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      1 /*
      2  * EAP peer method: EAP-TLS (RFC 2716)
      3  * Copyright (c) 2004-2008, 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/tls.h"
     13 #include "eap_i.h"
     14 #include "eap_tls_common.h"
     15 #include "eap_config.h"
     16 
     17 
     18 static void eap_tls_deinit(struct eap_sm *sm, void *priv);
     19 
     20 
     21 struct eap_tls_data {
     22 	struct eap_ssl_data ssl;
     23 	u8 *key_data;
     24 	u8 *session_id;
     25 	size_t id_len;
     26 	void *ssl_ctx;
     27 	u8 eap_type;
     28 };
     29 
     30 
     31 static void * eap_tls_init(struct eap_sm *sm)
     32 {
     33 	struct eap_tls_data *data;
     34 	struct eap_peer_config *config = eap_get_config(sm);
     35 	if (config == NULL ||
     36 	    ((sm->init_phase2 ? config->private_key2 : config->private_key)
     37 	     == NULL &&
     38 	     (sm->init_phase2 ? config->engine2 : config->engine) == 0)) {
     39 		wpa_printf(MSG_INFO, "EAP-TLS: Private key not configured");
     40 		return NULL;
     41 	}
     42 
     43 	data = os_zalloc(sizeof(*data));
     44 	if (data == NULL)
     45 		return NULL;
     46 
     47 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
     48 		sm->ssl_ctx;
     49 
     50 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config, EAP_TYPE_TLS)) {
     51 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
     52 		eap_tls_deinit(sm, data);
     53 		if (config->engine) {
     54 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting Smartcard "
     55 				   "PIN");
     56 			eap_sm_request_pin(sm);
     57 			sm->ignore = TRUE;
     58 		} else if (config->private_key && !config->private_key_passwd)
     59 		{
     60 			wpa_printf(MSG_DEBUG, "EAP-TLS: Requesting private "
     61 				   "key passphrase");
     62 			eap_sm_request_passphrase(sm);
     63 			sm->ignore = TRUE;
     64 		}
     65 		return NULL;
     66 	}
     67 
     68 	data->eap_type = EAP_TYPE_TLS;
     69 
     70 	return data;
     71 }
     72 
     73 
     74 #ifdef EAP_UNAUTH_TLS
     75 static void * eap_unauth_tls_init(struct eap_sm *sm)
     76 {
     77 	struct eap_tls_data *data;
     78 	struct eap_peer_config *config = eap_get_config(sm);
     79 
     80 	data = os_zalloc(sizeof(*data));
     81 	if (data == NULL)
     82 		return NULL;
     83 
     84 	data->ssl_ctx = sm->init_phase2 && sm->ssl_ctx2 ? sm->ssl_ctx2 :
     85 		sm->ssl_ctx;
     86 
     87 	if (eap_peer_tls_ssl_init(sm, &data->ssl, config,
     88 				  EAP_UNAUTH_TLS_TYPE)) {
     89 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
     90 		eap_tls_deinit(sm, data);
     91 		return NULL;
     92 	}
     93 
     94 	data->eap_type = EAP_UNAUTH_TLS_TYPE;
     95 
     96 	return data;
     97 }
     98 #endif /* EAP_UNAUTH_TLS */
     99 
    100 
    101 static void eap_tls_deinit(struct eap_sm *sm, void *priv)
    102 {
    103 	struct eap_tls_data *data = priv;
    104 	if (data == NULL)
    105 		return;
    106 	eap_peer_tls_ssl_deinit(sm, &data->ssl);
    107 	os_free(data->key_data);
    108 	os_free(data->session_id);
    109 	os_free(data);
    110 }
    111 
    112 
    113 static struct wpabuf * eap_tls_failure(struct eap_sm *sm,
    114 				       struct eap_tls_data *data,
    115 				       struct eap_method_ret *ret, int res,
    116 				       struct wpabuf *resp, u8 id)
    117 {
    118 	wpa_printf(MSG_DEBUG, "EAP-TLS: TLS processing failed");
    119 
    120 	ret->methodState = METHOD_DONE;
    121 	ret->decision = DECISION_FAIL;
    122 
    123 	if (res == -1) {
    124 		struct eap_peer_config *config = eap_get_config(sm);
    125 		if (config) {
    126 			/*
    127 			 * The TLS handshake failed. So better forget the old
    128 			 * PIN. It may be wrong, we cannot be sure but trying
    129 			 * the wrong one again might block it on the card--so
    130 			 * better ask the user again.
    131 			 */
    132 			os_free(config->pin);
    133 			config->pin = NULL;
    134 		}
    135 	}
    136 
    137 	if (resp) {
    138 		/*
    139 		 * This is likely an alert message, so send it instead of just
    140 		 * ACKing the error.
    141 		 */
    142 		return resp;
    143 	}
    144 
    145 	return eap_peer_tls_build_ack(id, data->eap_type, 0);
    146 }
    147 
    148 
    149 static void eap_tls_success(struct eap_sm *sm, struct eap_tls_data *data,
    150 			    struct eap_method_ret *ret)
    151 {
    152 	wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
    153 
    154 	ret->methodState = METHOD_DONE;
    155 	ret->decision = DECISION_UNCOND_SUCC;
    156 
    157 	os_free(data->key_data);
    158 	data->key_data = eap_peer_tls_derive_key(sm, &data->ssl,
    159 						 "client EAP encryption",
    160 						 EAP_TLS_KEY_LEN +
    161 						 EAP_EMSK_LEN);
    162 	if (data->key_data) {
    163 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived key",
    164 				data->key_data, EAP_TLS_KEY_LEN);
    165 		wpa_hexdump_key(MSG_DEBUG, "EAP-TLS: Derived EMSK",
    166 				data->key_data + EAP_TLS_KEY_LEN,
    167 				EAP_EMSK_LEN);
    168 	} else {
    169 		wpa_printf(MSG_INFO, "EAP-TLS: Failed to derive key");
    170 	}
    171 
    172 	os_free(data->session_id);
    173 	data->session_id = eap_peer_tls_derive_session_id(sm, &data->ssl,
    174 							  EAP_TYPE_TLS,
    175 			                                  &data->id_len);
    176 	if (data->session_id) {
    177 		wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived Session-Id",
    178 			    data->session_id, data->id_len);
    179 	} else {
    180 		wpa_printf(MSG_ERROR, "EAP-TLS: Failed to derive Session-Id");
    181 	}
    182 }
    183 
    184 
    185 static struct wpabuf * eap_tls_process(struct eap_sm *sm, void *priv,
    186 				       struct eap_method_ret *ret,
    187 				       const struct wpabuf *reqData)
    188 {
    189 	size_t left;
    190 	int res;
    191 	struct wpabuf *resp;
    192 	u8 flags, id;
    193 	const u8 *pos;
    194 	struct eap_tls_data *data = priv;
    195 
    196 	pos = eap_peer_tls_process_init(sm, &data->ssl, data->eap_type, ret,
    197 					reqData, &left, &flags);
    198 	if (pos == NULL)
    199 		return NULL;
    200 	id = eap_get_id(reqData);
    201 
    202 	if (flags & EAP_TLS_FLAGS_START) {
    203 		wpa_printf(MSG_DEBUG, "EAP-TLS: Start");
    204 		left = 0; /* make sure that this frame is empty, even though it
    205 			   * should always be, anyway */
    206 	}
    207 
    208 	resp = NULL;
    209 	res = eap_peer_tls_process_helper(sm, &data->ssl, data->eap_type, 0,
    210 					  id, pos, left, &resp);
    211 
    212 	if (res < 0) {
    213 		return eap_tls_failure(sm, data, ret, res, resp, id);
    214 	}
    215 
    216 	if (tls_connection_established(data->ssl_ctx, data->ssl.conn))
    217 		eap_tls_success(sm, data, ret);
    218 
    219 	if (res == 1) {
    220 		wpabuf_free(resp);
    221 		return eap_peer_tls_build_ack(id, data->eap_type, 0);
    222 	}
    223 
    224 	return resp;
    225 }
    226 
    227 
    228 static Boolean eap_tls_has_reauth_data(struct eap_sm *sm, void *priv)
    229 {
    230 	struct eap_tls_data *data = priv;
    231 	return tls_connection_established(data->ssl_ctx, data->ssl.conn);
    232 }
    233 
    234 
    235 static void eap_tls_deinit_for_reauth(struct eap_sm *sm, void *priv)
    236 {
    237 }
    238 
    239 
    240 static void * eap_tls_init_for_reauth(struct eap_sm *sm, void *priv)
    241 {
    242 	struct eap_tls_data *data = priv;
    243 	os_free(data->key_data);
    244 	data->key_data = NULL;
    245 	os_free(data->session_id);
    246 	data->session_id = NULL;
    247 	if (eap_peer_tls_reauth_init(sm, &data->ssl)) {
    248 		os_free(data);
    249 		return NULL;
    250 	}
    251 	return priv;
    252 }
    253 
    254 
    255 static int eap_tls_get_status(struct eap_sm *sm, void *priv, char *buf,
    256 			      size_t buflen, int verbose)
    257 {
    258 	struct eap_tls_data *data = priv;
    259 	return eap_peer_tls_status(sm, &data->ssl, buf, buflen, verbose);
    260 }
    261 
    262 
    263 static Boolean eap_tls_isKeyAvailable(struct eap_sm *sm, void *priv)
    264 {
    265 	struct eap_tls_data *data = priv;
    266 	return data->key_data != NULL;
    267 }
    268 
    269 
    270 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
    271 {
    272 	struct eap_tls_data *data = priv;
    273 	u8 *key;
    274 
    275 	if (data->key_data == NULL)
    276 		return NULL;
    277 
    278 	key = os_malloc(EAP_TLS_KEY_LEN);
    279 	if (key == NULL)
    280 		return NULL;
    281 
    282 	*len = EAP_TLS_KEY_LEN;
    283 	os_memcpy(key, data->key_data, EAP_TLS_KEY_LEN);
    284 
    285 	return key;
    286 }
    287 
    288 
    289 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
    290 {
    291 	struct eap_tls_data *data = priv;
    292 	u8 *key;
    293 
    294 	if (data->key_data == NULL)
    295 		return NULL;
    296 
    297 	key = os_malloc(EAP_EMSK_LEN);
    298 	if (key == NULL)
    299 		return NULL;
    300 
    301 	*len = EAP_EMSK_LEN;
    302 	os_memcpy(key, data->key_data + EAP_TLS_KEY_LEN, EAP_EMSK_LEN);
    303 
    304 	return key;
    305 }
    306 
    307 
    308 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
    309 {
    310 	struct eap_tls_data *data = priv;
    311 	u8 *id;
    312 
    313 	if (data->session_id == NULL)
    314 		return NULL;
    315 
    316 	id = os_malloc(data->id_len);
    317 	if (id == NULL)
    318 		return NULL;
    319 
    320 	*len = data->id_len;
    321 	os_memcpy(id, data->session_id, data->id_len);
    322 
    323 	return id;
    324 }
    325 
    326 
    327 int eap_peer_tls_register(void)
    328 {
    329 	struct eap_method *eap;
    330 	int ret;
    331 
    332 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
    333 				    EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
    334 	if (eap == NULL)
    335 		return -1;
    336 
    337 	eap->init = eap_tls_init;
    338 	eap->deinit = eap_tls_deinit;
    339 	eap->process = eap_tls_process;
    340 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
    341 	eap->getKey = eap_tls_getKey;
    342 	eap->getSessionId = eap_tls_get_session_id;
    343 	eap->get_status = eap_tls_get_status;
    344 	eap->has_reauth_data = eap_tls_has_reauth_data;
    345 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
    346 	eap->init_for_reauth = eap_tls_init_for_reauth;
    347 	eap->get_emsk = eap_tls_get_emsk;
    348 
    349 	ret = eap_peer_method_register(eap);
    350 	if (ret)
    351 		eap_peer_method_free(eap);
    352 	return ret;
    353 }
    354 
    355 
    356 #ifdef EAP_UNAUTH_TLS
    357 int eap_peer_unauth_tls_register(void)
    358 {
    359 	struct eap_method *eap;
    360 	int ret;
    361 
    362 	eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
    363 				    EAP_VENDOR_UNAUTH_TLS,
    364 				    EAP_VENDOR_TYPE_UNAUTH_TLS, "UNAUTH-TLS");
    365 	if (eap == NULL)
    366 		return -1;
    367 
    368 	eap->init = eap_unauth_tls_init;
    369 	eap->deinit = eap_tls_deinit;
    370 	eap->process = eap_tls_process;
    371 	eap->isKeyAvailable = eap_tls_isKeyAvailable;
    372 	eap->getKey = eap_tls_getKey;
    373 	eap->get_status = eap_tls_get_status;
    374 	eap->has_reauth_data = eap_tls_has_reauth_data;
    375 	eap->deinit_for_reauth = eap_tls_deinit_for_reauth;
    376 	eap->init_for_reauth = eap_tls_init_for_reauth;
    377 	eap->get_emsk = eap_tls_get_emsk;
    378 
    379 	ret = eap_peer_method_register(eap);
    380 	if (ret)
    381 		eap_peer_method_free(eap);
    382 	return ret;
    383 }
    384 #endif /* EAP_UNAUTH_TLS */
    385