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