1 /* 2 * EAP peer method: EAP-TNC (Trusted Network Connect) 3 * Copyright (c) 2007, Jouni Malinen <j (at) 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 } 435
