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- /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
- * project 1999.
- */
- /* ====================================================================
- * Copyright (c) 1999 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
- * licensing@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 <openssl/evp.h>
-
- #include <string.h>
-
- #include <openssl/hmac.h>
-
- #include "../internal.h"
-
-
- int PKCS5_PBKDF2_HMAC(const char *password, size_t password_len,
- const uint8_t *salt, size_t salt_len, unsigned iterations,
- const EVP_MD *digest, size_t key_len, uint8_t *out_key) {
- /* See RFC 8018, section 5.2. */
- int ret = 0;
- size_t md_len = EVP_MD_size(digest);
- uint32_t i = 1;
- HMAC_CTX hctx;
- HMAC_CTX_init(&hctx);
-
- if (!HMAC_Init_ex(&hctx, password, password_len, digest, NULL)) {
- goto err;
- }
-
- while (key_len > 0) {
- size_t todo = md_len;
- if (todo > key_len) {
- todo = key_len;
- }
-
- uint8_t i_buf[4];
- i_buf[0] = (uint8_t)((i >> 24) & 0xff);
- i_buf[1] = (uint8_t)((i >> 16) & 0xff);
- i_buf[2] = (uint8_t)((i >> 8) & 0xff);
- i_buf[3] = (uint8_t)(i & 0xff);
-
- /* Compute U_1. */
- uint8_t digest_tmp[EVP_MAX_MD_SIZE];
- if (!HMAC_Init_ex(&hctx, NULL, 0, NULL, NULL) ||
- !HMAC_Update(&hctx, salt, salt_len) ||
- !HMAC_Update(&hctx, i_buf, 4) ||
- !HMAC_Final(&hctx, digest_tmp, NULL)) {
- goto err;
- }
-
- OPENSSL_memcpy(out_key, digest_tmp, todo);
- for (unsigned j = 1; j < iterations; j++) {
- /* Compute the remaining U_* values and XOR. */
- if (!HMAC_Init_ex(&hctx, NULL, 0, NULL, NULL) ||
- !HMAC_Update(&hctx, digest_tmp, md_len) ||
- !HMAC_Final(&hctx, digest_tmp, NULL)) {
- goto err;
- }
- for (size_t k = 0; k < todo; k++) {
- out_key[k] ^= digest_tmp[k];
- }
- }
-
- key_len -= todo;
- out_key += todo;
- i++;
- }
-
- /* RFC 8018 describes iterations (c) as being a "positive integer", so a
- * value of 0 is an error.
- *
- * Unfortunately not all consumers of PKCS5_PBKDF2_HMAC() check their return
- * value, expecting it to succeed and unconditionally using |out_key|. As a
- * precaution for such callsites in external code, the old behavior of
- * iterations < 1 being treated as iterations == 1 is preserved, but
- * additionally an error result is returned.
- *
- * TODO(eroman): Figure out how to remove this compatibility hack, or change
- * the default to something more sensible like 2048. */
- if (iterations == 0) {
- goto err;
- }
-
- ret = 1;
-
- err:
- HMAC_CTX_cleanup(&hctx);
- return ret;
- }
-
- int PKCS5_PBKDF2_HMAC_SHA1(const char *password, size_t password_len,
- const uint8_t *salt, size_t salt_len,
- unsigned iterations, size_t key_len,
- uint8_t *out_key) {
- return PKCS5_PBKDF2_HMAC(password, password_len, salt, salt_len, iterations,
- EVP_sha1(), key_len, out_key);
- }
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