www.project-moonshot.org Git - mech_eap.orig/blob - libeap/src/eap_peer/eap_tnc.c

   1 /*
   2  * EAP peer method: EAP-TNC (Trusted Network Connect)
   3  * Copyright (c) 2007, 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 "base64.h"
  19 #include "eap_i.h"
  20 #include "tncc.h"
  21
  22
  23 struct eap_tnc_data {
  24         enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state;
  25         struct tncc_data *tncc;
  26         struct wpabuf *in_buf;
  27         struct wpabuf *out_buf;
  28         size_t out_used;
  29         size_t fragment_size;
  30 };
  31
  32
  33 /* EAP-TNC Flags */
  34 #define EAP_TNC_FLAGS_LENGTH_INCLUDED 0x80
  35 #define EAP_TNC_FLAGS_MORE_FRAGMENTS 0x40
  36 #define EAP_TNC_FLAGS_START 0x20
  37 #define EAP_TNC_VERSION_MASK 0x07
  38
  39 #define EAP_TNC_VERSION 1
  40
  41
  42 static void * eap_tnc_init(struct eap_sm *sm)
  43 {
  44         struct eap_tnc_data *data;
  45
  46         data = os_zalloc(sizeof(*data));
  47         if (data == NULL)
  48                 return NULL;
  49         data->state = WAIT_START;
  50         data->fragment_size = 1300;
  51         data->tncc = tncc_init();
  52         if (data->tncc == NULL) {
  53                 os_free(data);
  54                 return NULL;
  55         }
  56
  57         return data;
  58 }
  59
  60
  61 static void eap_tnc_deinit(struct eap_sm *sm, void *priv)
  62 {
  63         struct eap_tnc_data *data = priv;
  64
  65         wpabuf_free(data->in_buf);
  66         wpabuf_free(data->out_buf);
  67         tncc_deinit(data->tncc);
  68         os_free(data);
  69 }
  70
  71
  72 static struct wpabuf * eap_tnc_build_frag_ack(u8 id, u8 code)
  73 {
  74         struct wpabuf *msg;
  75
  76         msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1, code, id);
  77         if (msg == NULL) {
  78                 wpa_printf(MSG_ERROR, "EAP-TNC: Failed to allocate memory "
  79                            "for fragment ack");
  80                 return NULL;
  81         }
  82         wpabuf_put_u8(msg, EAP_TNC_VERSION); /* Flags */
  83
  84         wpa_printf(MSG_DEBUG, "EAP-TNC: Send fragment ack");
  85
  86         return msg;
  87 }
  88
  89
  90 static struct wpabuf * eap_tnc_build_msg(struct eap_tnc_data *data,
  91                                          struct eap_method_ret *ret, u8 id)
  92 {
  93         struct wpabuf *resp;
  94         u8 flags;
  95         size_t send_len, plen;
  96
  97         ret->ignore = FALSE;
  98         wpa_printf(MSG_DEBUG, "EAP-TNC: Generating Response");
  99         ret->allowNotifications = TRUE;
 100
 101         flags = EAP_TNC_VERSION;
 102         send_len = wpabuf_len(data->out_buf) - data->out_used;
 103         if (1 + send_len > data->fragment_size) {
 104                 send_len = data->fragment_size - 1;
 105                 flags |= EAP_TNC_FLAGS_MORE_FRAGMENTS;
 106                 if (data->out_used == 0) {
 107                         flags |= EAP_TNC_FLAGS_LENGTH_INCLUDED;
 108                         send_len -= 4;
 109                 }
 110         }
 111
 112         plen = 1 + send_len;
 113         if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
 114                 plen += 4;
 115         resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, plen,
 116                              EAP_CODE_RESPONSE, id);
 117         if (resp == NULL)
 118                 return NULL;
 119
 120         wpabuf_put_u8(resp, flags); /* Flags */
 121         if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)
 122                 wpabuf_put_be32(resp, wpabuf_len(data->out_buf));
 123
 124         wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used,
 125                         send_len);
 126         data->out_used += send_len;
 127
 128         ret->methodState = METHOD_MAY_CONT;
 129         ret->decision = DECISION_FAIL;
 130
 131         if (data->out_used == wpabuf_len(data->out_buf)) {
 132                 wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
 133                            "(message sent completely)",
 134                            (unsigned long) send_len);
 135                 wpabuf_free(data->out_buf);
 136                 data->out_buf = NULL;
 137                 data->out_used = 0;
 138         } else {
 139                 wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes "
 140                            "(%lu more to send)", (unsigned long) send_len,
 141                            (unsigned long) wpabuf_len(data->out_buf) -
 142                            data->out_used);
 143                 data->state = WAIT_FRAG_ACK;
 144         }
 145
 146         return resp;
 147 }
 148
 149
 150 static int eap_tnc_process_cont(struct eap_tnc_data *data,
 151                                 const u8 *buf, size_t len)
 152 {
 153         /* Process continuation of a pending message */
 154         if (len > wpabuf_tailroom(data->in_buf)) {
 155                 wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment overflow");
 156                 data->state = FAIL;
 157                 return -1;
 158         }
 159
 160         wpabuf_put_data(data->in_buf, buf, len);
 161         wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes, waiting for "
 162                    "%lu bytes more", (unsigned long) len,
 163                    (unsigned long) wpabuf_tailroom(data->in_buf));
 164
 165         return 0;
 166 }
 167
 168
 169 static struct wpabuf * eap_tnc_process_fragment(struct eap_tnc_data *data,
 170                                                 struct eap_method_ret *ret,
 171                                                 u8 id, u8 flags,
 172                                                 u32 message_length,
 173                                                 const u8 *buf, size_t len)
 174 {
 175         /* Process a fragment that is not the last one of the message */
 176         if (data->in_buf == NULL && !(flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)) {
 177                 wpa_printf(MSG_DEBUG, "EAP-TNC: No Message Length field in a "
 178                            "fragmented packet");
 179                 ret->ignore = TRUE;
 180                 return NULL;
 181         }
 182
 183         if (data->in_buf == NULL) {
 184                 /* First fragment of the message */
 185                 data->in_buf = wpabuf_alloc(message_length);
 186                 if (data->in_buf == NULL) {
 187                         wpa_printf(MSG_DEBUG, "EAP-TNC: No memory for "
 188                                    "message");
 189                         ret->ignore = TRUE;
 190                         return NULL;
 191                 }
 192                 wpabuf_put_data(data->in_buf, buf, len);
 193                 wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes in first "
 194                            "fragment, waiting for %lu bytes more",
 195                            (unsigned long) len,
 196                            (unsigned long) wpabuf_tailroom(data->in_buf));
 197         }
 198
 199         return eap_tnc_build_frag_ack(id, EAP_CODE_RESPONSE);
 200 }
 201
 202
 203 static struct wpabuf * eap_tnc_process(struct eap_sm *sm, void *priv,
 204                                        struct eap_method_ret *ret,
 205                                        const struct wpabuf *reqData)
 206 {
 207         struct eap_tnc_data *data = priv;
 208         struct wpabuf *resp;
 209         const u8 *pos, *end;
 210         u8 *rpos, *rpos1;
 211         size_t len, rlen;
 212         size_t imc_len;
 213         char *start_buf, *end_buf;
 214         size_t start_len, end_len;
 215         int tncs_done = 0;
 216         u8 flags, id;
 217         u32 message_length = 0;
 218         struct wpabuf tmpbuf;
 219
 220         pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TNC, reqData, &len);
 221         if (pos == NULL) {
 222                 wpa_printf(MSG_INFO, "EAP-TNC: Invalid frame (pos=%p len=%lu)",
 223                            pos, (unsigned long) len);
 224                 ret->ignore = TRUE;
 225                 return NULL;
 226         }
 227
 228         id = eap_get_id(reqData);
 229
 230         end = pos + len;
 231
 232         if (len == 0)
 233                 flags = 0; /* fragment ack */
 234         else
 235                 flags = *pos++;
 236
 237         if (len > 0 && (flags & EAP_TNC_VERSION_MASK) != EAP_TNC_VERSION) {
 238                 wpa_printf(MSG_DEBUG, "EAP-TNC: Unsupported version %d",
 239                            flags & EAP_TNC_VERSION_MASK);
 240                 ret->ignore = TRUE;
 241                 return NULL;
 242         }
 243
 244         if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED) {
 245                 if (end - pos < 4) {
 246                         wpa_printf(MSG_DEBUG, "EAP-TNC: Message underflow");
 247                         ret->ignore = TRUE;
 248                         return NULL;
 249                 }
 250                 message_length = WPA_GET_BE32(pos);
 251                 pos += 4;
 252
 253                 if (message_length < (u32) (end - pos)) {
 254                         wpa_printf(MSG_DEBUG, "EAP-TNC: Invalid Message "
 255                                    "Length (%d; %ld remaining in this msg)",
 256                                    message_length, (long) (end - pos));
 257                         ret->ignore = TRUE;
 258                         return NULL;
 259                 }
 260         }
 261
 262         wpa_printf(MSG_DEBUG, "EAP-TNC: Received packet: Flags 0x%x "
 263                    "Message Length %u", flags, message_length);
 264
 265         if (data->state == WAIT_FRAG_ACK) {
 266                 if (len > 1) {
 267                         wpa_printf(MSG_DEBUG, "EAP-TNC: Unexpected payload in "
 268                                    "WAIT_FRAG_ACK state");
 269                         ret->ignore = TRUE;
 270                         return NULL;
 271                 }
 272                 wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment acknowledged");
 273                 data->state = PROC_MSG;
 274                 return eap_tnc_build_msg(data, ret, id);
 275         }
 276
 277         if (data->in_buf && eap_tnc_process_cont(data, pos, end - pos) < 0) {
 278                 ret->ignore = TRUE;
 279                 return NULL;
 280         }
 281
 282         if (flags & EAP_TNC_FLAGS_MORE_FRAGMENTS) {
 283                 return eap_tnc_process_fragment(data, ret, id, flags,
 284                                                 message_length, pos,
 285                                                 end - pos);
 286         }
 287
 288         if (data->in_buf == NULL) {
 289                 /* Wrap unfragmented messages as wpabuf without extra copy */
 290                 wpabuf_set(&tmpbuf, pos, end - pos);
 291                 data->in_buf = &tmpbuf;
 292         }
 293
 294         if (data->state == WAIT_START) {
 295                 if (!(flags & EAP_TNC_FLAGS_START)) {
 296                         wpa_printf(MSG_DEBUG, "EAP-TNC: Server did not use "
 297                                    "start flag in the first message");
 298                         ret->ignore = TRUE;
 299                         goto fail;
 300                 }
 301
 302                 tncc_init_connection(data->tncc);
 303
 304                 data->state = PROC_MSG;
 305         } else {
 306                 enum tncc_process_res res;
 307
 308                 if (flags & EAP_TNC_FLAGS_START) {
 309                         wpa_printf(MSG_DEBUG, "EAP-TNC: Server used start "
 310                                    "flag again");
 311                         ret->ignore = TRUE;
 312                         goto fail;
 313                 }
 314
 315                 res = tncc_process_if_tnccs(data->tncc,
 316                                             wpabuf_head(data->in_buf),
 317                                             wpabuf_len(data->in_buf));
 318                 switch (res) {
 319                 case TNCCS_PROCESS_ERROR:
 320                         ret->ignore = TRUE;
 321                         goto fail;
 322                 case TNCCS_PROCESS_OK_NO_RECOMMENDATION:
 323                 case TNCCS_RECOMMENDATION_ERROR:
 324                         wpa_printf(MSG_DEBUG, "EAP-TNC: No "
 325                                    "TNCCS-Recommendation received");
 326                         break;
 327                 case TNCCS_RECOMMENDATION_ALLOW:
 328                         wpa_msg(sm->msg_ctx, MSG_INFO,
 329                                 "TNC: Recommendation = allow");
 330                         tncs_done = 1;
 331                         break;
 332                 case TNCCS_RECOMMENDATION_NONE:
 333                         wpa_msg(sm->msg_ctx, MSG_INFO,
 334                                 "TNC: Recommendation = none");
 335                         tncs_done = 1;
 336                         break;
 337                 case TNCCS_RECOMMENDATION_ISOLATE:
 338                         wpa_msg(sm->msg_ctx, MSG_INFO,
 339                                 "TNC: Recommendation = isolate");
 340                         tncs_done = 1;
 341                         break;
 342                 }
 343         }
 344
 345         if (data->in_buf != &tmpbuf)
 346                 wpabuf_free(data->in_buf);
 347         data->in_buf = NULL;
 348
 349         ret->ignore = FALSE;
 350         ret->methodState = METHOD_MAY_CONT;
 351         ret->decision = DECISION_UNCOND_SUCC;
 352         ret->allowNotifications = TRUE;
 353
 354         if (data->out_buf) {
 355                 data->state = PROC_MSG;
 356                 return eap_tnc_build_msg(data, ret, id);
 357         }
 358
 359         if (tncs_done) {
 360                 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1,
 361                                      EAP_CODE_RESPONSE, eap_get_id(reqData));
 362                 if (resp == NULL)
 363                         return NULL;
 364
 365                 wpabuf_put_u8(resp, EAP_TNC_VERSION);
 366                 wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS done - reply with an "
 367                            "empty ACK message");
 368                 return resp;
 369         }
 370
 371         imc_len = tncc_total_send_len(data->tncc);
 372
 373         start_buf = tncc_if_tnccs_start(data->tncc);
 374         if (start_buf == NULL)
 375                 return NULL;
 376         start_len = os_strlen(start_buf);
 377         end_buf = tncc_if_tnccs_end();
 378         if (end_buf == NULL) {
 379                 os_free(start_buf);
 380                 return NULL;
 381         }
 382         end_len = os_strlen(end_buf);
 383
 384         rlen = start_len + imc_len + end_len;
 385         resp = wpabuf_alloc(rlen);
 386         if (resp == NULL) {
 387                 os_free(start_buf);
 388                 os_free(end_buf);
 389                 return NULL;
 390         }
 391
 392         wpabuf_put_data(resp, start_buf, start_len);
 393         os_free(start_buf);
 394
 395         rpos1 = wpabuf_put(resp, 0);
 396         rpos = tncc_copy_send_buf(data->tncc, rpos1);
 397         wpabuf_put(resp, rpos - rpos1);
 398
 399         wpabuf_put_data(resp, end_buf, end_len);
 400         os_free(end_buf);
 401
 402         wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TNC: Response",
 403                           wpabuf_head(resp), wpabuf_len(resp));
 404
 405         data->out_buf = resp;
 406         data->state = PROC_MSG;
 407         return eap_tnc_build_msg(data, ret, id);
 408
 409 fail:
 410         if (data->in_buf == &tmpbuf)
 411                 data->in_buf = NULL;
 412         return NULL;
 413 }
 414
 415
 416 int eap_peer_tnc_register(void)
 417 {
 418         struct eap_method *eap;
 419         int ret;
 420
 421         eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION,
 422                                     EAP_VENDOR_IETF, EAP_TYPE_TNC, "TNC");
 423         if (eap == NULL)
 424                 return -1;
 425
 426         eap->init = eap_tnc_init;
 427         eap->deinit = eap_tnc_deinit;
 428         eap->process = eap_tnc_process;
 429
 430         ret = eap_peer_method_register(eap);
 431         if (ret)
 432                 eap_peer_method_free(eap);
 433         return ret;
 434 }