contrib/wpa/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         int phase2;
  26 };
  27
  28
  29 static const char * eap_tls_state_txt(int state)
  30 {
  31         switch (state) {
  32         case START:
  33                 return "START";
  34         case CONTINUE:
  35                 return "CONTINUE";
  36         case SUCCESS:
  37                 return "SUCCESS";
  38         case FAILURE:
  39                 return "FAILURE";
  40         default:
  41                 return "Unknown?!";
  42         }
  43 }
  44
  45
  46 static void eap_tls_state(struct eap_tls_data *data, int state)
  47 {
  48         wpa_printf(MSG_DEBUG, "EAP-TLS: %s -> %s",
  49                    eap_tls_state_txt(data->state),
  50                    eap_tls_state_txt(state));
  51         data->state = state;
  52         if (state == FAILURE)
  53                 tls_connection_remove_session(data->ssl.conn);
  54 }
  55
  56
  57 static void eap_tls_valid_session(struct eap_sm *sm, struct eap_tls_data *data)
  58 {
  59         struct wpabuf *buf;
  60
  61         if (!sm->tls_session_lifetime)
  62                 return;
  63
  64         buf = wpabuf_alloc(1);
  65         if (!buf)
  66                 return;
  67         wpabuf_put_u8(buf, data->eap_type);
  68         tls_connection_set_success_data(data->ssl.conn, buf);
  69 }
  70
  71
  72 static void * eap_tls_init(struct eap_sm *sm)
  73 {
  74         struct eap_tls_data *data;
  75
  76         data = os_zalloc(sizeof(*data));
  77         if (data == NULL)
  78                 return NULL;
  79         data->state = START;
  80
  81         if (eap_server_tls_ssl_init(sm, &data->ssl, 1, EAP_TYPE_TLS)) {
  82                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
  83                 eap_tls_reset(sm, data);
  84                 return NULL;
  85         }
  86
  87         data->eap_type = EAP_TYPE_TLS;
  88
  89         data->phase2 = sm->init_phase2;
  90
  91         return data;
  92 }
  93
  94
  95 #ifdef EAP_SERVER_UNAUTH_TLS
  96 static void * eap_unauth_tls_init(struct eap_sm *sm)
  97 {
  98         struct eap_tls_data *data;
  99
 100         data = os_zalloc(sizeof(*data));
 101         if (data == NULL)
 102                 return NULL;
 103         data->state = START;
 104
 105         if (eap_server_tls_ssl_init(sm, &data->ssl, 0, EAP_UNAUTH_TLS_TYPE)) {
 106                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
 107                 eap_tls_reset(sm, data);
 108                 return NULL;
 109         }
 110
 111         data->eap_type = EAP_UNAUTH_TLS_TYPE;
 112         return data;
 113 }
 114 #endif /* EAP_SERVER_UNAUTH_TLS */
 115
 116
 117 #ifdef CONFIG_HS20
 118 static void * eap_wfa_unauth_tls_init(struct eap_sm *sm)
 119 {
 120         struct eap_tls_data *data;
 121
 122         data = os_zalloc(sizeof(*data));
 123         if (data == NULL)
 124                 return NULL;
 125         data->state = START;
 126
 127         if (eap_server_tls_ssl_init(sm, &data->ssl, 0,
 128                                     EAP_WFA_UNAUTH_TLS_TYPE)) {
 129                 wpa_printf(MSG_INFO, "EAP-TLS: Failed to initialize SSL.");
 130                 eap_tls_reset(sm, data);
 131                 return NULL;
 132         }
 133
 134         data->eap_type = EAP_WFA_UNAUTH_TLS_TYPE;
 135         return data;
 136 }
 137 #endif /* CONFIG_HS20 */
 138
 139
 140 static void eap_tls_reset(struct eap_sm *sm, void *priv)
 141 {
 142         struct eap_tls_data *data = priv;
 143         if (data == NULL)
 144                 return;
 145         eap_server_tls_ssl_deinit(sm, &data->ssl);
 146         os_free(data);
 147 }
 148
 149
 150 static struct wpabuf * eap_tls_build_start(struct eap_sm *sm,
 151                                            struct eap_tls_data *data, u8 id)
 152 {
 153         struct wpabuf *req;
 154
 155         req = eap_tls_msg_alloc(data->eap_type, 1, EAP_CODE_REQUEST, id);
 156         if (req == NULL) {
 157                 wpa_printf(MSG_ERROR, "EAP-TLS: Failed to allocate memory for "
 158                            "request");
 159                 eap_tls_state(data, FAILURE);
 160                 return NULL;
 161         }
 162
 163         wpabuf_put_u8(req, EAP_TLS_FLAGS_START);
 164
 165         eap_tls_state(data, CONTINUE);
 166
 167         return req;
 168 }
 169
 170
 171 static struct wpabuf * eap_tls_buildReq(struct eap_sm *sm, void *priv, u8 id)
 172 {
 173         struct eap_tls_data *data = priv;
 174         struct wpabuf *res;
 175
 176         if (data->ssl.state == FRAG_ACK) {
 177                 return eap_server_tls_build_ack(id, data->eap_type, 0);
 178         }
 179
 180         if (data->ssl.state == WAIT_FRAG_ACK) {
 181                 res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0,
 182                                                id);
 183                 goto check_established;
 184         }
 185
 186         switch (data->state) {
 187         case START:
 188                 return eap_tls_build_start(sm, data, id);
 189         case CONTINUE:
 190                 if (tls_connection_established(sm->ssl_ctx, data->ssl.conn))
 191                         data->established = 1;
 192                 break;
 193         default:
 194                 wpa_printf(MSG_DEBUG, "EAP-TLS: %s - unexpected state %d",
 195                            __func__, data->state);
 196                 return NULL;
 197         }
 198
 199         res = eap_server_tls_build_msg(&data->ssl, data->eap_type, 0, id);
 200
 201 check_established:
 202         if (data->established && data->ssl.state != WAIT_FRAG_ACK) {
 203                 /* TLS handshake has been completed and there are no more
 204                  * fragments waiting to be sent out. */
 205                 wpa_printf(MSG_DEBUG, "EAP-TLS: Done");
 206                 eap_tls_state(data, SUCCESS);
 207                 eap_tls_valid_session(sm, data);
 208                 if (sm->serial_num) {
 209                         char user[128];
 210                         int user_len;
 211
 212                         user_len = os_snprintf(user, sizeof(user), "cert-%s",
 213                                                sm->serial_num);
 214                         if (eap_user_get(sm, (const u8 *) user, user_len,
 215                                          data->phase2) < 0)
 216                                 wpa_printf(MSG_DEBUG,
 217                                            "EAP-TLS: No user entry found based on the serial number of the client certificate ");
 218                         else
 219                                 wpa_printf(MSG_DEBUG,
 220                                            "EAP-TLS: Updated user entry based on the serial number of the client certificate ");
 221                 }
 222         }
 223
 224         return res;
 225 }
 226
 227
 228 static Boolean eap_tls_check(struct eap_sm *sm, void *priv,
 229                              struct wpabuf *respData)
 230 {
 231         struct eap_tls_data *data = priv;
 232         const u8 *pos;
 233         size_t len;
 234
 235         if (data->eap_type == EAP_UNAUTH_TLS_TYPE)
 236                 pos = eap_hdr_validate(EAP_VENDOR_UNAUTH_TLS,
 237                                        EAP_VENDOR_TYPE_UNAUTH_TLS, respData,
 238                                        &len);
 239         else if (data->eap_type == EAP_WFA_UNAUTH_TLS_TYPE)
 240                 pos = eap_hdr_validate(EAP_VENDOR_WFA_NEW,
 241                                        EAP_VENDOR_WFA_UNAUTH_TLS, respData,
 242                                        &len);
 243         else
 244                 pos = eap_hdr_validate(EAP_VENDOR_IETF, data->eap_type,
 245                                        respData, &len);
 246         if (pos == NULL || len < 1) {
 247                 wpa_printf(MSG_INFO, "EAP-TLS: Invalid frame");
 248                 return TRUE;
 249         }
 250
 251         return FALSE;
 252 }
 253
 254
 255 static void eap_tls_process_msg(struct eap_sm *sm, void *priv,
 256                                 const struct wpabuf *respData)
 257 {
 258         struct eap_tls_data *data = priv;
 259         if (data->state == SUCCESS && wpabuf_len(data->ssl.tls_in) == 0) {
 260                 wpa_printf(MSG_DEBUG, "EAP-TLS: Client acknowledged final TLS "
 261                            "handshake message");
 262                 return;
 263         }
 264         if (eap_server_tls_phase1(sm, &data->ssl) < 0)
 265                 eap_tls_state(data, FAILURE);
 266 }
 267
 268
 269 static void eap_tls_process(struct eap_sm *sm, void *priv,
 270                             struct wpabuf *respData)
 271 {
 272         struct eap_tls_data *data = priv;
 273         const struct wpabuf *buf;
 274         const u8 *pos;
 275
 276         if (eap_server_tls_process(sm, &data->ssl, respData, data,
 277                                    data->eap_type, NULL, eap_tls_process_msg) <
 278             0) {
 279                 eap_tls_state(data, FAILURE);
 280                 return;
 281         }
 282
 283         if (!tls_connection_established(sm->ssl_ctx, data->ssl.conn) ||
 284             !tls_connection_resumed(sm->ssl_ctx, data->ssl.conn))
 285                 return;
 286
 287         buf = tls_connection_get_success_data(data->ssl.conn);
 288         if (!buf || wpabuf_len(buf) < 1) {
 289                 wpa_printf(MSG_DEBUG,
 290                            "EAP-TLS: No success data in resumed session - reject attempt");
 291                 eap_tls_state(data, FAILURE);
 292                 return;
 293         }
 294
 295         pos = wpabuf_head(buf);
 296         if (*pos != data->eap_type) {
 297                 wpa_printf(MSG_DEBUG,
 298                            "EAP-TLS: Resumed session for another EAP type (%u) - reject attempt",
 299                            *pos);
 300                 eap_tls_state(data, FAILURE);
 301                 return;
 302         }
 303
 304         wpa_printf(MSG_DEBUG,
 305                    "EAP-TLS: Resuming previous session");
 306         eap_tls_state(data, SUCCESS);
 307         tls_connection_set_success_data_resumed(data->ssl.conn);
 308         /* TODO: Cache serial number with session and update EAP user
 309          * information based on the cached serial number */
 310 }
 311
 312
 313 static Boolean eap_tls_isDone(struct eap_sm *sm, void *priv)
 314 {
 315         struct eap_tls_data *data = priv;
 316         return data->state == SUCCESS || data->state == FAILURE;
 317 }
 318
 319
 320 static u8 * eap_tls_getKey(struct eap_sm *sm, void *priv, size_t *len)
 321 {
 322         struct eap_tls_data *data = priv;
 323         u8 *eapKeyData;
 324         const char *label;
 325
 326         if (data->state != SUCCESS)
 327                 return NULL;
 328
 329         if (data->ssl.tls_v13)
 330                 label = "EXPORTER_EAP_TLS_Key_Material";
 331         else
 332                 label = "client EAP encryption";
 333         eapKeyData = eap_server_tls_derive_key(sm, &data->ssl, label,
 334                                                NULL, 0,
 335                                                EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
 336         if (eapKeyData) {
 337                 *len = EAP_TLS_KEY_LEN;
 338                 wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived key",
 339                             eapKeyData, EAP_TLS_KEY_LEN);
 340                 os_memset(eapKeyData + EAP_TLS_KEY_LEN, 0, EAP_EMSK_LEN);
 341         } else {
 342                 wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive key");
 343         }
 344
 345         return eapKeyData;
 346 }
 347
 348
 349 static u8 * eap_tls_get_emsk(struct eap_sm *sm, void *priv, size_t *len)
 350 {
 351         struct eap_tls_data *data = priv;
 352         u8 *eapKeyData, *emsk;
 353         const char *label;
 354
 355         if (data->state != SUCCESS)
 356                 return NULL;
 357
 358         if (data->ssl.tls_v13)
 359                 label = "EXPORTER_EAP_TLS_Key_Material";
 360         else
 361                 label = "client EAP encryption";
 362         eapKeyData = eap_server_tls_derive_key(sm, &data->ssl, label,
 363                                                NULL, 0,
 364                                                EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
 365         if (eapKeyData) {
 366                 emsk = os_malloc(EAP_EMSK_LEN);
 367                 if (emsk)
 368                         os_memcpy(emsk, eapKeyData + EAP_TLS_KEY_LEN,
 369                                   EAP_EMSK_LEN);
 370                 bin_clear_free(eapKeyData, EAP_TLS_KEY_LEN + EAP_EMSK_LEN);
 371         } else
 372                 emsk = NULL;
 373
 374         if (emsk) {
 375                 *len = EAP_EMSK_LEN;
 376                 wpa_hexdump(MSG_DEBUG, "EAP-TLS: Derived EMSK",
 377                             emsk, EAP_EMSK_LEN);
 378         } else {
 379                 wpa_printf(MSG_DEBUG, "EAP-TLS: Failed to derive EMSK");
 380         }
 381
 382         return emsk;
 383 }
 384
 385
 386 static Boolean eap_tls_isSuccess(struct eap_sm *sm, void *priv)
 387 {
 388         struct eap_tls_data *data = priv;
 389         return data->state == SUCCESS;
 390 }
 391
 392
 393 static u8 * eap_tls_get_session_id(struct eap_sm *sm, void *priv, size_t *len)
 394 {
 395         struct eap_tls_data *data = priv;
 396
 397         if (data->state != SUCCESS)
 398                 return NULL;
 399
 400         return eap_server_tls_derive_session_id(sm, &data->ssl, EAP_TYPE_TLS,
 401                                                 len);
 402 }
 403
 404
 405 int eap_server_tls_register(void)
 406 {
 407         struct eap_method *eap;
 408
 409         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 410                                       EAP_VENDOR_IETF, EAP_TYPE_TLS, "TLS");
 411         if (eap == NULL)
 412                 return -1;
 413
 414         eap->init = eap_tls_init;
 415         eap->reset = eap_tls_reset;
 416         eap->buildReq = eap_tls_buildReq;
 417         eap->check = eap_tls_check;
 418         eap->process = eap_tls_process;
 419         eap->isDone = eap_tls_isDone;
 420         eap->getKey = eap_tls_getKey;
 421         eap->isSuccess = eap_tls_isSuccess;
 422         eap->get_emsk = eap_tls_get_emsk;
 423         eap->getSessionId = eap_tls_get_session_id;
 424
 425         return eap_server_method_register(eap);
 426 }
 427
 428
 429 #ifdef EAP_SERVER_UNAUTH_TLS
 430 int eap_server_unauth_tls_register(void)
 431 {
 432         struct eap_method *eap;
 433
 434         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 435                                       EAP_VENDOR_UNAUTH_TLS,
 436                                       EAP_VENDOR_TYPE_UNAUTH_TLS,
 437                                       "UNAUTH-TLS");
 438         if (eap == NULL)
 439                 return -1;
 440
 441         eap->init = eap_unauth_tls_init;
 442         eap->reset = eap_tls_reset;
 443         eap->buildReq = eap_tls_buildReq;
 444         eap->check = eap_tls_check;
 445         eap->process = eap_tls_process;
 446         eap->isDone = eap_tls_isDone;
 447         eap->getKey = eap_tls_getKey;
 448         eap->isSuccess = eap_tls_isSuccess;
 449         eap->get_emsk = eap_tls_get_emsk;
 450
 451         return eap_server_method_register(eap);
 452 }
 453 #endif /* EAP_SERVER_UNAUTH_TLS */
 454
 455
 456 #ifdef CONFIG_HS20
 457 int eap_server_wfa_unauth_tls_register(void)
 458 {
 459         struct eap_method *eap;
 460
 461         eap = eap_server_method_alloc(EAP_SERVER_METHOD_INTERFACE_VERSION,
 462                                       EAP_VENDOR_WFA_NEW,
 463                                       EAP_VENDOR_WFA_UNAUTH_TLS,
 464                                       "WFA-UNAUTH-TLS");
 465         if (eap == NULL)
 466                 return -1;
 467
 468         eap->init = eap_wfa_unauth_tls_init;
 469         eap->reset = eap_tls_reset;
 470         eap->buildReq = eap_tls_buildReq;
 471         eap->check = eap_tls_check;
 472         eap->process = eap_tls_process;
 473         eap->isDone = eap_tls_isDone;
 474         eap->getKey = eap_tls_getKey;
 475         eap->isSuccess = eap_tls_isSuccess;
 476         eap->get_emsk = eap_tls_get_emsk;
 477
 478         return eap_server_method_register(eap);
 479 }
 480 #endif /* CONFIG_HS20 */