2 * EAP-PEAP common routines
3 * Copyright (c) 2008, Jouni Malinen <j@w1.fi>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
9 * Alternatively, this software may be distributed under the terms of BSD
12 * See README and COPYING for more details.
18 #include "crypto/sha1.h"
19 #include "eap_peap_common.h"
21 void peap_prfplus(int version, const u8 *key, size_t key_len,
22 const char *label, const u8 *seed, size_t seed_len,
23 u8 *buf, size_t buf_len)
25 unsigned char counter = 0;
27 u8 hash[SHA1_MAC_LEN];
28 size_t label_len = os_strlen(label);
30 const unsigned char *addr[5];
35 addr[1] = (unsigned char *) label;
42 * PRF+(K, S, LEN) = T1 | T2 | ... | Tn
43 * T1 = HMAC-SHA1(K, S | 0x01 | 0x00 | 0x00)
44 * T2 = HMAC-SHA1(K, T1 | S | 0x02 | 0x00 | 0x00)
46 * Tn = HMAC-SHA1(K, Tn-1 | S | n | 0x00 | 0x00)
58 * PRF (K,S,LEN) = T1 | T2 | T3 | T4 | ... where:
59 * T1 = HMAC-SHA1(K, S | LEN | 0x01)
60 * T2 = HMAC-SHA1 (K, T1 | S | LEN | 0x02)
61 * T3 = HMAC-SHA1 (K, T2 | S | LEN | 0x03)
62 * T4 = HMAC-SHA1 (K, T3 | S | LEN | 0x04)
66 extra[0] = buf_len & 0xff;
75 while (pos < buf_len) {
78 hmac_sha1_vector(key, key_len, 5, addr, len, hash);
79 if (plen >= SHA1_MAC_LEN) {
80 os_memcpy(&buf[pos], hash, SHA1_MAC_LEN);
83 os_memcpy(&buf[pos], hash, plen);
86 len[0] = SHA1_MAC_LEN;