mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-12-21 05:48:23 +00:00
55 lines
2.3 KiB
C
55 lines
2.3 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/>.
|
|
*/
|
|
|
|
#ifndef __CHACHA_DRBG__
|
|
#define __CHACHA_DRBG__
|
|
|
|
#include "chacha20poly1305/chacha20poly1305.h"
|
|
#include "sha2.h"
|
|
|
|
// A very fast deterministic random bit generator based on CTR_DRBG in NIST SP
|
|
// 800-90A. Chacha is used instead of a block cipher in the counter mode, SHA256
|
|
// is used as a derivation function. The highest supported security strength is
|
|
// at least 256 bits. Reseeding is left up to caller.
|
|
|
|
// Length of inputs of chacha_drbg_init (entropy and nonce) or
|
|
// chacha_drbg_reseed (entropy and additional_input) that fill exactly
|
|
// block_count blocks of hash function in derivation_function. There is no need
|
|
// the input to have this length, it's just an optimalization.
|
|
#define CHACHA_DRBG_OPTIMAL_RESEED_LENGTH(block_count) \
|
|
((block_count)*SHA256_BLOCK_LENGTH - 1 - 4 - 9)
|
|
// 1 = sizeof(counter), 4 = sizeof(output_length) in
|
|
// derivation_function, 9 is length of SHA256 padding of message
|
|
// aligned to bytes
|
|
|
|
typedef struct _CHACHA_DRBG_CTX {
|
|
ECRYPT_ctx chacha_ctx;
|
|
uint32_t reseed_counter;
|
|
} CHACHA_DRBG_CTX;
|
|
|
|
void chacha_drbg_init(CHACHA_DRBG_CTX *ctx, const uint8_t *entropy,
|
|
size_t entropy_length, const uint8_t *nonce,
|
|
size_t nonce_length);
|
|
void chacha_drbg_generate(CHACHA_DRBG_CTX *ctx, uint8_t *output,
|
|
size_t output_length);
|
|
void chacha_drbg_reseed(CHACHA_DRBG_CTX *ctx, const uint8_t *entropy,
|
|
size_t entropy_length, const uint8_t *additional_input,
|
|
size_t additional_input_length);
|
|
#endif // __CHACHA_DRBG__
|