X-Git-Url: https://git.pterodactylus.net/?p=fms.git;a=blobdiff_plain;f=libs%2Flibtommath%2Fbn_mp_add.c;fp=libs%2Flibtommath%2Fbn_mp_add.c;h=a90eef67adb782ba7082be0e747f089be616d539;hp=0000000000000000000000000000000000000000;hb=109c20e6f822c6efa465af31249e5608469253b6;hpb=9ae3b1434e51788e6feb72e1415ec800d05c535a diff --git a/libs/libtommath/bn_mp_add.c b/libs/libtommath/bn_mp_add.c new file mode 100644 index 0000000..a90eef6 --- /dev/null +++ b/libs/libtommath/bn_mp_add.c @@ -0,0 +1,53 @@ +#include +#ifdef BN_MP_ADD_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@gmail.com, http://math.libtomcrypt.com + */ + +/* high level addition (handles signs) */ +int mp_add (mp_int * a, mp_int * b, mp_int * c) +{ + int sa, sb, res; + + /* get sign of both inputs */ + sa = a->sign; + sb = b->sign; + + /* handle two cases, not four */ + if (sa == sb) { + /* both positive or both negative */ + /* add their magnitudes, copy the sign */ + c->sign = sa; + res = s_mp_add (a, b, c); + } else { + /* one positive, the other negative */ + /* subtract the one with the greater magnitude from */ + /* the one of the lesser magnitude. The result gets */ + /* the sign of the one with the greater magnitude. */ + if (mp_cmp_mag (a, b) == MP_LT) { + c->sign = sb; + res = s_mp_sub (b, a, c); + } else { + c->sign = sa; + res = s_mp_sub (a, b, c); + } + } + return res; +} + +#endif + +/* $Source: /cvs/libtom/libtommath/bn_mp_add.c,v $ */ +/* $Revision: 1.3 $ */ +/* $Date: 2006/03/31 14:18:44 $ */