != MP_OKAY) { + goto CLEANUP; + } + + /* x = x - q */ + if ((res = mp_sub (x, &q, x)) != MP_OKAY) { + goto CLEANUP; + } + + /* If x < 0, add b**(k+1) to it */ + if (mp_cmp_d (x, 0) == MP_LT) { + mp_set (&q, 1); + if ((res = mp_lshd (&q, um + 1)) != MP_OKAY) + goto CLEANUP; + if ((res = mp_add (x, &q, x)) != MP_OKAY) + goto CLEANUP; + } + + /* Back off if it's too big */ + while (mp_cmp (x, m) != MP_LT) { + if ((res = s_mp_sub (x, m, x)) != MP_OKAY) { + goto CLEANUP; + } + } + +CLEANUP: + mp_clear (&q); + + return res; +} +#endif + +/* End: bn_mp_reduce.c */ + +/* Start: bn_mp_reduce_2k.c */ +#include <tommath.h> +#ifdef BN_MP_REDUCE_2K_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* reduces a modulo n where n is of the form 2**p - d */ +int +mp_reduce_2k(mp_int *a, mp_int *n, mp_digit d) +{ + mp_int q; + int p, res; + + if ((res = mp_init(&q)) != MP_OKAY) { + return res; + } + + p = mp_count_bits(n); +top: + /* q = a/2**p, a = a mod 2**p */ + if ((res = mp_div_2d(a, p, &q, a)) != MP_OKAY) { + goto ERR; + } + + if (d != 1) { + /* q = q * d */ + if ((res = mp_mul_d(&q, d, &q)) != MP_OKAY) { + goto ERR; + } + } + + /* a = a + q */ + if ((res = s_mp_add(a, &q, a)) != MP_OKAY) { + goto ERR; + } + + if (mp_cmp_mag(a, n) != MP_LT) { + s_mp_sub(a, n, a); + goto top; + } + +ERR: + mp_clear(&q); + return res; +} + +#endif + +/* End: bn_mp_reduce_2k.c */ + +/* Start: bn_mp_reduce_2k_setup.c */ +#include <tommath.h> +#ifdef BN_MP_REDUCE_2K_SETUP_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* determines the setup value */ +int +mp_reduce_2k_setup(mp_int *a, mp_digit *d) +{ + int res, p; + mp_int tmp; + + if ((res = mp_init(&tmp)) != MP_OKAY) { + return res; + } + + p = mp_count_bits(a); + if ((res = mp_2expt(&tmp, p)) != MP_OKAY) { + mp_clear(&tmp); + return res; + } + + if ((res = s_mp_sub(&tmp, a, &tmp)) != MP_OKAY) { + mp_clear(&tmp); + return res; + } + + *d = tmp.dp[0]; + mp_clear(&tmp); + return MP_OKAY; +} +#endif + +/* End: bn_mp_reduce_2k_setup.c */ + +/* Start: bn_mp_reduce_is_2k.c */ +#include <tommath.h> +#ifdef BN_MP_REDUCE_IS_2K_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* determines if mp_reduce_2k can be used */ +int mp_reduce_is_2k(mp_int *a) +{ + int ix, iy, iw; + mp_digit iz; + + if (a->used == 0) { + return 0; + } else if (a->used == 1) { + return 1; + } else if (a->used > 1) { + iy = mp_count_bits(a); + iz = 1; + iw = 1; + + /* Test every bit from the second digit up, must be 1 */ + for (ix = DIGIT_BIT; ix < iy; ix++) { + if ((a->dp[iw] & iz) == 0) { + return 0; + } + iz <<= 1; + if (iz > (mp_digit)MP_MASK) { + ++iw; + iz = 1; + } + } + } + return 1; +} + +#endif + +/* End: bn_mp_reduce_is_2k.c */ + +/* Start: bn_mp_reduce_setup.c */ +#include <tommath.h> +#ifdef BN_MP_REDUCE_SETUP_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* pre-calculate the value required for Barrett reduction + * For a given modulus "b" it calulates the value required in "a" + */ +int mp_reduce_setup (mp_int * a, mp_int * b) +{ + int res; + + if ((res = mp_2expt (a, b->used * 2 * DIGIT_BIT)) != MP_OKAY) { + return res; + } + return mp_div (a, b, a, NULL); +} +#endif + +/* End: bn_mp_reduce_setup.c */ + +/* Start: bn_mp_rshd.c */ +#include <tommath.h> +#ifdef BN_MP_RSHD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* shift right a certain amount of digits */ +void mp_rshd (mp_int * a, int b) +{ + int x; + + /* if b <= 0 then ignore it */ + if (b <= 0) { + return; + } + + /* if b > used then simply zero it and return */ + if (a->used <= b) { + mp_zero (a); + return; + } + + { + register mp_digit *bottom, *top; + + /* shift the digits down */ + + /* bottom */ + bottom = a->dp; + + /* top [offset into digits] */ + top = a->dp + b; + + /* this is implemented as a sliding window where + * the window is b-digits long and digits from + * the top of the window are copied to the bottom + * + * e.g. + + b-2 | b-1 | b0 | b1 | b2 | ... | bb | ----> + /\ | ----> + \-------------------/ ----> + */ + for (x = 0; x < (a->used - b); x++) { + *bottom++ = *top++; + } + + /* zero the top digits */ + for (; x < a->used; x++) { + *bottom++ = 0; + } + } + + /* remove excess digits */ + a->used -= b; +} +#endif + +/* End: bn_mp_rshd.c */ + +/* Start: bn_mp_set.c */ +#include <tommath.h> +#ifdef BN_MP_SET_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* set to a digit */ +void mp_set (mp_int * a, mp_digit b) +{ + mp_zero (a); + a->dp[0] = b & MP_MASK; + a->used = (a->dp[0] != 0) ? 1 : 0; +} +#endif + +/* End: bn_mp_set.c */ + +/* Start: bn_mp_set_int.c */ +#include <tommath.h> +#ifdef BN_MP_SET_INT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* set a 32-bit const */ +int mp_set_int (mp_int * a, unsigned long b) +{ + int x, res; + + mp_zero (a); + + /* set four bits at a time */ + for (x = 0; x < 8; x++) { + /* shift the number up four bits */ + if ((res = mp_mul_2d (a, 4, a)) != MP_OKAY) { + return res; + } + + /* OR in the top four bits of the source */ + a->dp[0] |= (b >> 28) & 15; + + /* shift the source up to the next four bits */ + b <<= 4; + + /* ensure that digits are not clamped off */ + a->used += 1; + } + mp_clamp (a); + return MP_OKAY; +} +#endif + +/* End: bn_mp_set_int.c */ + +/* Start: bn_mp_shrink.c */ +#include <tommath.h> +#ifdef BN_MP_SHRINK_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* shrink a bignum */ +int mp_shrink (mp_int * a) +{ + mp_digit *tmp; + if (a->alloc != a->used && a->used > 0) { + if ((tmp = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * a->used)) == NULL) { + return MP_MEM; + } + a->dp = tmp; + a->alloc = a->used; + } + return MP_OKAY; +} +#endif + +/* End: bn_mp_shrink.c */ + +/* Start: bn_mp_signed_bin_size.c */ +#include <tommath.h> +#ifdef BN_MP_SIGNED_BIN_SIZE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* get the size for an signed equivalent */ +int mp_signed_bin_size (mp_int * a) +{ + return 1 + mp_unsigned_bin_size (a); +} +#endif + +/* End: bn_mp_signed_bin_size.c */ + +/* Start: bn_mp_sqr.c */ +#include <tommath.h> +#ifdef BN_MP_SQR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* computes b = a*a */ +int +mp_sqr (mp_int * a, mp_int * b) +{ + int res; + +#ifdef BN_MP_TOOM_SQR_C + /* use Toom-Cook? */ + if (a->used >= TOOM_SQR_CUTOFF) { + res = mp_toom_sqr(a, b); + /* Karatsuba? */ + } else +#endif +#ifdef BN_MP_KARATSUBA_SQR_C +if (a->used >= KARATSUBA_SQR_CUTOFF) { + res = mp_karatsuba_sqr (a, b); + } else +#endif + { +#ifdef BN_FAST_S_MP_SQR_C + /* can we use the fast comba multiplier? */ + if ((a->used * 2 + 1) < MP_WARRAY && + a->used < + (1 << (sizeof(mp_word) * CHAR_BIT - 2*DIGIT_BIT - 1))) { + res = fast_s_mp_sqr (a, b); + } else +#endif +#ifdef BN_S_MP_SQR_C + res = s_mp_sqr (a, b); +#else + res = MP_VAL; +#endif + } + b->sign = MP_ZPOS; + return res; +} +#endif + +/* End: bn_mp_sqr.c */ + +/* Start: bn_mp_sqrmod.c */ +#include <tommath.h> +#ifdef BN_MP_SQRMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* c = a * a (mod b) */ +int +mp_sqrmod (mp_int * a, mp_int * b, mp_int * c) +{ + int res; + mp_int t; + + if ((res = mp_init (&t)) != MP_OKAY) { + return res; + } + + if ((res = mp_sqr (a, &t)) != MP_OKAY) { + mp_clear (&t); + return res; + } + res = mp_mod (&t, b, c); + mp_clear (&t); + return res; +} +#endif + +/* End: bn_mp_sqrmod.c */ + +/* Start: bn_mp_sqrt.c */ +#include <tommath.h> +#ifdef BN_MP_SQRT_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* this function is less generic than mp_n_root, simpler and faster */ +int mp_sqrt(mp_int *arg, mp_int *ret) +{ + int res; + mp_int t1,t2; + + /* must be positive */ + if (arg->sign == MP_NEG) { + return MP_VAL; + } + + /* easy out */ + if (mp_iszero(arg) == MP_YES) { + mp_zero(ret); + return MP_OKAY; + } + + if ((res = mp_init_copy(&t1, arg)) != MP_OKAY) { + return res; + } + + if ((res = mp_init(&t2)) != MP_OKAY) { + goto E2; + } + + /* First approx. (not very bad for large arg) */ + mp_rshd (&t1,t1.used/2); + + /* t1 > 0 */ + if ((res = mp_div(arg,&t1,&t2,NULL)) != MP_OKAY) { + goto E1; + } + if ((res = mp_add(&t1,&t2,&t1)) != MP_OKAY) { + goto E1; + } + if ((res = mp_div_2(&t1,&t1)) != MP_OKAY) { + goto E1; + } + /* And now t1 > sqrt(arg) */ + do { + if ((res = mp_div(arg,&t1,&t2,NULL)) != MP_OKAY) { + goto E1; + } + if ((res = mp_add(&t1,&t2,&t1)) != MP_OKAY) { + goto E1; + } + if ((res = mp_div_2(&t1,&t1)) != MP_OKAY) { + goto E1; + } + /* t1 >= sqrt(arg) >= t2 at this point */ + } while (mp_cmp_mag(&t1,&t2) == MP_GT); + + mp_exch(&t1,ret); + +E1: mp_clear(&t2); +E2: mp_clear(&t1); + return res; +} + +#endif + +/* End: bn_mp_sqrt.c */ + +/* Start: bn_mp_sub.c */ +#include <tommath.h> +#ifdef BN_MP_SUB_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* high level subtraction (handles signs) */ +int +mp_sub (mp_int * a, mp_int * b, mp_int * c) +{ + int sa, sb, res; + + sa = a->sign; + sb = b->sign; + + if (sa != sb) { + /* subtract a negative from a positive, OR */ + /* subtract a positive from a negative. */ + /* In either case, ADD their magnitudes, */ + /* and use the sign of the first number. */ + c->sign = sa; + res = s_mp_add (a, b, c); + } else { + /* subtract a positive from a positive, OR */ + /* subtract a negative from a negative. */ + /* First, take the difference between their */ + /* magnitudes, then... */ + if (mp_cmp_mag (a, b) != MP_LT) { + /* Copy the sign from the first */ + c->sign = sa; + /* The first has a larger or equal magnitude */ + res = s_mp_sub (a, b, c); + } else { + /* The result has the *opposite* sign from */ + /* the first number. */ + c->sign = (sa == MP_ZPOS) ? MP_NEG : MP_ZPOS; + /* The second has a larger magnitude */ + res = s_mp_sub (b, a, c); + } + } + return res; +} + +#endif + +/* End: bn_mp_sub.c */ + +/* Start: bn_mp_sub_d.c */ +#include <tommath.h> +#ifdef BN_MP_SUB_D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* single digit subtraction */ +int +mp_sub_d (mp_int * a, mp_digit b, mp_int * c) +{ + mp_digit *tmpa, *tmpc, mu; + int res, ix, oldused; + + /* grow c as required */ + if (c->alloc < a->used + 1) { + if ((res = mp_grow(c, a->used + 1)) != MP_OKAY) { + return res; + } + } + + /* if a is negative just do an unsigned + * addition [with fudged signs] + */ + if (a->sign == MP_NEG) { + a->sign = MP_ZPOS; + res = mp_add_d(a, b, c); + a->sign = c->sign = MP_NEG; + return res; + } + + /* setup regs */ + oldused = c->used; + tmpa = a->dp; + tmpc = c->dp; + + /* if a <= b simply fix the single digit */ + if ((a->used == 1 && a->dp[0] <= b) || a->used == 0) { + if (a->used == 1) { + *tmpc++ = b - *tmpa; + } else { + *tmpc++ = b; + } + ix = 1; + + /* negative/1digit */ + c->sign = MP_NEG; + c->used = 1; + } else { + /* positive/size */ + c->sign = MP_ZPOS; + c->used = a->used; + + /* subtract first digit */ + *tmpc = *tmpa++ - b; + mu = *tmpc >> (sizeof(mp_digit) * CHAR_BIT - 1); + *tmpc++ &= MP_MASK; + + /* handle rest of the digits */ + for (ix = 1; ix < a->used; ix++) { + *tmpc = *tmpa++ - mu; + mu = *tmpc >> (sizeof(mp_digit) * CHAR_BIT - 1); + *tmpc++ &= MP_MASK; + } + } + + /* zero excess digits */ + while (ix++ < oldused) { + *tmpc++ = 0; + } + mp_clamp(c); + return MP_OKAY; +} + +#endif + +/* End: bn_mp_sub_d.c */ + +/* Start: bn_mp_submod.c */ +#include <tommath.h> +#ifdef BN_MP_SUBMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* d = a - b (mod c) */ +int +mp_submod (mp_int * a, mp_int * b, mp_int * c, mp_int * d) +{ + int res; + mp_int t; + + + if ((res = mp_init (&t)) != MP_OKAY) { + return res; + } + + if ((res = mp_sub (a, b, &t)) != MP_OKAY) { + mp_clear (&t); + return res; + } + res = mp_mod (&t, c, d); + mp_clear (&t); + return res; +} +#endif + +/* End: bn_mp_submod.c */ + +/* Start: bn_mp_to_signed_bin.c */ +#include <tommath.h> +#ifdef BN_MP_TO_SIGNED_BIN_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* store in signed [big endian] format */ +int +mp_to_signed_bin (mp_int * a, unsigned char *b) +{ + int res; + + if ((res = mp_to_unsigned_bin (a, b + 1)) != MP_OKAY) { + return res; + } + b[0] = (unsigned char) ((a->sign == MP_ZPOS) ? 0 : 1); + return MP_OKAY; +} +#endif + +/* End: bn_mp_to_signed_bin.c */ + +/* Start: bn_mp_to_unsigned_bin.c */ +#include <tommath.h> +#ifdef BN_MP_TO_UNSIGNED_BIN_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* store in unsigned [big endian] format */ +int +mp_to_unsigned_bin (mp_int * a, unsigned char *b) +{ + int x, res; + mp_int t; + + if ((res = mp_init_copy (&t, a)) != MP_OKAY) { + return res; + } + + x = 0; + while (mp_iszero (&t) == 0) { +#ifndef MP_8BIT + b[x++] = (unsigned char) (t.dp[0] & 255); +#else + b[x++] = (unsigned char) (t.dp[0] | ((t.dp[1] & 0x01) << 7)); +#endif + if ((res = mp_div_2d (&t, 8, &t, NULL)) != MP_OKAY) { + mp_clear (&t); + return res; + } + } + bn_reverse (b, x); + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_mp_to_unsigned_bin.c */ + +/* Start: bn_mp_toom_mul.c */ +#include <tommath.h> +#ifdef BN_MP_TOOM_MUL_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* multiplication using the Toom-Cook 3-way algorithm + * + * Much more complicated than Karatsuba but has a lower asymptotic running time of + * O(N**1.464). This algorithm is only particularly useful on VERY large + * inputs (we're talking 1000s of digits here...). +*/ +int mp_toom_mul(mp_int *a, mp_int *b, mp_int *c) +{ + mp_int w0, w1, w2, w3, w4, tmp1, tmp2, a0, a1, a2, b0, b1, b2; + int res, B; + + /* init temps */ + if ((res = mp_init_multi(&w0, &w1, &w2, &w3, &w4, + &a0, &a1, &a2, &b0, &b1, + &b2, &tmp1, &tmp2, NULL)) != MP_OKAY) { + return res; + } + + /* B */ + B = MIN(a->used, b->used) / 3; + + /* a = a2 * B**2 + a1 * B + a0 */ + if ((res = mp_mod_2d(a, DIGIT_BIT * B, &a0)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_copy(a, &a1)) != MP_OKAY) { + goto ERR; + } + mp_rshd(&a1, B); + mp_mod_2d(&a1, DIGIT_BIT * B, &a1); + + if ((res = mp_copy(a, &a2)) != MP_OKAY) { + goto ERR; + } + mp_rshd(&a2, B*2); + + /* b = b2 * B**2 + b1 * B + b0 */ + if ((res = mp_mod_2d(b, DIGIT_BIT * B, &b0)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_copy(b, &b1)) != MP_OKAY) { + goto ERR; + } + mp_rshd(&b1, B); + mp_mod_2d(&b1, DIGIT_BIT * B, &b1); + + if ((res = mp_copy(b, &b2)) != MP_OKAY) { + goto ERR; + } + mp_rshd(&b2, B*2); + + /* w0 = a0*b0 */ + if ((res = mp_mul(&a0, &b0, &w0)) != MP_OKAY) { + goto ERR; + } + + /* w4 = a2 * b2 */ + if ((res = mp_mul(&a2, &b2, &w4)) != MP_OKAY) { + goto ERR; + } + + /* w1 = (a2 + 2(a1 + 2a0))(b2 + 2(b1 + 2b0)) */ + if ((res = mp_mul_2(&a0, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_mul_2(&tmp1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a2, &tmp1)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_mul_2(&b0, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp2, &b1, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_mul_2(&tmp2, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp2, &b2, &tmp2)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_mul(&tmp1, &tmp2, &w1)) != MP_OKAY) { + goto ERR; + } + + /* w3 = (a0 + 2(a1 + 2a2))(b0 + 2(b1 + 2b2)) */ + if ((res = mp_mul_2(&a2, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_mul_2(&tmp1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a0, &tmp1)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_mul_2(&b2, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp2, &b1, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_mul_2(&tmp2, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp2, &b0, &tmp2)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_mul(&tmp1, &tmp2, &w3)) != MP_OKAY) { + goto ERR; + } + + + /* w2 = (a2 + a1 + a0)(b2 + b1 + b0) */ + if ((res = mp_add(&a2, &a1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a0, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&b2, &b1, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp2, &b0, &tmp2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_mul(&tmp1, &tmp2, &w2)) != MP_OKAY) { + goto ERR; + } + + /* now solve the matrix + + 0 0 0 0 1 + 1 2 4 8 16 + 1 1 1 1 1 + 16 8 4 2 1 + 1 0 0 0 0 + + using 12 subtractions, 4 shifts, + 2 small divisions and 1 small multiplication + */ + + /* r1 - r4 */ + if ((res = mp_sub(&w1, &w4, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - r0 */ + if ((res = mp_sub(&w3, &w0, &w3)) != MP_OKAY) { + goto ERR; + } + /* r1/2 */ + if ((res = mp_div_2(&w1, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3/2 */ + if ((res = mp_div_2(&w3, &w3)) != MP_OKAY) { + goto ERR; + } + /* r2 - r0 - r4 */ + if ((res = mp_sub(&w2, &w0, &w2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w2, &w4, &w2)) != MP_OKAY) { + goto ERR; + } + /* r1 - r2 */ + if ((res = mp_sub(&w1, &w2, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - r2 */ + if ((res = mp_sub(&w3, &w2, &w3)) != MP_OKAY) { + goto ERR; + } + /* r1 - 8r0 */ + if ((res = mp_mul_2d(&w0, 3, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w1, &tmp1, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - 8r4 */ + if ((res = mp_mul_2d(&w4, 3, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w3, &tmp1, &w3)) != MP_OKAY) { + goto ERR; + } + /* 3r2 - r1 - r3 */ + if ((res = mp_mul_d(&w2, 3, &w2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w2, &w1, &w2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w2, &w3, &w2)) != MP_OKAY) { + goto ERR; + } + /* r1 - r2 */ + if ((res = mp_sub(&w1, &w2, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - r2 */ + if ((res = mp_sub(&w3, &w2, &w3)) != MP_OKAY) { + goto ERR; + } + /* r1/3 */ + if ((res = mp_div_3(&w1, &w1, NULL)) != MP_OKAY) { + goto ERR; + } + /* r3/3 */ + if ((res = mp_div_3(&w3, &w3, NULL)) != MP_OKAY) { + goto ERR; + } + + /* at this point shift W[n] by B*n */ + if ((res = mp_lshd(&w1, 1*B)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_lshd(&w2, 2*B)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_lshd(&w3, 3*B)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_lshd(&w4, 4*B)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_add(&w0, &w1, c)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&w2, &w3, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&w4, &tmp1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, c, c)) != MP_OKAY) { + goto ERR; + } + +ERR: + mp_clear_multi(&w0, &w1, &w2, &w3, &w4, + &a0, &a1, &a2, &b0, &b1, + &b2, &tmp1, &tmp2, NULL); + return res; +} + +#endif + +/* End: bn_mp_toom_mul.c */ + +/* Start: bn_mp_toom_sqr.c */ +#include <tommath.h> +#ifdef BN_MP_TOOM_SQR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* squaring using Toom-Cook 3-way algorithm */ +int +mp_toom_sqr(mp_int *a, mp_int *b) +{ + mp_int w0, w1, w2, w3, w4, tmp1, a0, a1, a2; + int res, B; + + /* init temps */ + if ((res = mp_init_multi(&w0, &w1, &w2, &w3, &w4, &a0, &a1, &a2, &tmp1, NULL)) != MP_OKAY) { + return res; + } + + /* B */ + B = a->used / 3; + + /* a = a2 * B**2 + a1 * B + a0 */ + if ((res = mp_mod_2d(a, DIGIT_BIT * B, &a0)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_copy(a, &a1)) != MP_OKAY) { + goto ERR; + } + mp_rshd(&a1, B); + mp_mod_2d(&a1, DIGIT_BIT * B, &a1); + + if ((res = mp_copy(a, &a2)) != MP_OKAY) { + goto ERR; + } + mp_rshd(&a2, B*2); + + /* w0 = a0*a0 */ + if ((res = mp_sqr(&a0, &w0)) != MP_OKAY) { + goto ERR; + } + + /* w4 = a2 * a2 */ + if ((res = mp_sqr(&a2, &w4)) != MP_OKAY) { + goto ERR; + } + + /* w1 = (a2 + 2(a1 + 2a0))**2 */ + if ((res = mp_mul_2(&a0, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_mul_2(&tmp1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a2, &tmp1)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_sqr(&tmp1, &w1)) != MP_OKAY) { + goto ERR; + } + + /* w3 = (a0 + 2(a1 + 2a2))**2 */ + if ((res = mp_mul_2(&a2, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_mul_2(&tmp1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a0, &tmp1)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_sqr(&tmp1, &w3)) != MP_OKAY) { + goto ERR; + } + + + /* w2 = (a2 + a1 + a0)**2 */ + if ((res = mp_add(&a2, &a1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, &a0, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sqr(&tmp1, &w2)) != MP_OKAY) { + goto ERR; + } + + /* now solve the matrix + + 0 0 0 0 1 + 1 2 4 8 16 + 1 1 1 1 1 + 16 8 4 2 1 + 1 0 0 0 0 + + using 12 subtractions, 4 shifts, 2 small divisions and 1 small multiplication. + */ + + /* r1 - r4 */ + if ((res = mp_sub(&w1, &w4, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - r0 */ + if ((res = mp_sub(&w3, &w0, &w3)) != MP_OKAY) { + goto ERR; + } + /* r1/2 */ + if ((res = mp_div_2(&w1, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3/2 */ + if ((res = mp_div_2(&w3, &w3)) != MP_OKAY) { + goto ERR; + } + /* r2 - r0 - r4 */ + if ((res = mp_sub(&w2, &w0, &w2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w2, &w4, &w2)) != MP_OKAY) { + goto ERR; + } + /* r1 - r2 */ + if ((res = mp_sub(&w1, &w2, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - r2 */ + if ((res = mp_sub(&w3, &w2, &w3)) != MP_OKAY) { + goto ERR; + } + /* r1 - 8r0 */ + if ((res = mp_mul_2d(&w0, 3, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w1, &tmp1, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - 8r4 */ + if ((res = mp_mul_2d(&w4, 3, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w3, &tmp1, &w3)) != MP_OKAY) { + goto ERR; + } + /* 3r2 - r1 - r3 */ + if ((res = mp_mul_d(&w2, 3, &w2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w2, &w1, &w2)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_sub(&w2, &w3, &w2)) != MP_OKAY) { + goto ERR; + } + /* r1 - r2 */ + if ((res = mp_sub(&w1, &w2, &w1)) != MP_OKAY) { + goto ERR; + } + /* r3 - r2 */ + if ((res = mp_sub(&w3, &w2, &w3)) != MP_OKAY) { + goto ERR; + } + /* r1/3 */ + if ((res = mp_div_3(&w1, &w1, NULL)) != MP_OKAY) { + goto ERR; + } + /* r3/3 */ + if ((res = mp_div_3(&w3, &w3, NULL)) != MP_OKAY) { + goto ERR; + } + + /* at this point shift W[n] by B*n */ + if ((res = mp_lshd(&w1, 1*B)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_lshd(&w2, 2*B)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_lshd(&w3, 3*B)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_lshd(&w4, 4*B)) != MP_OKAY) { + goto ERR; + } + + if ((res = mp_add(&w0, &w1, b)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&w2, &w3, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&w4, &tmp1, &tmp1)) != MP_OKAY) { + goto ERR; + } + if ((res = mp_add(&tmp1, b, b)) != MP_OKAY) { + goto ERR; + } + +ERR: + mp_clear_multi(&w0, &w1, &w2, &w3, &w4, &a0, &a1, &a2, &tmp1, NULL); + return res; +} + +#endif + +/* End: bn_mp_toom_sqr.c */ + +/* Start: bn_mp_toradix.c */ +#include <tommath.h> +#ifdef BN_MP_TORADIX_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* stores a bignum as a ASCII string in a given radix (2..64) */ +int mp_toradix (mp_int * a, char *str, int radix) +{ + int res, digs; + mp_int t; + mp_digit d; + char *_s = str; + + /* check range of the radix */ + if (radix < 2 || radix > 64) { + return MP_VAL; + } + + /* quick out if its zero */ + if (mp_iszero(a) == 1) { + *str++ = '0'; + *str = '\0'; + return MP_OKAY; + } + + if ((res = mp_init_copy (&t, a)) != MP_OKAY) { + return res; + } + + /* if it is negative output a - */ + if (t.sign == MP_NEG) { + ++_s; + *str++ = '-'; + t.sign = MP_ZPOS; + } + + digs = 0; + while (mp_iszero (&t) == 0) { + if ((res = mp_div_d (&t, (mp_digit) radix, &t, &d)) != MP_OKAY) { + mp_clear (&t); + return res; + } + *str++ = mp_s_rmap[d]; + ++digs; + } + + /* reverse the digits of the string. In this case _s points + * to the first digit [exluding the sign] of the number] + */ + bn_reverse ((unsigned char *)_s, digs); + + /* append a NULL so the string is properly terminated */ + *str = '\0'; + + mp_clear (&t); + return MP_OKAY; +} + +#endif + +/* End: bn_mp_toradix.c */ + +/* Start: bn_mp_toradix_n.c */ +#include <tommath.h> +#ifdef BN_MP_TORADIX_N_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* stores a bignum as a ASCII string in a given radix (2..64) + * + * Stores upto maxlen-1 chars and always a NULL byte + */ +int mp_toradix_n(mp_int * a, char *str, int radix, int maxlen) +{ + int res, digs; + mp_int t; + mp_digit d; + char *_s = str; + + /* check range of the maxlen, radix */ + if (maxlen < 3 || radix < 2 || radix > 64) { + return MP_VAL; + } + + /* quick out if its zero */ + if (mp_iszero(a) == 1) { + *str++ = '0'; + *str = '\0'; + return MP_OKAY; + } + + if ((res = mp_init_copy (&t, a)) != MP_OKAY) { + return res; + } + + /* if it is negative output a - */ + if (t.sign == MP_NEG) { + /* we have to reverse our digits later... but not the - sign!! */ + ++_s; + + /* store the flag and mark the number as positive */ + *str++ = '-'; + t.sign = MP_ZPOS; + + /* subtract a char */ + --maxlen; + } + + digs = 0; + while (mp_iszero (&t) == 0) { + if ((res = mp_div_d (&t, (mp_digit) radix, &t, &d)) != MP_OKAY) { + mp_clear (&t); + return res; + } + *str++ = mp_s_rmap[d]; + ++digs; + + if (--maxlen == 1) { + /* no more room */ + break; + } + } + + /* reverse the digits of the string. In this case _s points + * to the first digit [exluding the sign] of the number] + */ + bn_reverse ((unsigned char *)_s, digs); + + /* append a NULL so the string is properly terminated */ + *str = '\0'; + + mp_clear (&t); + return MP_OKAY; +} + +#endif + +/* End: bn_mp_toradix_n.c */ + +/* Start: bn_mp_unsigned_bin_size.c */ +#include <tommath.h> +#ifdef BN_MP_UNSIGNED_BIN_SIZE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* get the size for an unsigned equivalent */ +int +mp_unsigned_bin_size (mp_int * a) +{ + int size = mp_count_bits (a); + return (size / 8 + ((size & 7) != 0 ? 1 : 0)); +} +#endif + +/* End: bn_mp_unsigned_bin_size.c */ + +/* Start: bn_mp_xor.c */ +#include <tommath.h> +#ifdef BN_MP_XOR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* XOR two ints together */ +int +mp_xor (mp_int * a, mp_int * b, mp_int * c) +{ + int res, ix, px; + mp_int t, *x; + + if (a->used > b->used) { + if ((res = mp_init_copy (&t, a)) != MP_OKAY) { + return res; + } + px = b->used; + x = b; + } else { + if ((res = mp_init_copy (&t, b)) != MP_OKAY) { + return res; + } + px = a->used; + x = a; + } + + for (ix = 0; ix < px; ix++) { + + } + mp_clamp (&t); + mp_exch (c, &t); + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_mp_xor.c */ + +/* Start: bn_mp_zero.c */ +#include <tommath.h> +#ifdef BN_MP_ZERO_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* set to zero */ +void +mp_zero (mp_int * a) +{ + a->sign = MP_ZPOS; + a->used = 0; + memset (a->dp, 0, sizeof (mp_digit) * a->alloc); +} +#endif + +/* End: bn_mp_zero.c */ + +/* Start: bn_prime_tab.c */ +#include <tommath.h> +#ifdef BN_PRIME_TAB_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ +const mp_digit ltm_prime_tab[] = { + 0x0002, 0x0003, 0x0005, 0x0007, 0x000B, 0x000D, 0x0011, 0x0013, + 0x0017, 0x001D, 0x001F, 0x0025, 0x0029, 0x002B, 0x002F, 0x0035, + 0x003B, 0x003D, 0x0043, 0x0047, 0x0049, 0x004F, 0x0053, 0x0059, + 0x0061, 0x0065, 0x0067, 0x006B, 0x006D, 0x0071, 0x007F, +#ifndef MP_8BIT + 0x0083, + 0x0089, 0x008B, 0x0095, 0x0097, 0x009D, 0x00A3, 0x00A7, 0x00AD, + 0x00B3, 0x00B5, 0x00BF, 0x00C1, 0x00C5, 0x00C7, 0x00D3, 0x00DF, + 0x00E3, 0x00E5, 0x00E9, 0x00EF, 0x00F1, 0x00FB, 0x0101, 0x0107, + 0x010D, 0x010F, 0x0115, 0x0119, 0x011B, 0x0125, 0x0133, 0x0137, + + 0x0139, 0x013D, 0x014B, 0x0151, 0x015B, 0x015D, 0x0161, 0x0167, + 0x016F, 0x0175, 0x017B, 0x017F, 0x0185, 0x018D, 0x0191, 0x0199, + 0x01A3, 0x01A5, 0x01AF, 0x01B1, 0x01B7, 0x01BB, 0x01C1, 0x01C9, + 0x01CD, 0x01CF, 0x01D3, 0x01DF, 0x01E7, 0x01EB, 0x01F3, 0x01F7, + 0x01FD, 0x0209, 0x020B, 0x021D, 0x0223, 0x022D, 0x0233, 0x0239, + 0x023B, 0x0241, 0x024B, 0x0251, 0x0257, 0x0259, 0x025F, 0x0265, + 0x0269, 0x026B, 0x0277, 0x0281, 0x0283, 0x0287, 0x028D, 0x0293, + 0x0295, 0x02A1, 0x02A5, 0x02AB, 0x02B3, 0x02BD, 0x02C5, 0x02CF, + + 0x02D7, 0x02DD, 0x02E3, 0x02E7, 0x02EF, 0x02F5, 0x02F9, 0x0301, + 0x0305, 0x0313, 0x031D, 0x0329, 0x032B, 0x0335, 0x0337, 0x033B, + 0x033D, 0x0347, 0x0355, 0x0359, 0x035B, 0x035F, 0x036D, 0x0371, + 0x0373, 0x0377, 0x038B, 0x038F, 0x0397, 0x03A1, 0x03A9, 0x03AD, + 0x03B3, 0x03B9, 0x03C7, 0x03CB, 0x03D1, 0x03D7, 0x03DF, 0x03E5, + 0x03F1, 0x03F5, 0x03FB, 0x03FD, 0x0407, 0x0409, 0x040F, 0x0419, + 0x041B, 0x0425, 0x0427, 0x042D, 0x043F, 0x0443, 0x0445, 0x0449, + 0x044F, 0x0455, 0x045D, 0x0463, 0x0469, 0x047F, 0x0481, 0x048B, + + 0x0493, 0x049D, 0x04A3, 0x04A9, 0x04B1, 0x04BD, 0x04C1, 0x04C7, + 0x04CD, 0x04CF, 0x04D5, 0x04E1, 0x04EB, 0x04FD, 0x04FF, 0x0503, + 0x0509, 0x050B, 0x0511, 0x0515, 0x0517, 0x051B, 0x0527, 0x0529, + 0x052F, 0x0551, 0x0557, 0x055D, 0x0565, 0x0577, 0x0581, 0x058F, + 0x0593, 0x0595, 0x0599, 0x059F, 0x05A7, 0x05AB, 0x05AD, 0x05B3, + 0x05BF, 0x05C9, 0x05CB, 0x05CF, 0x05D1, 0x05D5, 0x05DB, 0x05E7, + 0x05F3, 0x05FB, 0x0607, 0x060D, 0x0611, 0x0617, 0x061F, 0x0623, + 0x062B, 0x062F, 0x063D, 0x0641, 0x0647, 0x0649, 0x064D, 0x0653 +#endif +}; +#endif + +/* End: bn_prime_tab.c */ + +/* Start: bn_reverse.c */ +#include <tommath.h> +#ifdef BN_REVERSE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* reverse an array, used for radix code */ +void +bn_reverse (unsigned char *s, int len) +{ + int ix, iy; + unsigned char t; + + ix = 0; + iy = len - 1; + while (ix < iy) { + t = s[ix]; + s[ix] = s[iy]; + s[iy] = t; + ++ix; + --iy; + } +} +#endif + +/* End: bn_reverse.c */ + +/* Start: bn_s_mp_add.c */ +#include <tommath.h> +#ifdef BN_S_MP_ADD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* low level addition, based on HAC pp.594, Algorithm 14.7 */ +int +s_mp_add (mp_int * a, mp_int * b, mp_int * c) +{ + mp_int *x; + int olduse, res, min, max; + + /* find sizes, we let |a| <= |b| which means we have to sort + * them. "x" will point to the input with the most digits + */ + if (a->used > b->used) { + min = b->used; + max = a->used; + x = a; + } else { + min = a->used; + max = b->used; + x = b; + } + + /* init result */ + if (c->alloc < max + 1) { + if ((res = mp_grow (c, max + 1)) != MP_OKAY) { + return res; + } + } + + /* get old used digit count and set new one */ + olduse = c->used; + c->used = max + 1; + + { + register mp_digit u, *tmpa, *tmpb, *tmpc; + register int i; + + /* alias for digit pointers */ + + /* first input */ + tmpa = a->dp; + + /* second input */ + tmpb = b->dp; + + /* destination */ + tmpc = c->dp; + + /* zero the carry */ + u = 0; + for (i = 0; i < min; i++) { + /* Compute the sum at one digit, T[i] = A[i] + B[i] + U */ + *tmpc = *tmpa++ + *tmpb++ + u; + + /* U = carry bit of T[i] */ + u = *tmpc >> ((mp_digit)DIGIT_BIT); + + /* take away carry bit from T[i] */ + *tmpc++ &= MP_MASK; + } + + /* now copy higher words if any, that is in A+B + * if A or B has more digits add those in + */ + if (min != max) { + for (; i < max; i++) { + /* T[i] = X[i] + U */ + *tmpc = x->dp[i] + u; + + /* U = carry bit of T[i] */ + u = *tmpc >> ((mp_digit)DIGIT_BIT); + + /* take away carry bit from T[i] */ + *tmpc++ &= MP_MASK; + } + } + + /* add carry */ + *tmpc++ = u; + + /* clear digits above oldused */ + for (i = c->used; i < olduse; i++) { + *tmpc++ = 0; + } + } + + mp_clamp (c); + return MP_OKAY; +} +#endif + +/* End: bn_s_mp_add.c */ + +/* Start: bn_s_mp_exptmod.c */ +#include <tommath.h> +#ifdef BN_S_MP_EXPTMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +#ifdef MP_LOW_MEM + #define TAB_SIZE 32 +#else + #define TAB_SIZE 256 +#endif + +int s_mp_exptmod (mp_int * G, mp_int * X, mp_int * P, mp_int * Y) +{ + mp_int M[TAB_SIZE], res, mu; + mp_digit buf; + int err, bitbuf, bitcpy, bitcnt, mode, digidx, x, y, winsize; + + /* find window size */ + x = mp_count_bits (X); + if (x <= 7) { + winsize = 2; + } else if (x <= 36) { + winsize = 3; + } else if (x <= 140) { + winsize = 4; + } else if (x <= 450) { + winsize = 5; + } else if (x <= 1303) { + winsize = 6; + } else if (x <= 3529) { + winsize = 7; + } else { + winsize = 8; + } + +#ifdef MP_LOW_MEM + if (winsize > 5) { + winsize = 5; + } +#endif + + /* init M array */ + /* init first cell */ + if ((err = mp_init(&M[1])) != MP_OKAY) { + return err; + } + + /* now init the second half of the array */ + for (x = 1<<(winsize-1); x < (1 << winsize); x++) { + if ((err = mp_init(&M[x])) != MP_OKAY) { + for (y = 1<<(winsize-1); y < x; y++) { + mp_clear (&M[y]); + } + mp_clear(&M[1]); + return err; + } + } + + /* create mu, used for Barrett reduction */ + if ((err = mp_init (&mu)) != MP_OKAY) { + goto LBL_M; + } + if ((err = mp_reduce_setup (&mu, P)) != MP_OKAY) { + goto LBL_MU; + } + + /* create M table + * + * The M table contains powers of the base, + * e.g. M[x] = G**x mod P + * + * The first half of the table is not + * computed though accept for M[0] and M[1] + */ + if ((err = mp_mod (G, P, &M[1])) != MP_OKAY) { + goto LBL_MU; + } + + /* compute the value at M[1<<(winsize-1)] by squaring + * M[1] (winsize-1) times + */ + if ((err = mp_copy (&M[1], &M[1 << (winsize - 1)])) != MP_OKAY) { + goto LBL_MU; + } + + for (x = 0; x < (winsize - 1); x++) { + if ((err = mp_sqr (&M[1 << (winsize - 1)], + &M[1 << (winsize - 1)])) != MP_OKAY) { + goto LBL_MU; + } + if ((err = mp_reduce (&M[1 << (winsize - 1)], P, &mu)) != MP_OKAY) { + goto LBL_MU; + } + } + + /* create upper table, that is M[x] = M[x-1] * M[1] (mod P) + * for x = (2**(winsize - 1) + 1) to (2**winsize - 1) + */ + for (x = (1 << (winsize - 1)) + 1; x < (1 << winsize); x++) { + if ((err = mp_mul (&M[x - 1], &M[1], &M[x])) != MP_OKAY) { + goto LBL_MU; + } + if ((err = mp_reduce (&M[x], P, &mu)) != MP_OKAY) { + goto LBL_MU; + } + } + + /* setup result */ + if ((err = mp_init (&res)) != MP_OKAY) { + goto LBL_MU; + } + mp_set (&res, 1); + + /* set initial mode and bit cnt */ + mode = 0; + bitcnt = 1; + buf = 0; + digidx = X->used - 1; + bitcpy = 0; + bitbuf = 0; + + for (;;) { + /* grab next digit as required */ + if (--bitcnt == 0) { + /* if digidx == -1 we are out of digits */ + if (digidx == -1) { + break; + } + /* read next digit and reset the bitcnt */ + buf = X->dp[digidx--]; + bitcnt = (int) DIGIT_BIT; + } + + /* grab the next msb from the exponent */ + y = (buf >> (mp_digit)(DIGIT_BIT - 1)) & 1; + buf <<= (mp_digit)1; + + /* if the bit is zero and mode == 0 then we ignore it + * These represent the leading zero bits before the first 1 bit + * in the exponent. Technically this opt is not required but it + * does lower the # of trivial squaring/reductions used + */ + if (mode == 0 && y == 0) { + continue; + } + + /* if the bit is zero and mode == 1 then we square */ + if (mode == 1 && y == 0) { + if ((err = mp_sqr (&res, &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = mp_reduce (&res, P, &mu)) != MP_OKAY) { + goto LBL_RES; + } + continue; + } + + /* else we add it to the window */ + bitbuf |= (y << (winsize - ++bitcpy)); + mode = 2; + + if (bitcpy == winsize) { + /* ok window is filled so square as required and multiply */ + /* square first */ + for (x = 0; x < winsize; x++) { + if ((err = mp_sqr (&res, &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = mp_reduce (&res, P, &mu)) != MP_OKAY) { + goto LBL_RES; + } + } + + /* then multiply */ + if ((err = mp_mul (&res, &M[bitbuf], &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = mp_reduce (&res, P, &mu)) != MP_OKAY) { + goto LBL_RES; + } + + /* empty window and reset */ + bitcpy = 0; + bitbuf = 0; + mode = 1; + } + } + + /* if bits remain then square/multiply */ + if (mode == 2 && bitcpy > 0) { + /* square then multiply if the bit is set */ + for (x = 0; x < bitcpy; x++) { + if ((err = mp_sqr (&res, &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = mp_reduce (&res, P, &mu)) != MP_OKAY) { + goto LBL_RES; + } + + bitbuf <<= 1; + if ((bitbuf & (1 << winsize)) != 0) { + /* then multiply */ + if ((err = mp_mul (&res, &M[1], &res)) != MP_OKAY) { + goto LBL_RES; + } + if ((err = mp_reduce (&res, P, &mu)) != MP_OKAY) { + goto LBL_RES; + } + } + } + } + + mp_exch (&res, Y); + err = MP_OKAY; +LBL_RES:mp_clear (&res); +LBL_MU:mp_clear (&mu); +LBL_M: + mp_clear(&M[1]); + for (x = 1<<(winsize-1); x < (1 << winsize); x++) { + mp_clear (&M[x]); + } + return err; +} +#endif + +/* End: bn_s_mp_exptmod.c */ + +/* Start: bn_s_mp_mul_digs.c */ +#include <tommath.h> +#ifdef BN_S_MP_MUL_DIGS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* multiplies |a| * |b| and only computes upto digs digits of result + * HAC pp. 595, Algorithm 14.12 Modified so you can control how + * many digits of output are created. + */ +int +s_mp_mul_digs (mp_int * a, mp_int * b, mp_int * c, int digs) +{ + mp_int t; + int res, pa, pb, ix, iy; + mp_digit u; + mp_word r; + mp_digit tmpx, *tmpt, *tmpy; + + /* can we use the fast multiplier? */ + if (((digs) < MP_WARRAY) && + MIN (a->used, b->used) < + (1 << ((CHAR_BIT * sizeof (mp_word)) - (2 * DIGIT_BIT)))) { + return fast_s_mp_mul_digs (a, b, c, digs); + } + + if ((res = mp_init_size (&t, digs)) != MP_OKAY) { + return res; + } + t.used = digs; + + /* compute the digits of the product directly */ + pa = a->used; + for (ix = 0; ix < pa; ix++) { + /* set the carry to zero */ + u = 0; + + /* limit ourselves to making digs digits of output */ + pb = MIN (b->used, digs - ix); + + /* setup some aliases */ + /* copy of the digit from a used within the nested loop */ + tmpx = a->dp[ix]; + + /* an alias for the destination shifted ix places */ + tmpt = t.dp + ix; + + /* an alias for the digits of b */ + tmpy = b->dp; + + /* compute the columns of the output and propagate the carry */ + for (iy = 0; iy < pb; iy++) { + /* compute the column as a mp_word */ + r = ((mp_word)*tmpt) + + ((mp_word)tmpx) * ((mp_word)*tmpy++) + + ((mp_word) u); + + /* the new column is the lower part of the result */ + *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK)); + + /* get the carry word from the result */ + u = (mp_digit) (r >> ((mp_word) DIGIT_BIT)); + } + /* set carry if it is placed below digs */ + if (ix + iy < digs) { + *tmpt = u; + } + } + + mp_clamp (&t); + mp_exch (&t, c); + + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_s_mp_mul_digs.c */ + +/* Start: bn_s_mp_mul_high_digs.c */ +#include <tommath.h> +#ifdef BN_S_MP_MUL_HIGH_DIGS_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* multiplies |a| * |b| and does not compute the lower digs digits + * [meant to get the higher part of the product] + */ +int +s_mp_mul_high_digs (mp_int * a, mp_int * b, mp_int * c, int digs) +{ + mp_int t; + int res, pa, pb, ix, iy; + mp_digit u; + mp_word r; + mp_digit tmpx, *tmpt, *tmpy; + + /* can we use the fast multiplier? */ +#ifdef BN_FAST_S_MP_MUL_HIGH_DIGS_C + if (((a->used + b->used + 1) < MP_WARRAY) + && MIN (a->used, b->used) < (1 << ((CHAR_BIT * sizeof (mp_word)) - (2 * DIGIT_BIT)))) { + return fast_s_mp_mul_high_digs (a, b, c, digs); + } +#endif + + if ((res = mp_init_size (&t, a->used + b->used + 1)) != MP_OKAY) { + return res; + } + t.used = a->used + b->used + 1; + + pa = a->used; + pb = b->used; + for (ix = 0; ix < pa; ix++) { + /* clear the carry */ + u = 0; + + /* left hand side of A[ix] * B[iy] */ + tmpx = a->dp[ix]; + + /* alias to the address of where the digits will be stored */ + tmpt = &(t.dp[digs]); + + /* alias for where to read the right hand side from */ + tmpy = b->dp + (digs - ix); + + for (iy = digs - ix; iy < pb; iy++) { + /* calculate the double precision result */ + r = ((mp_word)*tmpt) + + ((mp_word)tmpx) * ((mp_word)*tmpy++) + + ((mp_word) u); + + /* get the lower part */ + *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK)); + + /* carry the carry */ + u = (mp_digit) (r >> ((mp_word) DIGIT_BIT)); + } + *tmpt = u; + } + mp_clamp (&t); + mp_exch (&t, c); + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_s_mp_mul_high_digs.c */ + +/* Start: bn_s_mp_sqr.c */ +#include <tommath.h> +#ifdef BN_S_MP_SQR_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* low level squaring, b = a*a, HAC pp.596-597, Algorithm 14.16 */ +int +s_mp_sqr (mp_int * a, mp_int * b) +{ + mp_int t; + int res, ix, iy, pa; + mp_word r; + mp_digit u, tmpx, *tmpt; + + pa = a->used; + if ((res = mp_init_size (&t, 2*pa + 1)) != MP_OKAY) { + return res; + } + + /* default used is maximum possible size */ + t.used = 2*pa + 1; + + for (ix = 0; ix < pa; ix++) { + /* first calculate the digit at 2*ix */ + /* calculate double precision result */ + r = ((mp_word) t.dp[2*ix]) + + ((mp_word)a->dp[ix])*((mp_word)a->dp[ix]); + + /* store lower part in result */ + t.dp[ix+ix] = (mp_digit) (r & ((mp_word) MP_MASK)); + + /* get the carry */ + u = (mp_digit)(r >> ((mp_word) DIGIT_BIT)); + + /* left hand side of A[ix] * A[iy] */ + tmpx = a->dp[ix]; + + /* alias for where to store the results */ + tmpt = t.dp + (2*ix + 1); + + for (iy = ix + 1; iy < pa; iy++) { + /* first calculate the product */ + r = ((mp_word)tmpx) * ((mp_word)a->dp[iy]); + + /* now calculate the double precision result, note we use + * addition instead of *2 since it's easier to optimize + */ + r = ((mp_word) *tmpt) + r + r + ((mp_word) u); + + /* store lower part */ + *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK)); + + /* get carry */ + u = (mp_digit)(r >> ((mp_word) DIGIT_BIT)); + } + /* propagate upwards */ + while (u != ((mp_digit) 0)) { + r = ((mp_word) *tmpt) + ((mp_word) u); + *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK)); + u = (mp_digit)(r >> ((mp_word) DIGIT_BIT)); + } + } + + mp_clamp (&t); + mp_exch (&t, b); + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* End: bn_s_mp_sqr.c */ + +/* Start: bn_s_mp_sub.c */ +#include <tommath.h> +#ifdef BN_S_MP_SUB_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* low level subtraction (assumes |a| > |b|), HAC pp.595 Algorithm 14.9 */ +int +s_mp_sub (mp_int * a, mp_int * b, mp_int * c) +{ + int olduse, res, min, max; + + /* find sizes */ + min = b->used; + max = a->used; + + /* init result */ + if (c->alloc < max) { + if ((res = mp_grow (c, max)) != MP_OKAY) { + return res; + } + } + olduse = c->used; + c->used = max; + + { + register mp_digit u, *tmpa, *tmpb, *tmpc; + register int i; + + /* alias for digit pointers */ + tmpa = a->dp; + tmpb = b->dp; + tmpc = c->dp; + + /* set carry to zero */ + u = 0; + for (i = 0; i < min; i++) { + /* T[i] = A[i] - B[i] - U */ + *tmpc = *tmpa++ - *tmpb++ - u; + + /* U = carry bit of T[i] + * Note this saves performing an AND operation since + * if a carry does occur it will propagate all the way to the + * MSB. As a result a single shift is enough to get the carry + */ + u = *tmpc >> ((mp_digit)(CHAR_BIT * sizeof (mp_digit) - 1)); + + /* Clear carry from T[i] */ + *tmpc++ &= MP_MASK; + } + + /* now copy higher words if any, e.g. if A has more digits than B */ + for (; i < max; i++) { + /* T[i] = A[i] - U */ + *tmpc = *tmpa++ - u; + + /* U = carry bit of T[i] */ + u = *tmpc >> ((mp_digit)(CHAR_BIT * sizeof (mp_digit) - 1)); + + /* Clear carry from T[i] */ + *tmpc++ &= MP_MASK; + } + + /* clear digits above used (since we may not have grown result above) */ + for (i = c->used; i < olduse; i++) { + *tmpc++ = 0; + } + } + + mp_clamp (c); + return MP_OKAY; +} + +#endif + +/* End: bn_s_mp_sub.c */ + +/* Start: bncore.c */ +#include <tommath.h> +#ifdef BNCORE_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis + * + * LibTomMath is a library that provides multiple-precision + * integer arithmetic as well as number theoretic functionality. + * + * The library was designed directly after the MPI library by + * Michael Fromberger but has been written from scratch with + * additional optimizations in place. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org + */ + +/* Known optimal configurations + + CPU /Compiler /MUL CUTOFF/SQR CUTOFF +------------------------------------------------------------- + Intel P4 Northwood /GCC v3.4.1 / 88/ 128/LTM 0.32 ;-) + +*/ + +int KARATSUBA_MUL_CUTOFF = 88, /* Min. number of digits before Karatsuba multiplication is used. */ + KARATSUBA_SQR_CUTOFF = 128, /* Min. number of digits before Karatsuba squaring is used. */ + + TOOM_MUL_CUTOFF = 350, /* no optimal values of these are known yet so set em high */ + TOOM_SQR_CUTOFF = 400; +#endif + +/* End: bncore.c */ + + +/* EOF */ |