1 /*
2  * EAP peer/server: EAP-SIM/AKA/AKA' shared routines
3  * Copyright (c) 2004-2008, Jouni Malinen <j@w1.fi>
4  *
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.
8  *
9  * Alternatively, this software may be distributed under the terms of BSD
10  * license.
11  *
12  * See README and COPYING for more details.
13  */
14 
15 #include "includes.h"
16 
17 #include "common.h"
18 #include "eap_common/eap_defs.h"
19 #include "sha1.h"
20 #include "sha256.h"
21 #include "crypto.h"
22 #include "aes_wrap.h"
23 #include "wpabuf.h"
24 #include "eap_common/eap_sim_common.h"
25 
26 
27 static int eap_sim_prf(const u8 *key, u8 *x, size_t xlen)
28 {
29 	return fips186_2_prf(key, EAP_SIM_MK_LEN, x, xlen);
30 }
31 
32 
33 void eap_sim_derive_mk(const u8 *identity, size_t identity_len,
34 		       const u8 *nonce_mt, u16 selected_version,
35 		       const u8 *ver_list, size_t ver_list_len,
36 		       int num_chal, const u8 *kc, u8 *mk)
37 {
38 	u8 sel_ver[2];
39 	const unsigned char *addr[5];
40 	size_t len[5];
41 
42 	addr[0] = identity;
43 	len[0] = identity_len;
44 	addr[1] = kc;
45 	len[1] = num_chal * EAP_SIM_KC_LEN;
46 	addr[2] = nonce_mt;
47 	len[2] = EAP_SIM_NONCE_MT_LEN;
48 	addr[3] = ver_list;
49 	len[3] = ver_list_len;
50 	addr[4] = sel_ver;
51 	len[4] = 2;
52 
53 	WPA_PUT_BE16(sel_ver, selected_version);
54 
55 	/* MK = SHA1(Identity|n*Kc|NONCE_MT|Version List|Selected Version) */
56 	sha1_vector(5, addr, len, mk);
57 	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: MK", mk, EAP_SIM_MK_LEN);
58 }
59 
60 
61 void eap_aka_derive_mk(const u8 *identity, size_t identity_len,
62 		       const u8 *ik, const u8 *ck, u8 *mk)
63 {
64 	const u8 *addr[3];
65 	size_t len[3];
66 
67 	addr[0] = identity;
68 	len[0] = identity_len;
69 	addr[1] = ik;
70 	len[1] = EAP_AKA_IK_LEN;
71 	addr[2] = ck;
72 	len[2] = EAP_AKA_CK_LEN;
73 
74 	/* MK = SHA1(Identity|IK|CK) */
75 	sha1_vector(3, addr, len, mk);
76 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: IK", ik, EAP_AKA_IK_LEN);
77 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: CK", ck, EAP_AKA_CK_LEN);
78 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA: MK", mk, EAP_SIM_MK_LEN);
79 }
80 
81 
82 int eap_sim_derive_keys(const u8 *mk, u8 *k_encr, u8 *k_aut, u8 *msk, u8 *emsk)
83 {
84 	u8 buf[EAP_SIM_K_ENCR_LEN + EAP_SIM_K_AUT_LEN +
85 	       EAP_SIM_KEYING_DATA_LEN + EAP_EMSK_LEN], *pos;
86 	if (eap_sim_prf(mk, buf, sizeof(buf)) < 0) {
87 		wpa_printf(MSG_ERROR, "EAP-SIM: Failed to derive keys");
88 		return -1;
89 	}
90 	pos = buf;
91 	os_memcpy(k_encr, pos, EAP_SIM_K_ENCR_LEN);
92 	pos += EAP_SIM_K_ENCR_LEN;
93 	os_memcpy(k_aut, pos, EAP_SIM_K_AUT_LEN);
94 	pos += EAP_SIM_K_AUT_LEN;
95 	os_memcpy(msk, pos, EAP_SIM_KEYING_DATA_LEN);
96 	pos += EAP_SIM_KEYING_DATA_LEN;
97 	os_memcpy(emsk, pos, EAP_EMSK_LEN);
98 
99 	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: K_encr",
100 			k_encr, EAP_SIM_K_ENCR_LEN);
101 	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: K_aut",
102 			k_aut, EAP_SIM_K_AUT_LEN);
103 	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: keying material (MSK)",
104 			msk, EAP_SIM_KEYING_DATA_LEN);
105 	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: EMSK", emsk, EAP_EMSK_LEN);
106 	os_memset(buf, 0, sizeof(buf));
107 
108 	return 0;
109 }
110 
111 
112 int eap_sim_derive_keys_reauth(u16 _counter,
113 			       const u8 *identity, size_t identity_len,
114 			       const u8 *nonce_s, const u8 *mk, u8 *msk,
115 			       u8 *emsk)
116 {
117 	u8 xkey[SHA1_MAC_LEN];
118 	u8 buf[EAP_SIM_KEYING_DATA_LEN + EAP_EMSK_LEN + 32];
119 	u8 counter[2];
120 	const u8 *addr[4];
121 	size_t len[4];
122 
123 	while (identity_len > 0 && identity[identity_len - 1] == 0) {
124 		wpa_printf(MSG_DEBUG, "EAP-SIM: Workaround - drop null "
125 			   "character from the end of identity");
126 		identity_len--;
127 	}
128 	addr[0] = identity;
129 	len[0] = identity_len;
130 	addr[1] = counter;
131 	len[1] = 2;
132 	addr[2] = nonce_s;
133 	len[2] = EAP_SIM_NONCE_S_LEN;
134 	addr[3] = mk;
135 	len[3] = EAP_SIM_MK_LEN;
136 
137 	WPA_PUT_BE16(counter, _counter);
138 
139 	wpa_printf(MSG_DEBUG, "EAP-SIM: Deriving keying data from reauth");
140 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-SIM: Identity",
141 			  identity, identity_len);
142 	wpa_hexdump(MSG_DEBUG, "EAP-SIM: counter", counter, 2);
143 	wpa_hexdump(MSG_DEBUG, "EAP-SIM: NONCE_S", nonce_s,
144 		    EAP_SIM_NONCE_S_LEN);
145 	wpa_hexdump_key(MSG_DEBUG, "EAP-SIM: MK", mk, EAP_SIM_MK_LEN);
146 
147 	/* XKEY' = SHA1(Identity|counter|NONCE_S|MK) */
148 	sha1_vector(4, addr, len, xkey);
149 	wpa_hexdump(MSG_DEBUG, "EAP-SIM: XKEY'", xkey, SHA1_MAC_LEN);
150 
151 	if (eap_sim_prf(xkey, buf, sizeof(buf)) < 0) {
152 		wpa_printf(MSG_ERROR, "EAP-SIM: Failed to derive keys");
153 		return -1;
154 	}
155 	if (msk) {
156 		os_memcpy(msk, buf, EAP_SIM_KEYING_DATA_LEN);
157 		wpa_hexdump(MSG_DEBUG, "EAP-SIM: keying material (MSK)",
158 			    msk, EAP_SIM_KEYING_DATA_LEN);
159 	}
160 	if (emsk) {
161 		os_memcpy(emsk, buf + EAP_SIM_KEYING_DATA_LEN, EAP_EMSK_LEN);
162 		wpa_hexdump(MSG_DEBUG, "EAP-SIM: EMSK", emsk, EAP_EMSK_LEN);
163 	}
164 	os_memset(buf, 0, sizeof(buf));
165 
166 	return 0;
167 }
168 
169 
170 int eap_sim_verify_mac(const u8 *k_aut, const struct wpabuf *req,
171 		       const u8 *mac, const u8 *extra, size_t extra_len)
172 {
173 	unsigned char hmac[SHA1_MAC_LEN];
174 	const u8 *addr[2];
175 	size_t len[2];
176 	u8 *tmp;
177 
178 	if (mac == NULL || wpabuf_len(req) < EAP_SIM_MAC_LEN ||
179 	    mac < wpabuf_head_u8(req) ||
180 	    mac > wpabuf_head_u8(req) + wpabuf_len(req) - EAP_SIM_MAC_LEN)
181 		return -1;
182 
183 	tmp = os_malloc(wpabuf_len(req));
184 	if (tmp == NULL)
185 		return -1;
186 
187 	addr[0] = tmp;
188 	len[0] = wpabuf_len(req);
189 	addr[1] = extra;
190 	len[1] = extra_len;
191 
192 	/* HMAC-SHA1-128 */
193 	os_memcpy(tmp, wpabuf_head(req), wpabuf_len(req));
194 	os_memset(tmp + (mac - wpabuf_head_u8(req)), 0, EAP_SIM_MAC_LEN);
195 	wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Verify MAC - msg",
196 		    tmp, wpabuf_len(req));
197 	wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Verify MAC - extra data",
198 		    extra, extra_len);
199 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: Verify MAC - K_aut",
200 			k_aut, EAP_SIM_K_AUT_LEN);
201 	hmac_sha1_vector(k_aut, EAP_SIM_K_AUT_LEN, 2, addr, len, hmac);
202 	wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Verify MAC: MAC",
203 		    hmac, EAP_SIM_MAC_LEN);
204 	os_free(tmp);
205 
206 	return (os_memcmp(hmac, mac, EAP_SIM_MAC_LEN) == 0) ? 0 : 1;
207 }
208 
209 
210 void eap_sim_add_mac(const u8 *k_aut, const u8 *msg, size_t msg_len, u8 *mac,
211 		     const u8 *extra, size_t extra_len)
212 {
213 	unsigned char hmac[SHA1_MAC_LEN];
214 	const u8 *addr[2];
215 	size_t len[2];
216 
217 	addr[0] = msg;
218 	len[0] = msg_len;
219 	addr[1] = extra;
220 	len[1] = extra_len;
221 
222 	/* HMAC-SHA1-128 */
223 	os_memset(mac, 0, EAP_SIM_MAC_LEN);
224 	wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Add MAC - msg", msg, msg_len);
225 	wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Add MAC - extra data",
226 		    extra, extra_len);
227 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-SIM: Add MAC - K_aut",
228 			k_aut, EAP_SIM_K_AUT_LEN);
229 	hmac_sha1_vector(k_aut, EAP_SIM_K_AUT_LEN, 2, addr, len, hmac);
230 	os_memcpy(mac, hmac, EAP_SIM_MAC_LEN);
231 	wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Add MAC: MAC",
232 		    mac, EAP_SIM_MAC_LEN);
233 }
234 
235 
236 #ifdef EAP_AKA_PRIME
237 static void prf_prime(const u8 *k, const char *seed1,
238 		      const u8 *seed2, size_t seed2_len,
239 		      const u8 *seed3, size_t seed3_len,
240 		      u8 *res, size_t res_len)
241 {
242 	const u8 *addr[5];
243 	size_t len[5];
244 	u8 hash[SHA256_MAC_LEN];
245 	u8 iter;
246 
247 	/*
248 	 * PRF'(K,S) = T1 | T2 | T3 | T4 | ...
249 	 * T1 = HMAC-SHA-256 (K, S | 0x01)
250 	 * T2 = HMAC-SHA-256 (K, T1 | S | 0x02)
251 	 * T3 = HMAC-SHA-256 (K, T2 | S | 0x03)
252 	 * T4 = HMAC-SHA-256 (K, T3 | S | 0x04)
253 	 * ...
254 	 */
255 
256 	addr[0] = hash;
257 	len[0] = 0;
258 	addr[1] = (const u8 *) seed1;
259 	len[1] = os_strlen(seed1);
260 	addr[2] = seed2;
261 	len[2] = seed2_len;
262 	addr[3] = seed3;
263 	len[3] = seed3_len;
264 	addr[4] = &iter;
265 	len[4] = 1;
266 
267 	iter = 0;
268 	while (res_len) {
269 		size_t hlen;
270 		iter++;
271 		hmac_sha256_vector(k, 32, 5, addr, len, hash);
272 		len[0] = SHA256_MAC_LEN;
273 		hlen = res_len > SHA256_MAC_LEN ? SHA256_MAC_LEN : res_len;
274 		os_memcpy(res, hash, hlen);
275 		res += hlen;
276 		res_len -= hlen;
277 	}
278 }
279 
280 
281 void eap_aka_prime_derive_keys(const u8 *identity, size_t identity_len,
282 			       const u8 *ik, const u8 *ck, u8 *k_encr,
283 			       u8 *k_aut, u8 *k_re, u8 *msk, u8 *emsk)
284 {
285 	u8 key[EAP_AKA_IK_LEN + EAP_AKA_CK_LEN];
286 	u8 keys[EAP_SIM_K_ENCR_LEN + EAP_AKA_PRIME_K_AUT_LEN +
287 		EAP_AKA_PRIME_K_RE_LEN + EAP_MSK_LEN + EAP_EMSK_LEN];
288 	u8 *pos;
289 
290 	/*
291 	 * MK = PRF'(IK'|CK',"EAP-AKA'"|Identity)
292 	 * K_encr = MK[0..127]
293 	 * K_aut  = MK[128..383]
294 	 * K_re   = MK[384..639]
295 	 * MSK    = MK[640..1151]
296 	 * EMSK   = MK[1152..1663]
297 	 */
298 
299 	os_memcpy(key, ik, EAP_AKA_IK_LEN);
300 	os_memcpy(key + EAP_AKA_IK_LEN, ck, EAP_AKA_CK_LEN);
301 
302 	prf_prime(key, "EAP-AKA'", identity, identity_len, NULL, 0,
303 		  keys, sizeof(keys));
304 
305 	pos = keys;
306 	os_memcpy(k_encr, pos, EAP_SIM_K_ENCR_LEN);
307 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': K_encr",
308 			k_encr, EAP_SIM_K_ENCR_LEN);
309 	pos += EAP_SIM_K_ENCR_LEN;
310 
311 	os_memcpy(k_aut, pos, EAP_AKA_PRIME_K_AUT_LEN);
312 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': K_aut",
313 			k_aut, EAP_AKA_PRIME_K_AUT_LEN);
314 	pos += EAP_AKA_PRIME_K_AUT_LEN;
315 
316 	os_memcpy(k_re, pos, EAP_AKA_PRIME_K_RE_LEN);
317 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': K_re",
318 			k_re, EAP_AKA_PRIME_K_RE_LEN);
319 	pos += EAP_AKA_PRIME_K_RE_LEN;
320 
321 	os_memcpy(msk, pos, EAP_MSK_LEN);
322 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': MSK", msk, EAP_MSK_LEN);
323 	pos += EAP_MSK_LEN;
324 
325 	os_memcpy(emsk, pos, EAP_EMSK_LEN);
326 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': EMSK", emsk, EAP_EMSK_LEN);
327 }
328 
329 
330 int eap_aka_prime_derive_keys_reauth(const u8 *k_re, u16 counter,
331 				     const u8 *identity, size_t identity_len,
332 				     const u8 *nonce_s, u8 *msk, u8 *emsk)
333 {
334 	u8 seed3[2 + EAP_SIM_NONCE_S_LEN];
335 	u8 keys[EAP_MSK_LEN + EAP_EMSK_LEN];
336 	u8 *pos;
337 
338 	/*
339 	 * MK = PRF'(K_re,"EAP-AKA' re-auth"|Identity|counter|NONCE_S)
340 	 * MSK  = MK[0..511]
341 	 * EMSK = MK[512..1023]
342 	 */
343 
344 	WPA_PUT_BE16(seed3, counter);
345 	os_memcpy(seed3 + 2, nonce_s, EAP_SIM_NONCE_S_LEN);
346 
347 	prf_prime(k_re, "EAP-AKA' re-auth", identity, identity_len,
348 		  seed3, sizeof(seed3),
349 		  keys, sizeof(keys));
350 
351 	pos = keys;
352 	os_memcpy(msk, pos, EAP_MSK_LEN);
353 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': MSK", msk, EAP_MSK_LEN);
354 	pos += EAP_MSK_LEN;
355 
356 	os_memcpy(emsk, pos, EAP_EMSK_LEN);
357 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': EMSK", emsk, EAP_EMSK_LEN);
358 
359 	os_memset(keys, 0, sizeof(keys));
360 
361 	return 0;
362 }
363 
364 
365 int eap_sim_verify_mac_sha256(const u8 *k_aut, const struct wpabuf *req,
366 			      const u8 *mac, const u8 *extra, size_t extra_len)
367 {
368 	unsigned char hmac[SHA256_MAC_LEN];
369 	const u8 *addr[2];
370 	size_t len[2];
371 	u8 *tmp;
372 
373 	if (mac == NULL || wpabuf_len(req) < EAP_SIM_MAC_LEN ||
374 	    mac < wpabuf_head_u8(req) ||
375 	    mac > wpabuf_head_u8(req) + wpabuf_len(req) - EAP_SIM_MAC_LEN)
376 		return -1;
377 
378 	tmp = os_malloc(wpabuf_len(req));
379 	if (tmp == NULL)
380 		return -1;
381 
382 	addr[0] = tmp;
383 	len[0] = wpabuf_len(req);
384 	addr[1] = extra;
385 	len[1] = extra_len;
386 
387 	/* HMAC-SHA-256-128 */
388 	os_memcpy(tmp, wpabuf_head(req), wpabuf_len(req));
389 	os_memset(tmp + (mac - wpabuf_head_u8(req)), 0, EAP_SIM_MAC_LEN);
390 	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Verify MAC - msg",
391 		    tmp, wpabuf_len(req));
392 	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Verify MAC - extra data",
393 		    extra, extra_len);
394 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-AKA': Verify MAC - K_aut",
395 			k_aut, EAP_AKA_PRIME_K_AUT_LEN);
396 	hmac_sha256_vector(k_aut, EAP_AKA_PRIME_K_AUT_LEN, 2, addr, len, hmac);
397 	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Verify MAC: MAC",
398 		    hmac, EAP_SIM_MAC_LEN);
399 	os_free(tmp);
400 
401 	return (os_memcmp(hmac, mac, EAP_SIM_MAC_LEN) == 0) ? 0 : 1;
402 }
403 
404 
405 void eap_sim_add_mac_sha256(const u8 *k_aut, const u8 *msg, size_t msg_len,
406 			    u8 *mac, const u8 *extra, size_t extra_len)
407 {
408 	unsigned char hmac[SHA256_MAC_LEN];
409 	const u8 *addr[2];
410 	size_t len[2];
411 
412 	addr[0] = msg;
413 	len[0] = msg_len;
414 	addr[1] = extra;
415 	len[1] = extra_len;
416 
417 	/* HMAC-SHA-256-128 */
418 	os_memset(mac, 0, EAP_SIM_MAC_LEN);
419 	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Add MAC - msg", msg, msg_len);
420 	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Add MAC - extra data",
421 		    extra, extra_len);
422 	wpa_hexdump_key(MSG_MSGDUMP, "EAP-AKA': Add MAC - K_aut",
423 			k_aut, EAP_AKA_PRIME_K_AUT_LEN);
424 	hmac_sha256_vector(k_aut, EAP_AKA_PRIME_K_AUT_LEN, 2, addr, len, hmac);
425 	os_memcpy(mac, hmac, EAP_SIM_MAC_LEN);
426 	wpa_hexdump(MSG_MSGDUMP, "EAP-AKA': Add MAC: MAC",
427 		    mac, EAP_SIM_MAC_LEN);
428 }
429 
430 
431 void eap_aka_prime_derive_ck_ik_prime(u8 *ck, u8 *ik, const u8 *sqn_ak,
432 				      const u8 *network_name,
433 				      size_t network_name_len)
434 {
435 	u8 key[EAP_AKA_CK_LEN + EAP_AKA_IK_LEN];
436 	u8 hash[SHA256_MAC_LEN];
437 	const u8 *addr[5];
438 	size_t len[5];
439 	u8 fc;
440 	u8 l0[2], l1[2];
441 
442 	/* 3GPP TS 33.402 V8.0.0
443 	 * (CK', IK') = F(CK, IK, <access network identity>)
444 	 */
445 	/* TODO: CK', IK' generation should really be moved into the actual
446 	 * AKA procedure with network name passed in there and option to use
447 	 * AMF separation bit = 1 (3GPP TS 33.401). */
448 
449 	/* Change Request 33.402 CR 0033 to version 8.1.1 from
450 	 * 3GPP TSG-SA WG3 Meeting #53 in September 2008:
451 	 *
452 	 * CK' || IK' = HMAC-SHA-256(Key, S)
453 	 * S = FC || P0 || L0 || P1 || L1 || ... || Pn || Ln
454 	 * Key = CK || IK
455 	 * FC = 0x20
456 	 * P0 = access network identity (3GPP TS 24.302)
457 	 * L0 = length of acceess network identity (2 octets, big endian)
458 	 * P1 = SQN xor AK (if AK is not used, AK is treaded as 000..0
459 	 * L1 = 0x00 0x06
460 	 */
461 
462 	fc = 0x20;
463 
464 	wpa_printf(MSG_DEBUG, "EAP-AKA': Derive (CK',IK') from (CK,IK)");
465 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': CK", ck, EAP_AKA_CK_LEN);
466 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': IK", ik, EAP_AKA_IK_LEN);
467 	wpa_printf(MSG_DEBUG, "EAP-AKA': FC = 0x%x", fc);
468 	wpa_hexdump_ascii(MSG_DEBUG, "EAP-AKA': P0 = Access network identity",
469 			  network_name, network_name_len);
470 	wpa_hexdump(MSG_DEBUG, "EAP-AKA': P1 = SQN xor AK", sqn_ak, 6);
471 
472 	os_memcpy(key, ck, EAP_AKA_CK_LEN);
473 	os_memcpy(key + EAP_AKA_CK_LEN, ik, EAP_AKA_IK_LEN);
474 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': Key = CK || IK",
475 			key, sizeof(key));
476 
477 	addr[0] = &fc;
478 	len[0] = 1;
479 	addr[1] = network_name;
480 	len[1] = network_name_len;
481 	WPA_PUT_BE16(l0, network_name_len);
482 	addr[2] = l0;
483 	len[2] = 2;
484 	addr[3] = sqn_ak;
485 	len[3] = 6;
486 	WPA_PUT_BE16(l1, 6);
487 	addr[4] = l1;
488 	len[4] = 2;
489 
490 	hmac_sha256_vector(key, sizeof(key), 5, addr, len, hash);
491 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': KDF output (CK' || IK')",
492 			hash, sizeof(hash));
493 
494 	os_memcpy(ck, hash, EAP_AKA_CK_LEN);
495 	os_memcpy(ik, hash + EAP_AKA_CK_LEN, EAP_AKA_IK_LEN);
496 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': CK'", ck, EAP_AKA_CK_LEN);
497 	wpa_hexdump_key(MSG_DEBUG, "EAP-AKA': IK'", ik, EAP_AKA_IK_LEN);
498 }
499 #endif /* EAP_AKA_PRIME */
500 
501 
502 int eap_sim_parse_attr(const u8 *start, const u8 *end,
503 		       struct eap_sim_attrs *attr, int aka, int encr)
504 {
505 	const u8 *pos = start, *apos;
506 	size_t alen, plen, i, list_len;
507 
508 	os_memset(attr, 0, sizeof(*attr));
509 	attr->id_req = NO_ID_REQ;
510 	attr->notification = -1;
511 	attr->counter = -1;
512 	attr->selected_version = -1;
513 	attr->client_error_code = -1;
514 
515 	while (pos < end) {
516 		if (pos + 2 > end) {
517 			wpa_printf(MSG_INFO, "EAP-SIM: Attribute overflow(1)");
518 			return -1;
519 		}
520 		wpa_printf(MSG_MSGDUMP, "EAP-SIM: Attribute: Type=%d Len=%d",
521 			   pos[0], pos[1] * 4);
522 		if (pos + pos[1] * 4 > end) {
523 			wpa_printf(MSG_INFO, "EAP-SIM: Attribute overflow "
524 				   "(pos=%p len=%d end=%p)",
525 				   pos, pos[1] * 4, end);
526 			return -1;
527 		}
528 		if (pos[1] == 0) {
529 			wpa_printf(MSG_INFO, "EAP-SIM: Attribute underflow");
530 			return -1;
531 		}
532 		apos = pos + 2;
533 		alen = pos[1] * 4 - 2;
534 		wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Attribute data",
535 			    apos, alen);
536 
537 		switch (pos[0]) {
538 		case EAP_SIM_AT_RAND:
539 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_RAND");
540 			apos += 2;
541 			alen -= 2;
542 			if ((!aka && (alen % GSM_RAND_LEN)) ||
543 			    (aka && alen != EAP_AKA_RAND_LEN)) {
544 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_RAND"
545 					   " (len %lu)",
546 					   (unsigned long) alen);
547 				return -1;
548 			}
549 			attr->rand = apos;
550 			attr->num_chal = alen / GSM_RAND_LEN;
551 			break;
552 		case EAP_SIM_AT_AUTN:
553 			wpa_printf(MSG_DEBUG, "EAP-AKA: AT_AUTN");
554 			if (!aka) {
555 				wpa_printf(MSG_DEBUG, "EAP-SIM: "
556 					   "Unexpected AT_AUTN");
557 				return -1;
558 			}
559 			apos += 2;
560 			alen -= 2;
561 			if (alen != EAP_AKA_AUTN_LEN) {
562 				wpa_printf(MSG_INFO, "EAP-AKA: Invalid AT_AUTN"
563 					   " (len %lu)",
564 					   (unsigned long) alen);
565 				return -1;
566 			}
567 			attr->autn = apos;
568 			break;
569 		case EAP_SIM_AT_PADDING:
570 			if (!encr) {
571 				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
572 					   "AT_PADDING");
573 				return -1;
574 			}
575 			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) AT_PADDING");
576 			for (i = 2; i < alen; i++) {
577 				if (apos[i] != 0) {
578 					wpa_printf(MSG_INFO, "EAP-SIM: (encr) "
579 						   "AT_PADDING used a non-zero"
580 						   " padding byte");
581 					wpa_hexdump(MSG_DEBUG, "EAP-SIM: "
582 						    "(encr) padding bytes",
583 						    apos + 2, alen - 2);
584 					return -1;
585 				}
586 			}
587 			break;
588 		case EAP_SIM_AT_NONCE_MT:
589 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_NONCE_MT");
590 			if (alen != 2 + EAP_SIM_NONCE_MT_LEN) {
591 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
592 					   "AT_NONCE_MT length");
593 				return -1;
594 			}
595 			attr->nonce_mt = apos + 2;
596 			break;
597 		case EAP_SIM_AT_PERMANENT_ID_REQ:
598 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_PERMANENT_ID_REQ");
599 			attr->id_req = PERMANENT_ID;
600 			break;
601 		case EAP_SIM_AT_MAC:
602 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_MAC");
603 			if (alen != 2 + EAP_SIM_MAC_LEN) {
604 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_MAC "
605 					   "length");
606 				return -1;
607 			}
608 			attr->mac = apos + 2;
609 			break;
610 		case EAP_SIM_AT_NOTIFICATION:
611 			if (alen != 2) {
612 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
613 					   "AT_NOTIFICATION length %lu",
614 					   (unsigned long) alen);
615 				return -1;
616 			}
617 			attr->notification = apos[0] * 256 + apos[1];
618 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_NOTIFICATION %d",
619 				   attr->notification);
620 			break;
621 		case EAP_SIM_AT_ANY_ID_REQ:
622 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_ANY_ID_REQ");
623 			attr->id_req = ANY_ID;
624 			break;
625 		case EAP_SIM_AT_IDENTITY:
626 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_IDENTITY");
627 			plen = WPA_GET_BE16(apos);
628 			apos += 2;
629 			alen -= 2;
630 			if (plen > alen) {
631 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
632 					   "AT_IDENTITY (Actual Length %lu, "
633 					   "remaining length %lu)",
634 					   (unsigned long) plen,
635 					   (unsigned long) alen);
636 				return -1;
637 			}
638 
639 			attr->identity = apos;
640 			attr->identity_len = plen;
641 			break;
642 		case EAP_SIM_AT_VERSION_LIST:
643 			if (aka) {
644 				wpa_printf(MSG_DEBUG, "EAP-AKA: "
645 					   "Unexpected AT_VERSION_LIST");
646 				return -1;
647 			}
648 			list_len = apos[0] * 256 + apos[1];
649 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_VERSION_LIST");
650 			if (list_len < 2 || list_len > alen - 2) {
651 				wpa_printf(MSG_WARNING, "EAP-SIM: Invalid "
652 					   "AT_VERSION_LIST (list_len=%lu "
653 					   "attr_len=%lu)",
654 					   (unsigned long) list_len,
655 					   (unsigned long) alen);
656 				return -1;
657 			}
658 			attr->version_list = apos + 2;
659 			attr->version_list_len = list_len;
660 			break;
661 		case EAP_SIM_AT_SELECTED_VERSION:
662 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_SELECTED_VERSION");
663 			if (alen != 2) {
664 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
665 					   "AT_SELECTED_VERSION length %lu",
666 					   (unsigned long) alen);
667 				return -1;
668 			}
669 			attr->selected_version = apos[0] * 256 + apos[1];
670 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_SELECTED_VERSION "
671 				   "%d", attr->selected_version);
672 			break;
673 		case EAP_SIM_AT_FULLAUTH_ID_REQ:
674 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_FULLAUTH_ID_REQ");
675 			attr->id_req = FULLAUTH_ID;
676 			break;
677 		case EAP_SIM_AT_COUNTER:
678 			if (!encr) {
679 				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
680 					   "AT_COUNTER");
681 				return -1;
682 			}
683 			if (alen != 2) {
684 				wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
685 					   "AT_COUNTER (alen=%lu)",
686 					   (unsigned long) alen);
687 				return -1;
688 			}
689 			attr->counter = apos[0] * 256 + apos[1];
690 			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) AT_COUNTER %d",
691 				   attr->counter);
692 			break;
693 		case EAP_SIM_AT_COUNTER_TOO_SMALL:
694 			if (!encr) {
695 				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
696 					   "AT_COUNTER_TOO_SMALL");
697 				return -1;
698 			}
699 			if (alen != 2) {
700 				wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
701 					   "AT_COUNTER_TOO_SMALL (alen=%lu)",
702 					   (unsigned long) alen);
703 				return -1;
704 			}
705 			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
706 				   "AT_COUNTER_TOO_SMALL");
707 			attr->counter_too_small = 1;
708 			break;
709 		case EAP_SIM_AT_NONCE_S:
710 			if (!encr) {
711 				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
712 					   "AT_NONCE_S");
713 				return -1;
714 			}
715 			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
716 				   "AT_NONCE_S");
717 			if (alen != 2 + EAP_SIM_NONCE_S_LEN) {
718 				wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid "
719 					   "AT_NONCE_S (alen=%lu)",
720 					   (unsigned long) alen);
721 				return -1;
722 			}
723 			attr->nonce_s = apos + 2;
724 			break;
725 		case EAP_SIM_AT_CLIENT_ERROR_CODE:
726 			if (alen != 2) {
727 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
728 					   "AT_CLIENT_ERROR_CODE length %lu",
729 					   (unsigned long) alen);
730 				return -1;
731 			}
732 			attr->client_error_code = apos[0] * 256 + apos[1];
733 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_CLIENT_ERROR_CODE "
734 				   "%d", attr->client_error_code);
735 			break;
736 		case EAP_SIM_AT_IV:
737 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_IV");
738 			if (alen != 2 + EAP_SIM_MAC_LEN) {
739 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_IV "
740 					   "length %lu", (unsigned long) alen);
741 				return -1;
742 			}
743 			attr->iv = apos + 2;
744 			break;
745 		case EAP_SIM_AT_ENCR_DATA:
746 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_ENCR_DATA");
747 			attr->encr_data = apos + 2;
748 			attr->encr_data_len = alen - 2;
749 			if (attr->encr_data_len % 16) {
750 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
751 					   "AT_ENCR_DATA length %lu",
752 					   (unsigned long)
753 					   attr->encr_data_len);
754 				return -1;
755 			}
756 			break;
757 		case EAP_SIM_AT_NEXT_PSEUDONYM:
758 			if (!encr) {
759 				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
760 					   "AT_NEXT_PSEUDONYM");
761 				return -1;
762 			}
763 			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
764 				   "AT_NEXT_PSEUDONYM");
765 			plen = apos[0] * 256 + apos[1];
766 			if (plen > alen - 2) {
767 				wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid"
768 					   " AT_NEXT_PSEUDONYM (actual"
769 					   " len %lu, attr len %lu)",
770 					   (unsigned long) plen,
771 					   (unsigned long) alen);
772 				return -1;
773 			}
774 			attr->next_pseudonym = pos + 4;
775 			attr->next_pseudonym_len = plen;
776 			break;
777 		case EAP_SIM_AT_NEXT_REAUTH_ID:
778 			if (!encr) {
779 				wpa_printf(MSG_ERROR, "EAP-SIM: Unencrypted "
780 					   "AT_NEXT_REAUTH_ID");
781 				return -1;
782 			}
783 			wpa_printf(MSG_DEBUG, "EAP-SIM: (encr) "
784 				   "AT_NEXT_REAUTH_ID");
785 			plen = apos[0] * 256 + apos[1];
786 			if (plen > alen - 2) {
787 				wpa_printf(MSG_INFO, "EAP-SIM: (encr) Invalid"
788 					   " AT_NEXT_REAUTH_ID (actual"
789 					   " len %lu, attr len %lu)",
790 					   (unsigned long) plen,
791 					   (unsigned long) alen);
792 				return -1;
793 			}
794 			attr->next_reauth_id = pos + 4;
795 			attr->next_reauth_id_len = plen;
796 			break;
797 		case EAP_SIM_AT_RES:
798 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_RES");
799 			attr->res_len_bits = WPA_GET_BE16(apos);
800 			apos += 2;
801 			alen -= 2;
802 			if (!aka || alen < EAP_AKA_MIN_RES_LEN ||
803 			    alen > EAP_AKA_MAX_RES_LEN) {
804 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid AT_RES "
805 					   "(len %lu)",
806 					   (unsigned long) alen);
807 				return -1;
808 			}
809 			attr->res = apos;
810 			attr->res_len = alen;
811 			break;
812 		case EAP_SIM_AT_AUTS:
813 			wpa_printf(MSG_DEBUG, "EAP-AKA: AT_AUTS");
814 			if (!aka) {
815 				wpa_printf(MSG_DEBUG, "EAP-SIM: "
816 					   "Unexpected AT_AUTS");
817 				return -1;
818 			}
819 			if (alen != EAP_AKA_AUTS_LEN) {
820 				wpa_printf(MSG_INFO, "EAP-AKA: Invalid AT_AUTS"
821 					   " (len %lu)",
822 					   (unsigned long) alen);
823 				return -1;
824 			}
825 			attr->auts = apos;
826 			break;
827 		case EAP_SIM_AT_CHECKCODE:
828 			wpa_printf(MSG_DEBUG, "EAP-AKA: AT_CHECKCODE");
829 			if (!aka) {
830 				wpa_printf(MSG_DEBUG, "EAP-SIM: "
831 					   "Unexpected AT_CHECKCODE");
832 				return -1;
833 			}
834 			apos += 2;
835 			alen -= 2;
836 			if (alen != 0 && alen != EAP_AKA_CHECKCODE_LEN &&
837 			    alen != EAP_AKA_PRIME_CHECKCODE_LEN) {
838 				wpa_printf(MSG_INFO, "EAP-AKA: Invalid "
839 					   "AT_CHECKCODE (len %lu)",
840 					   (unsigned long) alen);
841 				return -1;
842 			}
843 			attr->checkcode = apos;
844 			attr->checkcode_len = alen;
845 			break;
846 		case EAP_SIM_AT_RESULT_IND:
847 			if (encr) {
848 				wpa_printf(MSG_ERROR, "EAP-SIM: Encrypted "
849 					   "AT_RESULT_IND");
850 				return -1;
851 			}
852 			if (alen != 2) {
853 				wpa_printf(MSG_INFO, "EAP-SIM: Invalid "
854 					   "AT_RESULT_IND (alen=%lu)",
855 					   (unsigned long) alen);
856 				return -1;
857 			}
858 			wpa_printf(MSG_DEBUG, "EAP-SIM: AT_RESULT_IND");
859 			attr->result_ind = 1;
860 			break;
861 #ifdef EAP_AKA_PRIME
862 		case EAP_SIM_AT_KDF_INPUT:
863 			if (aka != 2) {
864 				wpa_printf(MSG_INFO, "EAP-AKA: Unexpected "
865 					   "AT_KDF_INPUT");
866 				return -1;
867 			}
868 
869 			wpa_printf(MSG_DEBUG, "EAP-AKA: AT_KDF_INPUT");
870 			plen = WPA_GET_BE16(apos);
871 			apos += 2;
872 			alen -= 2;
873 			if (plen > alen) {
874 				wpa_printf(MSG_INFO, "EAP-AKA': Invalid "
875 					   "AT_KDF_INPUT (Actual Length %lu, "
876 					   "remaining length %lu)",
877 					   (unsigned long) plen,
878 					   (unsigned long) alen);
879 				return -1;
880 			}
881 			attr->kdf_input = apos;
882 			attr->kdf_input_len = plen;
883 			break;
884 		case EAP_SIM_AT_KDF:
885 			if (aka != 2) {
886 				wpa_printf(MSG_INFO, "EAP-AKA: Unexpected "
887 					   "AT_KDF");
888 				return -1;
889 			}
890 
891 			wpa_printf(MSG_DEBUG, "EAP-AKA: AT_KDF");
892 			if (alen != 2) {
893 				wpa_printf(MSG_INFO, "EAP-AKA': Invalid "
894 					   "AT_KDF (len %lu)",
895 					   (unsigned long) alen);
896 				return -1;
897 			}
898 			if (attr->kdf_count == EAP_AKA_PRIME_KDF_MAX) {
899 				wpa_printf(MSG_DEBUG, "EAP-AKA': Too many "
900 					   "AT_KDF attributes - ignore this");
901 				continue;
902 			}
903 			attr->kdf[attr->kdf_count] = WPA_GET_BE16(apos);
904 			attr->kdf_count++;
905 			break;
906 		case EAP_SIM_AT_BIDDING:
907 			wpa_printf(MSG_DEBUG, "EAP-AKA: AT_BIDDING");
908 			if (alen != 2) {
909 				wpa_printf(MSG_INFO, "EAP-AKA: Invalid "
910 					   "AT_BIDDING (len %lu)",
911 					   (unsigned long) alen);
912 				return -1;
913 			}
914 			attr->bidding = apos;
915 			break;
916 #endif /* EAP_AKA_PRIME */
917 		default:
918 			if (pos[0] < 128) {
919 				wpa_printf(MSG_INFO, "EAP-SIM: Unrecognized "
920 					   "non-skippable attribute %d",
921 					   pos[0]);
922 				return -1;
923 			}
924 
925 			wpa_printf(MSG_DEBUG, "EAP-SIM: Unrecognized skippable"
926 				   " attribute %d ignored", pos[0]);
927 			break;
928 		}
929 
930 		pos += pos[1] * 4;
931 	}
932 
933 	wpa_printf(MSG_DEBUG, "EAP-SIM: Attributes parsed successfully "
934 		   "(aka=%d encr=%d)", aka, encr);
935 
936 	return 0;
937 }
938 
939 
940 u8 * eap_sim_parse_encr(const u8 *k_encr, const u8 *encr_data,
941 			size_t encr_data_len, const u8 *iv,
942 			struct eap_sim_attrs *attr, int aka)
943 {
944 	u8 *decrypted;
945 
946 	if (!iv) {
947 		wpa_printf(MSG_INFO, "EAP-SIM: Encrypted data, but no IV");
948 		return NULL;
949 	}
950 
951 	decrypted = os_malloc(encr_data_len);
952 	if (decrypted == NULL)
953 		return NULL;
954 	os_memcpy(decrypted, encr_data, encr_data_len);
955 
956 	if (aes_128_cbc_decrypt(k_encr, iv, decrypted, encr_data_len)) {
957 		os_free(decrypted);
958 		return NULL;
959 	}
960 	wpa_hexdump(MSG_MSGDUMP, "EAP-SIM: Decrypted AT_ENCR_DATA",
961 		    decrypted, encr_data_len);
962 
963 	if (eap_sim_parse_attr(decrypted, decrypted + encr_data_len, attr,
964 			       aka, 1)) {
965 		wpa_printf(MSG_INFO, "EAP-SIM: (encr) Failed to parse "
966 			   "decrypted AT_ENCR_DATA");
967 		os_free(decrypted);
968 		return NULL;
969 	}
970 
971 	return decrypted;
972 }
973 
974 
975 #define EAP_SIM_INIT_LEN 128
976 
977 struct eap_sim_msg {
978 	struct wpabuf *buf;
979 	size_t mac, iv, encr; /* index from buf */
980 	int type;
981 };
982 
983 
984 struct eap_sim_msg * eap_sim_msg_init(int code, int id, int type, int subtype)
985 {
986 	struct eap_sim_msg *msg;
987 	struct eap_hdr *eap;
988 	u8 *pos;
989 
990 	msg = os_zalloc(sizeof(*msg));
991 	if (msg == NULL)
992 		return NULL;
993 
994 	msg->type = type;
995 	msg->buf = wpabuf_alloc(EAP_SIM_INIT_LEN);
996 	if (msg->buf == NULL) {
997 		os_free(msg);
998 		return NULL;
999 	}
1000 	eap = wpabuf_put(msg->buf, sizeof(*eap));
1001 	eap->code = code;
1002 	eap->identifier = id;
1003 
1004 	pos = wpabuf_put(msg->buf, 4);
1005 	*pos++ = type;
1006 	*pos++ = subtype;
1007 	*pos++ = 0; /* Reserved */
1008 	*pos++ = 0; /* Reserved */
1009 
1010 	return msg;
1011 }
1012 
1013 
1014 struct wpabuf * eap_sim_msg_finish(struct eap_sim_msg *msg, const u8 *k_aut,
1015 				   const u8 *extra, size_t extra_len)
1016 {
1017 	struct eap_hdr *eap;
1018 	struct wpabuf *buf;
1019 
1020 	if (msg == NULL)
1021 		return NULL;
1022 
1023 	eap = wpabuf_mhead(msg->buf);
1024 	eap->length = host_to_be16(wpabuf_len(msg->buf));
1025 
1026 #ifdef EAP_AKA_PRIME
1027 	if (k_aut && msg->mac && msg->type == EAP_TYPE_AKA_PRIME) {
1028 		eap_sim_add_mac_sha256(k_aut, (u8 *) wpabuf_head(msg->buf),
1029 				       wpabuf_len(msg->buf),
1030 				       (u8 *) wpabuf_mhead(msg->buf) +
1031 				       msg->mac, extra, extra_len);
1032 	} else
1033 #endif /* EAP_AKA_PRIME */
1034 	if (k_aut && msg->mac) {
1035 		eap_sim_add_mac(k_aut, (u8 *) wpabuf_head(msg->buf),
1036 				wpabuf_len(msg->buf),
1037 				(u8 *) wpabuf_mhead(msg->buf) + msg->mac,
1038 				extra, extra_len);
1039 	}
1040 
1041 	buf = msg->buf;
1042 	os_free(msg);
1043 	return buf;
1044 }
1045 
1046 
1047 void eap_sim_msg_free(struct eap_sim_msg *msg)
1048 {
1049 	if (msg) {
1050 		wpabuf_free(msg->buf);
1051 		os_free(msg);
1052 	}
1053 }
1054 
1055 
1056 u8 * eap_sim_msg_add_full(struct eap_sim_msg *msg, u8 attr,
1057 			  const u8 *data, size_t len)
1058 {
1059 	int attr_len = 2 + len;
1060 	int pad_len;
1061 	u8 *start;
1062 
1063 	if (msg == NULL)
1064 		return NULL;
1065 
1066 	pad_len = (4 - attr_len % 4) % 4;
1067 	attr_len += pad_len;
1068 	if (wpabuf_resize(&msg->buf, attr_len))
1069 		return NULL;
1070 	start = wpabuf_put(msg->buf, 0);
1071 	wpabuf_put_u8(msg->buf, attr);
1072 	wpabuf_put_u8(msg->buf, attr_len / 4);
1073 	wpabuf_put_data(msg->buf, data, len);
1074 	if (pad_len)
1075 		os_memset(wpabuf_put(msg->buf, pad_len), 0, pad_len);
1076 	return start;
1077 }
1078 
1079 
1080 u8 * eap_sim_msg_add(struct eap_sim_msg *msg, u8 attr, u16 value,
1081 		     const u8 *data, size_t len)
1082 {
1083 	int attr_len = 4 + len;
1084 	int pad_len;
1085 	u8 *start;
1086 
1087 	if (msg == NULL)
1088 		return NULL;
1089 
1090 	pad_len = (4 - attr_len % 4) % 4;
1091 	attr_len += pad_len;
1092 	if (wpabuf_resize(&msg->buf, attr_len))
1093 		return NULL;
1094 	start = wpabuf_put(msg->buf, 0);
1095 	wpabuf_put_u8(msg->buf, attr);
1096 	wpabuf_put_u8(msg->buf, attr_len / 4);
1097 	wpabuf_put_be16(msg->buf, value);
1098 	if (data)
1099 		wpabuf_put_data(msg->buf, data, len);
1100 	else
1101 		wpabuf_put(msg->buf, len);
1102 	if (pad_len)
1103 		os_memset(wpabuf_put(msg->buf, pad_len), 0, pad_len);
1104 	return start;
1105 }
1106 
1107 
1108 u8 * eap_sim_msg_add_mac(struct eap_sim_msg *msg, u8 attr)
1109 {
1110 	u8 *pos = eap_sim_msg_add(msg, attr, 0, NULL, EAP_SIM_MAC_LEN);
1111 	if (pos)
1112 		msg->mac = (pos - wpabuf_head_u8(msg->buf)) + 4;
1113 	return pos;
1114 }
1115 
1116 
1117 int eap_sim_msg_add_encr_start(struct eap_sim_msg *msg, u8 attr_iv,
1118 			       u8 attr_encr)
1119 {
1120 	u8 *pos = eap_sim_msg_add(msg, attr_iv, 0, NULL, EAP_SIM_IV_LEN);
1121 	if (pos == NULL)
1122 		return -1;
1123 	msg->iv = (pos - wpabuf_head_u8(msg->buf)) + 4;
1124 	if (os_get_random(wpabuf_mhead_u8(msg->buf) + msg->iv,
1125 			  EAP_SIM_IV_LEN)) {
1126 		msg->iv = 0;
1127 		return -1;
1128 	}
1129 
1130 	pos = eap_sim_msg_add(msg, attr_encr, 0, NULL, 0);
1131 	if (pos == NULL) {
1132 		msg->iv = 0;
1133 		return -1;
1134 	}
1135 	msg->encr = pos - wpabuf_head_u8(msg->buf);
1136 
1137 	return 0;
1138 }
1139 
1140 
1141 int eap_sim_msg_add_encr_end(struct eap_sim_msg *msg, u8 *k_encr, int attr_pad)
1142 {
1143 	size_t encr_len;
1144 
1145 	if (msg == NULL || k_encr == NULL || msg->iv == 0 || msg->encr == 0)
1146 		return -1;
1147 
1148 	encr_len = wpabuf_len(msg->buf) - msg->encr - 4;
1149 	if (encr_len % 16) {
1150 		u8 *pos;
1151 		int pad_len = 16 - (encr_len % 16);
1152 		if (pad_len < 4) {
1153 			wpa_printf(MSG_WARNING, "EAP-SIM: "
1154 				   "eap_sim_msg_add_encr_end - invalid pad_len"
1155 				   " %d", pad_len);
1156 			return -1;
1157 		}
1158 		wpa_printf(MSG_DEBUG, "   *AT_PADDING");
1159 		pos = eap_sim_msg_add(msg, attr_pad, 0, NULL, pad_len - 4);
1160 		if (pos == NULL)
1161 			return -1;
1162 		os_memset(pos + 4, 0, pad_len - 4);
1163 		encr_len += pad_len;
1164 	}
1165 	wpa_printf(MSG_DEBUG, "   (AT_ENCR_DATA data len %lu)",
1166 		   (unsigned long) encr_len);
1167 	wpabuf_mhead_u8(msg->buf)[msg->encr + 1] = encr_len / 4 + 1;
1168 	return aes_128_cbc_encrypt(k_encr, wpabuf_head_u8(msg->buf) + msg->iv,
1169 				   wpabuf_mhead_u8(msg->buf) + msg->encr + 4,
1170 				   encr_len);
1171 }
1172 
1173 
1174 void eap_sim_report_notification(void *msg_ctx, int notification, int aka)
1175 {
1176 #ifndef CONFIG_NO_STDOUT_DEBUG
1177 	const char *type = aka ? "AKA" : "SIM";
1178 #endif /* CONFIG_NO_STDOUT_DEBUG */
1179 
1180 	switch (notification) {
1181 	case EAP_SIM_GENERAL_FAILURE_AFTER_AUTH:
1182 		wpa_printf(MSG_WARNING, "EAP-%s: General failure "
1183 			   "notification (after authentication)", type);
1184 		break;
1185 	case EAP_SIM_TEMPORARILY_DENIED:
1186 		wpa_printf(MSG_WARNING, "EAP-%s: Failure notification: "
1187 			   "User has been temporarily denied access to the "
1188 			   "requested service", type);
1189 		break;
1190 	case EAP_SIM_NOT_SUBSCRIBED:
1191 		wpa_printf(MSG_WARNING, "EAP-%s: Failure notification: "
1192 			   "User has not subscribed to the requested service",
1193 			   type);
1194 		break;
1195 	case EAP_SIM_GENERAL_FAILURE_BEFORE_AUTH:
1196 		wpa_printf(MSG_WARNING, "EAP-%s: General failure "
1197 			   "notification (before authentication)", type);
1198 		break;
1199 	case EAP_SIM_SUCCESS:
1200 		wpa_printf(MSG_INFO, "EAP-%s: Successful authentication "
1201 			   "notification", type);
1202 		break;
1203 	default:
1204 		if (notification >= 32768) {
1205 			wpa_printf(MSG_INFO, "EAP-%s: Unrecognized "
1206 				   "non-failure notification %d",
1207 				   type, notification);
1208 		} else {
1209 			wpa_printf(MSG_WARNING, "EAP-%s: Unrecognized "
1210 				   "failure notification %d",
1211 				   type, notification);
1212 		}
1213 	}
1214 }
1215