mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-16 04:29:08 +00:00
63 lines
2.3 KiB
C
63 lines
2.3 KiB
C
/**
|
|
* Copyright (c) 2013-2014 Tomas Dzetkulic
|
|
* Copyright (c) 2013-2014 Pavol Rusnak
|
|
* Copyright (c) 2015 Jochen Hoenicke
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining
|
|
* a copy of this software and associated documentation files (the "Software"),
|
|
* to deal in the Software without restriction, including without limitation
|
|
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
|
|
* and/or sell copies of the Software, and to permit persons to whom the
|
|
* Software is furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included
|
|
* in all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
|
|
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES
|
|
* OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
|
|
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
|
|
* OTHER DEALINGS IN THE SOFTWARE.
|
|
*/
|
|
#include <assert.h>
|
|
|
|
#include "hmac_drbg.h"
|
|
#include "memzero.h"
|
|
#include "rfc6979.h"
|
|
|
|
void init_rfc6979(const uint8_t *priv_key, const uint8_t *hash,
|
|
const ecdsa_curve *curve, rfc6979_state *state) {
|
|
if (curve) {
|
|
bignum256 hash_bn = {0};
|
|
bn_read_be(hash, &hash_bn);
|
|
|
|
// Make sure hash is partly reduced modulo order
|
|
assert(bn_bitcount(&curve->order) >= 256);
|
|
bn_mod(&hash_bn, &curve->order);
|
|
|
|
uint8_t hash_reduced[32] = {0};
|
|
bn_write_be(&hash_bn, hash_reduced);
|
|
memzero(&hash_bn, sizeof(hash_bn));
|
|
hmac_drbg_init(state, priv_key, 32, hash_reduced, 32);
|
|
memzero(hash_reduced, sizeof(hash_reduced));
|
|
} else {
|
|
hmac_drbg_init(state, priv_key, 32, hash, 32);
|
|
}
|
|
}
|
|
|
|
// generate next number from deterministic random number generator
|
|
void generate_rfc6979(uint8_t rnd[32], rfc6979_state *state) {
|
|
hmac_drbg_generate(state, rnd, 32);
|
|
}
|
|
|
|
// generate K in a deterministic way, according to RFC6979
|
|
// http://tools.ietf.org/html/rfc6979
|
|
void generate_k_rfc6979(bignum256 *k, rfc6979_state *state) {
|
|
uint8_t buf[32] = {0};
|
|
generate_rfc6979(buf, state);
|
|
bn_read_be(buf, k);
|
|
memzero(buf, sizeof(buf));
|
|
}
|