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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 17:20:00 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 17:20:00 +0000 |
commit | 8daa83a594a2e98f39d764422bfbdbc62c9efd44 (patch) | |
tree | 4099e8021376c7d8c05bdf8503093d80e9c7bad0 /third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mul.c | |
parent | Initial commit. (diff) | |
download | samba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.tar.xz samba-8daa83a594a2e98f39d764422bfbdbc62c9efd44.zip |
Adding upstream version 2:4.20.0+dfsg.upstream/2%4.20.0+dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mul.c | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mul.c b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mul.c new file mode 100644 index 0000000..561913a --- /dev/null +++ b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mul.c @@ -0,0 +1,52 @@ +#include "tommath_private.h" +#ifdef BN_MP_MUL_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ + +/* high level multiplication (handles sign) */ +mp_err mp_mul(const mp_int *a, const mp_int *b, mp_int *c) +{ + mp_err err; + int min_len = MP_MIN(a->used, b->used), + max_len = MP_MAX(a->used, b->used), + digs = a->used + b->used + 1; + mp_sign neg = (a->sign == b->sign) ? MP_ZPOS : MP_NEG; + + if (MP_HAS(S_MP_BALANCE_MUL) && + /* Check sizes. The smaller one needs to be larger than the Karatsuba cut-off. + * The bigger one needs to be at least about one MP_KARATSUBA_MUL_CUTOFF bigger + * to make some sense, but it depends on architecture, OS, position of the + * stars... so YMMV. + * Using it to cut the input into slices small enough for fast_s_mp_mul_digs + * was actually slower on the author's machine, but YMMV. + */ + (min_len >= MP_KARATSUBA_MUL_CUTOFF) && + ((max_len / 2) >= MP_KARATSUBA_MUL_CUTOFF) && + /* Not much effect was observed below a ratio of 1:2, but again: YMMV. */ + (max_len >= (2 * min_len))) { + err = s_mp_balance_mul(a,b,c); + } else if (MP_HAS(S_MP_TOOM_MUL) && + (min_len >= MP_TOOM_MUL_CUTOFF)) { + err = s_mp_toom_mul(a, b, c); + } else if (MP_HAS(S_MP_KARATSUBA_MUL) && + (min_len >= MP_KARATSUBA_MUL_CUTOFF)) { + err = s_mp_karatsuba_mul(a, b, c); + } else if (MP_HAS(S_MP_MUL_DIGS_FAST) && + /* can we use the fast multiplier? + * + * The fast multiplier can be used if the output will + * have less than MP_WARRAY digits and the number of + * digits won't affect carry propagation + */ + (digs < MP_WARRAY) && + (min_len <= MP_MAXFAST)) { + err = s_mp_mul_digs_fast(a, b, c, digs); + } else if (MP_HAS(S_MP_MUL_DIGS)) { + err = s_mp_mul_digs(a, b, c, digs); + } else { + err = MP_VAL; + } + c->sign = (c->used > 0) ? neg : MP_ZPOS; + return err; +} +#endif |