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/* -*- mode:C; c-file-style: "bsd" -*- */
/* Copyright (c) 2008-2013 Yubico AB
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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 COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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 <string.h>
#include <ykpbkdf2.h>
#include "sha.h"
int yk_hmac_sha1(const char *key, size_t key_len,
const char *text, size_t text_len,
uint8_t *output, size_t output_size)
{
if (output_size < SHA1HashSize)
return 0;
if (hmac(SHA1,
(const unsigned char *)text, (int)text_len,
(const unsigned char *)key, (int)key_len,
output))
return 0;
return 1;
}
int yk_pbkdf2(const char *passphrase,
const unsigned char *salt, size_t salt_len,
unsigned int iterations,
unsigned char *dk, size_t dklen,
YK_PRF_METHOD *prf_method)
{
if (salt_len > (255 - 4)) {
return 0;
}
size_t l = ((dklen - 1 + prf_method->output_size)
/ prf_method->output_size);
#if 0 /* r for "rest" is unused but may be interesting in the future */
size_t r = dklen - ((l - 1) * prf_method->output_size);
#endif
unsigned int block_count;
memset(dk, 0, dklen);
for (block_count = 1; block_count <= l; block_count++) {
unsigned char block[256]; /* A big chunk, that's 2048 bits */
size_t block_len;
unsigned int iteration;
size_t i;
memcpy(block, salt, salt_len);
block[salt_len + 0] = (block_count & 0xff000000) >> 24;
block[salt_len + 1] = (block_count & 0x00ff0000) >> 16;
block[salt_len + 2] = (block_count & 0x0000ff00) >> 8;
block[salt_len + 3] = (block_count & 0x000000ff) >> 0;
block_len = salt_len + 4;
for (iteration = 0; iteration < iterations; iteration++) {
if (!prf_method->prf_fn(passphrase, strlen(passphrase),
(char *)block, block_len,
block, sizeof(block)))
return 0;
block_len = prf_method->output_size;
for(i = 0; i < dklen; i++) {
dk[i] ^= block[i];
}
}
if (block_len > dklen)
block_len = dklen; /* This happens in the last block */
dk += block_len;
dklen -= block_len;
}
return 1;
}
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