libeap/src/eap_server/eap_server_tls.c

   1 /*
   2  * hostapd / EAP-TLS (RFC 2716)
   3  * Copyright (c) 2004-2008, Jouni Malinen <j@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 "eap_i.h"
  13 #include "eap_tls_common.h"
  14 #include "crypto/tls.h"
  15
  16
  17 static void eap_tls_reset(struct eap_sm *sm, void *priv);
  18
  19
  20 struct eap_tls_data {
  21         struct eap_ssl_data ssl;
  22         enum { START, CONTINUE, SUCCESS, FAILURE } state;
  23         int established;
  24         u8 eap_type;
  25 };
  26
  27
  28 static const char * eap_tls_state_txt(int state)
  29 {
  30         switch (state) {
  31         case START:
  32                 return "START";
  33         case CONTINUE:
  34                 return "CONTINUE";
  35         case SUCCESS:
  36                 return "SUCCESS";
  37         case FAILURE:
  38                 return "FAILURE";
  39         default:
  40                 return "Unknown?!";
  41         }
  42 }
  43
  44
  45 static void eap_tls_state(struct eap_tls_data *data, int state)
  46 {
  47         wpa_printf(MSG_DEBUG, "EAP-TLS: %s -> %s",
  48                    eap_tls_state_txt(data->state),
  49                    eap_tls_state_txt(state));
  50         data->state = state;
  51         if (state == FAILURE)
  52                 tls_connection_remove_session(data->ssl.conn);
  53 }
  54
  55
  56 static void eap_tls_valid_session(struct eap_sm *sm, struct eap_tls_data *data)
  57 {
  58         struct wpabuf *buf;
  59
  60         if (!sm->tls_session_lifetime)
  61                 return;
  62
  63         buf = wpabuf_alloc(1);
  64         if (!buf)
  65                 return;
  66         wpabuf_put_u8(buf, data->eap_type);
  67         tls_connection_set_success_data(data->ssl.conn, buf);
  68 }
  69
  70
  71 static void * eap_tls_init(struct eap_sm *sm)
  72 {
  73         struct eap_tls_data *data;
  74
  75         data = os_zalloc(sizeof(*data));
  76         if (data == NULL)
  77                 return NULL;
  78         data->state = START;
  79
  80         if (eap_server_tls_ssl_init(sm, &data->ssl, 1, EAP_TYPE_TLS)) {
  81                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
  82                 eap_tls_reset(sm, data);
  83                 return NULL;
  84         }
  85
  86         data->eap_type = EAP_TYPE_TLS;
  87
  88         return data;
  89 }
  90
  91
  92 #ifdef EAP_SERVER_UNAUTH_TLS
  93 static void * eap_unauth_tls_init(struct eap_sm *sm)
  94 {
  95         struct eap_tls_data *data;
  96
  97         data = os_zalloc(sizeof(*data));
  98         if (data == NULL)
  99                 return NULL;
 100         data->state = START;
 101
 102         if (eap_server_tls_ssl_init(sm, &data->ssl, 0, EAP_UNAUTH_TLS_TYPE)) {
 103                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
 104                 eap_tls_reset(sm, data);
 105                 return NULL;
 106         }
 107
 108         data->eap_type = EAP_UNAUTH_TLS_TYPE;
 109         return data;
 110 }
 111 #endif /* EAP_SERVER_UNAUTH_TLS */
 112
 113
 114 #ifdef CONFIG_HS20
 115 static void * eap_wfa_unauth_tls_init(struct eap_sm *sm)
 116 {
 117         struct eap_tls_data *data;
 118
 119         data = os_zalloc(sizeof(*data));
 120         if (data == NULL)
 121                 return NULL;
 122         data->state = START;
 123
 124         if (eap_server_tls_ssl_init(sm, &data->ssl, 0,
 125                                     EAP_WFA_UNAUTH_TLS_TYPE)) {
 126                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
 127                 eap_tls_reset(sm, data);
 128                 return NULL;
 129         }
 130
 131         data->eap_type = EAP_WFA_UNAUTH_TLS_TYPE;
 132         return data;
 133 }
 134 #endif /* CONFIG_HS20 */
 135
 136
 137 static void eap_tls_reset(struct eap_sm *sm, void *priv)
 138 {
 139         struct eap_tls_data *data = priv;
 140         if (data == NULL)
 141                 return;
 142         eap_server_tls_ssl_deinit(sm, &data->ssl);
 143         os_free(data);
 144 }
 145
 146
 147 static struct wpabuf * eap_tls_build_start(struct eap_sm *sm,
 148                                            struct eap_tls_data *data, u8 id)
 149 {
 150         struct wpabuf *req;
 151
 152         req = eap_tls_msg_alloc(data->eap_type, 1, EAP_CODE_REQUEST, id);
 153         if (req == NULL) {
 154                 wpa_printf(MSG_ERROR, "EAP-TLS: Failed to allocate memory for "
 155                            "request");
 156                 eap_tls_state(data, FAILURE);
 157                 return NULL;
 158         }
 159
 160         wpabuf_put_u8(req, EAP_TLS_FLAGS_START);
 161
 162         eap_tls_state(data, CONTINUE);
 163
 164         return req;
 165 }
 166
 167
 168 static struct wpabuf * eap_tls_buildReq(struct eap_sm *sm, void *priv, u8 id)
 169 {
 170         struct eap_tls_data *data = priv;
 171         struct wpabuf *res;
 172
 173         if (data->ssl.state == FRAG_ACK) {
 174                 return eap_server_tls_build_ack(id, data->eap_type, 0);
 175         }
 176
 177         if (data->ssl.state == WAIT_FRAG_ACK) {
 178                 res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0,
 179                                                id);
 180                 goto check_established;
 181         }
 182
 183         switch (data->state) {
 184         case START:
 185                 return eap_tls_build_start(sm, data, id);
 186         case CONTINUE:
 187                 if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
 188                         data->established = 1;
 189                 break;
 190         default:
 191                 wpa_printf(MSG_DEBUG, "EAP-TLS: %s - unexpected state %d",
 192                            __func__, data->state);
 193                 return NULL;
 194         }
 195
 196         res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0, id);
 197
 198 check_established:
 199         if (data->established && data->ssl.state != WAIT_FRAG_ACK) {
 200                 /* TLS handshake has been completed and there are no more
 201                  * fragments waiting to be sent out. */
 202                 wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
 203                 eap_tls_state(data, SUCCESS);
 204                 eap_tls_valid_session(sm, data);
 205         }
 206
 207         return res;
 208 }
 209
 210
 211 static Boolean eap_tls_check(struct eap_sm *sm, void *priv,
 212                              struct wpabuf *respData)
 213 {
 214         struct eap_tls_data *data = priv;
 215         const u8 *pos;
 216         size_t len;
 217
 218         if (data->eap_type == EAP_UNAUTH_TLS_TYPE)
 219                 pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
 220                                        EAP_VENDOR_TYPE_UNAUTH_TLS, respData,
 221                                        &len);
 222         else if (data->eap_type == EAP_WFA_UNAUTH_TLS_TYPE)
 223                 pos = eap_hdr_validate(EAP_VENDOR_WFA_NEW,
 224                                        EAP_VENDOR_WFA_UNAUTH_TLS, respData,
 225                                        &len);
 226         else
 227                 pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_type,
 228                                        respData, &len);
 229         if (pos == NULL || len < 1) {
 230                 wpa_printf(MSG_INFO, "EAP-TLS: Invalid frame");
 231                 return TRUE;
 232         }
 233
 234         return FALSE;
 235 }
 236
 237
 238 static void eap_tls_process_msg(struct eap_sm *sm, void *priv,
 239                                 const struct wpabuf *respData)
 240 {
 241         struct eap_tls_data *data = priv;
 242         if (data->state == SUCCESS && wpabuf_len(data->ssl.tls_in) == 0) {
 243                 wpa_printf(MSG_DEBUG, "EAP-TLS: Client acknowledged final TLS "
 244                            "handshake message");
 245                 return;
 246         }
 247         if (eap_server_tls_phase1(sm, &data->ssl) < 0)
 248                 eap_tls_state(data, FAILURE);
 249 }
 250
 251
 252 static void eap_tls_process(struct eap_sm *sm, void *priv,
 253                             struct wpabuf *respData)
 254 {
 255         struct eap_tls_data *data = priv;
 256         const struct wpabuf *buf;
 257         const u8 *pos;
 258
 259         if (eap_server_tls_process(sm, &data->ssl, respData, data,
 260                                    data->eap_type, NULL, eap_tls_process_msg) <
 261             0) {
 262                 eap_tls_state(data, FAILURE);
 263                 return;
 264         }
 265
 266         if (!tls_connection_established(sm->ssl_ctx, data->ssl.conn) ||
 267             !tls_connection_resumed(sm->ssl_ctx, data->ssl.conn))
 268                 return;
 269
 270         buf = tls_connection_get_success_data(data->ssl.conn);
 271         if (!buf || wpabuf_len(buf) < 1) {
 272                 wpa_printf(MSG_DEBUG,
 273                            "EAP-TLS: No success data in resumed session - reject attempt");
 274                 eap_tls_state(data, FAILURE);
 275                 return;
 276         }
 277
 278         pos = wpabuf_head(buf);
 279         if (*pos != data->eap_type) {
 280                 wpa_printf(MSG_DEBUG,
 281                            "EAP-TLS: Resumed session for another EAP type (%u) - reject attempt",
 282                            *pos);
 283                 eap_tls_state(data, FAILURE);
 284                 return;
 285         }
 286
 287         wpa_printf(MSG_DEBUG,
 288                    "EAP-TLS: Resuming previous session");
 289         eap_tls_state(data, SUCCESS);
 290         tls_connection_set_success_data_resumed(data->ssl.conn);
 291 }
 292
 293
 294 static Boolean eap_tls_isDone(struct eap_sm *sm, void *priv)
 295 {
 296         struct eap_tls_data *data = priv;
 297         return data->state == SUCCESS || data->state == FAILURE;
 298 }
 299
 300
 301 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
 302 {
 303         struct eap_tls_data *data = priv;
 304         u8 *eapKeyData;
 305
 306         if (data->state != SUCCESS)
 307                 return NULL;
 308
 309         eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
 310                                                "client EAP encryption",
 311                                                EAP_TLS_KEY_LEN);
 312         if (eapKeyData) {
 313                 *len = EAP_TLS_KEY_LEN;
 314                 wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived key",
 315                             eapKeyData, EAP_TLS_KEY_LEN);
 316         } else {
 317                 wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive key");
 318         }
 319
 320         return eapKeyData;
 321 }
 322
 323
 324 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 325 {
 326         struct eap_tls_data *data = priv;
 327         u8 *eapKeyData, *emsk;
 328
 329         if (data->state != SUCCESS)
 330                 return NULL;
 331
 332         eapKeyData = eap_server_tls_derive_key(sm, &data->ssl,
 333                                                "client EAP encryption",
 334                                                EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
 335         if (eapKeyData) {
 336                 emsk = os_malloc(EAP_EMSK_LEN);
 337                 if (emsk)
 338                         os_memcpy(emsk, eapKeyData + EAP_TLS_KEY_LEN,
 339                                   EAP_EMSK_LEN);
 340                 bin_clear_free(eapKeyData, EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
 341         } else
 342                 emsk = NULL;
 343
 344         if (emsk) {
 345                 *len = EAP_EMSK_LEN;
 346                 wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived EMSK",
 347                             emsk, EAP_EMSK_LEN);
 348         } else {
 349                 wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive EMSK");
 350         }
 351
 352         return emsk;
 353 }
 354
 355
 356 static Boolean eap_tls_isSuccess(struct eap_sm *sm, void *priv)
 357 {
 358         struct eap_tls_data *data = priv;
 359         return data->state == SUCCESS;
 360 }
 361
 362
 363 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
 364 {
 365         struct eap_tls_data *data = priv;
 366
 367         if (data->state != SUCCESS)
 368                 return NULL;
 369
 370         return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_TLS,
 371                                                 len);
 372 }
 373
 374
 375 int eap_server_tls_register(void)
 376 {
 377         struct eap_method *eap;
 378         int ret;
 379
 380         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 381                                       EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
 382         if (eap == NULL)
 383                 return -1;
 384
 385         eap->init = eap_tls_init;
 386         eap->reset = eap_tls_reset;
 387         eap->buildReq = eap_tls_buildReq;
 388         eap->check = eap_tls_check;
 389         eap->process = eap_tls_process;
 390         eap->isDone = eap_tls_isDone;
 391         eap->getKey = eap_tls_getKey;
 392         eap->isSuccess = eap_tls_isSuccess;
 393         eap->get_emsk = eap_tls_get_emsk;
 394         eap->getSessionId = eap_tls_get_session_id;
 395
 396         ret = eap_server_method_register(eap);
 397         if (ret)
 398                 eap_server_method_free(eap);
 399         return ret;
 400 }
 401
 402
 403 #ifdef EAP_SERVER_UNAUTH_TLS
 404 int eap_server_unauth_tls_register(void)
 405 {
 406         struct eap_method *eap;
 407         int ret;
 408
 409         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 410                                       EAP_VENDOR_UNAUTH_TLS,
 411                                       EAP_VENDOR_TYPE_UNAUTH_TLS,
 412                                       "UNAUTH-TLS");
 413         if (eap == NULL)
 414                 return -1;
 415
 416         eap->init = eap_unauth_tls_init;
 417         eap->reset = eap_tls_reset;
 418         eap->buildReq = eap_tls_buildReq;
 419         eap->check = eap_tls_check;
 420         eap->process = eap_tls_process;
 421         eap->isDone = eap_tls_isDone;
 422         eap->getKey = eap_tls_getKey;
 423         eap->isSuccess = eap_tls_isSuccess;
 424         eap->get_emsk = eap_tls_get_emsk;
 425
 426         ret = eap_server_method_register(eap);
 427         if (ret)
 428                 eap_server_method_free(eap);
 429         return ret;
 430 }
 431 #endif /* EAP_SERVER_UNAUTH_TLS */
 432
 433
 434 #ifdef CONFIG_HS20
 435 int eap_server_wfa_unauth_tls_register(void)
 436 {
 437         struct eap_method *eap;
 438         int ret;
 439
 440         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 441                                       EAP_VENDOR_WFA_NEW,
 442                                       EAP_VENDOR_WFA_UNAUTH_TLS,
 443                                       "WFA-UNAUTH-TLS");
 444         if (eap == NULL)
 445                 return -1;
 446
 447         eap->init = eap_wfa_unauth_tls_init;
 448         eap->reset = eap_tls_reset;
 449         eap->buildReq = eap_tls_buildReq;
 450         eap->check = eap_tls_check;
 451         eap->process = eap_tls_process;
 452         eap->isDone = eap_tls_isDone;
 453         eap->getKey = eap_tls_getKey;
 454         eap->isSuccess = eap_tls_isSuccess;
 455         eap->get_emsk = eap_tls_get_emsk;
 456
 457         ret = eap_server_method_register(eap);
 458         if (ret)
 459                 eap_server_method_free(eap);
 460         return ret;
 461 }
 462 #endif /* CONFIG_HS20 */