diff options
Diffstat (limited to 'libtommath/bn_mp_lshd.c')
-rw-r--r-- | libtommath/bn_mp_lshd.c | 92 |
1 files changed, 48 insertions, 44 deletions
diff --git a/libtommath/bn_mp_lshd.c b/libtommath/bn_mp_lshd.c index ce1e63b..888989a 100644 --- a/libtommath/bn_mp_lshd.c +++ b/libtommath/bn_mp_lshd.c @@ -1,4 +1,4 @@ -#include <tommath.h> +#include <tommath_private.h> #ifdef BN_MP_LSHD_C /* LibTomMath, multiple-precision integer library -- Tom St Denis * @@ -12,52 +12,56 @@ * The library is free for all purposes without any express * guarantee it works. * - * Tom St Denis, tomstdenis@gmail.com, http://math.libtomcrypt.com + * Tom St Denis, tstdenis82@gmail.com, http://libtom.org */ /* shift left a certain amount of digits */ -int mp_lshd (mp_int * a, int b) +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; + 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; + } + } + + { + 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 + +/* ref: $Format:%D$ */ +/* git commit: $Format:%H$ */ +/* commit time: $Format:%ai$ */ |