2 * EAP-PEAP common routines
3 * Copyright (c) 2008-2011, Jouni Malinen <j@w1.fi>
5 * This software may be distributed under the terms of the BSD license.
6 * See README for more details.
12 #include "crypto/sha1.h"
13 #include "eap_peap_common.h"
15 int peap_prfplus(int version, const u8 *key, size_t key_len,
16 const char *label, const u8 *seed, size_t seed_len,
17 u8 *buf, size_t buf_len)
19 unsigned char counter = 0;
21 u8 hash[SHA1_MAC_LEN];
22 size_t label_len = os_strlen(label);
24 const unsigned char *addr[5];
29 addr[1] = (unsigned char *) label;
36 * PRF+(K, S, LEN) = T1 | T2 | ... | Tn
37 * T1 = HMAC-SHA1(K, S | 0x01 | 0x00 | 0x00)
38 * T2 = HMAC-SHA1(K, T1 | S | 0x02 | 0x00 | 0x00)
40 * Tn = HMAC-SHA1(K, Tn-1 | S | n | 0x00 | 0x00)
52 * PRF (K,S,LEN) = T1 | T2 | T3 | T4 | ... where:
53 * T1 = HMAC-SHA1(K, S | LEN | 0x01)
54 * T2 = HMAC-SHA1 (K, T1 | S | LEN | 0x02)
55 * T3 = HMAC-SHA1 (K, T2 | S | LEN | 0x03)
56 * T4 = HMAC-SHA1 (K, T3 | S | LEN | 0x04)
60 extra[0] = buf_len & 0xff;
69 while (pos < buf_len) {
72 if (hmac_sha1_vector(key, key_len, 5, addr, len, hash) < 0)
74 if (plen >= SHA1_MAC_LEN) {
75 os_memcpy(&buf[pos], hash, SHA1_MAC_LEN);
78 os_memcpy(&buf[pos], hash, plen);
81 len[0] = SHA1_MAC_LEN;