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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_mod_2d.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 'third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mod_2d.c')
-rw-r--r-- | third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mod_2d.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mod_2d.c b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mod_2d.c new file mode 100644 index 0000000..5bf57a1 --- /dev/null +++ b/third_party/heimdal/lib/hcrypto/libtommath/bn_mp_mod_2d.c @@ -0,0 +1,38 @@ +#include "tommath_private.h" +#ifdef BN_MP_MOD_2D_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ + +/* calc a value mod 2**b */ +mp_err mp_mod_2d(const mp_int *a, int b, mp_int *c) +{ + int x; + mp_err err; + + /* if b is <= 0 then zero the int */ + if (b <= 0) { + mp_zero(c); + return MP_OKAY; + } + + /* if the modulus is larger than the value than return */ + if (b >= (a->used * MP_DIGIT_BIT)) { + return mp_copy(a, c); + } + + /* copy */ + if ((err = mp_copy(a, c)) != MP_OKAY) { + return err; + } + + /* zero digits above the last digit of the modulus */ + x = (b / MP_DIGIT_BIT) + (((b % MP_DIGIT_BIT) == 0) ? 0 : 1); + MP_ZERO_DIGITS(c->dp + x, c->used - x); + + /* clear the digit that is not completely outside/inside the modulus */ + c->dp[b / MP_DIGIT_BIT] &= + ((mp_digit)1 << (mp_digit)(b % MP_DIGIT_BIT)) - (mp_digit)1; + mp_clamp(c); + return MP_OKAY; +} +#endif |