| /* |
| * dhcpcd - DHCP client daemon |
| * Copyright (c) 2006-2015 Roy Marples <roy@marples.name> |
| * 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. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <inttypes.h> |
| #include <string.h> |
| |
| #include "crypt.h" |
| |
| #include "../config.h" |
| #ifdef HAVE_MD5_H |
| # ifndef DEPGEN |
| # include <md5.h> |
| # endif |
| #else |
| # include "md5.h" |
| #endif |
| |
| #define HMAC_PAD_LEN 64 |
| #define IPAD 0x36 |
| #define OPAD 0x5C |
| |
| /* hmac_md5 as per RFC3118 */ |
| void |
| hmac_md5(const uint8_t *text, size_t text_len, |
| const uint8_t *key, size_t key_len, |
| uint8_t *digest) |
| { |
| uint8_t k_ipad[HMAC_PAD_LEN], k_opad[HMAC_PAD_LEN]; |
| uint8_t tk[MD5_DIGEST_LENGTH]; |
| int i; |
| MD5_CTX context; |
| |
| /* Ensure key is no bigger than HMAC_PAD_LEN */ |
| if (key_len > HMAC_PAD_LEN) { |
| MD5Init(&context); |
| MD5Update(&context, key, (unsigned int)key_len); |
| MD5Final(tk, &context); |
| key = tk; |
| key_len = MD5_DIGEST_LENGTH; |
| } |
| |
| /* store key in pads */ |
| memcpy(k_ipad, key, key_len); |
| memcpy(k_opad, key, key_len); |
| memset(k_ipad + key_len, 0, sizeof(k_ipad) - key_len); |
| memset(k_opad + key_len, 0, sizeof(k_opad) - key_len); |
| |
| /* XOR key with ipad and opad values */ |
| for (i = 0; i < HMAC_PAD_LEN; i++) { |
| k_ipad[i] ^= IPAD; |
| k_opad[i] ^= OPAD; |
| } |
| |
| /* inner MD5 */ |
| MD5Init(&context); |
| MD5Update(&context, k_ipad, HMAC_PAD_LEN); |
| MD5Update(&context, text, (unsigned int)text_len); |
| MD5Final(digest, &context); |
| |
| /* outer MD5 */ |
| MD5Init(&context); |
| MD5Update(&context, k_opad, HMAC_PAD_LEN); |
| MD5Update(&context, digest, MD5_DIGEST_LENGTH); |
| MD5Final(digest, &context); |
| } |