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_s_mp_sqr.c | 84 ++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 source4/heimdal/lib/hcrypto/libtommath/bn_s_mp_sqr.c (limited to 'source4/heimdal/lib/hcrypto/libtommath/bn_s_mp_sqr.c') diff --git a/source4/heimdal/lib/hcrypto/libtommath/bn_s_mp_sqr.c b/source4/heimdal/lib/hcrypto/libtommath/bn_s_mp_sqr.c new file mode 100644 index 0000000000..d2531c2925 --- /dev/null +++ b/source4/heimdal/lib/hcrypto/libtommath/bn_s_mp_sqr.c @@ -0,0 +1,84 @@ +#include +#ifdef BN_S_MP_SQR_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 + */ + +/* low level squaring, b = a*a, HAC pp.596-597, Algorithm 14.16 */ +int s_mp_sqr (mp_int * a, mp_int * b) +{ + mp_int t; + int res, ix, iy, pa; + mp_word r; + mp_digit u, tmpx, *tmpt; + + pa = a->used; + if ((res = mp_init_size (&t, 2*pa + 1)) != MP_OKAY) { + return res; + } + + /* default used is maximum possible size */ + t.used = 2*pa + 1; + + for (ix = 0; ix < pa; ix++) { + /* first calculate the digit at 2*ix */ + /* calculate double precision result */ + r = ((mp_word) t.dp[2*ix]) + + ((mp_word)a->dp[ix])*((mp_word)a->dp[ix]); + + /* store lower part in result */ + t.dp[ix+ix] = (mp_digit) (r & ((mp_word) MP_MASK)); + + /* get the carry */ + u = (mp_digit)(r >> ((mp_word) DIGIT_BIT)); + + /* left hand side of A[ix] * A[iy] */ + tmpx = a->dp[ix]; + + /* alias for where to store the results */ + tmpt = t.dp + (2*ix + 1); + + for (iy = ix + 1; iy < pa; iy++) { + /* first calculate the product */ + r = ((mp_word)tmpx) * ((mp_word)a->dp[iy]); + + /* now calculate the double precision result, note we use + * addition instead of *2 since it's easier to optimize + */ + r = ((mp_word) *tmpt) + r + r + ((mp_word) u); + + /* store lower part */ + *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK)); + + /* get carry */ + u = (mp_digit)(r >> ((mp_word) DIGIT_BIT)); + } + /* propagate upwards */ + while (u != ((mp_digit) 0)) { + r = ((mp_word) *tmpt) + ((mp_word) u); + *tmpt++ = (mp_digit) (r & ((mp_word) MP_MASK)); + u = (mp_digit)(r >> ((mp_word) DIGIT_BIT)); + } + } + + mp_clamp (&t); + mp_exch (&t, b); + mp_clear (&t); + return MP_OKAY; +} +#endif + +/* $Source: /cvs/libtom/libtommath/bn_s_mp_sqr.c,v $ */ +/* $Revision: 1.4 $ */ +/* $Date: 2006/12/28 01:25:13 $ */ -- cgit