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Diffstat (limited to '')
-rw-r--r-- | third_party/heimdal/lib/hcrypto/libtommath/bn_mp_invmod.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_invmod.c b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_invmod.c new file mode 100644 index 0000000..7b35a24 --- /dev/null +++ b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_invmod.c @@ -0,0 +1,23 @@ +#include "tommath_private.h" +#ifdef BN_MP_INVMOD_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ + +/* hac 14.61, pp608 */ +mp_err mp_invmod(const mp_int *a, const mp_int *b, mp_int *c) +{ + /* b cannot be negative and has to be >1 */ + if ((b->sign == MP_NEG) || (mp_cmp_d(b, 1uL) != MP_GT)) { + return MP_VAL; + } + + /* if the modulus is odd we can use a faster routine instead */ + if (MP_HAS(S_MP_INVMOD_FAST) && MP_IS_ODD(b)) { + return s_mp_invmod_fast(a, b, c); + } + + return MP_HAS(S_MP_INVMOD_SLOW) + ? s_mp_invmod_slow(a, b, c) + : MP_VAL; +} +#endif |