mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-17 11:58:13 +00:00
63 lines
2.2 KiB
C
63 lines
2.2 KiB
C
/*
|
|
* This file is part of the Trezor project, https://trezor.io/
|
|
*
|
|
* Copyright (c) SatoshiLabs
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program 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 a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include "chacha_drbg.h"
|
|
|
|
#include <stdint.h>
|
|
|
|
#define MAX(a, b) (a) > (b) ? (a) : (b)
|
|
|
|
void chacha_drbg_init(CHACHA_DRBG_CTX *ctx,
|
|
const uint8_t entropy[CHACHA_DRBG_SEED_LENGTH]) {
|
|
uint8_t buffer[MAX(CHACHA_DRBG_KEY_LENGTH, CHACHA_DRBG_IV_LENGTH)] = {0};
|
|
ECRYPT_keysetup(&ctx->chacha_ctx, buffer, CHACHA_DRBG_KEY_LENGTH * 8,
|
|
CHACHA_DRBG_IV_LENGTH * 8);
|
|
ECRYPT_ivsetup(&ctx->chacha_ctx, buffer);
|
|
|
|
chacha_drbg_reseed(ctx, entropy);
|
|
}
|
|
|
|
static void chacha_drbg_update(CHACHA_DRBG_CTX *ctx,
|
|
const uint8_t data[CHACHA_DRBG_SEED_LENGTH]) {
|
|
uint8_t buffer[CHACHA_DRBG_SEED_LENGTH] = {0};
|
|
|
|
if (data)
|
|
ECRYPT_encrypt_bytes(&ctx->chacha_ctx, data, buffer,
|
|
CHACHA_DRBG_SEED_LENGTH);
|
|
else
|
|
ECRYPT_keystream_bytes(&ctx->chacha_ctx, buffer, CHACHA_DRBG_SEED_LENGTH);
|
|
|
|
ECRYPT_keysetup(&ctx->chacha_ctx, buffer, CHACHA_DRBG_KEY_LENGTH * 8,
|
|
CHACHA_DRBG_IV_LENGTH * 8);
|
|
ECRYPT_ivsetup(&ctx->chacha_ctx, buffer + CHACHA_DRBG_KEY_LENGTH);
|
|
}
|
|
|
|
void chacha_drbg_generate(CHACHA_DRBG_CTX *ctx, uint8_t *output,
|
|
uint8_t output_length) {
|
|
ECRYPT_keystream_bytes(&ctx->chacha_ctx, output, output_length);
|
|
chacha_drbg_update(ctx, NULL);
|
|
ctx->reseed_counter++;
|
|
}
|
|
|
|
void chacha_drbg_reseed(CHACHA_DRBG_CTX *ctx,
|
|
const uint8_t entropy[CHACHA_DRBG_SEED_LENGTH]) {
|
|
chacha_drbg_update(ctx, entropy);
|
|
ctx->reseed_counter = 1;
|
|
}
|