1 /* Written by Dr Stephen N Henson (steve (at) openssl.org) for the OpenSSL 2 * project 1999. 3 */ 4 /* ==================================================================== 5 * Copyright (c) 1999 The OpenSSL Project. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in 16 * the documentation and/or other materials provided with the 17 * distribution. 18 * 19 * 3. All advertising materials mentioning features or use of this 20 * software must display the following acknowledgment: 21 * "This product includes software developed by the OpenSSL Project 22 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" 23 * 24 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 25 * endorse or promote products derived from this software without 26 * prior written permission. For written permission, please contact 27 * licensing (at) OpenSSL.org. 28 * 29 * 5. Products derived from this software may not be called "OpenSSL" 30 * nor may "OpenSSL" appear in their names without prior written 31 * permission of the OpenSSL Project. 32 * 33 * 6. Redistributions of any form whatsoever must retain the following 34 * acknowledgment: 35 * "This product includes software developed by the OpenSSL Project 36 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" 37 * 38 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 39 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 41 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 42 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 43 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 44 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 45 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 46 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 47 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 48 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 49 * OF THE POSSIBILITY OF SUCH DAMAGE. 50 * ==================================================================== 51 * 52 * This product includes cryptographic software written by Eric Young 53 * (eay (at) cryptsoft.com). This product includes software written by Tim 54 * Hudson (tjh (at) cryptsoft.com). */ 55 56 #include <openssl/evp.h> 57 58 #include <string.h> 59 60 #include <openssl/hmac.h> 61 62 63 int PKCS5_PBKDF2_HMAC(const char *password, size_t password_len, 64 const uint8_t *salt, size_t salt_len, unsigned iterations, 65 const EVP_MD *digest, size_t key_len, uint8_t *out_key) { 66 uint8_t digest_tmp[EVP_MAX_MD_SIZE], *p, itmp[4]; 67 size_t cplen, mdlen, tkeylen, k; 68 unsigned j; 69 uint32_t i = 1; 70 HMAC_CTX hctx_tpl, hctx; 71 72 mdlen = EVP_MD_size(digest); 73 HMAC_CTX_init(&hctx_tpl); 74 p = out_key; 75 tkeylen = key_len; 76 if (!HMAC_Init_ex(&hctx_tpl, password, password_len, digest, NULL)) { 77 HMAC_CTX_cleanup(&hctx_tpl); 78 return 0; 79 } 80 while (tkeylen) { 81 if (tkeylen > mdlen) { 82 cplen = mdlen; 83 } else { 84 cplen = tkeylen; 85 } 86 /* We are unlikely to ever use more than 256 blocks (5120 bits!) 87 * but just in case... */ 88 itmp[0] = (uint8_t)((i >> 24) & 0xff); 89 itmp[1] = (uint8_t)((i >> 16) & 0xff); 90 itmp[2] = (uint8_t)((i >> 8) & 0xff); 91 itmp[3] = (uint8_t)(i & 0xff); 92 if (!HMAC_CTX_copy(&hctx, &hctx_tpl)) { 93 HMAC_CTX_cleanup(&hctx_tpl); 94 return 0; 95 } 96 if (!HMAC_Update(&hctx, salt, salt_len) || 97 !HMAC_Update(&hctx, itmp, 4) || 98 !HMAC_Final(&hctx, digest_tmp, NULL)) { 99 HMAC_CTX_cleanup(&hctx_tpl); 100 HMAC_CTX_cleanup(&hctx); 101 return 0; 102 } 103 HMAC_CTX_cleanup(&hctx); 104 memcpy(p, digest_tmp, cplen); 105 for (j = 1; j < iterations; j++) { 106 if (!HMAC_CTX_copy(&hctx, &hctx_tpl)) { 107 HMAC_CTX_cleanup(&hctx_tpl); 108 return 0; 109 } 110 if (!HMAC_Update(&hctx, digest_tmp, mdlen) || 111 !HMAC_Final(&hctx, digest_tmp, NULL)) { 112 HMAC_CTX_cleanup(&hctx_tpl); 113 HMAC_CTX_cleanup(&hctx); 114 return 0; 115 } 116 HMAC_CTX_cleanup(&hctx); 117 for (k = 0; k < cplen; k++) { 118 p[k] ^= digest_tmp[k]; 119 } 120 } 121 tkeylen -= cplen; 122 i++; 123 p += cplen; 124 } 125 HMAC_CTX_cleanup(&hctx_tpl); 126 127 // RFC 2898 describes iterations (c) as being a "positive integer", so a 128 // value of 0 is an error. 129 // 130 // Unfortunatley not all consumers of PKCS5_PBKDF2_HMAC() check their return 131 // value, expecting it to succeed and unconditonally using |out_key|. 132 // As a precaution for such callsites in external code, the old behavior 133 // of iterations < 1 being treated as iterations == 1 is preserved, but 134 // additionally an error result is returned. 135 // 136 // TODO(eroman): Figure out how to remove this compatibility hack, or change 137 // the default to something more sensible like 2048. 138 if (iterations == 0) { 139 return 0; 140 } 141 142 return 1; 143 } 144 145 int PKCS5_PBKDF2_HMAC_SHA1(const char *password, size_t password_len, 146 const uint8_t *salt, size_t salt_len, 147 unsigned iterations, size_t key_len, 148 uint8_t *out_key) { 149 return PKCS5_PBKDF2_HMAC(password, password_len, salt, salt_len, iterations, 150 EVP_sha1(), key_len, out_key); 151 } 152
