mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-26 01:18:28 +00:00
78 lines
2.9 KiB
C
78 lines
2.9 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 "rfc6979.h"
|
|
#include <string.h>
|
|
#include "hmac.h"
|
|
#include "memzero.h"
|
|
|
|
void init_rfc6979(const uint8_t *priv_key, const uint8_t *hash,
|
|
rfc6979_state *state) {
|
|
uint8_t bx[2 * 32];
|
|
uint8_t buf[32 + 1 + 2 * 32];
|
|
|
|
memcpy(bx, priv_key, 32);
|
|
memcpy(bx + 32, hash, 32);
|
|
|
|
memset(state->v, 1, sizeof(state->v));
|
|
memset(state->k, 0, sizeof(state->k));
|
|
|
|
memcpy(buf, state->v, sizeof(state->v));
|
|
buf[sizeof(state->v)] = 0x00;
|
|
memcpy(buf + sizeof(state->v) + 1, bx, 64);
|
|
hmac_sha256(state->k, sizeof(state->k), buf, sizeof(buf), state->k);
|
|
hmac_sha256(state->k, sizeof(state->k), state->v, sizeof(state->v), state->v);
|
|
|
|
memcpy(buf, state->v, sizeof(state->v));
|
|
buf[sizeof(state->v)] = 0x01;
|
|
memcpy(buf + sizeof(state->v) + 1, bx, 64);
|
|
hmac_sha256(state->k, sizeof(state->k), buf, sizeof(buf), state->k);
|
|
hmac_sha256(state->k, sizeof(state->k), state->v, sizeof(state->v), state->v);
|
|
|
|
memzero(bx, sizeof(bx));
|
|
memzero(buf, sizeof(buf));
|
|
}
|
|
|
|
// generate next number from deterministic random number generator
|
|
void generate_rfc6979(uint8_t rnd[32], rfc6979_state *state) {
|
|
uint8_t buf[32 + 1];
|
|
|
|
hmac_sha256(state->k, sizeof(state->k), state->v, sizeof(state->v), state->v);
|
|
memcpy(buf, state->v, sizeof(state->v));
|
|
buf[sizeof(state->v)] = 0x00;
|
|
hmac_sha256(state->k, sizeof(state->k), buf, sizeof(state->v) + 1, state->k);
|
|
hmac_sha256(state->k, sizeof(state->k), state->v, sizeof(state->v), state->v);
|
|
memcpy(rnd, buf, 32);
|
|
memzero(buf, sizeof(buf));
|
|
}
|
|
|
|
// 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];
|
|
generate_rfc6979(buf, state);
|
|
bn_read_be(buf, k);
|
|
memzero(buf, sizeof(buf));
|
|
}
|