toxcore/toxencryptsave/crypto_pwhash_scryptsalsa208sha256/pbkdf2-sha256.c

98 lines
3.4 KiB
C

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#ifdef VANILLA_NACL /* toxcore only uses this when libsodium is unavailable */
/*-
* Copyright 2005,2007,2009 Colin Percival
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <crypto_hash_sha256.h>
#include <crypto_auth_hmacsha256.h>
#include "pbkdf2-sha256.h"
#include "sysendian.h"
#include "../../toxcore/crypto_core.h"
/**
* PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen):
* Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and
* write the output to buf. The value dkLen must be at most 32 * (2^32 - 1).
*/
void
PBKDF2_SHA256(const uint8_t * passwd, size_t passwdlen, const uint8_t * salt,
size_t saltlen, uint64_t c, uint8_t * buf, size_t dkLen)
{
uint8_t key[32] = {0};
size_t i;
uint8_t salt_and_ivec[saltlen + 4];
uint8_t U[32];
uint8_t T[32];
uint64_t j;
int k;
size_t clen;
if (passwdlen > 32) {
/* For some reason libsodium allows 64byte keys meaning keys
* between 32byte and 64bytes are not compatible with libsodium.
toxencryptsave should only give 32byte passwds so this isn't an issue here.*/
crypto_hash_sha256(key, passwd, passwdlen);
} else {
memcpy(key, passwd, passwdlen);
}
memcpy(salt_and_ivec, salt, saltlen);
for (i = 0; i * 32 < dkLen; i++) {
be32enc(salt_and_ivec + saltlen, (uint32_t)(i + 1));
crypto_auth_hmacsha256(U, salt_and_ivec, sizeof(salt_and_ivec), key);
memcpy(T, U, 32);
for (j = 2; j <= c; j++) {
crypto_auth_hmacsha256(U, U, 32, key);
for (k = 0; k < 32; k++) {
T[k] ^= U[k];
}
}
clen = dkLen - i * 32;
if (clen > 32) {
clen = 32;
}
memcpy(&buf[i * 32], T, clen);
}
crypto_memzero((void *) key, sizeof(key));
}
#endif