From ab6e3fce040f9ad27cbce44e9038a24f15b601c8 Mon Sep 17 00:00:00 2001 From: Matthieu Patou Date: Sun, 15 Aug 2010 18:31:28 +0400 Subject: s4:heimdal: import lorikeet-heimdal-201009250123 (commit 42cabfb5b683dbcb97d583c397b897507689e382) I based this on Matthieu's import of lorikeet-heimdal, and then updated it to this commit. Andrew Bartlett --- .../heimdal/lib/hcrypto/libtommath/bn_mp_add_d.c | 112 +++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 source4/heimdal/lib/hcrypto/libtommath/bn_mp_add_d.c (limited to 'source4/heimdal/lib/hcrypto/libtommath/bn_mp_add_d.c') diff --git a/source4/heimdal/lib/hcrypto/libtommath/bn_mp_add_d.c b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_add_d.c new file mode 100644 index 0000000000..8ca36c1124 --- /dev/null +++ b/source4/heimdal/lib/hcrypto/libtommath/bn_mp_add_d.c @@ -0,0 +1,112 @@ +#include +#ifdef BN_MP_ADD_D_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://libtom.org + */ + +/* single digit addition */ +int +mp_add_d (mp_int * a, mp_digit b, mp_int * c) +{ + int res, ix, oldused; + mp_digit *tmpa, *tmpc, mu; + + /* grow c as required */ + if (c->alloc < a->used + 1) { + if ((res = mp_grow(c, a->used + 1)) != MP_OKAY) { + return res; + } + } + + /* if a is negative and |a| >= b, call c = |a| - b */ + if (a->sign == MP_NEG && (a->used > 1 || a->dp[0] >= b)) { + /* temporarily fix sign of a */ + a->sign = MP_ZPOS; + + /* c = |a| - b */ + res = mp_sub_d(a, b, c); + + /* fix sign */ + a->sign = c->sign = MP_NEG; + + /* clamp */ + mp_clamp(c); + + return res; + } + + /* old number of used digits in c */ + oldused = c->used; + + /* sign always positive */ + c->sign = MP_ZPOS; + + /* source alias */ + tmpa = a->dp; + + /* destination alias */ + tmpc = c->dp; + + /* if a is positive */ + if (a->sign == MP_ZPOS) { + /* add digit, after this we're propagating + * the carry. + */ + *tmpc = *tmpa++ + b; + mu = *tmpc >> DIGIT_BIT; + *tmpc++ &= MP_MASK; + + /* now handle rest of the digits */ + for (ix = 1; ix < a->used; ix++) { + *tmpc = *tmpa++ + mu; + mu = *tmpc >> DIGIT_BIT; + *tmpc++ &= MP_MASK; + } + /* set final carry */ + ix++; + *tmpc++ = mu; + + /* setup size */ + c->used = a->used + 1; + } else { + /* a was negative and |a| < b */ + c->used = 1; + + /* the result is a single digit */ + if (a->used == 1) { + *tmpc++ = b - a->dp[0]; + } else { + *tmpc++ = b; + } + + /* setup count so the clearing of oldused + * can fall through correctly + */ + ix = 1; + } + + /* now zero to oldused */ + while (ix++ < oldused) { + *tmpc++ = 0; + } + mp_clamp(c); + + return MP_OKAY; +} + +#endif + +/* $Source: /cvs/libtom/libtommath/bn_mp_add_d.c,v $ */ +/* $Revision: 1.5 $ */ +/* $Date: 2006/12/28 01:25:13 $ */ -- cgit