1/*
2 * TLSv1 server (RFC 2246)
3 * Copyright (c) 2006-2007, 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 "sha1.h"
19#include "tls.h"
20#include "tlsv1_common.h"
21#include "tlsv1_record.h"
22#include "tlsv1_server.h"
23#include "tlsv1_server_i.h"
24
25/* TODO:
26 * Support for a message fragmented across several records (RFC 2246, 6.2.1)
27 */
28
29
30void tlsv1_server_alert(struct tlsv1_server *conn, u8 level, u8 description)
31{
32	conn->alert_level = level;
33	conn->alert_description = description;
34}
35
36
37int tlsv1_server_derive_keys(struct tlsv1_server *conn,
38			     const u8 *pre_master_secret,
39			     size_t pre_master_secret_len)
40{
41	u8 seed[2 * TLS_RANDOM_LEN];
42	u8 key_block[TLS_MAX_KEY_BLOCK_LEN];
43	u8 *pos;
44	size_t key_block_len;
45
46	if (pre_master_secret) {
47		wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: pre_master_secret",
48				pre_master_secret, pre_master_secret_len);
49		os_memcpy(seed, conn->client_random, TLS_RANDOM_LEN);
50		os_memcpy(seed + TLS_RANDOM_LEN, conn->server_random,
51			  TLS_RANDOM_LEN);
52		if (tls_prf(pre_master_secret, pre_master_secret_len,
53			    "master secret", seed, 2 * TLS_RANDOM_LEN,
54			    conn->master_secret, TLS_MASTER_SECRET_LEN)) {
55			wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive "
56				   "master_secret");
57			return -1;
58		}
59		wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: master_secret",
60				conn->master_secret, TLS_MASTER_SECRET_LEN);
61	}
62
63	os_memcpy(seed, conn->server_random, TLS_RANDOM_LEN);
64	os_memcpy(seed + TLS_RANDOM_LEN, conn->client_random, TLS_RANDOM_LEN);
65	key_block_len = 2 * (conn->rl.hash_size + conn->rl.key_material_len +
66			     conn->rl.iv_size);
67	if (tls_prf(conn->master_secret, TLS_MASTER_SECRET_LEN,
68		    "key expansion", seed, 2 * TLS_RANDOM_LEN,
69		    key_block, key_block_len)) {
70		wpa_printf(MSG_DEBUG, "TLSv1: Failed to derive key_block");
71		return -1;
72	}
73	wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: key_block",
74			key_block, key_block_len);
75
76	pos = key_block;
77
78	/* client_write_MAC_secret */
79	os_memcpy(conn->rl.read_mac_secret, pos, conn->rl.hash_size);
80	pos += conn->rl.hash_size;
81	/* server_write_MAC_secret */
82	os_memcpy(conn->rl.write_mac_secret, pos, conn->rl.hash_size);
83	pos += conn->rl.hash_size;
84
85	/* client_write_key */
86	os_memcpy(conn->rl.read_key, pos, conn->rl.key_material_len);
87	pos += conn->rl.key_material_len;
88	/* server_write_key */
89	os_memcpy(conn->rl.write_key, pos, conn->rl.key_material_len);
90	pos += conn->rl.key_material_len;
91
92	/* client_write_IV */
93	os_memcpy(conn->rl.read_iv, pos, conn->rl.iv_size);
94	pos += conn->rl.iv_size;
95	/* server_write_IV */
96	os_memcpy(conn->rl.write_iv, pos, conn->rl.iv_size);
97	pos += conn->rl.iv_size;
98
99	return 0;
100}
101
102
103/**
104 * tlsv1_server_handshake - Process TLS handshake
105 * @conn: TLSv1 server connection data from tlsv1_server_init()
106 * @in_data: Input data from TLS peer
107 * @in_len: Input data length
108 * @out_len: Length of the output buffer.
109 * Returns: Pointer to output data, %NULL on failure
110 */
111u8 * tlsv1_server_handshake(struct tlsv1_server *conn,
112			    const u8 *in_data, size_t in_len,
113			    size_t *out_len)
114{
115	const u8 *pos, *end;
116	u8 *msg = NULL, *in_msg, *in_pos, *in_end, alert, ct;
117	size_t in_msg_len;
118
119	if (in_data == NULL || in_len == 0) {
120		wpa_printf(MSG_DEBUG, "TLSv1: No input data to server");
121		return NULL;
122	}
123
124	pos = in_data;
125	end = in_data + in_len;
126	in_msg = os_malloc(in_len);
127	if (in_msg == NULL)
128		return NULL;
129
130	/* Each received packet may include multiple records */
131	while (pos < end) {
132		in_msg_len = in_len;
133		if (tlsv1_record_receive(&conn->rl, pos, end - pos,
134					 in_msg, &in_msg_len, &alert)) {
135			wpa_printf(MSG_DEBUG, "TLSv1: Processing received "
136				   "record failed");
137			tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, alert);
138			goto failed;
139		}
140		ct = pos[0];
141
142		in_pos = in_msg;
143		in_end = in_msg + in_msg_len;
144
145		/* Each received record may include multiple messages of the
146		 * same ContentType. */
147		while (in_pos < in_end) {
148			in_msg_len = in_end - in_pos;
149			if (tlsv1_server_process_handshake(conn, ct, in_pos,
150							   &in_msg_len) < 0)
151				goto failed;
152			in_pos += in_msg_len;
153		}
154
155		pos += TLS_RECORD_HEADER_LEN + WPA_GET_BE16(pos + 3);
156	}
157
158	os_free(in_msg);
159	in_msg = NULL;
160
161	msg = tlsv1_server_handshake_write(conn, out_len);
162
163failed:
164	os_free(in_msg);
165	if (conn->alert_level) {
166		if (conn->state == FAILED) {
167			/* Avoid alert loops */
168			wpa_printf(MSG_DEBUG, "TLSv1: Drop alert loop");
169			os_free(msg);
170			return NULL;
171		}
172		conn->state = FAILED;
173		os_free(msg);
174		msg = tlsv1_server_send_alert(conn, conn->alert_level,
175					      conn->alert_description,
176					      out_len);
177	}
178
179	return msg;
180}
181
182
183/**
184 * tlsv1_server_encrypt - Encrypt data into TLS tunnel
185 * @conn: TLSv1 server connection data from tlsv1_server_init()
186 * @in_data: Pointer to plaintext data to be encrypted
187 * @in_len: Input buffer length
188 * @out_data: Pointer to output buffer (encrypted TLS data)
189 * @out_len: Maximum out_data length
190 * Returns: Number of bytes written to out_data, -1 on failure
191 *
192 * This function is used after TLS handshake has been completed successfully to
193 * send data in the encrypted tunnel.
194 */
195int tlsv1_server_encrypt(struct tlsv1_server *conn,
196			 const u8 *in_data, size_t in_len,
197			 u8 *out_data, size_t out_len)
198{
199	size_t rlen;
200
201	wpa_hexdump_key(MSG_MSGDUMP, "TLSv1: Plaintext AppData",
202			in_data, in_len);
203
204	os_memcpy(out_data + TLS_RECORD_HEADER_LEN, in_data, in_len);
205
206	if (tlsv1_record_send(&conn->rl, TLS_CONTENT_TYPE_APPLICATION_DATA,
207			      out_data, out_len, in_len, &rlen) < 0) {
208		wpa_printf(MSG_DEBUG, "TLSv1: Failed to create a record");
209		tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
210				   TLS_ALERT_INTERNAL_ERROR);
211		return -1;
212	}
213
214	return rlen;
215}
216
217
218/**
219 * tlsv1_server_decrypt - Decrypt data from TLS tunnel
220 * @conn: TLSv1 server connection data from tlsv1_server_init()
221 * @in_data: Pointer to input buffer (encrypted TLS data)
222 * @in_len: Input buffer length
223 * @out_data: Pointer to output buffer (decrypted data from TLS tunnel)
224 * @out_len: Maximum out_data length
225 * Returns: Number of bytes written to out_data, -1 on failure
226 *
227 * This function is used after TLS handshake has been completed successfully to
228 * receive data from the encrypted tunnel.
229 */
230int tlsv1_server_decrypt(struct tlsv1_server *conn,
231			 const u8 *in_data, size_t in_len,
232			 u8 *out_data, size_t out_len)
233{
234	const u8 *in_end, *pos;
235	int res;
236	u8 alert, *out_end, *out_pos;
237	size_t olen;
238
239	pos = in_data;
240	in_end = in_data + in_len;
241	out_pos = out_data;
242	out_end = out_data + out_len;
243
244	while (pos < in_end) {
245		if (pos[0] != TLS_CONTENT_TYPE_APPLICATION_DATA) {
246			wpa_printf(MSG_DEBUG, "TLSv1: Unexpected content type "
247				   "0x%x", pos[0]);
248			tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
249					   TLS_ALERT_UNEXPECTED_MESSAGE);
250			return -1;
251		}
252
253		olen = out_end - out_pos;
254		res = tlsv1_record_receive(&conn->rl, pos, in_end - pos,
255					   out_pos, &olen, &alert);
256		if (res < 0) {
257			wpa_printf(MSG_DEBUG, "TLSv1: Record layer processing "
258				   "failed");
259			tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL, alert);
260			return -1;
261		}
262		out_pos += olen;
263		if (out_pos > out_end) {
264			wpa_printf(MSG_DEBUG, "TLSv1: Buffer not large enough "
265				   "for processing the received record");
266			tlsv1_server_alert(conn, TLS_ALERT_LEVEL_FATAL,
267					   TLS_ALERT_INTERNAL_ERROR);
268			return -1;
269		}
270
271		pos += TLS_RECORD_HEADER_LEN + WPA_GET_BE16(pos + 3);
272	}
273
274	return out_pos - out_data;
275}
276
277
278/**
279 * tlsv1_server_global_init - Initialize TLSv1 server
280 * Returns: 0 on success, -1 on failure
281 *
282 * This function must be called before using any other TLSv1 server functions.
283 */
284int tlsv1_server_global_init(void)
285{
286	return crypto_global_init();
287}
288
289
290/**
291 * tlsv1_server_global_deinit - Deinitialize TLSv1 server
292 *
293 * This function can be used to deinitialize the TLSv1 server that was
294 * initialized by calling tlsv1_server_global_init(). No TLSv1 server functions
295 * can be called after this before calling tlsv1_server_global_init() again.
296 */
297void tlsv1_server_global_deinit(void)
298{
299	crypto_global_deinit();
300}
301
302
303/**
304 * tlsv1_server_init - Initialize TLSv1 server connection
305 * @cred: Pointer to server credentials from tlsv1_server_cred_alloc()
306 * Returns: Pointer to TLSv1 server connection data or %NULL on failure
307 */
308struct tlsv1_server * tlsv1_server_init(struct tlsv1_credentials *cred)
309{
310	struct tlsv1_server *conn;
311	size_t count;
312	u16 *suites;
313
314	conn = os_zalloc(sizeof(*conn));
315	if (conn == NULL)
316		return NULL;
317
318	conn->cred = cred;
319
320	conn->state = CLIENT_HELLO;
321
322	if (tls_verify_hash_init(&conn->verify) < 0) {
323		wpa_printf(MSG_DEBUG, "TLSv1: Failed to initialize verify "
324			   "hash");
325		os_free(conn);
326		return NULL;
327	}
328
329	count = 0;
330	suites = conn->cipher_suites;
331#ifndef CONFIG_CRYPTO_INTERNAL
332	suites[count++] = TLS_RSA_WITH_AES_256_CBC_SHA;
333#endif /* CONFIG_CRYPTO_INTERNAL */
334	suites[count++] = TLS_RSA_WITH_AES_128_CBC_SHA;
335	suites[count++] = TLS_RSA_WITH_3DES_EDE_CBC_SHA;
336	suites[count++] = TLS_RSA_WITH_RC4_128_SHA;
337	suites[count++] = TLS_RSA_WITH_RC4_128_MD5;
338	conn->num_cipher_suites = count;
339
340	return conn;
341}
342
343
344static void tlsv1_server_clear_data(struct tlsv1_server *conn)
345{
346	tlsv1_record_set_cipher_suite(&conn->rl, TLS_NULL_WITH_NULL_NULL);
347	tlsv1_record_change_write_cipher(&conn->rl);
348	tlsv1_record_change_read_cipher(&conn->rl);
349	tls_verify_hash_free(&conn->verify);
350
351	crypto_public_key_free(conn->client_rsa_key);
352	conn->client_rsa_key = NULL;
353
354	os_free(conn->session_ticket);
355	conn->session_ticket = NULL;
356	conn->session_ticket_len = 0;
357	conn->use_session_ticket = 0;
358
359	os_free(conn->dh_secret);
360	conn->dh_secret = NULL;
361	conn->dh_secret_len = 0;
362}
363
364
365/**
366 * tlsv1_server_deinit - Deinitialize TLSv1 server connection
367 * @conn: TLSv1 server connection data from tlsv1_server_init()
368 */
369void tlsv1_server_deinit(struct tlsv1_server *conn)
370{
371	tlsv1_server_clear_data(conn);
372	os_free(conn);
373}
374
375
376/**
377 * tlsv1_server_established - Check whether connection has been established
378 * @conn: TLSv1 server connection data from tlsv1_server_init()
379 * Returns: 1 if connection is established, 0 if not
380 */
381int tlsv1_server_established(struct tlsv1_server *conn)
382{
383	return conn->state == ESTABLISHED;
384}
385
386
387/**
388 * tlsv1_server_prf - Use TLS-PRF to derive keying material
389 * @conn: TLSv1 server connection data from tlsv1_server_init()
390 * @label: Label (e.g., description of the key) for PRF
391 * @server_random_first: seed is 0 = client_random|server_random,
392 * 1 = server_random|client_random
393 * @out: Buffer for output data from TLS-PRF
394 * @out_len: Length of the output buffer
395 * Returns: 0 on success, -1 on failure
396 */
397int tlsv1_server_prf(struct tlsv1_server *conn, const char *label,
398		     int server_random_first, u8 *out, size_t out_len)
399{
400	u8 seed[2 * TLS_RANDOM_LEN];
401
402	if (conn->state != ESTABLISHED)
403		return -1;
404
405	if (server_random_first) {
406		os_memcpy(seed, conn->server_random, TLS_RANDOM_LEN);
407		os_memcpy(seed + TLS_RANDOM_LEN, conn->client_random,
408			  TLS_RANDOM_LEN);
409	} else {
410		os_memcpy(seed, conn->client_random, TLS_RANDOM_LEN);
411		os_memcpy(seed + TLS_RANDOM_LEN, conn->server_random,
412			  TLS_RANDOM_LEN);
413	}
414
415	return tls_prf(conn->master_secret, TLS_MASTER_SECRET_LEN,
416		       label, seed, 2 * TLS_RANDOM_LEN, out, out_len);
417}
418
419
420/**
421 * tlsv1_server_get_cipher - Get current cipher name
422 * @conn: TLSv1 server connection data from tlsv1_server_init()
423 * @buf: Buffer for the cipher name
424 * @buflen: buf size
425 * Returns: 0 on success, -1 on failure
426 *
427 * Get the name of the currently used cipher.
428 */
429int tlsv1_server_get_cipher(struct tlsv1_server *conn, char *buf,
430			    size_t buflen)
431{
432	char *cipher;
433
434	switch (conn->rl.cipher_suite) {
435	case TLS_RSA_WITH_RC4_128_MD5:
436		cipher = "RC4-MD5";
437		break;
438	case TLS_RSA_WITH_RC4_128_SHA:
439		cipher = "RC4-SHA";
440		break;
441	case TLS_RSA_WITH_DES_CBC_SHA:
442		cipher = "DES-CBC-SHA";
443		break;
444	case TLS_RSA_WITH_3DES_EDE_CBC_SHA:
445		cipher = "DES-CBC3-SHA";
446		break;
447	case TLS_DH_anon_WITH_AES_128_CBC_SHA:
448		cipher = "ADH-AES-128-SHA";
449		break;
450	case TLS_RSA_WITH_AES_256_CBC_SHA:
451		cipher = "AES-256-SHA";
452		break;
453	case TLS_RSA_WITH_AES_128_CBC_SHA:
454		cipher = "AES-128-SHA";
455		break;
456	default:
457		return -1;
458	}
459
460	if (os_strlcpy(buf, cipher, buflen) >= buflen)
461		return -1;
462	return 0;
463}
464
465
466/**
467 * tlsv1_server_shutdown - Shutdown TLS connection
468 * @conn: TLSv1 server connection data from tlsv1_server_init()
469 * Returns: 0 on success, -1 on failure
470 */
471int tlsv1_server_shutdown(struct tlsv1_server *conn)
472{
473	conn->state = CLIENT_HELLO;
474
475	if (tls_verify_hash_init(&conn->verify) < 0) {
476		wpa_printf(MSG_DEBUG, "TLSv1: Failed to re-initialize verify "
477			   "hash");
478		return -1;
479	}
480
481	tlsv1_server_clear_data(conn);
482
483	return 0;
484}
485
486
487/**
488 * tlsv1_server_resumed - Was session resumption used
489 * @conn: TLSv1 server connection data from tlsv1_server_init()
490 * Returns: 1 if current session used session resumption, 0 if not
491 */
492int tlsv1_server_resumed(struct tlsv1_server *conn)
493{
494	return 0;
495}
496
497
498/**
499 * tlsv1_server_get_keys - Get master key and random data from TLS connection
500 * @conn: TLSv1 server connection data from tlsv1_server_init()
501 * @keys: Structure of key/random data (filled on success)
502 * Returns: 0 on success, -1 on failure
503 */
504int tlsv1_server_get_keys(struct tlsv1_server *conn, struct tls_keys *keys)
505{
506	os_memset(keys, 0, sizeof(*keys));
507	if (conn->state == CLIENT_HELLO)
508		return -1;
509
510	keys->client_random = conn->client_random;
511	keys->client_random_len = TLS_RANDOM_LEN;
512
513	if (conn->state != SERVER_HELLO) {
514		keys->server_random = conn->server_random;
515		keys->server_random_len = TLS_RANDOM_LEN;
516		keys->master_key = conn->master_secret;
517		keys->master_key_len = TLS_MASTER_SECRET_LEN;
518	}
519
520	return 0;
521}
522
523
524/**
525 * tlsv1_server_get_keyblock_size - Get TLS key_block size
526 * @conn: TLSv1 server connection data from tlsv1_server_init()
527 * Returns: Size of the key_block for the negotiated cipher suite or -1 on
528 * failure
529 */
530int tlsv1_server_get_keyblock_size(struct tlsv1_server *conn)
531{
532	if (conn->state == CLIENT_HELLO || conn->state == SERVER_HELLO)
533		return -1;
534
535	return 2 * (conn->rl.hash_size + conn->rl.key_material_len +
536		    conn->rl.iv_size);
537}
538
539
540/**
541 * tlsv1_server_set_cipher_list - Configure acceptable cipher suites
542 * @conn: TLSv1 server connection data from tlsv1_server_init()
543 * @ciphers: Zero (TLS_CIPHER_NONE) terminated list of allowed ciphers
544 * (TLS_CIPHER_*).
545 * Returns: 0 on success, -1 on failure
546 */
547int tlsv1_server_set_cipher_list(struct tlsv1_server *conn, u8 *ciphers)
548{
549#ifdef EAP_FAST
550	size_t count;
551	u16 *suites;
552
553	/* TODO: implement proper configuration of cipher suites */
554	if (ciphers[0] == TLS_CIPHER_ANON_DH_AES128_SHA) {
555		count = 0;
556		suites = conn->cipher_suites;
557#ifndef CONFIG_CRYPTO_INTERNAL
558		suites[count++] = TLS_RSA_WITH_AES_256_CBC_SHA;
559#endif /* CONFIG_CRYPTO_INTERNAL */
560		suites[count++] = TLS_RSA_WITH_AES_128_CBC_SHA;
561		suites[count++] = TLS_RSA_WITH_3DES_EDE_CBC_SHA;
562		suites[count++] = TLS_RSA_WITH_RC4_128_SHA;
563		suites[count++] = TLS_RSA_WITH_RC4_128_MD5;
564#ifndef CONFIG_CRYPTO_INTERNAL
565		suites[count++] = TLS_DH_anon_WITH_AES_256_CBC_SHA;
566#endif /* CONFIG_CRYPTO_INTERNAL */
567		suites[count++] = TLS_DH_anon_WITH_AES_128_CBC_SHA;
568		suites[count++] = TLS_DH_anon_WITH_3DES_EDE_CBC_SHA;
569		suites[count++] = TLS_DH_anon_WITH_RC4_128_MD5;
570		suites[count++] = TLS_DH_anon_WITH_DES_CBC_SHA;
571		conn->num_cipher_suites = count;
572	}
573
574	return 0;
575#else /* EAP_FAST */
576	return -1;
577#endif /* EAP_FAST */
578}
579
580
581int tlsv1_server_set_verify(struct tlsv1_server *conn, int verify_peer)
582{
583	conn->verify_peer = verify_peer;
584	return 0;
585}
586
587
588void tlsv1_server_set_session_ticket_cb(struct tlsv1_server *conn,
589					tlsv1_server_session_ticket_cb cb,
590					void *ctx)
591{
592	wpa_printf(MSG_DEBUG, "TLSv1: SessionTicket callback set %p (ctx %p)",
593		   cb, ctx);
594	conn->session_ticket_cb = cb;
595	conn->session_ticket_cb_ctx = ctx;
596}
597