Mercurial > dropbear
view libtommath/bn_mp_invmod.c @ 1634:aabde6f57fce
Add a sanity check for DROPBEAR_SVR_MULTIUSER==0 mode
author | Matt Johnston <matt@ucc.asn.au> |
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date | Wed, 20 Mar 2019 22:57:06 +0800 |
parents | 8bba51a55704 |
children | f52919ffd3b1 |
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#include <tommath_private.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, [email protected], http://libtom.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) == MP_YES)) { 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) == MP_YES) && (mp_cmp_d(b, 1) != MP_EQ)) { return fast_mp_invmod (a, b, c); } #endif #ifdef BN_MP_INVMOD_SLOW_C return mp_invmod_slow(a, b, c); #else return MP_VAL; #endif } #endif /* ref: $Format:%D$ */ /* git commit: $Format:%H$ */ /* commit time: $Format:%ai$ */