1 /* 2 * EAP peer method: EAP-TNC (Trusted Network Connect) 3 * Copyright (c) 2007, 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 "tncc.h" 14 15 16 struct eap_tnc_data { 17 enum { WAIT_START, PROC_MSG, WAIT_FRAG_ACK, DONE, FAIL } state; 18 struct tncc_data *tncc; 19 struct wpabuf *in_buf; 20 struct wpabuf *out_buf; 21 size_t out_used; 22 size_t fragment_size; 23 }; 24 25 26 /* EAP-TNC Flags */ 27 #define EAP_TNC_FLAGS_LENGTH_INCLUDED 0x80 28 #define EAP_TNC_FLAGS_MORE_FRAGMENTS 0x40 29 #define EAP_TNC_FLAGS_START 0x20 30 #define EAP_TNC_VERSION_MASK 0x07 31 32 #define EAP_TNC_VERSION 1 33 34 35 static void * eap_tnc_init(struct eap_sm *sm) 36 { 37 struct eap_tnc_data *data; 38 39 data = os_zalloc(sizeof(*data)); 40 if (data == NULL) 41 return NULL; 42 data->state = WAIT_START; 43 data->fragment_size = 1300; 44 data->tncc = tncc_init(); 45 if (data->tncc == NULL) { 46 os_free(data); 47 return NULL; 48 } 49 50 return data; 51 } 52 53 54 static void eap_tnc_deinit(struct eap_sm *sm, void *priv) 55 { 56 struct eap_tnc_data *data = priv; 57 58 wpabuf_free(data->in_buf); 59 wpabuf_free(data->out_buf); 60 tncc_deinit(data->tncc); 61 os_free(data); 62 } 63 64 65 static struct wpabuf * eap_tnc_build_frag_ack(u8 id, u8 code) 66 { 67 struct wpabuf *msg; 68 69 msg = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1, code, id); 70 if (msg == NULL) { 71 wpa_printf(MSG_ERROR, "EAP-TNC: Failed to allocate memory " 72 "for fragment ack"); 73 return NULL; 74 } 75 wpabuf_put_u8(msg, EAP_TNC_VERSION); /* Flags */ 76 77 wpa_printf(MSG_DEBUG, "EAP-TNC: Send fragment ack"); 78 79 return msg; 80 } 81 82 83 static struct wpabuf * eap_tnc_build_msg(struct eap_tnc_data *data, 84 struct eap_method_ret *ret, u8 id) 85 { 86 struct wpabuf *resp; 87 u8 flags; 88 size_t send_len, plen; 89 90 ret->ignore = FALSE; 91 wpa_printf(MSG_DEBUG, "EAP-TNC: Generating Response"); 92 ret->allowNotifications = TRUE; 93 94 flags = EAP_TNC_VERSION; 95 send_len = wpabuf_len(data->out_buf) - data->out_used; 96 if (1 + send_len > data->fragment_size) { 97 send_len = data->fragment_size - 1; 98 flags |= EAP_TNC_FLAGS_MORE_FRAGMENTS; 99 if (data->out_used == 0) { 100 flags |= EAP_TNC_FLAGS_LENGTH_INCLUDED; 101 send_len -= 4; 102 } 103 } 104 105 plen = 1 + send_len; 106 if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED) 107 plen += 4; 108 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, plen, 109 EAP_CODE_RESPONSE, id); 110 if (resp == NULL) 111 return NULL; 112 113 wpabuf_put_u8(resp, flags); /* Flags */ 114 if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED) 115 wpabuf_put_be32(resp, wpabuf_len(data->out_buf)); 116 117 wpabuf_put_data(resp, wpabuf_head_u8(data->out_buf) + data->out_used, 118 send_len); 119 data->out_used += send_len; 120 121 ret->methodState = METHOD_MAY_CONT; 122 ret->decision = DECISION_FAIL; 123 124 if (data->out_used == wpabuf_len(data->out_buf)) { 125 wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes " 126 "(message sent completely)", 127 (unsigned long) send_len); 128 wpabuf_free(data->out_buf); 129 data->out_buf = NULL; 130 data->out_used = 0; 131 } else { 132 wpa_printf(MSG_DEBUG, "EAP-TNC: Sending out %lu bytes " 133 "(%lu more to send)", (unsigned long) send_len, 134 (unsigned long) wpabuf_len(data->out_buf) - 135 data->out_used); 136 data->state = WAIT_FRAG_ACK; 137 } 138 139 return resp; 140 } 141 142 143 static int eap_tnc_process_cont(struct eap_tnc_data *data, 144 const u8 *buf, size_t len) 145 { 146 /* Process continuation of a pending message */ 147 if (len > wpabuf_tailroom(data->in_buf)) { 148 wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment overflow"); 149 data->state = FAIL; 150 return -1; 151 } 152 153 wpabuf_put_data(data->in_buf, buf, len); 154 wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes, waiting for " 155 "%lu bytes more", (unsigned long) len, 156 (unsigned long) wpabuf_tailroom(data->in_buf)); 157 158 return 0; 159 } 160 161 162 static struct wpabuf * eap_tnc_process_fragment(struct eap_tnc_data *data, 163 struct eap_method_ret *ret, 164 u8 id, u8 flags, 165 u32 message_length, 166 const u8 *buf, size_t len) 167 { 168 /* Process a fragment that is not the last one of the message */ 169 if (data->in_buf == NULL && !(flags & EAP_TNC_FLAGS_LENGTH_INCLUDED)) { 170 wpa_printf(MSG_DEBUG, "EAP-TNC: No Message Length field in a " 171 "fragmented packet"); 172 ret->ignore = TRUE; 173 return NULL; 174 } 175 176 if (data->in_buf == NULL) { 177 /* First fragment of the message */ 178 data->in_buf = wpabuf_alloc(message_length); 179 if (data->in_buf == NULL) { 180 wpa_printf(MSG_DEBUG, "EAP-TNC: No memory for " 181 "message"); 182 ret->ignore = TRUE; 183 return NULL; 184 } 185 wpabuf_put_data(data->in_buf, buf, len); 186 wpa_printf(MSG_DEBUG, "EAP-TNC: Received %lu bytes in first " 187 "fragment, waiting for %lu bytes more", 188 (unsigned long) len, 189 (unsigned long) wpabuf_tailroom(data->in_buf)); 190 } 191 192 return eap_tnc_build_frag_ack(id, EAP_CODE_RESPONSE); 193 } 194 195 196 static struct wpabuf * eap_tnc_process(struct eap_sm *sm, void *priv, 197 struct eap_method_ret *ret, 198 const struct wpabuf *reqData) 199 { 200 struct eap_tnc_data *data = priv; 201 struct wpabuf *resp; 202 const u8 *pos, *end; 203 u8 *rpos, *rpos1; 204 size_t len, rlen; 205 size_t imc_len; 206 char *start_buf, *end_buf; 207 size_t start_len, end_len; 208 int tncs_done = 0; 209 u8 flags, id; 210 u32 message_length = 0; 211 struct wpabuf tmpbuf; 212 213 pos = eap_hdr_validate(EAP_VENDOR_IETF, EAP_TYPE_TNC, reqData, &len); 214 if (pos == NULL) { 215 wpa_printf(MSG_INFO, "EAP-TNC: Invalid frame (pos=%p len=%lu)", 216 pos, (unsigned long) len); 217 ret->ignore = TRUE; 218 return NULL; 219 } 220 221 id = eap_get_id(reqData); 222 223 end = pos + len; 224 225 if (len == 0) 226 flags = 0; /* fragment ack */ 227 else 228 flags = *pos++; 229 230 if (len > 0 && (flags & EAP_TNC_VERSION_MASK) != EAP_TNC_VERSION) { 231 wpa_printf(MSG_DEBUG, "EAP-TNC: Unsupported version %d", 232 flags & EAP_TNC_VERSION_MASK); 233 ret->ignore = TRUE; 234 return NULL; 235 } 236 237 if (flags & EAP_TNC_FLAGS_LENGTH_INCLUDED) { 238 if (end - pos < 4) { 239 wpa_printf(MSG_DEBUG, "EAP-TNC: Message underflow"); 240 ret->ignore = TRUE; 241 return NULL; 242 } 243 message_length = WPA_GET_BE32(pos); 244 pos += 4; 245 246 if (message_length < (u32) (end - pos) || 247 message_length > 75000) { 248 wpa_printf(MSG_DEBUG, "EAP-TNC: Invalid Message " 249 "Length (%d; %ld remaining in this msg)", 250 message_length, (long) (end - pos)); 251 ret->ignore = TRUE; 252 return NULL; 253 } 254 } 255 256 wpa_printf(MSG_DEBUG, "EAP-TNC: Received packet: Flags 0x%x " 257 "Message Length %u", flags, message_length); 258 259 if (data->state == WAIT_FRAG_ACK) { 260 if (len > 1) { 261 wpa_printf(MSG_DEBUG, "EAP-TNC: Unexpected payload in " 262 "WAIT_FRAG_ACK state"); 263 ret->ignore = TRUE; 264 return NULL; 265 } 266 wpa_printf(MSG_DEBUG, "EAP-TNC: Fragment acknowledged"); 267 data->state = PROC_MSG; 268 return eap_tnc_build_msg(data, ret, id); 269 } 270 271 if (data->in_buf && eap_tnc_process_cont(data, pos, end - pos) < 0) { 272 ret->ignore = TRUE; 273 return NULL; 274 } 275 276 if (flags & EAP_TNC_FLAGS_MORE_FRAGMENTS) { 277 return eap_tnc_process_fragment(data, ret, id, flags, 278 message_length, pos, 279 end - pos); 280 } 281 282 if (data->in_buf == NULL) { 283 /* Wrap unfragmented messages as wpabuf without extra copy */ 284 wpabuf_set(&tmpbuf, pos, end - pos); 285 data->in_buf = &tmpbuf; 286 } 287 288 if (data->state == WAIT_START) { 289 if (!(flags & EAP_TNC_FLAGS_START)) { 290 wpa_printf(MSG_DEBUG, "EAP-TNC: Server did not use " 291 "start flag in the first message"); 292 ret->ignore = TRUE; 293 goto fail; 294 } 295 296 tncc_init_connection(data->tncc); 297 298 data->state = PROC_MSG; 299 } else { 300 enum tncc_process_res res; 301 302 if (flags & EAP_TNC_FLAGS_START) { 303 wpa_printf(MSG_DEBUG, "EAP-TNC: Server used start " 304 "flag again"); 305 ret->ignore = TRUE; 306 goto fail; 307 } 308 309 res = tncc_process_if_tnccs(data->tncc, 310 wpabuf_head(data->in_buf), 311 wpabuf_len(data->in_buf)); 312 switch (res) { 313 case TNCCS_PROCESS_ERROR: 314 ret->ignore = TRUE; 315 goto fail; 316 case TNCCS_PROCESS_OK_NO_RECOMMENDATION: 317 case TNCCS_RECOMMENDATION_ERROR: 318 wpa_printf(MSG_DEBUG, "EAP-TNC: No " 319 "TNCCS-Recommendation received"); 320 break; 321 case TNCCS_RECOMMENDATION_ALLOW: 322 wpa_msg(sm->msg_ctx, MSG_INFO, 323 "TNC: Recommendation = allow"); 324 tncs_done = 1; 325 break; 326 case TNCCS_RECOMMENDATION_NONE: 327 wpa_msg(sm->msg_ctx, MSG_INFO, 328 "TNC: Recommendation = none"); 329 tncs_done = 1; 330 break; 331 case TNCCS_RECOMMENDATION_ISOLATE: 332 wpa_msg(sm->msg_ctx, MSG_INFO, 333 "TNC: Recommendation = isolate"); 334 tncs_done = 1; 335 break; 336 } 337 } 338 339 if (data->in_buf != &tmpbuf) 340 wpabuf_free(data->in_buf); 341 data->in_buf = NULL; 342 343 ret->ignore = FALSE; 344 ret->methodState = METHOD_MAY_CONT; 345 ret->decision = DECISION_UNCOND_SUCC; 346 ret->allowNotifications = TRUE; 347 348 if (data->out_buf) { 349 data->state = PROC_MSG; 350 return eap_tnc_build_msg(data, ret, id); 351 } 352 353 if (tncs_done) { 354 resp = eap_msg_alloc(EAP_VENDOR_IETF, EAP_TYPE_TNC, 1, 355 EAP_CODE_RESPONSE, eap_get_id(reqData)); 356 if (resp == NULL) 357 return NULL; 358 359 wpabuf_put_u8(resp, EAP_TNC_VERSION); 360 wpa_printf(MSG_DEBUG, "EAP-TNC: TNCS done - reply with an " 361 "empty ACK message"); 362 return resp; 363 } 364 365 imc_len = tncc_total_send_len(data->tncc); 366 367 start_buf = tncc_if_tnccs_start(data->tncc); 368 if (start_buf == NULL) 369 return NULL; 370 start_len = os_strlen(start_buf); 371 end_buf = tncc_if_tnccs_end(); 372 if (end_buf == NULL) { 373 os_free(start_buf); 374 return NULL; 375 } 376 end_len = os_strlen(end_buf); 377 378 rlen = start_len + imc_len + end_len; 379 resp = wpabuf_alloc(rlen); 380 if (resp == NULL) { 381 os_free(start_buf); 382 os_free(end_buf); 383 return NULL; 384 } 385 386 wpabuf_put_data(resp, start_buf, start_len); 387 os_free(start_buf); 388 389 rpos1 = wpabuf_put(resp, 0); 390 rpos = tncc_copy_send_buf(data->tncc, rpos1); 391 wpabuf_put(resp, rpos - rpos1); 392 393 wpabuf_put_data(resp, end_buf, end_len); 394 os_free(end_buf); 395 396 wpa_hexdump_ascii(MSG_MSGDUMP, "EAP-TNC: Response", 397 wpabuf_head(resp), wpabuf_len(resp)); 398 399 data->out_buf = resp; 400 data->state = PROC_MSG; 401 return eap_tnc_build_msg(data, ret, id); 402 403 fail: 404 if (data->in_buf == &tmpbuf) 405 data->in_buf = NULL; 406 return NULL; 407 } 408 409 410 int eap_peer_tnc_register(void) 411 { 412 struct eap_method *eap; 413 int ret; 414 415 eap = eap_peer_method_alloc(EAP_PEER_METHOD_INTERFACE_VERSION, 416 EAP_VENDOR_IETF, EAP_TYPE_TNC, "TNC"); 417 if (eap == NULL) 418 return -1; 419 420 eap->init = eap_tnc_init; 421 eap->deinit = eap_tnc_deinit; 422 eap->process = eap_tnc_process; 423 424 ret = eap_peer_method_register(eap); 425 if (ret) 426 eap_peer_method_free(eap); 427 return ret; 428 } 429