Disconnect hostapd from building in base
[dragonfly.git] / contrib / hostapd / src / crypto / sha256.c
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1/*
2 * SHA-256 hash implementation and interface functions
4781064b 3 * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
ebfa2275 4 *
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5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
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7 */
8
9#include "includes.h"
10
11#include "common.h"
12#include "sha256.h"
13#include "crypto.h"
14
15
16/**
17 * hmac_sha256_vector - HMAC-SHA256 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 (32 bytes)
4781064b 24 * Returns: 0 on success, -1 on failure
ebfa2275 25 */
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26int hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
27 const u8 *addr[], const size_t *len, u8 *mac)
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28{
29 unsigned char k_pad[64]; /* padding - key XORd with ipad/opad */
30 unsigned char tk[32];
31 const u8 *_addr[6];
32 size_t _len[6], i;
33
34 if (num_elem > 5) {
35 /*
36 * Fixed limit on the number of fragments to avoid having to
37 * allocate memory (which could fail).
38 */
4781064b 39 return -1;
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40 }
41
42 /* if key is longer than 64 bytes reset it to key = SHA256(key) */
43 if (key_len > 64) {
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44 if (sha256_vector(1, &key, &key_len, tk) < 0)
45 return -1;
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46 key = tk;
47 key_len = 32;
48 }
49
50 /* the HMAC_SHA256 transform looks like:
51 *
52 * SHA256(K XOR opad, SHA256(K XOR ipad, text))
53 *
54 * where K is an n byte key
55 * ipad is the byte 0x36 repeated 64 times
56 * opad is the byte 0x5c repeated 64 times
57 * and text is the data being protected */
58
59 /* start out by storing key in ipad */
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60 os_memset(k_pad, 0, sizeof(k_pad));
61 os_memcpy(k_pad, key, key_len);
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62 /* XOR key with ipad values */
63 for (i = 0; i < 64; i++)
64 k_pad[i] ^= 0x36;
65
66 /* perform inner SHA256 */
67 _addr[0] = k_pad;
68 _len[0] = 64;
69 for (i = 0; i < num_elem; i++) {
70 _addr[i + 1] = addr[i];
71 _len[i + 1] = len[i];
72 }
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73 if (sha256_vector(1 + num_elem, _addr, _len, mac) < 0)
74 return -1;
ebfa2275 75
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76 os_memset(k_pad, 0, sizeof(k_pad));
77 os_memcpy(k_pad, key, key_len);
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78 /* XOR key with opad values */
79 for (i = 0; i < 64; i++)
80 k_pad[i] ^= 0x5c;
81
82 /* perform outer SHA256 */
83 _addr[0] = k_pad;
84 _len[0] = 64;
85 _addr[1] = mac;
86 _len[1] = SHA256_MAC_LEN;
4781064b 87 return sha256_vector(2, _addr, _len, mac);
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88}
89
90
91/**
92 * hmac_sha256 - HMAC-SHA256 over data buffer (RFC 2104)
93 * @key: Key for HMAC operations
94 * @key_len: Length of the key in bytes
95 * @data: Pointers to the data area
96 * @data_len: Length of the data area
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97 * @mac: Buffer for the hash (32 bytes)
98 * Returns: 0 on success, -1 on failure
ebfa2275 99 */
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100int hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
101 size_t data_len, u8 *mac)
ebfa2275 102{
4781064b 103 return hmac_sha256_vector(key, key_len, 1, &data, &data_len, mac);
ebfa2275 104}