/src/dropbear/libtommath/bn_mp_invmod.c
Line | Count | Source (jump to first uncovered line) |
1 | | #include "tommath_private.h" |
2 | | #ifdef BN_MP_INVMOD_C |
3 | | /* LibTomMath, multiple-precision integer library -- Tom St Denis */ |
4 | | /* SPDX-License-Identifier: Unlicense */ |
5 | | |
6 | | /* hac 14.61, pp608 */ |
7 | | mp_err mp_invmod(const mp_int *a, const mp_int *b, mp_int *c) |
8 | 0 | { |
9 | | /* b cannot be negative and has to be >1 */ |
10 | 0 | if ((b->sign == MP_NEG) || (mp_cmp_d(b, 1uL) != MP_GT)) { |
11 | 0 | return MP_VAL; |
12 | 0 | } |
13 | | |
14 | | /* if the modulus is odd we can use a faster routine instead */ |
15 | 0 | if (MP_HAS(S_MP_INVMOD_FAST) && MP_IS_ODD(b)) { |
16 | 0 | return s_mp_invmod_fast(a, b, c); |
17 | 0 | } |
18 | | |
19 | 0 | return MP_HAS(S_MP_INVMOD_SLOW) |
20 | 0 | ? s_mp_invmod_slow(a, b, c) |
21 | 0 | : MP_VAL; |
22 | 0 | } |
23 | | #endif |