From e94ab6b703ee50ea020565e1b8729a9b1d524d84 Mon Sep 17 00:00:00 2001 From: Daiki Ueno Date: Mon, 29 Jul 2019 14:00:30 +0200 Subject: nettle: add functions for deterministic ECDSA/DSA This adds functions to perform deterministic ECDSA/DSA, namely _gnutls_{ecdsa,dsa}_compute_k(), which computes the k value according to RFC 6979. The retrieved k value can be given to nettle_{ecdsa,dsa}_sign() through a wrapper random function. Signed-off-by: Daiki Ueno --- lib/nettle/int/mpn-base256.c | 97 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 lib/nettle/int/mpn-base256.c (limited to 'lib/nettle/int/mpn-base256.c') diff --git a/lib/nettle/int/mpn-base256.c b/lib/nettle/int/mpn-base256.c new file mode 100644 index 0000000000..88dd00bd20 --- /dev/null +++ b/lib/nettle/int/mpn-base256.c @@ -0,0 +1,97 @@ +/* gmp-glue.c + + Copyright (C) 2013 Niels Möller + Copyright (C) 2013 Red Hat + + This file is part of GNU Nettle. + + GNU Nettle is free software: you can redistribute it and/or + modify it under the terms of either: + + * the GNU Lesser General Public License as published by the Free + Software Foundation; either version 3 of the License, or (at your + option) any later version. + + or + + * the GNU General Public License as published by the Free + Software Foundation; either version 2 of the License, or (at your + option) any later version. + + or both in parallel, as here. + + GNU Nettle is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + General Public License for more details. + + You should have received copies of the GNU General Public License and + the GNU Lesser General Public License along with this program. If + not, see http://www.gnu.org/licenses/. +*/ + +#if HAVE_CONFIG_H +# include "config.h" +#endif + +#include "mpn-base256.h" + +void +mpn_set_base256 (mp_limb_t *rp, mp_size_t rn, + const uint8_t *xp, size_t xn) +{ + size_t xi; + mp_limb_t out; + unsigned bits; + for (xi = xn, out = bits = 0; xi > 0 && rn > 0; ) + { + mp_limb_t in = xp[--xi]; + out |= (in << bits) & GMP_NUMB_MASK; + bits += 8; + if (bits >= GMP_NUMB_BITS) + { + *rp++ = out; + rn--; + + bits -= GMP_NUMB_BITS; + out = in >> (8 - bits); + } + } + if (rn > 0) + { + *rp++ = out; + if (--rn > 0) + mpn_zero (rp, rn); + } +} + +void +mpn_get_base256 (uint8_t *rp, size_t rn, + const mp_limb_t *xp, mp_size_t xn) +{ + unsigned bits; + mp_limb_t in; + for (bits = in = 0; xn > 0 && rn > 0; ) + { + if (bits >= 8) + { + rp[--rn] = in; + in >>= 8; + bits -= 8; + } + else + { + uint8_t old = in; + in = *xp++; + xn--; + rp[--rn] = old | (in << bits); + in >>= (8 - bits); + bits += GMP_NUMB_BITS - 8; + } + } + while (rn > 0) + { + rp[--rn] = in; + in >>= 8; + } +} -- cgit v1.2.1