diff options
Diffstat (limited to 'libtommath/bn_mp_invmod.c')
-rw-r--r-- | libtommath/bn_mp_invmod.c | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/libtommath/bn_mp_invmod.c b/libtommath/bn_mp_invmod.c new file mode 100644 index 0000000..11e1638 --- /dev/null +++ b/libtommath/bn_mp_invmod.c @@ -0,0 +1,43 @@ +#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 + +/* $Source: /root/tcl/repos-to-convert/tcl/libtommath/bn_mp_invmod.c,v $ */ +/* $Revision: 1.1.1.1.2.1 $ */ +/* $Date: 2005/09/26 20:16:53 $ */ |