1189251Ssam/* 2189251Ssam * MD5 hash implementation and interface functions 3189251Ssam * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> 4189251Ssam * 5189251Ssam * This program is free software; you can redistribute it and/or modify 6189251Ssam * it under the terms of the GNU General Public License version 2 as 7189251Ssam * published by the Free Software Foundation. 8189251Ssam * 9189251Ssam * Alternatively, this software may be distributed under the terms of BSD 10189251Ssam * license. 11189251Ssam * 12189251Ssam * See README and COPYING for more details. 13189251Ssam */ 14189251Ssam 15189251Ssam#include "includes.h" 16189251Ssam 17189251Ssam#include "common.h" 18189251Ssam#include "md5.h" 19189251Ssam#include "crypto.h" 20189251Ssam 21189251Ssam 22189251Ssam/** 23189251Ssam * hmac_md5_vector - HMAC-MD5 over data vector (RFC 2104) 24189251Ssam * @key: Key for HMAC operations 25189251Ssam * @key_len: Length of the key in bytes 26189251Ssam * @num_elem: Number of elements in the data vector 27189251Ssam * @addr: Pointers to the data areas 28189251Ssam * @len: Lengths of the data blocks 29189251Ssam * @mac: Buffer for the hash (16 bytes) 30214734Srpaulo * Returns: 0 on success, -1 on failure 31189251Ssam */ 32214734Srpauloint hmac_md5_vector(const u8 *key, size_t key_len, size_t num_elem, 33214734Srpaulo const u8 *addr[], const size_t *len, u8 *mac) 34189251Ssam{ 35189251Ssam u8 k_pad[64]; /* padding - key XORd with ipad/opad */ 36189251Ssam u8 tk[16]; 37189251Ssam const u8 *_addr[6]; 38189251Ssam size_t i, _len[6]; 39189251Ssam 40189251Ssam if (num_elem > 5) { 41189251Ssam /* 42189251Ssam * Fixed limit on the number of fragments to avoid having to 43189251Ssam * allocate memory (which could fail). 44189251Ssam */ 45214734Srpaulo return -1; 46189251Ssam } 47189251Ssam 48189251Ssam /* if key is longer than 64 bytes reset it to key = MD5(key) */ 49189251Ssam if (key_len > 64) { 50214734Srpaulo if (md5_vector(1, &key, &key_len, tk)) 51214734Srpaulo return -1; 52189251Ssam key = tk; 53189251Ssam key_len = 16; 54189251Ssam } 55189251Ssam 56189251Ssam /* the HMAC_MD5 transform looks like: 57189251Ssam * 58189251Ssam * MD5(K XOR opad, MD5(K XOR ipad, text)) 59189251Ssam * 60189251Ssam * where K is an n byte key 61189251Ssam * ipad is the byte 0x36 repeated 64 times 62189251Ssam * opad is the byte 0x5c repeated 64 times 63189251Ssam * and text is the data being protected */ 64189251Ssam 65189251Ssam /* start out by storing key in ipad */ 66189251Ssam os_memset(k_pad, 0, sizeof(k_pad)); 67189251Ssam os_memcpy(k_pad, key, key_len); 68189251Ssam 69189251Ssam /* XOR key with ipad values */ 70189251Ssam for (i = 0; i < 64; i++) 71189251Ssam k_pad[i] ^= 0x36; 72189251Ssam 73189251Ssam /* perform inner MD5 */ 74189251Ssam _addr[0] = k_pad; 75189251Ssam _len[0] = 64; 76189251Ssam for (i = 0; i < num_elem; i++) { 77189251Ssam _addr[i + 1] = addr[i]; 78189251Ssam _len[i + 1] = len[i]; 79189251Ssam } 80214734Srpaulo if (md5_vector(1 + num_elem, _addr, _len, mac)) 81214734Srpaulo return -1; 82189251Ssam 83189251Ssam os_memset(k_pad, 0, sizeof(k_pad)); 84189251Ssam os_memcpy(k_pad, key, key_len); 85189251Ssam /* XOR key with opad values */ 86189251Ssam for (i = 0; i < 64; i++) 87189251Ssam k_pad[i] ^= 0x5c; 88189251Ssam 89189251Ssam /* perform outer MD5 */ 90189251Ssam _addr[0] = k_pad; 91189251Ssam _len[0] = 64; 92189251Ssam _addr[1] = mac; 93189251Ssam _len[1] = MD5_MAC_LEN; 94214734Srpaulo return md5_vector(2, _addr, _len, mac); 95189251Ssam} 96189251Ssam 97189251Ssam 98189251Ssam/** 99189251Ssam * hmac_md5 - HMAC-MD5 over data buffer (RFC 2104) 100189251Ssam * @key: Key for HMAC operations 101189251Ssam * @key_len: Length of the key in bytes 102189251Ssam * @data: Pointers to the data area 103189251Ssam * @data_len: Length of the data area 104189251Ssam * @mac: Buffer for the hash (16 bytes) 105214734Srpaulo * Returns: 0 on success, -1 on failure 106189251Ssam */ 107214734Srpauloint hmac_md5(const u8 *key, size_t key_len, const u8 *data, size_t data_len, 108189251Ssam u8 *mac) 109189251Ssam{ 110214734Srpaulo return hmac_md5_vector(key, key_len, 1, &data, &data_len, mac); 111189251Ssam} 112