166 lines
4.1 KiB
C
166 lines
4.1 KiB
C
/*
|
|
* SHA1 hash implementation and interface functions
|
|
* Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Alternatively, this software may be distributed under the terms of BSD
|
|
* license.
|
|
*
|
|
* See README and COPYING for more details.
|
|
*/
|
|
|
|
#include "crypto/includes.h"
|
|
|
|
#include "crypto/common.h"
|
|
#include "crypto/sha1.h"
|
|
#include "crypto/crypto.h"
|
|
|
|
|
|
/**
|
|
* hmac_sha1_vector - HMAC-SHA1 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 (20 bytes)
|
|
* Returns: 0 on success, -1 on failure
|
|
*/
|
|
int
|
|
hmac_sha1_vector(const u8 *key, size_t key_len, size_t num_elem,
|
|
const u8 *addr[], const size_t *len, u8 *mac)
|
|
{
|
|
unsigned char k_pad[64]; /* padding - key XORd with ipad/opad */
|
|
unsigned char tk[20];
|
|
const u8 *_addr[6];
|
|
size_t _len[6], i;
|
|
|
|
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 = SHA1(key) */
|
|
if (key_len > 64) {
|
|
if (sha1_vector(1, &key, &key_len, tk))
|
|
return -1;
|
|
key = tk;
|
|
key_len = 20;
|
|
}
|
|
|
|
/* the HMAC_SHA1 transform looks like:
|
|
*
|
|
* SHA1(K XOR opad, SHA1(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 SHA1 */
|
|
_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 (sha1_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 SHA1 */
|
|
_addr[0] = k_pad;
|
|
_len[0] = 64;
|
|
_addr[1] = mac;
|
|
_len[1] = SHA1_MAC_LEN;
|
|
return sha1_vector(2, _addr, _len, mac);
|
|
}
|
|
|
|
|
|
/**
|
|
* hmac_sha1 - HMAC-SHA1 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 (20 bytes)
|
|
* Returns: 0 on success, -1 of failure
|
|
*/
|
|
int
|
|
hmac_sha1(const u8 *key, size_t key_len, const u8 *data, size_t data_len,
|
|
u8 *mac)
|
|
{
|
|
return hmac_sha1_vector(key, key_len, 1, &data, &data_len, mac);
|
|
}
|
|
|
|
/**
|
|
* sha1_prf - SHA1-based Pseudo-Random Function (PRF) (IEEE 802.11i, 8.5.1.1)
|
|
* @key: Key for PRF
|
|
* @key_len: Length of the key in bytes
|
|
* @label: A unique label for each purpose of the PRF
|
|
* @data: Extra data to bind into the key
|
|
* @data_len: Length of the data
|
|
* @buf: Buffer for the generated pseudo-random key
|
|
* @buf_len: Number of bytes of key to generate
|
|
* Returns: 0 on success, -1 of failure
|
|
*
|
|
* This function is used to derive new, cryptographically separate keys from a
|
|
* given key (e.g., PMK in IEEE 802.11i).
|
|
*/
|
|
int
|
|
sha1_prf(const u8 *key, size_t key_len, const char *label,
|
|
const u8 *data, size_t data_len, u8 *buf, size_t buf_len)
|
|
{
|
|
u8 counter = 0;
|
|
size_t pos, plen;
|
|
u8 hash[SHA1_MAC_LEN];
|
|
size_t label_len = os_strlen(label) + 1;
|
|
const unsigned char *addr[3];
|
|
size_t len[3];
|
|
|
|
addr[0] = (u8 *) label;
|
|
len[0] = label_len;
|
|
addr[1] = data;
|
|
len[1] = data_len;
|
|
addr[2] = &counter;
|
|
len[2] = 1;
|
|
|
|
pos = 0;
|
|
while (pos < buf_len) {
|
|
plen = buf_len - pos;
|
|
if (plen >= SHA1_MAC_LEN) {
|
|
if (hmac_sha1_vector(key, key_len, 3, addr, len,
|
|
&buf[pos]))
|
|
return -1;
|
|
pos += SHA1_MAC_LEN;
|
|
} else {
|
|
if (hmac_sha1_vector(key, key_len, 3, addr, len,
|
|
hash))
|
|
return -1;
|
|
os_memcpy(&buf[pos], hash, plen);
|
|
break;
|
|
}
|
|
counter++;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|