contrib/wpa_supplicant/src/eap_peer/eap_wsc.c

   1 /*
   2  * EAP-WSC peer for Wi-Fi Protected Setup
   3  * Copyright (c) 2007-2008, 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 "uuid.h"
  19 #include "eap_i.h"
  20 #include "eap_common/eap_wsc_common.h"
  21 #include "wps/wps.h"
  22 #include "wps/wps_defs.h"
  23
  24
  25 struct eap_wsc_data {
  26         enum { WAIT_START, MESG, FRAG_ACK, WAIT_FRAG_ACK, DONE, FAIL } state;
  27         int registrar;
  28         struct wpabuf *in_buf;
  29         struct wpabuf *out_buf;
  30         enum wsc_op_code in_op_code, out_op_code;
  31         size_t out_used;
  32         size_t fragment_size;
  33         struct wps_data *wps;
  34         struct wps_context *wps_ctx;
  35 };
  36
  37
  38 static const char * eap_wsc_state_txt(int state)
  39 {
  40         switch (state) {
  41         case WAIT_START:
  42                 return "WAIT_START";
  43         case MESG:
  44                 return "MESG";
  45         case FRAG_ACK:
  46                 return "FRAG_ACK";
  47         case WAIT_FRAG_ACK:
  48                 return "WAIT_FRAG_ACK";
  49         case DONE:
  50                 return "DONE";
  51         case FAIL:
  52                 return "FAIL";
  53         default:
  54                 return "?";
  55         }
  56 }
  57
  58
  59 static void eap_wsc_state(struct eap_wsc_data *data, int state)
  60 {
  61         wpa_printf(MSG_DEBUG, "EAP-WSC: %s -> %s",
  62                    eap_wsc_state_txt(data->state),
  63                    eap_wsc_state_txt(state));
  64         data->state = state;
  65 }
  66
  67
  68 static void * eap_wsc_init(struct eap_sm *sm)
  69 {
  70         struct eap_wsc_data *data;
  71         const u8 *identity;
  72         size_t identity_len;
  73         int registrar;
  74         struct wps_config cfg;
  75         const char *pos;
  76         const char *phase1;
  77         struct wps_context *wps;
  78
  79         wps = sm->wps;
  80         if (wps == NULL) {
  81                 wpa_printf(MSG_ERROR, "EAP-WSC: WPS context not available");
  82                 return NULL;
  83         }
  84
  85         identity = eap_get_config_identity(sm, &identity_len);
  86
  87         if (identity && identity_len == WSC_ID_REGISTRAR_LEN &&
  88             os_memcmp(identity, WSC_ID_REGISTRAR, WSC_ID_REGISTRAR_LEN) == 0)
  89                 registrar = 1; /* Supplicant is Registrar */
  90         else if (identity && identity_len == WSC_ID_ENROLLEE_LEN &&
  91             os_memcmp(identity, WSC_ID_ENROLLEE, WSC_ID_ENROLLEE_LEN) == 0)
  92                 registrar = 0; /* Supplicant is Enrollee */
  93         else {
  94                 wpa_hexdump_ascii(MSG_INFO, "EAP-WSC: Unexpected identity",
  95                                   identity, identity_len);
  96                 return NULL;
  97         }
  98
  99         data = os_zalloc(sizeof(*data));
 100         if (data == NULL)
 101                 return NULL;
 102         data->state = registrar ? MESG : WAIT_START;
 103         data->registrar = registrar;
 104         data->wps_ctx = wps;
 105
 106         os_memset(&cfg, 0, sizeof(cfg));
 107         cfg.wps = wps;
 108         cfg.registrar = registrar;
 109
 110         phase1 = eap_get_config_phase1(sm);
 111         if (phase1 == NULL) {
 112                 wpa_printf(MSG_INFO, "EAP-WSC: phase1 configuration data not "
 113                            "set");
 114                 os_free(data);
 115                 return NULL;
 116         }
 117
 118         pos = os_strstr(phase1, "pin=");
 119         if (pos) {
 120                 pos += 4;
 121                 cfg.pin = (const u8 *) pos;
 122                 while (*pos != '\0' && *pos != ' ')
 123                         pos++;
 124                 cfg.pin_len = pos - (const char *) cfg.pin;
 125         } else {
 126                 pos = os_strstr(phase1, "pbc=1");
 127                 if (pos)
 128                         cfg.pbc = 1;
 129         }
 130
 131         if (cfg.pin == NULL && !cfg.pbc) {
 132                 wpa_printf(MSG_INFO, "EAP-WSC: PIN or PBC not set in phase1 "
 133                            "configuration data");
 134                 os_free(data);
 135                 return NULL;
 136         }
 137
 138         data->wps = wps_init(&cfg);
 139         if (data->wps == NULL) {
 140                 os_free(data);
 141                 return NULL;
 142         }
 143         data->fragment_size = WSC_FRAGMENT_SIZE;
 144
 145         if (registrar && cfg.pin) {
 146                 wps_registrar_add_pin(data->wps_ctx->registrar, NULL,
 147                                       cfg.pin, cfg.pin_len, 0);
 148         }
 149
 150         return data;
 151 }
 152
 153
 154 static void eap_wsc_deinit(struct eap_sm *sm, void *priv)
 155 {
 156         struct eap_wsc_data *data = priv;
 157         wpabuf_free(data->in_buf);
 158         wpabuf_free(data->out_buf);
 159         wps_deinit(data->wps);
 160         os_free(data->wps_ctx->network_key);
 161         data->wps_ctx->network_key = NULL;
 162         os_free(data);
 163 }
 164
 165
 166 static struct wpabuf * eap_wsc_build_msg(struct eap_wsc_data *data,
 167                                          struct eap_method_ret *ret, u8 id)
 168 {
 169         struct wpabuf *resp;
 170         u8 flags;
 171         size_t send_len, plen;
 172
 173         ret->ignore = FALSE;
 174         wpa_printf(MSG_DEBUG, "EAP-WSC: Generating Response");
 175         ret->allowNotifications = TRUE;
 176
 177         flags = 0;
 178         send_len = wpabuf_len(data->out_buf) - data->out_used;
 179         if (2 + send_len > data->fragment_size) {
 180                 send_len = data->fragment_size - 2;
 181                 flags |= WSC_FLAGS_MF;
 182                 if (data->out_used == 0) {
 183                         flags |= WSC_FLAGS_LF;
 184                         send_len -= 2;
 185                 }
 186         }
 187         plen = 2 + send_len;
 188         if (flags & WSC_FLAGS_LF)
 189                 plen += 2;
 190         resp = eap_msg_alloc(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, plen,
 191                              EAP_CODE_RESPONSE, id);
 192         if (resp == NULL)
 193                 return NULL;
 194
 195         wpabuf_put_u8(resp, data->out_op_code); /* Op-Code */
 196         wpabuf_put_u8(resp, flags); /* Flags */
 197         if (flags & WSC_FLAGS_LF)
 198                 wpabuf_put_be16(resp, wpabuf_len(data->out_buf));
 199
 200         wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
 201                         send_len);
 202         data->out_used += send_len;
 203
 204         ret->methodState = METHOD_MAY_CONT;
 205         ret->decision = DECISION_FAIL;
 206
 207         if (data->out_used == wpabuf_len(data->out_buf)) {
 208                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 209                            "(message sent completely)",
 210                            (unsigned long) send_len);
 211                 wpabuf_free(data->out_buf);
 212                 data->out_buf = NULL;
 213                 data->out_used = 0;
 214                 if ((data->state == FAIL && data->out_op_code == WSC_ACK) ||
 215                     data->out_op_code == WSC_NACK ||
 216                     data->out_op_code == WSC_Done) {
 217                         eap_wsc_state(data, FAIL);
 218                         ret->methodState = METHOD_DONE;
 219                 } else
 220                         eap_wsc_state(data, MESG);
 221         } else {
 222                 wpa_printf(MSG_DEBUG, "EAP-WSC: Sending out %lu bytes "
 223                            "(%lu more to send)", (unsigned long) send_len,
 224                            (unsigned long) wpabuf_len(data->out_buf) -
 225                            data->out_used);
 226                 eap_wsc_state(data, WAIT_FRAG_ACK);
 227         }
 228
 229         return resp;
 230 }
 231
 232
 233 static int eap_wsc_process_cont(struct eap_wsc_data *data,
 234                                 const u8 *buf, size_t len, u8 op_code)
 235 {
 236         /* Process continuation of a pending message */
 237         if (op_code != data->in_op_code) {
 238                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d in "
 239                            "fragment (expected %d)",
 240                            op_code, data->in_op_code);
 241                 return -1;
 242         }
 243
 244         if (len > wpabuf_tailroom(data->in_buf)) {
 245                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment overflow");
 246                 eap_wsc_state(data, FAIL);
 247                 return -1;
 248         }
 249
 250         wpabuf_put_data(data->in_buf, buf, len);
 251         wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes, waiting "
 252                    "for %lu bytes more", (unsigned long) len,
 253                    (unsigned long) wpabuf_tailroom(data->in_buf));
 254
 255         return 0;
 256 }
 257
 258
 259 static struct wpabuf * eap_wsc_process_fragment(struct eap_wsc_data *data,
 260                                                 struct eap_method_ret *ret,
 261                                                 u8 id, u8 flags, u8 op_code,
 262                                                 u16 message_length,
 263                                                 const u8 *buf, size_t len)
 264 {
 265         /* Process a fragment that is not the last one of the message */
 266         if (data->in_buf == NULL && !(flags & WSC_FLAGS_LF)) {
 267                 wpa_printf(MSG_DEBUG, "EAP-WSC: No Message Length field in a "
 268                            "fragmented packet");
 269                 ret->ignore = TRUE;
 270                 return NULL;
 271         }
 272
 273         if (data->in_buf == NULL) {
 274                 /* First fragment of the message */
 275                 data->in_buf = wpabuf_alloc(message_length);
 276                 if (data->in_buf == NULL) {
 277                         wpa_printf(MSG_DEBUG, "EAP-WSC: No memory for "
 278                                    "message");
 279                         ret->ignore = TRUE;
 280                         return NULL;
 281                 }
 282                 data->in_op_code = op_code;
 283                 wpabuf_put_data(data->in_buf, buf, len);
 284                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received %lu bytes in first "
 285                            "fragment, waiting for %lu bytes more",
 286                            (unsigned long) len,
 287                            (unsigned long) wpabuf_tailroom(data->in_buf));
 288         }
 289
 290         return eap_wsc_build_frag_ack(id, EAP_CODE_RESPONSE);
 291 }
 292
 293
 294 static struct wpabuf * eap_wsc_process(struct eap_sm *sm, void *priv,
 295                                        struct eap_method_ret *ret,
 296                                        const struct wpabuf *reqData)
 297 {
 298         struct eap_wsc_data *data = priv;
 299         const u8 *start, *pos, *end;
 300         size_t len;
 301         u8 op_code, flags, id;
 302         u16 message_length = 0;
 303         enum wps_process_res res;
 304         struct wpabuf tmpbuf;
 305
 306         pos = eap_hdr_validate(EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC, reqData,
 307                                &len);
 308         if (pos == NULL || len < 2) {
 309                 ret->ignore = TRUE;
 310                 return NULL;
 311         }
 312
 313         id = eap_get_id(reqData);
 314
 315         start = pos;
 316         end = start + len;
 317
 318         op_code = *pos++;
 319         flags = *pos++;
 320         if (flags & WSC_FLAGS_LF) {
 321                 if (end - pos < 2) {
 322                         wpa_printf(MSG_DEBUG, "EAP-WSC: Message underflow");
 323                         ret->ignore = TRUE;
 324                         return NULL;
 325                 }
 326                 message_length = WPA_GET_BE16(pos);
 327                 pos += 2;
 328
 329                 if (message_length < end - pos) {
 330                         wpa_printf(MSG_DEBUG, "EAP-WSC: Invalid Message "
 331                                    "Length");
 332                         ret->ignore = TRUE;
 333                         return NULL;
 334                 }
 335         }
 336
 337         wpa_printf(MSG_DEBUG, "EAP-WSC: Received packet: Op-Code %d "
 338                    "Flags 0x%x Message Length %d",
 339                    op_code, flags, message_length);
 340
 341         if (data->state == WAIT_FRAG_ACK) {
 342                 if (op_code != WSC_FRAG_ACK) {
 343                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 344                                    "in WAIT_FRAG_ACK state", op_code);
 345                         ret->ignore = TRUE;
 346                         return NULL;
 347                 }
 348                 wpa_printf(MSG_DEBUG, "EAP-WSC: Fragment acknowledged");
 349                 eap_wsc_state(data, MESG);
 350                 return eap_wsc_build_msg(data, ret, id);
 351         }
 352
 353         if (op_code != WSC_ACK && op_code != WSC_NACK && op_code != WSC_MSG &&
 354             op_code != WSC_Done && op_code != WSC_Start) {
 355                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 356                            op_code);
 357                 ret->ignore = TRUE;
 358                 return NULL;
 359         }
 360
 361         if (data->state == WAIT_START) {
 362                 if (op_code != WSC_Start) {
 363                         wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d "
 364                                    "in WAIT_START state", op_code);
 365                         ret->ignore = TRUE;
 366                         return NULL;
 367                 }
 368                 wpa_printf(MSG_DEBUG, "EAP-WSC: Received start");
 369                 eap_wsc_state(data, MESG);
 370                 /* Start message has empty payload, skip processing */
 371                 goto send_msg;
 372         } else if (op_code == WSC_Start) {
 373                 wpa_printf(MSG_DEBUG, "EAP-WSC: Unexpected Op-Code %d",
 374                            op_code);
 375                 ret->ignore = TRUE;
 376                 return NULL;
 377         }
 378
 379         if (data->in_buf &&
 380             eap_wsc_process_cont(data, pos, end - pos, op_code) < 0) {
 381                 ret->ignore = TRUE;
 382                 return NULL;
 383         }
 384
 385         if (flags & WSC_FLAGS_MF) {
 386                 return eap_wsc_process_fragment(data, ret, id, flags, op_code,
 387                                                 message_length, pos,
 388                                                 end - pos);
 389         }
 390
 391         if (data->in_buf == NULL) {
 392                 /* Wrap unfragmented messages as wpabuf without extra copy */
 393                 wpabuf_set(&tmpbuf, pos, end - pos);
 394                 data->in_buf = &tmpbuf;
 395         }
 396
 397         res = wps_process_msg(data->wps, op_code, data->in_buf);
 398         switch (res) {
 399         case WPS_DONE:
 400                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing completed "
 401                            "successfully - wait for EAP failure");
 402                 eap_wsc_state(data, FAIL);
 403                 break;
 404         case WPS_CONTINUE:
 405                 eap_wsc_state(data, MESG);
 406                 break;
 407         case WPS_FAILURE:
 408         case WPS_PENDING:
 409                 wpa_printf(MSG_DEBUG, "EAP-WSC: WPS processing failed");
 410                 eap_wsc_state(data, FAIL);
 411                 break;
 412         }
 413
 414         if (data->in_buf != &tmpbuf)
 415                 wpabuf_free(data->in_buf);
 416         data->in_buf = NULL;
 417
 418 send_msg:
 419         if (data->out_buf == NULL) {
 420                 data->out_buf = wps_get_msg(data->wps, &data->out_op_code);
 421                 if (data->out_buf == NULL) {
 422                         wpa_printf(MSG_DEBUG, "EAP-WSC: Failed to receive "
 423                                    "message from WPS");
 424                         return NULL;
 425                 }
 426                 data->out_used = 0;
 427         }
 428
 429         eap_wsc_state(data, MESG);
 430         return eap_wsc_build_msg(data, ret, id);
 431 }
 432
 433
 434 int eap_peer_wsc_register(void)
 435 {
 436         struct eap_method *eap;
 437         int ret;
 438
 439         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 440                                     EAP_VENDOR_WFA, EAP_VENDOR_TYPE_WSC,
 441                                     "WSC");
 442         if (eap == NULL)
 443                 return -1;
 444
 445         eap->init = eap_wsc_init;
 446         eap->deinit = eap_wsc_deinit;
 447         eap->process = eap_wsc_process;
 448
 449         ret = eap_peer_method_register(eap);
 450         if (ret)
 451                 eap_peer_method_free(eap);
 452         return ret;
 453 }