Mercurial > dropbear
view libtommath/bn_mp_xor.c @ 343:ffbe6f691ca3
CHECKCLEARTOWRITE() can normally be defined blank
author | Matt Johnston <matt@ucc.asn.au> |
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date | Sun, 09 Jul 2006 14:58:19 +0000 |
parents | eed26cff980b |
children | 5ff8218bcee9 |
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#include <tommath.h> #ifdef BN_MP_XOR_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://math.libtomcrypt.org */ /* XOR two ints together */ int mp_xor (mp_int * a, mp_int * b, mp_int * c) { int res, ix, px; mp_int t, *x; if (a->used > b->used) { if ((res = mp_init_copy (&t, a)) != MP_OKAY) { return res; } px = b->used; x = b; } else { if ((res = mp_init_copy (&t, b)) != MP_OKAY) { return res; } px = a->used; x = a; } for (ix = 0; ix < px; ix++) { t.dp[ix] ^= x->dp[ix]; } mp_clamp (&t); mp_exch (c, &t); mp_clear (&t); return MP_OKAY; } #endif