Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 1 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| 2 | * All rights reserved. |
| 3 | * |
| 4 | * This package is an SSL implementation written |
| 5 | * by Eric Young (eay@cryptsoft.com). |
| 6 | * The implementation was written so as to conform with Netscapes SSL. |
| 7 | * |
| 8 | * This library is free for commercial and non-commercial use as long as |
| 9 | * the following conditions are aheared to. The following conditions |
| 10 | * apply to all code found in this distribution, be it the RC4, RSA, |
| 11 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| 12 | * included with this distribution is covered by the same copyright terms |
| 13 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| 14 | * |
| 15 | * Copyright remains Eric Young's, and as such any Copyright notices in |
| 16 | * the code are not to be removed. |
| 17 | * If this package is used in a product, Eric Young should be given attribution |
| 18 | * as the author of the parts of the library used. |
| 19 | * This can be in the form of a textual message at program startup or |
| 20 | * in documentation (online or textual) provided with the package. |
| 21 | * |
| 22 | * Redistribution and use in source and binary forms, with or without |
| 23 | * modification, are permitted provided that the following conditions |
| 24 | * are met: |
| 25 | * 1. Redistributions of source code must retain the copyright |
| 26 | * notice, this list of conditions and the following disclaimer. |
| 27 | * 2. Redistributions in binary form must reproduce the above copyright |
| 28 | * notice, this list of conditions and the following disclaimer in the |
| 29 | * documentation and/or other materials provided with the distribution. |
| 30 | * 3. All advertising materials mentioning features or use of this software |
| 31 | * must display the following acknowledgement: |
| 32 | * "This product includes cryptographic software written by |
| 33 | * Eric Young (eay@cryptsoft.com)" |
| 34 | * The word 'cryptographic' can be left out if the rouines from the library |
| 35 | * being used are not cryptographic related :-). |
| 36 | * 4. If you include any Windows specific code (or a derivative thereof) from |
| 37 | * the apps directory (application code) you must include an acknowledgement: |
| 38 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| 39 | * |
| 40 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| 41 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 43 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 44 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 45 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 46 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 47 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 48 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 49 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 50 | * SUCH DAMAGE. |
| 51 | * |
| 52 | * The licence and distribution terms for any publically available version or |
| 53 | * derivative of this code cannot be changed. i.e. this code cannot simply be |
| 54 | * copied and put under another distribution licence |
| 55 | * [including the GNU Public Licence.] */ |
| 56 | |
| 57 | #include <openssl/cipher.h> |
| 58 | |
| 59 | #include <assert.h> |
| 60 | |
| 61 | #include <openssl/digest.h> |
| 62 | #include <openssl/mem.h> |
| 63 | |
| 64 | #include "internal.h" |
| 65 | |
| 66 | |
| 67 | #define PKCS5_SALT_LEN 8 |
| 68 | |
| 69 | int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md, |
| 70 | const uint8_t *salt, const uint8_t *data, size_t data_len, |
| 71 | unsigned count, uint8_t *key, uint8_t *iv) { |
| 72 | EVP_MD_CTX c; |
| 73 | uint8_t md_buf[EVP_MAX_MD_SIZE]; |
| 74 | unsigned niv, nkey, addmd = 0; |
| 75 | unsigned mds = 0, i; |
| 76 | int rv = 0; |
| 77 | |
| 78 | nkey = type->key_len; |
| 79 | niv = type->iv_len; |
| 80 | |
| 81 | assert(nkey <= EVP_MAX_KEY_LENGTH); |
| 82 | assert(niv <= EVP_MAX_IV_LENGTH); |
| 83 | |
| 84 | if (data == NULL) { |
| 85 | return nkey; |
| 86 | } |
| 87 | |
| 88 | EVP_MD_CTX_init(&c); |
| 89 | for (;;) { |
| 90 | if (!EVP_DigestInit_ex(&c, md, NULL)) { |
| 91 | return 0; |
| 92 | } |
| 93 | if (addmd++) { |
| 94 | if (!EVP_DigestUpdate(&c, md_buf, mds)) { |
| 95 | goto err; |
| 96 | } |
| 97 | } |
| 98 | if (!EVP_DigestUpdate(&c, data, data_len)) { |
| 99 | goto err; |
| 100 | } |
| 101 | if (salt != NULL) { |
| 102 | if (!EVP_DigestUpdate(&c, salt, PKCS5_SALT_LEN)) { |
| 103 | goto err; |
| 104 | } |
| 105 | } |
| 106 | if (!EVP_DigestFinal_ex(&c, md_buf, &mds)) { |
| 107 | goto err; |
| 108 | } |
| 109 | |
| 110 | for (i = 1; i < count; i++) { |
| 111 | if (!EVP_DigestInit_ex(&c, md, NULL) || |
| 112 | !EVP_DigestUpdate(&c, md_buf, mds) || |
| 113 | !EVP_DigestFinal_ex(&c, md_buf, &mds)) { |
| 114 | goto err; |
| 115 | } |
| 116 | } |
| 117 | |
| 118 | i = 0; |
| 119 | if (nkey) { |
| 120 | for (;;) { |
| 121 | if (nkey == 0 || i == mds) { |
| 122 | break; |
| 123 | } |
| 124 | if (key != NULL) { |
| 125 | *(key++) = md_buf[i]; |
| 126 | } |
| 127 | nkey--; |
| 128 | i++; |
| 129 | } |
| 130 | } |
| 131 | |
| 132 | if (niv && i != mds) { |
| 133 | for (;;) { |
| 134 | if (niv == 0 || i == mds) { |
| 135 | break; |
| 136 | } |
| 137 | if (iv != NULL) { |
| 138 | *(iv++) = md_buf[i]; |
| 139 | } |
| 140 | niv--; |
| 141 | i++; |
| 142 | } |
| 143 | } |
| 144 | if (nkey == 0 && niv == 0) { |
| 145 | break; |
| 146 | } |
| 147 | } |
| 148 | rv = type->key_len; |
| 149 | |
| 150 | err: |
| 151 | EVP_MD_CTX_cleanup(&c); |
| 152 | OPENSSL_cleanse(md_buf, EVP_MAX_MD_SIZE); |
| 153 | return rv; |
| 154 | } |