ref: 2bbc75bddc6f2a07056ff017108e35f14061041b
dir: /third_party/boringssl/src/crypto/fipsmodule/tls/kdf.c/
/* ====================================================================
* Copyright (c) 1998-2007 The OpenSSL Project. 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.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* openssl-core@openssl.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED 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 OpenSSL PROJECT OR
* ITS 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.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#include <assert.h>
#include <openssl/digest.h>
#include <openssl/hmac.h>
#include <openssl/mem.h>
#include "internal.h"
#include "../../internal.h"
// tls1_P_hash computes the TLS P_<hash> function as described in RFC 5246,
// section 5. It XORs |out_len| bytes to |out|, using |md| as the hash and
// |secret| as the secret. |label|, |seed1|, and |seed2| are concatenated to
// form the seed parameter. It returns true on success and false on failure.
static int tls1_P_hash(uint8_t *out, size_t out_len,
const EVP_MD *md,
const uint8_t *secret, size_t secret_len,
const char *label, size_t label_len,
const uint8_t *seed1, size_t seed1_len,
const uint8_t *seed2, size_t seed2_len) {
HMAC_CTX ctx, ctx_tmp, ctx_init;
uint8_t A1[EVP_MAX_MD_SIZE];
unsigned A1_len;
int ret = 0;
const size_t chunk = EVP_MD_size(md);
HMAC_CTX_init(&ctx);
HMAC_CTX_init(&ctx_tmp);
HMAC_CTX_init(&ctx_init);
if (!HMAC_Init_ex(&ctx_init, secret, secret_len, md, NULL) ||
!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
!HMAC_Update(&ctx, (const uint8_t *) label, label_len) ||
!HMAC_Update(&ctx, seed1, seed1_len) ||
!HMAC_Update(&ctx, seed2, seed2_len) ||
!HMAC_Final(&ctx, A1, &A1_len)) {
goto err;
}
for (;;) {
unsigned len;
uint8_t hmac[EVP_MAX_MD_SIZE];
if (!HMAC_CTX_copy_ex(&ctx, &ctx_init) ||
!HMAC_Update(&ctx, A1, A1_len) ||
// Save a copy of |ctx| to compute the next A1 value below.
(out_len > chunk && !HMAC_CTX_copy_ex(&ctx_tmp, &ctx)) ||
!HMAC_Update(&ctx, (const uint8_t *) label, label_len) ||
!HMAC_Update(&ctx, seed1, seed1_len) ||
!HMAC_Update(&ctx, seed2, seed2_len) ||
!HMAC_Final(&ctx, hmac, &len)) {
goto err;
}
assert(len == chunk);
// XOR the result into |out|.
if (len > out_len) {
len = out_len;
}
for (unsigned i = 0; i < len; i++) {
out[i] ^= hmac[i];
}
out += len;
out_len -= len;
if (out_len == 0) {
break;
}
// Calculate the next A1 value.
if (!HMAC_Final(&ctx_tmp, A1, &A1_len)) {
goto err;
}
}
ret = 1;
err:
OPENSSL_cleanse(A1, sizeof(A1));
HMAC_CTX_cleanup(&ctx);
HMAC_CTX_cleanup(&ctx_tmp);
HMAC_CTX_cleanup(&ctx_init);
return ret;
}
int CRYPTO_tls1_prf(const EVP_MD *digest,
uint8_t *out, size_t out_len,
const uint8_t *secret, size_t secret_len,
const char *label, size_t label_len,
const uint8_t *seed1, size_t seed1_len,
const uint8_t *seed2, size_t seed2_len) {
if (out_len == 0) {
return 1;
}
OPENSSL_memset(out, 0, out_len);
if (digest == EVP_md5_sha1()) {
// If using the MD5/SHA1 PRF, |secret| is partitioned between MD5 and SHA-1.
size_t secret_half = secret_len - (secret_len / 2);
if (!tls1_P_hash(out, out_len, EVP_md5(), secret, secret_half, label,
label_len, seed1, seed1_len, seed2, seed2_len)) {
return 0;
}
// Note that, if |secret_len| is odd, the two halves share a byte.
secret += secret_len - secret_half;
secret_len = secret_half;
digest = EVP_sha1();
}
return tls1_P_hash(out, out_len, digest, secret, secret_len, label, label_len,
seed1, seed1_len, seed2, seed2_len);
}