mirror of
https://github.com/vanhoefm/fragattacks.git
synced 2024-11-26 17:28:29 -05:00
d6150094e0
This makes it easier to conditionally build in SHA1 functions based on which TLS/crypto library is used. Signed-hostap: Jouni Malinen <j@w1.fi>
105 lines
2.6 KiB
C
105 lines
2.6 KiB
C
/*
|
|
* SHA1 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 "sha1.h"
|
|
#include "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);
|
|
}
|