workbench/network/WirelessManager/src/crypto/sha1.c

   1 /*
   2  * SHA1 hash implementation and interface functions
   3  * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Alternatively, this software may be distributed under the terms of BSD
  10  * license.
  11  *
  12  * See README and COPYING for more details.
  13  */
  14
  15 #include "includes.h"
  16
  17 #include "common.h"
  18 #include "sha1.h"
  19 #include "crypto.h"
  20
  21
  22 /**
  23  * hmac_sha1_vector - HMAC-SHA1 over data vector (RFC 2104)
  24  * @key: Key for HMAC operations
  25  * @key_len: Length of the key in bytes
  26  * @num_elem: Number of elements in the data vector
  27  * @addr: Pointers to the data areas
  28  * @len: Lengths of the data blocks
  29  * @mac: Buffer for the hash (20 bytes)
  30  * Returns: 0 on success, -1 on failure
  31  */
  32 int hmac_sha1_vector(const u8 *key, size_t key_len, size_t num_elem,
  33                      const u8 *addr[], const size_t *len, u8 *mac)
  34 {
  35         unsigned char k_pad[64]; /* padding - key XORd with ipad/opad */
  36         unsigned char tk[20];
  37         const u8 *_addr[6];
  38         size_t _len[6], i;
  39
  40         if (num_elem > 5) {
  41                 /*
  42                  * Fixed limit on the number of fragments to avoid having to
  43                  * allocate memory (which could fail).
  44                  */
  45                 return -1;
  46         }
  47
  48         /* if key is longer than 64 bytes reset it to key = SHA1(key) */
  49         if (key_len > 64) {
  50                 if (sha1_vector(1, &key, &key_len, tk))
  51                         return -1;
  52                 key = tk;
  53                 key_len = 20;
  54         }
  55
  56         /* the HMAC_SHA1 transform looks like:
  57          *
  58          * SHA1(K XOR opad, SHA1(K XOR ipad, text))
  59          *
  60          * where K is an n byte key
  61          * ipad is the byte 0x36 repeated 64 times
  62          * opad is the byte 0x5c repeated 64 times
  63          * and text is the data being protected */
  64
  65         /* start out by storing key in ipad */
  66         os_memset(k_pad, 0, sizeof(k_pad));
  67         os_memcpy(k_pad, key, key_len);
  68         /* XOR key with ipad values */
  69         for (i = 0; i < 64; i++)
  70                 k_pad[i] ^= 0x36;
  71
  72         /* perform inner SHA1 */
  73         _addr[0] = k_pad;
  74         _len[0] = 64;
  75         for (i = 0; i < num_elem; i++) {
  76                 _addr[i + 1] = addr[i];
  77                 _len[i + 1] = len[i];
  78         }
  79         if (sha1_vector(1 + num_elem, _addr, _len, mac))
  80                 return -1;
  81
  82         os_memset(k_pad, 0, sizeof(k_pad));
  83         os_memcpy(k_pad, key, key_len);
  84         /* XOR key with opad values */
  85         for (i = 0; i < 64; i++)
  86                 k_pad[i] ^= 0x5c;
  87
  88         /* perform outer SHA1 */
  89         _addr[0] = k_pad;
  90         _len[0] = 64;
  91         _addr[1] = mac;
  92         _len[1] = SHA1_MAC_LEN;
  93         return sha1_vector(2, _addr, _len, mac);
  94 }
  95
  96
  97 /**
  98  * hmac_sha1 - HMAC-SHA1 over data buffer (RFC 2104)
  99  * @key: Key for HMAC operations
 100  * @key_len: Length of the key in bytes
 101  * @data: Pointers to the data area
 102  * @data_len: Length of the data area
 103  * @mac: Buffer for the hash (20 bytes)
 104  * Returns: 0 on success, -1 of failure
 105  */
 106 int hmac_sha1(const u8 *key, size_t key_len, const u8 *data, size_t data_len,
 107                u8 *mac)
 108 {
 109         return hmac_sha1_vector(key, key_len, 1, &data, &data_len, mac);
 110 }
 111
 112
 113 /**
 114  * sha1_prf - SHA1-based Pseudo-Random Function (PRF) (IEEE 802.11i, 8.5.1.1)
 115  * @key: Key for PRF
 116  * @key_len: Length of the key in bytes
 117  * @label: A unique label for each purpose of the PRF
 118  * @data: Extra data to bind into the key
 119  * @data_len: Length of the data
 120  * @buf: Buffer for the generated pseudo-random key
 121  * @buf_len: Number of bytes of key to generate
 122  * Returns: 0 on success, -1 of failure
 123  *
 124  * This function is used to derive new, cryptographically separate keys from a
 125  * given key (e.g., PMK in IEEE 802.11i).
 126  */
 127 int sha1_prf(const u8 *key, size_t key_len, const char *label,
 128              const u8 *data, size_t data_len, u8 *buf, size_t buf_len)
 129 {
 130         u8 counter = 0;
 131         size_t pos, plen;
 132         u8 hash[SHA1_MAC_LEN];
 133         size_t label_len = os_strlen(label) + 1;
 134         const unsigned char *addr[3];
 135         size_t len[3];
 136
 137         addr[0] = (u8 *) label;
 138         len[0] = label_len;
 139         addr[1] = data;
 140         len[1] = data_len;
 141         addr[2] = &counter;
 142         len[2] = 1;
 143
 144         pos = 0;
 145         while (pos < buf_len) {
 146                 plen = buf_len - pos;
 147                 if (plen >= SHA1_MAC_LEN) {
 148                         if (hmac_sha1_vector(key, key_len, 3, addr, len,
 149                                              &buf[pos]))
 150                                 return -1;
 151                         pos += SHA1_MAC_LEN;
 152                 } else {
 153                         if (hmac_sha1_vector(key, key_len, 3, addr, len,
 154                                              hash))
 155                                 return -1;
 156                         os_memcpy(&buf[pos], hash, plen);
 157                         break;
 158                 }
 159                 counter++;
 160         }
 161
 162         return 0;
 163 }