text: /*
   * MD5 hash implementation and interface functions
   * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
   *
   * This software may be distributed under the terms of the BSD license.
   * See README for more details.
   */
  
  #include "includes.h"
  
  #include "common.h"
  #include "md5.h"
  #include "crypto.h"
  
  #if !CFG_USE_MBEDTLS
  
  /**
   * hmac_md5_vector - HMAC-MD5 over data vector (RFC 2104)
   * @key: Key for HMAC operations
   * @key_len: Length of the key in bytes
   * @num_elem: Number of elements in the data vector
   * @addr: Pointers to the data areas
   * @len: Lengths of the data blocks
   * @mac: Buffer for the hash (16 bytes)
   * Returns: 0 on success, -1 on failure
   */
  int hmac_md5_vector(const u8 *key, size_t key_len, size_t num_elem,
  		    const u8 *addr[], const size_t *len, u8 *mac)
  {
  	u8 k_pad[64]; /* padding - key XORd with ipad/opad */
  	u8 tk[16];
  	const u8 *_addr[6];
  	size_t i, _len[6];
  	int res;
  
  	if (num_elem > 5) {
  		/*
  		 * Fixed limit on the number of fragments to avoid having to
  		 * allocate memory (which could fail).
  		 */
  		return -1;
  	}
  
          /* if key is longer than 64 bytes reset it to key = MD5(key) */
          if (key_len > 64) {
  		if (md5_vector(1, &key, &key_len, tk))
  			return -1;
  		key = tk;
  		key_len = 16;
          }
  
  	/* the HMAC_MD5 transform looks like:
  	 *
  	 * MD5(K XOR opad, MD5(K XOR ipad, text))
  	 *
  	 * where K is an n byte key
  	 * ipad is the byte 0x36 repeated 64 times
  	 * opad is the byte 0x5c repeated 64 times
  	 * and text is the data being protected */
  
  	/* start out by storing key in ipad */
  	os_memset(k_pad, 0, sizeof(k_pad));
  	os_memcpy(k_pad, key, key_len);
  
  	/* XOR key with ipad values */
  	for (i = 0; i < 64; i++)
  		k_pad[i] ^= 0x36;
  
  	/* perform inner MD5 */
  	_addr[0] = k_pad;
  	_len[0] = 64;
  	for (i = 0; i < num_elem; i++) {
  		_addr[i + 1] = addr[i];
  		_len[i + 1] = len[i];
  	}
  	if (md5_vector(1 + num_elem, _addr, _len, mac))
  		return -1;
  
  	os_memset(k_pad, 0, sizeof(k_pad));
  	os_memcpy(k_pad, key, key_len);
  	/* XOR key with opad values */
  	for (i = 0; i < 64; i++)
  		k_pad[i] ^= 0x5c;
  
  	/* perform outer MD5 */
  	_addr[0] = k_pad;
  	_len[0] = 64;
  	_addr[1] = mac;
  	_len[1] = MD5_MAC_LEN;
  	res = md5_vector(2, _addr, _len, mac);
  	os_memset(k_pad, 0, sizeof(k_pad));
  	os_memset(tk, 0, sizeof(tk));
  	return res;
  }
  
  
  /**
   * hmac_md5 - HMAC-MD5 over data buffer (RFC 2104)
   * @key: Key for HMAC operations
   * @key_len: Length of the key in bytes
   * @data: Pointers to the data area
   * @data_len: Length of the data area
   * @mac: Buffer for the hash (16 bytes)
   * Returns: 0 on success, -1 on failure
   */
  int hmac_md5(const u8 *key, size_t key_len, const u8 *data, size_t data_len,
  	      u8 *mac)
  {
  	return hmac_md5_vector(key, key_len, 1, &data, &data_len, mac);
  }
  #endif
  