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      1 /*
      2  * EAP peer: EAP-TLS/PEAP/TTLS/FAST common functions
      3  * Copyright (c) 2004-2012, Jouni Malinen <j (at) w1.fi>
      4  *
      5  * This software may be distributed under the terms of the BSD license.
      6  * See README for more details.
      7  */
      8 
      9 #include "includes.h"
     10 
     11 #include "common.h"
     12 #include "crypto/sha1.h"
     13 #include "crypto/tls.h"
     14 #include "eap_i.h"
     15 #include "eap_tls_common.h"
     16 #include "eap_config.h"
     17 
     18 
     19 static struct wpabuf * eap_tls_msg_alloc(EapType type, size_t payload_len,
     20 					 u8 code, u8 identifier)
     21 {
     22 	if (type == EAP_UNAUTH_TLS_TYPE)
     23 		return eap_msg_alloc(EAP_VENDOR_UNAUTH_TLS,
     24 				     EAP_VENDOR_TYPE_UNAUTH_TLS, payload_len,
     25 				     code, identifier);
     26 	return eap_msg_alloc(EAP_VENDOR_IETF, type, payload_len, code,
     27 			     identifier);
     28 }
     29 
     30 
     31 static int eap_tls_check_blob(struct eap_sm *sm, const char **name,
     32 			      const u8 **data, size_t *data_len)
     33 {
     34 	const struct wpa_config_blob *blob;
     35 
     36 	if (*name == NULL || os_strncmp(*name, "blob://", 7) != 0)
     37 		return 0;
     38 
     39 	blob = eap_get_config_blob(sm, *name + 7);
     40 	if (blob == NULL) {
     41 		wpa_printf(MSG_ERROR, "%s: Named configuration blob '%s' not "
     42 			   "found", __func__, *name + 7);
     43 		return -1;
     44 	}
     45 
     46 	*name = NULL;
     47 	*data = blob->data;
     48 	*data_len = blob->len;
     49 
     50 	return 0;
     51 }
     52 
     53 
     54 static void eap_tls_params_flags(struct tls_connection_params *params,
     55 				 const char *txt)
     56 {
     57 	if (txt == NULL)
     58 		return;
     59 	if (os_strstr(txt, "tls_allow_md5=1"))
     60 		params->flags |= TLS_CONN_ALLOW_SIGN_RSA_MD5;
     61 	if (os_strstr(txt, "tls_disable_time_checks=1"))
     62 		params->flags |= TLS_CONN_DISABLE_TIME_CHECKS;
     63 	if (os_strstr(txt, "tls_disable_session_ticket=1"))
     64 		params->flags |= TLS_CONN_DISABLE_SESSION_TICKET;
     65 	if (os_strstr(txt, "tls_disable_session_ticket=0"))
     66 		params->flags &= ~TLS_CONN_DISABLE_SESSION_TICKET;
     67 }
     68 
     69 
     70 static void eap_tls_params_from_conf1(struct tls_connection_params *params,
     71 				      struct eap_peer_config *config)
     72 {
     73 	params->ca_cert = (char *) config->ca_cert;
     74 	params->ca_path = (char *) config->ca_path;
     75 	params->client_cert = (char *) config->client_cert;
     76 	params->private_key = (char *) config->private_key;
     77 	params->private_key_passwd = (char *) config->private_key_passwd;
     78 	params->dh_file = (char *) config->dh_file;
     79 	params->subject_match = (char *) config->subject_match;
     80 	params->altsubject_match = (char *) config->altsubject_match;
     81 	params->engine = config->engine;
     82 	params->engine_id = config->engine_id;
     83 	params->pin = config->pin;
     84 	params->key_id = config->key_id;
     85 	params->cert_id = config->cert_id;
     86 	params->ca_cert_id = config->ca_cert_id;
     87 	eap_tls_params_flags(params, config->phase1);
     88 }
     89 
     90 
     91 static void eap_tls_params_from_conf2(struct tls_connection_params *params,
     92 				      struct eap_peer_config *config)
     93 {
     94 	params->ca_cert = (char *) config->ca_cert2;
     95 	params->ca_path = (char *) config->ca_path2;
     96 	params->client_cert = (char *) config->client_cert2;
     97 	params->private_key = (char *) config->private_key2;
     98 	params->private_key_passwd = (char *) config->private_key2_passwd;
     99 	params->dh_file = (char *) config->dh_file2;
    100 	params->subject_match = (char *) config->subject_match2;
    101 	params->altsubject_match = (char *) config->altsubject_match2;
    102 	params->engine = config->engine2;
    103 	params->engine_id = config->engine2_id;
    104 	params->pin = config->pin2;
    105 	params->key_id = config->key2_id;
    106 	params->cert_id = config->cert2_id;
    107 	params->ca_cert_id = config->ca_cert2_id;
    108 	eap_tls_params_flags(params, config->phase2);
    109 }
    110 
    111 
    112 static int eap_tls_params_from_conf(struct eap_sm *sm,
    113 				    struct eap_ssl_data *data,
    114 				    struct tls_connection_params *params,
    115 				    struct eap_peer_config *config, int phase2)
    116 {
    117 	os_memset(params, 0, sizeof(*params));
    118 	if (sm->workaround && data->eap_type != EAP_TYPE_FAST) {
    119 		/*
    120 		 * Some deployed authentication servers seem to be unable to
    121 		 * handle the TLS Session Ticket extension (they are supposed
    122 		 * to ignore unrecognized TLS extensions, but end up rejecting
    123 		 * the ClientHello instead). As a workaround, disable use of
    124 		 * TLS Sesson Ticket extension for EAP-TLS, EAP-PEAP, and
    125 		 * EAP-TTLS (EAP-FAST uses session ticket, so any server that
    126 		 * supports EAP-FAST does not need this workaround).
    127 		 */
    128 		params->flags |= TLS_CONN_DISABLE_SESSION_TICKET;
    129 	}
    130 	if (phase2) {
    131 		wpa_printf(MSG_DEBUG, "TLS: using phase2 config options");
    132 		eap_tls_params_from_conf2(params, config);
    133 	} else {
    134 		wpa_printf(MSG_DEBUG, "TLS: using phase1 config options");
    135 		eap_tls_params_from_conf1(params, config);
    136 	}
    137 
    138 	/*
    139 	 * Use blob data, if available. Otherwise, leave reference to external
    140 	 * file as-is.
    141 	 */
    142 	if (eap_tls_check_blob(sm, &params->ca_cert, &params->ca_cert_blob,
    143 			       &params->ca_cert_blob_len) ||
    144 	    eap_tls_check_blob(sm, &params->client_cert,
    145 			       &params->client_cert_blob,
    146 			       &params->client_cert_blob_len) ||
    147 	    eap_tls_check_blob(sm, &params->private_key,
    148 			       &params->private_key_blob,
    149 			       &params->private_key_blob_len) ||
    150 	    eap_tls_check_blob(sm, &params->dh_file, &params->dh_blob,
    151 			       &params->dh_blob_len)) {
    152 		wpa_printf(MSG_INFO, "SSL: Failed to get configuration blobs");
    153 		return -1;
    154 	}
    155 
    156 	return 0;
    157 }
    158 
    159 
    160 static int eap_tls_init_connection(struct eap_sm *sm,
    161 				   struct eap_ssl_data *data,
    162 				   struct eap_peer_config *config,
    163 				   struct tls_connection_params *params)
    164 {
    165 	int res;
    166 
    167 	data->conn = tls_connection_init(data->ssl_ctx);
    168 	if (data->conn == NULL) {
    169 		wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
    170 			   "connection");
    171 		return -1;
    172 	}
    173 
    174 	res = tls_connection_set_params(data->ssl_ctx, data->conn, params);
    175 	if (res == TLS_SET_PARAMS_ENGINE_PRV_INIT_FAILED) {
    176 		/*
    177 		 * At this point with the pkcs11 engine the PIN might be wrong.
    178 		 * We reset the PIN in the configuration to be sure to not use
    179 		 * it again and the calling function must request a new one.
    180 		 */
    181 		os_free(config->pin);
    182 		config->pin = NULL;
    183 	} else if (res == TLS_SET_PARAMS_ENGINE_PRV_VERIFY_FAILED) {
    184 		wpa_printf(MSG_INFO, "TLS: Failed to load private key");
    185 		/*
    186 		 * We do not know exactly but maybe the PIN was wrong,
    187 		 * so ask for a new one.
    188 		 */
    189 		os_free(config->pin);
    190 		config->pin = NULL;
    191 		eap_sm_request_pin(sm);
    192 		sm->ignore = TRUE;
    193 		tls_connection_deinit(data->ssl_ctx, data->conn);
    194 		data->conn = NULL;
    195 		return -1;
    196 	} else if (res) {
    197 		wpa_printf(MSG_INFO, "TLS: Failed to set TLS connection "
    198 			   "parameters");
    199 		tls_connection_deinit(data->ssl_ctx, data->conn);
    200 		data->conn = NULL;
    201 		return -1;
    202 	}
    203 
    204 	return 0;
    205 }
    206 
    207 
    208 /**
    209  * eap_peer_tls_ssl_init - Initialize shared TLS functionality
    210  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    211  * @data: Data for TLS processing
    212  * @config: Pointer to the network configuration
    213  * @eap_type: EAP method used in Phase 1 (EAP_TYPE_TLS/PEAP/TTLS/FAST)
    214  * Returns: 0 on success, -1 on failure
    215  *
    216  * This function is used to initialize shared TLS functionality for EAP-TLS,
    217  * EAP-PEAP, EAP-TTLS, and EAP-FAST.
    218  */
    219 int eap_peer_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
    220 			  struct eap_peer_config *config, u8 eap_type)
    221 {
    222 	struct tls_connection_params params;
    223 
    224 	if (config == NULL)
    225 		return -1;
    226 
    227 	data->eap = sm;
    228 	data->eap_type = eap_type;
    229 	data->phase2 = sm->init_phase2;
    230 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
    231 		sm->ssl_ctx;
    232 	if (eap_tls_params_from_conf(sm, data, &params, config, data->phase2) <
    233 	    0)
    234 		return -1;
    235 
    236 	if (eap_tls_init_connection(sm, data, config, &params) < 0)
    237 		return -1;
    238 
    239 	data->tls_out_limit = config->fragment_size;
    240 	if (data->phase2) {
    241 		/* Limit the fragment size in the inner TLS authentication
    242 		 * since the outer authentication with EAP-PEAP does not yet
    243 		 * support fragmentation */
    244 		if (data->tls_out_limit > 100)
    245 			data->tls_out_limit -= 100;
    246 	}
    247 
    248 	if (config->phase1 &&
    249 	    os_strstr(config->phase1, "include_tls_length=1")) {
    250 		wpa_printf(MSG_DEBUG, "TLS: Include TLS Message Length in "
    251 			   "unfragmented packets");
    252 		data->include_tls_length = 1;
    253 	}
    254 
    255 	return 0;
    256 }
    257 
    258 
    259 /**
    260  * eap_peer_tls_ssl_deinit - Deinitialize shared TLS functionality
    261  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    262  * @data: Data for TLS processing
    263  *
    264  * This function deinitializes shared TLS functionality that was initialized
    265  * with eap_peer_tls_ssl_init().
    266  */
    267 void eap_peer_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
    268 {
    269 	tls_connection_deinit(data->ssl_ctx, data->conn);
    270 	eap_peer_tls_reset_input(data);
    271 	eap_peer_tls_reset_output(data);
    272 }
    273 
    274 
    275 /**
    276  * eap_peer_tls_derive_key - Derive a key based on TLS session data
    277  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    278  * @data: Data for TLS processing
    279  * @label: Label string for deriving the keys, e.g., "client EAP encryption"
    280  * @len: Length of the key material to generate (usually 64 for MSK)
    281  * Returns: Pointer to allocated key on success or %NULL on failure
    282  *
    283  * This function uses TLS-PRF to generate pseudo-random data based on the TLS
    284  * session data (client/server random and master key). Each key type may use a
    285  * different label to bind the key usage into the generated material.
    286  *
    287  * The caller is responsible for freeing the returned buffer.
    288  */
    289 u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
    290 			     const char *label, size_t len)
    291 {
    292 #ifndef CONFIG_FIPS
    293 	struct tls_keys keys;
    294 #endif /* CONFIG_FIPS */
    295 	u8 *rnd = NULL, *out;
    296 
    297 	out = os_malloc(len);
    298 	if (out == NULL)
    299 		return NULL;
    300 
    301 	/* First, try to use TLS library function for PRF, if available. */
    302 	if (tls_connection_prf(data->ssl_ctx, data->conn, label, 0, out, len)
    303 	    == 0)
    304 		return out;
    305 
    306 #ifndef CONFIG_FIPS
    307 	/*
    308 	 * TLS library did not support key generation, so get the needed TLS
    309 	 * session parameters and use an internal implementation of TLS PRF to
    310 	 * derive the key.
    311 	 */
    312 	if (tls_connection_get_keys(data->ssl_ctx, data->conn, &keys))
    313 		goto fail;
    314 
    315 	if (keys.client_random == NULL || keys.server_random == NULL ||
    316 	    keys.master_key == NULL)
    317 		goto fail;
    318 
    319 	rnd = os_malloc(keys.client_random_len + keys.server_random_len);
    320 	if (rnd == NULL)
    321 		goto fail;
    322 	os_memcpy(rnd, keys.client_random, keys.client_random_len);
    323 	os_memcpy(rnd + keys.client_random_len, keys.server_random,
    324 		  keys.server_random_len);
    325 
    326 	if (tls_prf_sha1_md5(keys.master_key, keys.master_key_len,
    327 			     label, rnd, keys.client_random_len +
    328 			     keys.server_random_len, out, len))
    329 		goto fail;
    330 
    331 	os_free(rnd);
    332 	return out;
    333 
    334 fail:
    335 #endif /* CONFIG_FIPS */
    336 	os_free(out);
    337 	os_free(rnd);
    338 	return NULL;
    339 }
    340 
    341 
    342 /**
    343  * eap_peer_tls_reassemble_fragment - Reassemble a received fragment
    344  * @data: Data for TLS processing
    345  * @in_data: Next incoming TLS segment
    346  * Returns: 0 on success, 1 if more data is needed for the full message, or
    347  * -1 on error
    348  */
    349 static int eap_peer_tls_reassemble_fragment(struct eap_ssl_data *data,
    350 					    const struct wpabuf *in_data)
    351 {
    352 	size_t tls_in_len, in_len;
    353 
    354 	tls_in_len = data->tls_in ? wpabuf_len(data->tls_in) : 0;
    355 	in_len = in_data ? wpabuf_len(in_data) : 0;
    356 
    357 	if (tls_in_len + in_len == 0) {
    358 		/* No message data received?! */
    359 		wpa_printf(MSG_WARNING, "SSL: Invalid reassembly state: "
    360 			   "tls_in_left=%lu tls_in_len=%lu in_len=%lu",
    361 			   (unsigned long) data->tls_in_left,
    362 			   (unsigned long) tls_in_len,
    363 			   (unsigned long) in_len);
    364 		eap_peer_tls_reset_input(data);
    365 		return -1;
    366 	}
    367 
    368 	if (tls_in_len + in_len > 65536) {
    369 		/*
    370 		 * Limit length to avoid rogue servers from causing large
    371 		 * memory allocations.
    372 		 */
    373 		wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size over "
    374 			   "64 kB)");
    375 		eap_peer_tls_reset_input(data);
    376 		return -1;
    377 	}
    378 
    379 	if (in_len > data->tls_in_left) {
    380 		/* Sender is doing something odd - reject message */
    381 		wpa_printf(MSG_INFO, "SSL: more data than TLS message length "
    382 			   "indicated");
    383 		eap_peer_tls_reset_input(data);
    384 		return -1;
    385 	}
    386 
    387 	if (wpabuf_resize(&data->tls_in, in_len) < 0) {
    388 		wpa_printf(MSG_INFO, "SSL: Could not allocate memory for TLS "
    389 			   "data");
    390 		eap_peer_tls_reset_input(data);
    391 		return -1;
    392 	}
    393 	if (in_data)
    394 		wpabuf_put_buf(data->tls_in, in_data);
    395 	data->tls_in_left -= in_len;
    396 
    397 	if (data->tls_in_left > 0) {
    398 		wpa_printf(MSG_DEBUG, "SSL: Need %lu bytes more input "
    399 			   "data", (unsigned long) data->tls_in_left);
    400 		return 1;
    401 	}
    402 
    403 	return 0;
    404 }
    405 
    406 
    407 /**
    408  * eap_peer_tls_data_reassemble - Reassemble TLS data
    409  * @data: Data for TLS processing
    410  * @in_data: Next incoming TLS segment
    411  * @need_more_input: Variable for returning whether more input data is needed
    412  * to reassemble this TLS packet
    413  * Returns: Pointer to output data, %NULL on error or when more data is needed
    414  * for the full message (in which case, *need_more_input is also set to 1).
    415  *
    416  * This function reassembles TLS fragments. Caller must not free the returned
    417  * data buffer since an internal pointer to it is maintained.
    418  */
    419 static const struct wpabuf * eap_peer_tls_data_reassemble(
    420 	struct eap_ssl_data *data, const struct wpabuf *in_data,
    421 	int *need_more_input)
    422 {
    423 	*need_more_input = 0;
    424 
    425 	if (data->tls_in_left > wpabuf_len(in_data) || data->tls_in) {
    426 		/* Message has fragments */
    427 		int res = eap_peer_tls_reassemble_fragment(data, in_data);
    428 		if (res) {
    429 			if (res == 1)
    430 				*need_more_input = 1;
    431 			return NULL;
    432 		}
    433 
    434 		/* Message is now fully reassembled. */
    435 	} else {
    436 		/* No fragments in this message, so just make a copy of it. */
    437 		data->tls_in_left = 0;
    438 		data->tls_in = wpabuf_dup(in_data);
    439 		if (data->tls_in == NULL)
    440 			return NULL;
    441 	}
    442 
    443 	return data->tls_in;
    444 }
    445 
    446 
    447 /**
    448  * eap_tls_process_input - Process incoming TLS message
    449  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    450  * @data: Data for TLS processing
    451  * @in_data: Message received from the server
    452  * @in_len: Length of in_data
    453  * @out_data: Buffer for returning a pointer to application data (if available)
    454  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
    455  * is available, -1 on failure
    456  */
    457 static int eap_tls_process_input(struct eap_sm *sm, struct eap_ssl_data *data,
    458 				 const u8 *in_data, size_t in_len,
    459 				 struct wpabuf **out_data)
    460 {
    461 	const struct wpabuf *msg;
    462 	int need_more_input;
    463 	struct wpabuf *appl_data;
    464 	struct wpabuf buf;
    465 
    466 	wpabuf_set(&buf, in_data, in_len);
    467 	msg = eap_peer_tls_data_reassemble(data, &buf, &need_more_input);
    468 	if (msg == NULL)
    469 		return need_more_input ? 1 : -1;
    470 
    471 	/* Full TLS message reassembled - continue handshake processing */
    472 	if (data->tls_out) {
    473 		/* This should not happen.. */
    474 		wpa_printf(MSG_INFO, "SSL: eap_tls_process_input - pending "
    475 			   "tls_out data even though tls_out_len = 0");
    476 		wpabuf_free(data->tls_out);
    477 		WPA_ASSERT(data->tls_out == NULL);
    478 	}
    479 	appl_data = NULL;
    480 	data->tls_out = tls_connection_handshake(data->ssl_ctx, data->conn,
    481 						 msg, &appl_data);
    482 
    483 	eap_peer_tls_reset_input(data);
    484 
    485 	if (appl_data &&
    486 	    tls_connection_established(data->ssl_ctx, data->conn) &&
    487 	    !tls_connection_get_failed(data->ssl_ctx, data->conn)) {
    488 		wpa_hexdump_buf_key(MSG_MSGDUMP, "SSL: Application data",
    489 				    appl_data);
    490 		*out_data = appl_data;
    491 		return 2;
    492 	}
    493 
    494 	wpabuf_free(appl_data);
    495 
    496 	return 0;
    497 }
    498 
    499 
    500 /**
    501  * eap_tls_process_output - Process outgoing TLS message
    502  * @data: Data for TLS processing
    503  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
    504  * @peap_version: Version number for EAP-PEAP/TTLS
    505  * @id: EAP identifier for the response
    506  * @ret: Return value to use on success
    507  * @out_data: Buffer for returning the allocated output buffer
    508  * Returns: ret (0 or 1) on success, -1 on failure
    509  */
    510 static int eap_tls_process_output(struct eap_ssl_data *data, EapType eap_type,
    511 				  int peap_version, u8 id, int ret,
    512 				  struct wpabuf **out_data)
    513 {
    514 	size_t len;
    515 	u8 *flags;
    516 	int more_fragments, length_included;
    517 
    518 	if (data->tls_out == NULL)
    519 		return -1;
    520 	len = wpabuf_len(data->tls_out) - data->tls_out_pos;
    521 	wpa_printf(MSG_DEBUG, "SSL: %lu bytes left to be sent out (of total "
    522 		   "%lu bytes)",
    523 		   (unsigned long) len,
    524 		   (unsigned long) wpabuf_len(data->tls_out));
    525 
    526 	/*
    527 	 * Limit outgoing message to the configured maximum size. Fragment
    528 	 * message if needed.
    529 	 */
    530 	if (len > data->tls_out_limit) {
    531 		more_fragments = 1;
    532 		len = data->tls_out_limit;
    533 		wpa_printf(MSG_DEBUG, "SSL: sending %lu bytes, more fragments "
    534 			   "will follow", (unsigned long) len);
    535 	} else
    536 		more_fragments = 0;
    537 
    538 	length_included = data->tls_out_pos == 0 &&
    539 		(wpabuf_len(data->tls_out) > data->tls_out_limit ||
    540 		 data->include_tls_length);
    541 	if (!length_included &&
    542 	    eap_type == EAP_TYPE_PEAP && peap_version == 0 &&
    543 	    !tls_connection_established(data->eap->ssl_ctx, data->conn)) {
    544 		/*
    545 		 * Windows Server 2008 NPS really wants to have the TLS Message
    546 		 * length included in phase 0 even for unfragmented frames or
    547 		 * it will get very confused with Compound MAC calculation and
    548 		 * Outer TLVs.
    549 		 */
    550 		length_included = 1;
    551 	}
    552 
    553 	*out_data = eap_tls_msg_alloc(eap_type, 1 + length_included * 4 + len,
    554 				      EAP_CODE_RESPONSE, id);
    555 	if (*out_data == NULL)
    556 		return -1;
    557 
    558 	flags = wpabuf_put(*out_data, 1);
    559 	*flags = peap_version;
    560 	if (more_fragments)
    561 		*flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
    562 	if (length_included) {
    563 		*flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
    564 		wpabuf_put_be32(*out_data, wpabuf_len(data->tls_out));
    565 	}
    566 
    567 	wpabuf_put_data(*out_data,
    568 			wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
    569 			len);
    570 	data->tls_out_pos += len;
    571 
    572 	if (!more_fragments)
    573 		eap_peer_tls_reset_output(data);
    574 
    575 	return ret;
    576 }
    577 
    578 
    579 /**
    580  * eap_peer_tls_process_helper - Process TLS handshake message
    581  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    582  * @data: Data for TLS processing
    583  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
    584  * @peap_version: Version number for EAP-PEAP/TTLS
    585  * @id: EAP identifier for the response
    586  * @in_data: Message received from the server
    587  * @in_len: Length of in_data
    588  * @out_data: Buffer for returning a pointer to the response message
    589  * Returns: 0 on success, 1 if more input data is needed, 2 if application data
    590  * is available, or -1 on failure
    591  *
    592  * This function can be used to process TLS handshake messages. It reassembles
    593  * the received fragments and uses a TLS library to process the messages. The
    594  * response data from the TLS library is fragmented to suitable output messages
    595  * that the caller can send out.
    596  *
    597  * out_data is used to return the response message if the return value of this
    598  * function is 0, 2, or -1. In case of failure, the message is likely a TLS
    599  * alarm message. The caller is responsible for freeing the allocated buffer if
    600  * *out_data is not %NULL.
    601  *
    602  * This function is called for each received TLS message during the TLS
    603  * handshake after eap_peer_tls_process_init() call and possible processing of
    604  * TLS Flags field. Once the handshake has been completed, i.e., when
    605  * tls_connection_established() returns 1, EAP method specific decrypting of
    606  * the tunneled data is used.
    607  */
    608 int eap_peer_tls_process_helper(struct eap_sm *sm, struct eap_ssl_data *data,
    609 				EapType eap_type, int peap_version,
    610 				u8 id, const u8 *in_data, size_t in_len,
    611 				struct wpabuf **out_data)
    612 {
    613 	int ret = 0;
    614 
    615 	*out_data = NULL;
    616 
    617 	if (data->tls_out && wpabuf_len(data->tls_out) > 0 && in_len > 0) {
    618 		wpa_printf(MSG_DEBUG, "SSL: Received non-ACK when output "
    619 			   "fragments are waiting to be sent out");
    620 		return -1;
    621 	}
    622 
    623 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
    624 		/*
    625 		 * No more data to send out - expect to receive more data from
    626 		 * the AS.
    627 		 */
    628 		int res = eap_tls_process_input(sm, data, in_data, in_len,
    629 						out_data);
    630 		if (res) {
    631 			/*
    632 			 * Input processing failed (res = -1) or more data is
    633 			 * needed (res = 1).
    634 			 */
    635 			return res;
    636 		}
    637 
    638 		/*
    639 		 * The incoming message has been reassembled and processed. The
    640 		 * response was allocated into data->tls_out buffer.
    641 		 */
    642 	}
    643 
    644 	if (data->tls_out == NULL) {
    645 		/*
    646 		 * No outgoing fragments remaining from the previous message
    647 		 * and no new message generated. This indicates an error in TLS
    648 		 * processing.
    649 		 */
    650 		eap_peer_tls_reset_output(data);
    651 		return -1;
    652 	}
    653 
    654 	if (tls_connection_get_failed(data->ssl_ctx, data->conn)) {
    655 		/* TLS processing has failed - return error */
    656 		wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
    657 			   "report error");
    658 		ret = -1;
    659 		/* TODO: clean pin if engine used? */
    660 	}
    661 
    662 	if (data->tls_out == NULL || wpabuf_len(data->tls_out) == 0) {
    663 		/*
    664 		 * TLS negotiation should now be complete since all other cases
    665 		 * needing more data should have been caught above based on
    666 		 * the TLS Message Length field.
    667 		 */
    668 		wpa_printf(MSG_DEBUG, "SSL: No data to be sent out");
    669 		wpabuf_free(data->tls_out);
    670 		data->tls_out = NULL;
    671 		return 1;
    672 	}
    673 
    674 	/* Send the pending message (in fragments, if needed). */
    675 	return eap_tls_process_output(data, eap_type, peap_version, id, ret,
    676 				      out_data);
    677 }
    678 
    679 
    680 /**
    681  * eap_peer_tls_build_ack - Build a TLS ACK frame
    682  * @id: EAP identifier for the response
    683  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
    684  * @peap_version: Version number for EAP-PEAP/TTLS
    685  * Returns: Pointer to the allocated ACK frame or %NULL on failure
    686  */
    687 struct wpabuf * eap_peer_tls_build_ack(u8 id, EapType eap_type,
    688 				       int peap_version)
    689 {
    690 	struct wpabuf *resp;
    691 
    692 	resp = eap_tls_msg_alloc(eap_type, 1, EAP_CODE_RESPONSE, id);
    693 	if (resp == NULL)
    694 		return NULL;
    695 	wpa_printf(MSG_DEBUG, "SSL: Building ACK (type=%d id=%d ver=%d)",
    696 		   (int) eap_type, id, peap_version);
    697 	wpabuf_put_u8(resp, peap_version); /* Flags */
    698 	return resp;
    699 }
    700 
    701 
    702 /**
    703  * eap_peer_tls_reauth_init - Re-initialize shared TLS for session resumption
    704  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    705  * @data: Data for TLS processing
    706  * Returns: 0 on success, -1 on failure
    707  */
    708 int eap_peer_tls_reauth_init(struct eap_sm *sm, struct eap_ssl_data *data)
    709 {
    710 	eap_peer_tls_reset_input(data);
    711 	eap_peer_tls_reset_output(data);
    712 	return tls_connection_shutdown(data->ssl_ctx, data->conn);
    713 }
    714 
    715 
    716 /**
    717  * eap_peer_tls_status - Get TLS status
    718  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    719  * @data: Data for TLS processing
    720  * @buf: Buffer for status information
    721  * @buflen: Maximum buffer length
    722  * @verbose: Whether to include verbose status information
    723  * Returns: Number of bytes written to buf.
    724  */
    725 int eap_peer_tls_status(struct eap_sm *sm, struct eap_ssl_data *data,
    726 			char *buf, size_t buflen, int verbose)
    727 {
    728 	char name[128];
    729 	int len = 0, ret;
    730 
    731 	if (tls_get_cipher(data->ssl_ctx, data->conn, name, sizeof(name)) == 0)
    732 	{
    733 		ret = os_snprintf(buf + len, buflen - len,
    734 				  "EAP TLS cipher=%s\n", name);
    735 		if (ret < 0 || (size_t) ret >= buflen - len)
    736 			return len;
    737 		len += ret;
    738 	}
    739 
    740 	return len;
    741 }
    742 
    743 
    744 /**
    745  * eap_peer_tls_process_init - Initial validation/processing of EAP requests
    746  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    747  * @data: Data for TLS processing
    748  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
    749  * @ret: Return values from EAP request validation and processing
    750  * @reqData: EAP request to be processed (eapReqData)
    751  * @len: Buffer for returning length of the remaining payload
    752  * @flags: Buffer for returning TLS flags
    753  * Returns: Pointer to payload after TLS flags and length or %NULL on failure
    754  *
    755  * This function validates the EAP header and processes the optional TLS
    756  * Message Length field. If this is the first fragment of a TLS message, the
    757  * TLS reassembly code is initialized to receive the indicated number of bytes.
    758  *
    759  * EAP-TLS, EAP-PEAP, EAP-TTLS, and EAP-FAST methods are expected to use this
    760  * function as the first step in processing received messages. They will need
    761  * to process the flags (apart from Message Length Included) that are returned
    762  * through the flags pointer and the message payload that will be returned (and
    763  * the length is returned through the len pointer). Return values (ret) are set
    764  * for continuation of EAP method processing. The caller is responsible for
    765  * setting these to indicate completion (either success or failure) based on
    766  * the authentication result.
    767  */
    768 const u8 * eap_peer_tls_process_init(struct eap_sm *sm,
    769 				     struct eap_ssl_data *data,
    770 				     EapType eap_type,
    771 				     struct eap_method_ret *ret,
    772 				     const struct wpabuf *reqData,
    773 				     size_t *len, u8 *flags)
    774 {
    775 	const u8 *pos;
    776 	size_t left;
    777 	unsigned int tls_msg_len;
    778 
    779 	if (tls_get_errors(data->ssl_ctx)) {
    780 		wpa_printf(MSG_INFO, "SSL: TLS errors detected");
    781 		ret->ignore = TRUE;
    782 		return NULL;
    783 	}
    784 
    785 	if (eap_type == EAP_UNAUTH_TLS_TYPE)
    786 		pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
    787 				       EAP_VENDOR_TYPE_UNAUTH_TLS, reqData,
    788 				       &left);
    789 	else
    790 		pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, reqData,
    791 				       &left);
    792 	if (pos == NULL) {
    793 		ret->ignore = TRUE;
    794 		return NULL;
    795 	}
    796 	if (left == 0) {
    797 		wpa_printf(MSG_DEBUG, "SSL: Invalid TLS message: no Flags "
    798 			   "octet included");
    799 		if (!sm->workaround) {
    800 			ret->ignore = TRUE;
    801 			return NULL;
    802 		}
    803 
    804 		wpa_printf(MSG_DEBUG, "SSL: Workaround - assume no Flags "
    805 			   "indicates ACK frame");
    806 		*flags = 0;
    807 	} else {
    808 		*flags = *pos++;
    809 		left--;
    810 	}
    811 	wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - "
    812 		   "Flags 0x%02x", (unsigned long) wpabuf_len(reqData),
    813 		   *flags);
    814 	if (*flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
    815 		if (left < 4) {
    816 			wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
    817 				   "length");
    818 			ret->ignore = TRUE;
    819 			return NULL;
    820 		}
    821 		tls_msg_len = WPA_GET_BE32(pos);
    822 		wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
    823 			   tls_msg_len);
    824 		if (data->tls_in_left == 0) {
    825 			data->tls_in_total = tls_msg_len;
    826 			data->tls_in_left = tls_msg_len;
    827 			wpabuf_free(data->tls_in);
    828 			data->tls_in = NULL;
    829 		}
    830 		pos += 4;
    831 		left -= 4;
    832 	}
    833 
    834 	ret->ignore = FALSE;
    835 	ret->methodState = METHOD_MAY_CONT;
    836 	ret->decision = DECISION_FAIL;
    837 	ret->allowNotifications = TRUE;
    838 
    839 	*len = left;
    840 	return pos;
    841 }
    842 
    843 
    844 /**
    845  * eap_peer_tls_reset_input - Reset input buffers
    846  * @data: Data for TLS processing
    847  *
    848  * This function frees any allocated memory for input buffers and resets input
    849  * state.
    850  */
    851 void eap_peer_tls_reset_input(struct eap_ssl_data *data)
    852 {
    853 	data->tls_in_left = data->tls_in_total = 0;
    854 	wpabuf_free(data->tls_in);
    855 	data->tls_in = NULL;
    856 }
    857 
    858 
    859 /**
    860  * eap_peer_tls_reset_output - Reset output buffers
    861  * @data: Data for TLS processing
    862  *
    863  * This function frees any allocated memory for output buffers and resets
    864  * output state.
    865  */
    866 void eap_peer_tls_reset_output(struct eap_ssl_data *data)
    867 {
    868 	data->tls_out_pos = 0;
    869 	wpabuf_free(data->tls_out);
    870 	data->tls_out = NULL;
    871 }
    872 
    873 
    874 /**
    875  * eap_peer_tls_decrypt - Decrypt received phase 2 TLS message
    876  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    877  * @data: Data for TLS processing
    878  * @in_data: Message received from the server
    879  * @in_decrypted: Buffer for returning a pointer to the decrypted message
    880  * Returns: 0 on success, 1 if more input data is needed, or -1 on failure
    881  */
    882 int eap_peer_tls_decrypt(struct eap_sm *sm, struct eap_ssl_data *data,
    883 			 const struct wpabuf *in_data,
    884 			 struct wpabuf **in_decrypted)
    885 {
    886 	const struct wpabuf *msg;
    887 	int need_more_input;
    888 
    889 	msg = eap_peer_tls_data_reassemble(data, in_data, &need_more_input);
    890 	if (msg == NULL)
    891 		return need_more_input ? 1 : -1;
    892 
    893 	*in_decrypted = tls_connection_decrypt(data->ssl_ctx, data->conn, msg);
    894 	eap_peer_tls_reset_input(data);
    895 	if (*in_decrypted == NULL) {
    896 		wpa_printf(MSG_INFO, "SSL: Failed to decrypt Phase 2 data");
    897 		return -1;
    898 	}
    899 	return 0;
    900 }
    901 
    902 
    903 /**
    904  * eap_peer_tls_encrypt - Encrypt phase 2 TLS message
    905  * @sm: Pointer to EAP state machine allocated with eap_peer_sm_init()
    906  * @data: Data for TLS processing
    907  * @eap_type: EAP type (EAP_TYPE_TLS, EAP_TYPE_PEAP, ...)
    908  * @peap_version: Version number for EAP-PEAP/TTLS
    909  * @id: EAP identifier for the response
    910  * @in_data: Plaintext phase 2 data to encrypt or %NULL to continue fragments
    911  * @out_data: Buffer for returning a pointer to the encrypted response message
    912  * Returns: 0 on success, -1 on failure
    913  */
    914 int eap_peer_tls_encrypt(struct eap_sm *sm, struct eap_ssl_data *data,
    915 			 EapType eap_type, int peap_version, u8 id,
    916 			 const struct wpabuf *in_data,
    917 			 struct wpabuf **out_data)
    918 {
    919 	if (in_data) {
    920 		eap_peer_tls_reset_output(data);
    921 		data->tls_out = tls_connection_encrypt(data->ssl_ctx,
    922 						       data->conn, in_data);
    923 		if (data->tls_out == NULL) {
    924 			wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 "
    925 				   "data (in_len=%lu)",
    926 				   (unsigned long) wpabuf_len(in_data));
    927 			eap_peer_tls_reset_output(data);
    928 			return -1;
    929 		}
    930 	}
    931 
    932 	return eap_tls_process_output(data, eap_type, peap_version, id, 0,
    933 				      out_data);
    934 }
    935 
    936 
    937 /**
    938  * eap_peer_select_phase2_methods - Select phase 2 EAP method
    939  * @config: Pointer to the network configuration
    940  * @prefix: 'phase2' configuration prefix, e.g., "auth="
    941  * @types: Buffer for returning allocated list of allowed EAP methods
    942  * @num_types: Buffer for returning number of allocated EAP methods
    943  * Returns: 0 on success, -1 on failure
    944  *
    945  * This function is used to parse EAP method list and select allowed methods
    946  * for Phase2 authentication.
    947  */
    948 int eap_peer_select_phase2_methods(struct eap_peer_config *config,
    949 				   const char *prefix,
    950 				   struct eap_method_type **types,
    951 				   size_t *num_types)
    952 {
    953 	char *start, *pos, *buf;
    954 	struct eap_method_type *methods = NULL, *_methods;
    955 	u8 method;
    956 	size_t num_methods = 0, prefix_len;
    957 
    958 	if (config == NULL || config->phase2 == NULL)
    959 		goto get_defaults;
    960 
    961 	start = buf = os_strdup(config->phase2);
    962 	if (buf == NULL)
    963 		return -1;
    964 
    965 	prefix_len = os_strlen(prefix);
    966 
    967 	while (start && *start != '\0') {
    968 		int vendor;
    969 		pos = os_strstr(start, prefix);
    970 		if (pos == NULL)
    971 			break;
    972 		if (start != pos && *(pos - 1) != ' ') {
    973 			start = pos + prefix_len;
    974 			continue;
    975 		}
    976 
    977 		start = pos + prefix_len;
    978 		pos = os_strchr(start, ' ');
    979 		if (pos)
    980 			*pos++ = '\0';
    981 		method = eap_get_phase2_type(start, &vendor);
    982 		if (vendor == EAP_VENDOR_IETF && method == EAP_TYPE_NONE) {
    983 			wpa_printf(MSG_ERROR, "TLS: Unsupported Phase2 EAP "
    984 				   "method '%s'", start);
    985 		} else {
    986 			num_methods++;
    987 			_methods = os_realloc_array(methods, num_methods,
    988 						    sizeof(*methods));
    989 			if (_methods == NULL) {
    990 				os_free(methods);
    991 				os_free(buf);
    992 				return -1;
    993 			}
    994 			methods = _methods;
    995 			methods[num_methods - 1].vendor = vendor;
    996 			methods[num_methods - 1].method = method;
    997 		}
    998 
    999 		start = pos;
   1000 	}
   1001 
   1002 	os_free(buf);
   1003 
   1004 get_defaults:
   1005 	if (methods == NULL)
   1006 		methods = eap_get_phase2_types(config, &num_methods);
   1007 
   1008 	if (methods == NULL) {
   1009 		wpa_printf(MSG_ERROR, "TLS: No Phase2 EAP methods available");
   1010 		return -1;
   1011 	}
   1012 	wpa_hexdump(MSG_DEBUG, "TLS: Phase2 EAP types",
   1013 		    (u8 *) methods,
   1014 		    num_methods * sizeof(struct eap_method_type));
   1015 
   1016 	*types = methods;
   1017 	*num_types = num_methods;
   1018 
   1019 	return 0;
   1020 }
   1021 
   1022 
   1023 /**
   1024  * eap_peer_tls_phase2_nak - Generate EAP-Nak for Phase 2
   1025  * @types: Buffer for returning allocated list of allowed EAP methods
   1026  * @num_types: Buffer for returning number of allocated EAP methods
   1027  * @hdr: EAP-Request header (and the following EAP type octet)
   1028  * @resp: Buffer for returning the EAP-Nak message
   1029  * Returns: 0 on success, -1 on failure
   1030  */
   1031 int eap_peer_tls_phase2_nak(struct eap_method_type *types, size_t num_types,
   1032 			    struct eap_hdr *hdr, struct wpabuf **resp)
   1033 {
   1034 	u8 *pos = (u8 *) (hdr + 1);
   1035 	size_t i;
   1036 
   1037 	/* TODO: add support for expanded Nak */
   1038 	wpa_printf(MSG_DEBUG, "TLS: Phase 2 Request: Nak type=%d", *pos);
   1039 	wpa_hexdump(MSG_DEBUG, "TLS: Allowed Phase2 EAP types",
   1040 		    (u8 *) types, num_types * sizeof(struct eap_method_type));
   1041 	*resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_NAK, num_types,
   1042 			      EAP_CODE_RESPONSE, hdr->identifier);
   1043 	if (*resp == NULL)
   1044 		return -1;
   1045 
   1046 	for (i = 0; i < num_types; i++) {
   1047 		if (types[i].vendor == EAP_VENDOR_IETF &&
   1048 		    types[i].method < 256)
   1049 			wpabuf_put_u8(*resp, types[i].method);
   1050 	}
   1051 
   1052 	eap_update_len(*resp);
   1053 
   1054 	return 0;
   1055 }
   1056