1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 2009, Markus Moeller, <markus_moeller (at) compuserve.com> 9 * Copyright (C) 2012 - 2017, Daniel Stenberg, <daniel (at) haxx.se>, et al. 10 * 11 * This software is licensed as described in the file COPYING, which 12 * you should have received as part of this distribution. The terms 13 * are also available at https://curl.haxx.se/docs/copyright.html. 14 * 15 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 16 * copies of the Software, and permit persons to whom the Software is 17 * furnished to do so, under the terms of the COPYING file. 18 * 19 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 20 * KIND, either express or implied. 21 * 22 ***************************************************************************/ 23 24 #include "curl_setup.h" 25 26 #if defined(HAVE_GSSAPI) && !defined(CURL_DISABLE_PROXY) 27 28 #include "curl_gssapi.h" 29 #include "urldata.h" 30 #include "sendf.h" 31 #include "connect.h" 32 #include "timeval.h" 33 #include "socks.h" 34 #include "warnless.h" 35 36 /* The last 3 #include files should be in this order */ 37 #include "curl_printf.h" 38 #include "curl_memory.h" 39 #include "memdebug.h" 40 41 static gss_ctx_id_t gss_context = GSS_C_NO_CONTEXT; 42 43 /* 44 * Helper GSS-API error functions. 45 */ 46 static int check_gss_err(struct Curl_easy *data, 47 OM_uint32 major_status, 48 OM_uint32 minor_status, 49 const char *function) 50 { 51 if(GSS_ERROR(major_status)) { 52 OM_uint32 maj_stat, min_stat; 53 OM_uint32 msg_ctx = 0; 54 gss_buffer_desc status_string; 55 char buf[1024]; 56 size_t len; 57 58 len = 0; 59 msg_ctx = 0; 60 while(!msg_ctx) { 61 /* convert major status code (GSS-API error) to text */ 62 maj_stat = gss_display_status(&min_stat, major_status, 63 GSS_C_GSS_CODE, 64 GSS_C_NULL_OID, 65 &msg_ctx, &status_string); 66 if(maj_stat == GSS_S_COMPLETE) { 67 if(sizeof(buf) > len + status_string.length + 1) { 68 strcpy(buf + len, (char *) status_string.value); 69 len += status_string.length; 70 } 71 gss_release_buffer(&min_stat, &status_string); 72 break; 73 } 74 gss_release_buffer(&min_stat, &status_string); 75 } 76 if(sizeof(buf) > len + 3) { 77 strcpy(buf + len, ".\n"); 78 len += 2; 79 } 80 msg_ctx = 0; 81 while(!msg_ctx) { 82 /* convert minor status code (underlying routine error) to text */ 83 maj_stat = gss_display_status(&min_stat, minor_status, 84 GSS_C_MECH_CODE, 85 GSS_C_NULL_OID, 86 &msg_ctx, &status_string); 87 if(maj_stat == GSS_S_COMPLETE) { 88 if(sizeof(buf) > len + status_string.length) 89 strcpy(buf + len, (char *) status_string.value); 90 gss_release_buffer(&min_stat, &status_string); 91 break; 92 } 93 gss_release_buffer(&min_stat, &status_string); 94 } 95 failf(data, "GSS-API error: %s failed:\n%s", function, buf); 96 return 1; 97 } 98 99 return 0; 100 } 101 102 CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex, 103 struct connectdata *conn) 104 { 105 struct Curl_easy *data = conn->data; 106 curl_socket_t sock = conn->sock[sockindex]; 107 CURLcode code; 108 ssize_t actualread; 109 ssize_t written; 110 int result; 111 OM_uint32 gss_major_status, gss_minor_status, gss_status; 112 OM_uint32 gss_ret_flags; 113 int gss_conf_state, gss_enc; 114 gss_buffer_desc service = GSS_C_EMPTY_BUFFER; 115 gss_buffer_desc gss_send_token = GSS_C_EMPTY_BUFFER; 116 gss_buffer_desc gss_recv_token = GSS_C_EMPTY_BUFFER; 117 gss_buffer_desc gss_w_token = GSS_C_EMPTY_BUFFER; 118 gss_buffer_desc* gss_token = GSS_C_NO_BUFFER; 119 gss_name_t server = GSS_C_NO_NAME; 120 gss_name_t gss_client_name = GSS_C_NO_NAME; 121 unsigned short us_length; 122 char *user = NULL; 123 unsigned char socksreq[4]; /* room for GSS-API exchange header only */ 124 const char *serviceptr = data->set.str[STRING_PROXY_SERVICE_NAME] ? 125 data->set.str[STRING_PROXY_SERVICE_NAME] : "rcmd"; 126 const size_t serviceptr_length = strlen(serviceptr); 127 128 /* GSS-API request looks like 129 * +----+------+-----+----------------+ 130 * |VER | MTYP | LEN | TOKEN | 131 * +----+------+----------------------+ 132 * | 1 | 1 | 2 | up to 2^16 - 1 | 133 * +----+------+-----+----------------+ 134 */ 135 136 /* prepare service name */ 137 if(strchr(serviceptr, '/')) { 138 service.length = serviceptr_length; 139 service.value = malloc(service.length); 140 if(!service.value) 141 return CURLE_OUT_OF_MEMORY; 142 memcpy(service.value, serviceptr, service.length); 143 144 gss_major_status = gss_import_name(&gss_minor_status, &service, 145 (gss_OID) GSS_C_NULL_OID, &server); 146 } 147 else { 148 service.value = malloc(serviceptr_length + 149 strlen(conn->socks_proxy.host.name) + 2); 150 if(!service.value) 151 return CURLE_OUT_OF_MEMORY; 152 service.length = serviceptr_length + 153 strlen(conn->socks_proxy.host.name) + 1; 154 snprintf(service.value, service.length + 1, "%s@%s", 155 serviceptr, conn->socks_proxy.host.name); 156 157 gss_major_status = gss_import_name(&gss_minor_status, &service, 158 GSS_C_NT_HOSTBASED_SERVICE, &server); 159 } 160 161 gss_release_buffer(&gss_status, &service); /* clear allocated memory */ 162 163 if(check_gss_err(data, gss_major_status, 164 gss_minor_status, "gss_import_name()")) { 165 failf(data, "Failed to create service name."); 166 gss_release_name(&gss_status, &server); 167 return CURLE_COULDNT_CONNECT; 168 } 169 170 /* As long as we need to keep sending some context info, and there's no */ 171 /* errors, keep sending it... */ 172 for(;;) { 173 gss_major_status = Curl_gss_init_sec_context(data, 174 &gss_minor_status, 175 &gss_context, 176 server, 177 &Curl_krb5_mech_oid, 178 NULL, 179 gss_token, 180 &gss_send_token, 181 TRUE, 182 &gss_ret_flags); 183 184 if(gss_token != GSS_C_NO_BUFFER) 185 gss_release_buffer(&gss_status, &gss_recv_token); 186 if(check_gss_err(data, gss_major_status, 187 gss_minor_status, "gss_init_sec_context")) { 188 gss_release_name(&gss_status, &server); 189 gss_release_buffer(&gss_status, &gss_recv_token); 190 gss_release_buffer(&gss_status, &gss_send_token); 191 gss_delete_sec_context(&gss_status, &gss_context, NULL); 192 failf(data, "Failed to initial GSS-API token."); 193 return CURLE_COULDNT_CONNECT; 194 } 195 196 if(gss_send_token.length != 0) { 197 socksreq[0] = 1; /* GSS-API subnegotiation version */ 198 socksreq[1] = 1; /* authentication message type */ 199 us_length = htons((short)gss_send_token.length); 200 memcpy(socksreq + 2, &us_length, sizeof(short)); 201 202 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written); 203 if(code || (4 != written)) { 204 failf(data, "Failed to send GSS-API authentication request."); 205 gss_release_name(&gss_status, &server); 206 gss_release_buffer(&gss_status, &gss_recv_token); 207 gss_release_buffer(&gss_status, &gss_send_token); 208 gss_delete_sec_context(&gss_status, &gss_context, NULL); 209 return CURLE_COULDNT_CONNECT; 210 } 211 212 code = Curl_write_plain(conn, sock, (char *)gss_send_token.value, 213 gss_send_token.length, &written); 214 215 if(code || ((ssize_t)gss_send_token.length != written)) { 216 failf(data, "Failed to send GSS-API authentication token."); 217 gss_release_name(&gss_status, &server); 218 gss_release_buffer(&gss_status, &gss_recv_token); 219 gss_release_buffer(&gss_status, &gss_send_token); 220 gss_delete_sec_context(&gss_status, &gss_context, NULL); 221 return CURLE_COULDNT_CONNECT; 222 } 223 224 } 225 226 gss_release_buffer(&gss_status, &gss_send_token); 227 gss_release_buffer(&gss_status, &gss_recv_token); 228 if(gss_major_status != GSS_S_CONTINUE_NEEDED) break; 229 230 /* analyse response */ 231 232 /* GSS-API response looks like 233 * +----+------+-----+----------------+ 234 * |VER | MTYP | LEN | TOKEN | 235 * +----+------+----------------------+ 236 * | 1 | 1 | 2 | up to 2^16 - 1 | 237 * +----+------+-----+----------------+ 238 */ 239 240 result = Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread); 241 if(result || (actualread != 4)) { 242 failf(data, "Failed to receive GSS-API authentication response."); 243 gss_release_name(&gss_status, &server); 244 gss_delete_sec_context(&gss_status, &gss_context, NULL); 245 return CURLE_COULDNT_CONNECT; 246 } 247 248 /* ignore the first (VER) byte */ 249 if(socksreq[1] == 255) { /* status / message type */ 250 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 251 socksreq[0], socksreq[1]); 252 gss_release_name(&gss_status, &server); 253 gss_delete_sec_context(&gss_status, &gss_context, NULL); 254 return CURLE_COULDNT_CONNECT; 255 } 256 257 if(socksreq[1] != 1) { /* status / messgae type */ 258 failf(data, "Invalid GSS-API authentication response type (%d %d).", 259 socksreq[0], socksreq[1]); 260 gss_release_name(&gss_status, &server); 261 gss_delete_sec_context(&gss_status, &gss_context, NULL); 262 return CURLE_COULDNT_CONNECT; 263 } 264 265 memcpy(&us_length, socksreq + 2, sizeof(short)); 266 us_length = ntohs(us_length); 267 268 gss_recv_token.length = us_length; 269 gss_recv_token.value = malloc(us_length); 270 if(!gss_recv_token.value) { 271 failf(data, 272 "Could not allocate memory for GSS-API authentication " 273 "response token."); 274 gss_release_name(&gss_status, &server); 275 gss_delete_sec_context(&gss_status, &gss_context, NULL); 276 return CURLE_OUT_OF_MEMORY; 277 } 278 279 result = Curl_blockread_all(conn, sock, (char *)gss_recv_token.value, 280 gss_recv_token.length, &actualread); 281 282 if(result || (actualread != us_length)) { 283 failf(data, "Failed to receive GSS-API authentication token."); 284 gss_release_name(&gss_status, &server); 285 gss_release_buffer(&gss_status, &gss_recv_token); 286 gss_delete_sec_context(&gss_status, &gss_context, NULL); 287 return CURLE_COULDNT_CONNECT; 288 } 289 290 gss_token = &gss_recv_token; 291 } 292 293 gss_release_name(&gss_status, &server); 294 295 /* Everything is good so far, user was authenticated! */ 296 gss_major_status = gss_inquire_context(&gss_minor_status, gss_context, 297 &gss_client_name, NULL, NULL, NULL, 298 NULL, NULL, NULL); 299 if(check_gss_err(data, gss_major_status, 300 gss_minor_status, "gss_inquire_context")) { 301 gss_delete_sec_context(&gss_status, &gss_context, NULL); 302 gss_release_name(&gss_status, &gss_client_name); 303 failf(data, "Failed to determine user name."); 304 return CURLE_COULDNT_CONNECT; 305 } 306 gss_major_status = gss_display_name(&gss_minor_status, gss_client_name, 307 &gss_send_token, NULL); 308 if(check_gss_err(data, gss_major_status, 309 gss_minor_status, "gss_display_name")) { 310 gss_delete_sec_context(&gss_status, &gss_context, NULL); 311 gss_release_name(&gss_status, &gss_client_name); 312 gss_release_buffer(&gss_status, &gss_send_token); 313 failf(data, "Failed to determine user name."); 314 return CURLE_COULDNT_CONNECT; 315 } 316 user = malloc(gss_send_token.length + 1); 317 if(!user) { 318 gss_delete_sec_context(&gss_status, &gss_context, NULL); 319 gss_release_name(&gss_status, &gss_client_name); 320 gss_release_buffer(&gss_status, &gss_send_token); 321 return CURLE_OUT_OF_MEMORY; 322 } 323 324 memcpy(user, gss_send_token.value, gss_send_token.length); 325 user[gss_send_token.length] = '\0'; 326 gss_release_name(&gss_status, &gss_client_name); 327 gss_release_buffer(&gss_status, &gss_send_token); 328 infof(data, "SOCKS5 server authencticated user %s with GSS-API.\n",user); 329 free(user); 330 user = NULL; 331 332 /* Do encryption */ 333 socksreq[0] = 1; /* GSS-API subnegotiation version */ 334 socksreq[1] = 2; /* encryption message type */ 335 336 gss_enc = 0; /* no data protection */ 337 /* do confidentiality protection if supported */ 338 if(gss_ret_flags & GSS_C_CONF_FLAG) 339 gss_enc = 2; 340 /* else do integrity protection */ 341 else if(gss_ret_flags & GSS_C_INTEG_FLAG) 342 gss_enc = 1; 343 344 infof(data, "SOCKS5 server supports GSS-API %s data protection.\n", 345 (gss_enc == 0)?"no":((gss_enc==1)?"integrity":"confidentiality")); 346 /* force for the moment to no data protection */ 347 gss_enc = 0; 348 /* 349 * Sending the encryption type in clear seems wrong. It should be 350 * protected with gss_seal()/gss_wrap(). See RFC1961 extract below 351 * The NEC reference implementations on which this is based is 352 * therefore at fault 353 * 354 * +------+------+------+.......................+ 355 * + ver | mtyp | len | token | 356 * +------+------+------+.......................+ 357 * + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets | 358 * +------+------+------+.......................+ 359 * 360 * Where: 361 * 362 * - "ver" is the protocol version number, here 1 to represent the 363 * first version of the SOCKS/GSS-API protocol 364 * 365 * - "mtyp" is the message type, here 2 to represent a protection 366 * -level negotiation message 367 * 368 * - "len" is the length of the "token" field in octets 369 * 370 * - "token" is the GSS-API encapsulated protection level 371 * 372 * The token is produced by encapsulating an octet containing the 373 * required protection level using gss_seal()/gss_wrap() with conf_req 374 * set to FALSE. The token is verified using gss_unseal()/ 375 * gss_unwrap(). 376 * 377 */ 378 if(data->set.socks5_gssapi_nec) { 379 us_length = htons((short)1); 380 memcpy(socksreq + 2, &us_length, sizeof(short)); 381 } 382 else { 383 gss_send_token.length = 1; 384 gss_send_token.value = malloc(1); 385 if(!gss_send_token.value) { 386 gss_delete_sec_context(&gss_status, &gss_context, NULL); 387 return CURLE_OUT_OF_MEMORY; 388 } 389 memcpy(gss_send_token.value, &gss_enc, 1); 390 391 gss_major_status = gss_wrap(&gss_minor_status, gss_context, 0, 392 GSS_C_QOP_DEFAULT, &gss_send_token, 393 &gss_conf_state, &gss_w_token); 394 395 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_wrap")) { 396 gss_release_buffer(&gss_status, &gss_send_token); 397 gss_release_buffer(&gss_status, &gss_w_token); 398 gss_delete_sec_context(&gss_status, &gss_context, NULL); 399 failf(data, "Failed to wrap GSS-API encryption value into token."); 400 return CURLE_COULDNT_CONNECT; 401 } 402 gss_release_buffer(&gss_status, &gss_send_token); 403 404 us_length = htons((short)gss_w_token.length); 405 memcpy(socksreq + 2, &us_length, sizeof(short)); 406 } 407 408 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written); 409 if(code || (4 != written)) { 410 failf(data, "Failed to send GSS-API encryption request."); 411 gss_release_buffer(&gss_status, &gss_w_token); 412 gss_delete_sec_context(&gss_status, &gss_context, NULL); 413 return CURLE_COULDNT_CONNECT; 414 } 415 416 if(data->set.socks5_gssapi_nec) { 417 memcpy(socksreq, &gss_enc, 1); 418 code = Curl_write_plain(conn, sock, socksreq, 1, &written); 419 if(code || ( 1 != written)) { 420 failf(data, "Failed to send GSS-API encryption type."); 421 gss_delete_sec_context(&gss_status, &gss_context, NULL); 422 return CURLE_COULDNT_CONNECT; 423 } 424 } 425 else { 426 code = Curl_write_plain(conn, sock, (char *)gss_w_token.value, 427 gss_w_token.length, &written); 428 if(code || ((ssize_t)gss_w_token.length != written)) { 429 failf(data, "Failed to send GSS-API encryption type."); 430 gss_release_buffer(&gss_status, &gss_w_token); 431 gss_delete_sec_context(&gss_status, &gss_context, NULL); 432 return CURLE_COULDNT_CONNECT; 433 } 434 gss_release_buffer(&gss_status, &gss_w_token); 435 } 436 437 result = Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread); 438 if(result || (actualread != 4)) { 439 failf(data, "Failed to receive GSS-API encryption response."); 440 gss_delete_sec_context(&gss_status, &gss_context, NULL); 441 return CURLE_COULDNT_CONNECT; 442 } 443 444 /* ignore the first (VER) byte */ 445 if(socksreq[1] == 255) { /* status / message type */ 446 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 447 socksreq[0], socksreq[1]); 448 gss_delete_sec_context(&gss_status, &gss_context, NULL); 449 return CURLE_COULDNT_CONNECT; 450 } 451 452 if(socksreq[1] != 2) { /* status / messgae type */ 453 failf(data, "Invalid GSS-API encryption response type (%d %d).", 454 socksreq[0], socksreq[1]); 455 gss_delete_sec_context(&gss_status, &gss_context, NULL); 456 return CURLE_COULDNT_CONNECT; 457 } 458 459 memcpy(&us_length, socksreq + 2, sizeof(short)); 460 us_length = ntohs(us_length); 461 462 gss_recv_token.length = us_length; 463 gss_recv_token.value = malloc(gss_recv_token.length); 464 if(!gss_recv_token.value) { 465 gss_delete_sec_context(&gss_status, &gss_context, NULL); 466 return CURLE_OUT_OF_MEMORY; 467 } 468 result = Curl_blockread_all(conn, sock, (char *)gss_recv_token.value, 469 gss_recv_token.length, &actualread); 470 471 if(result || (actualread != us_length)) { 472 failf(data, "Failed to receive GSS-API encryptrion type."); 473 gss_release_buffer(&gss_status, &gss_recv_token); 474 gss_delete_sec_context(&gss_status, &gss_context, NULL); 475 return CURLE_COULDNT_CONNECT; 476 } 477 478 if(!data->set.socks5_gssapi_nec) { 479 gss_major_status = gss_unwrap(&gss_minor_status, gss_context, 480 &gss_recv_token, &gss_w_token, 481 0, GSS_C_QOP_DEFAULT); 482 483 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_unwrap")) { 484 gss_release_buffer(&gss_status, &gss_recv_token); 485 gss_release_buffer(&gss_status, &gss_w_token); 486 gss_delete_sec_context(&gss_status, &gss_context, NULL); 487 failf(data, "Failed to unwrap GSS-API encryption value into token."); 488 return CURLE_COULDNT_CONNECT; 489 } 490 gss_release_buffer(&gss_status, &gss_recv_token); 491 492 if(gss_w_token.length != 1) { 493 failf(data, "Invalid GSS-API encryption response length (%d).", 494 gss_w_token.length); 495 gss_release_buffer(&gss_status, &gss_w_token); 496 gss_delete_sec_context(&gss_status, &gss_context, NULL); 497 return CURLE_COULDNT_CONNECT; 498 } 499 500 memcpy(socksreq, gss_w_token.value, gss_w_token.length); 501 gss_release_buffer(&gss_status, &gss_w_token); 502 } 503 else { 504 if(gss_recv_token.length != 1) { 505 failf(data, "Invalid GSS-API encryption response length (%d).", 506 gss_recv_token.length); 507 gss_release_buffer(&gss_status, &gss_recv_token); 508 gss_delete_sec_context(&gss_status, &gss_context, NULL); 509 return CURLE_COULDNT_CONNECT; 510 } 511 512 memcpy(socksreq, gss_recv_token.value, gss_recv_token.length); 513 gss_release_buffer(&gss_status, &gss_recv_token); 514 } 515 516 infof(data, "SOCKS5 access with%s protection granted.\n", 517 (socksreq[0] == 0)?"out GSS-API data": 518 ((socksreq[0] == 1)?" GSS-API integrity":" GSS-API confidentiality")); 519 520 conn->socks5_gssapi_enctype = socksreq[0]; 521 if(socksreq[0] == 0) 522 gss_delete_sec_context(&gss_status, &gss_context, NULL); 523 524 return CURLE_OK; 525 } 526 527 #endif /* HAVE_GSSAPI && !CURL_DISABLE_PROXY */ 528
