16d49e1aeSJan Lentfer /*
26d49e1aeSJan Lentfer * EAP-PEAP common routines
3*3ff40c12SJohn Marino * Copyright (c) 2008-2011, Jouni Malinen <j@w1.fi>
46d49e1aeSJan Lentfer *
5*3ff40c12SJohn Marino * This software may be distributed under the terms of the BSD license.
6*3ff40c12SJohn Marino * See README for more details.
76d49e1aeSJan Lentfer */
86d49e1aeSJan Lentfer
96d49e1aeSJan Lentfer #include "includes.h"
106d49e1aeSJan Lentfer
116d49e1aeSJan Lentfer #include "common.h"
12*3ff40c12SJohn Marino #include "crypto/sha1.h"
136d49e1aeSJan Lentfer #include "eap_peap_common.h"
146d49e1aeSJan Lentfer
peap_prfplus(int version,const u8 * key,size_t key_len,const char * label,const u8 * seed,size_t seed_len,u8 * buf,size_t buf_len)15*3ff40c12SJohn Marino int peap_prfplus(int version, const u8 *key, size_t key_len,
166d49e1aeSJan Lentfer const char *label, const u8 *seed, size_t seed_len,
176d49e1aeSJan Lentfer u8 *buf, size_t buf_len)
186d49e1aeSJan Lentfer {
196d49e1aeSJan Lentfer unsigned char counter = 0;
206d49e1aeSJan Lentfer size_t pos, plen;
216d49e1aeSJan Lentfer u8 hash[SHA1_MAC_LEN];
226d49e1aeSJan Lentfer size_t label_len = os_strlen(label);
236d49e1aeSJan Lentfer u8 extra[2];
246d49e1aeSJan Lentfer const unsigned char *addr[5];
256d49e1aeSJan Lentfer size_t len[5];
266d49e1aeSJan Lentfer
276d49e1aeSJan Lentfer addr[0] = hash;
286d49e1aeSJan Lentfer len[0] = 0;
296d49e1aeSJan Lentfer addr[1] = (unsigned char *) label;
306d49e1aeSJan Lentfer len[1] = label_len;
316d49e1aeSJan Lentfer addr[2] = seed;
326d49e1aeSJan Lentfer len[2] = seed_len;
336d49e1aeSJan Lentfer
346d49e1aeSJan Lentfer if (version == 0) {
356d49e1aeSJan Lentfer /*
366d49e1aeSJan Lentfer * PRF+(K, S, LEN) = T1 | T2 | ... | Tn
376d49e1aeSJan Lentfer * T1 = HMAC-SHA1(K, S | 0x01 | 0x00 | 0x00)
386d49e1aeSJan Lentfer * T2 = HMAC-SHA1(K, T1 | S | 0x02 | 0x00 | 0x00)
396d49e1aeSJan Lentfer * ...
406d49e1aeSJan Lentfer * Tn = HMAC-SHA1(K, Tn-1 | S | n | 0x00 | 0x00)
416d49e1aeSJan Lentfer */
426d49e1aeSJan Lentfer
436d49e1aeSJan Lentfer extra[0] = 0;
446d49e1aeSJan Lentfer extra[1] = 0;
456d49e1aeSJan Lentfer
466d49e1aeSJan Lentfer addr[3] = &counter;
476d49e1aeSJan Lentfer len[3] = 1;
486d49e1aeSJan Lentfer addr[4] = extra;
496d49e1aeSJan Lentfer len[4] = 2;
506d49e1aeSJan Lentfer } else {
516d49e1aeSJan Lentfer /*
526d49e1aeSJan Lentfer * PRF (K,S,LEN) = T1 | T2 | T3 | T4 | ... where:
536d49e1aeSJan Lentfer * T1 = HMAC-SHA1(K, S | LEN | 0x01)
546d49e1aeSJan Lentfer * T2 = HMAC-SHA1 (K, T1 | S | LEN | 0x02)
556d49e1aeSJan Lentfer * T3 = HMAC-SHA1 (K, T2 | S | LEN | 0x03)
566d49e1aeSJan Lentfer * T4 = HMAC-SHA1 (K, T3 | S | LEN | 0x04)
576d49e1aeSJan Lentfer * ...
586d49e1aeSJan Lentfer */
596d49e1aeSJan Lentfer
606d49e1aeSJan Lentfer extra[0] = buf_len & 0xff;
616d49e1aeSJan Lentfer
626d49e1aeSJan Lentfer addr[3] = extra;
636d49e1aeSJan Lentfer len[3] = 1;
646d49e1aeSJan Lentfer addr[4] = &counter;
656d49e1aeSJan Lentfer len[4] = 1;
666d49e1aeSJan Lentfer }
676d49e1aeSJan Lentfer
686d49e1aeSJan Lentfer pos = 0;
696d49e1aeSJan Lentfer while (pos < buf_len) {
706d49e1aeSJan Lentfer counter++;
716d49e1aeSJan Lentfer plen = buf_len - pos;
72*3ff40c12SJohn Marino if (hmac_sha1_vector(key, key_len, 5, addr, len, hash) < 0)
73*3ff40c12SJohn Marino return -1;
746d49e1aeSJan Lentfer if (plen >= SHA1_MAC_LEN) {
756d49e1aeSJan Lentfer os_memcpy(&buf[pos], hash, SHA1_MAC_LEN);
766d49e1aeSJan Lentfer pos += SHA1_MAC_LEN;
776d49e1aeSJan Lentfer } else {
786d49e1aeSJan Lentfer os_memcpy(&buf[pos], hash, plen);
796d49e1aeSJan Lentfer break;
806d49e1aeSJan Lentfer }
816d49e1aeSJan Lentfer len[0] = SHA1_MAC_LEN;
826d49e1aeSJan Lentfer }
83*3ff40c12SJohn Marino
84*3ff40c12SJohn Marino return 0;
856d49e1aeSJan Lentfer }
86