]>
Commit | Line | Data |
---|---|---|
6fc6879b JM |
1 | /* |
2 | * MD5 hash implementation and interface functions | |
3 | * Copyright (c) 2003-2005, Jouni Malinen <j@w1.fi> | |
4 | * | |
0f3d578e JM |
5 | * This software may be distributed under the terms of the BSD license. |
6 | * See README for more details. | |
6fc6879b JM |
7 | */ |
8 | ||
9 | #include "includes.h" | |
10 | ||
11 | #include "common.h" | |
12 | #include "md5.h" | |
13 | #include "crypto.h" | |
14 | ||
15 | ||
16 | /** | |
17 | * hmac_md5_vector - HMAC-MD5 over data vector (RFC 2104) | |
18 | * @key: Key for HMAC operations | |
19 | * @key_len: Length of the key in bytes | |
20 | * @num_elem: Number of elements in the data vector | |
21 | * @addr: Pointers to the data areas | |
22 | * @len: Lengths of the data blocks | |
23 | * @mac: Buffer for the hash (16 bytes) | |
0a5d68ab | 24 | * Returns: 0 on success, -1 on failure |
6fc6879b | 25 | */ |
0a5d68ab JM |
26 | int hmac_md5_vector(const u8 *key, size_t key_len, size_t num_elem, |
27 | const u8 *addr[], const size_t *len, u8 *mac) | |
6fc6879b JM |
28 | { |
29 | u8 k_pad[64]; /* padding - key XORd with ipad/opad */ | |
30 | u8 tk[16]; | |
31 | const u8 *_addr[6]; | |
32 | size_t i, _len[6]; | |
51f34270 | 33 | int res; |
6fc6879b JM |
34 | |
35 | if (num_elem > 5) { | |
36 | /* | |
37 | * Fixed limit on the number of fragments to avoid having to | |
38 | * allocate memory (which could fail). | |
39 | */ | |
0a5d68ab | 40 | return -1; |
6fc6879b JM |
41 | } |
42 | ||
43 | /* if key is longer than 64 bytes reset it to key = MD5(key) */ | |
44 | if (key_len > 64) { | |
0a5d68ab JM |
45 | if (md5_vector(1, &key, &key_len, tk)) |
46 | return -1; | |
6fc6879b JM |
47 | key = tk; |
48 | key_len = 16; | |
49 | } | |
50 | ||
51 | /* the HMAC_MD5 transform looks like: | |
52 | * | |
53 | * MD5(K XOR opad, MD5(K XOR ipad, text)) | |
54 | * | |
55 | * where K is an n byte key | |
56 | * ipad is the byte 0x36 repeated 64 times | |
57 | * opad is the byte 0x5c repeated 64 times | |
58 | * and text is the data being protected */ | |
59 | ||
60 | /* start out by storing key in ipad */ | |
61 | os_memset(k_pad, 0, sizeof(k_pad)); | |
62 | os_memcpy(k_pad, key, key_len); | |
63 | ||
64 | /* XOR key with ipad values */ | |
65 | for (i = 0; i < 64; i++) | |
66 | k_pad[i] ^= 0x36; | |
67 | ||
68 | /* perform inner MD5 */ | |
69 | _addr[0] = k_pad; | |
70 | _len[0] = 64; | |
71 | for (i = 0; i < num_elem; i++) { | |
72 | _addr[i + 1] = addr[i]; | |
73 | _len[i + 1] = len[i]; | |
74 | } | |
0a5d68ab JM |
75 | if (md5_vector(1 + num_elem, _addr, _len, mac)) |
76 | return -1; | |
6fc6879b JM |
77 | |
78 | os_memset(k_pad, 0, sizeof(k_pad)); | |
79 | os_memcpy(k_pad, key, key_len); | |
80 | /* XOR key with opad values */ | |
81 | for (i = 0; i < 64; i++) | |
82 | k_pad[i] ^= 0x5c; | |
83 | ||
84 | /* perform outer MD5 */ | |
85 | _addr[0] = k_pad; | |
86 | _len[0] = 64; | |
87 | _addr[1] = mac; | |
88 | _len[1] = MD5_MAC_LEN; | |
51f34270 JM |
89 | res = md5_vector(2, _addr, _len, mac); |
90 | os_memset(k_pad, 0, sizeof(k_pad)); | |
91 | os_memset(tk, 0, sizeof(tk)); | |
92 | return res; | |
6fc6879b JM |
93 | } |
94 | ||
95 | ||
96 | /** | |
97 | * hmac_md5 - HMAC-MD5 over data buffer (RFC 2104) | |
98 | * @key: Key for HMAC operations | |
99 | * @key_len: Length of the key in bytes | |
100 | * @data: Pointers to the data area | |
101 | * @data_len: Length of the data area | |
102 | * @mac: Buffer for the hash (16 bytes) | |
0a5d68ab | 103 | * Returns: 0 on success, -1 on failure |
6fc6879b | 104 | */ |
0a5d68ab | 105 | int hmac_md5(const u8 *key, size_t key_len, const u8 *data, size_t data_len, |
6fc6879b JM |
106 | u8 *mac) |
107 | { | |
0a5d68ab | 108 | return hmac_md5_vector(key, key_len, 1, &data, &data_len, mac); |
6fc6879b | 109 | } |