1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 2009, 2011, Markus Moeller, <markus_moeller (at) compuserve.com> 9 * Copyright (C) 2012 - 2016, 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"; 126 127 /* GSS-API request looks like 128 * +----+------+-----+----------------+ 129 * |VER | MTYP | LEN | TOKEN | 130 * +----+------+----------------------+ 131 * | 1 | 1 | 2 | up to 2^16 - 1 | 132 * +----+------+-----+----------------+ 133 */ 134 135 /* prepare service name */ 136 if(strchr(serviceptr, '/')) { 137 service.value = malloc(strlen(serviceptr)); 138 if(!service.value) 139 return CURLE_OUT_OF_MEMORY; 140 service.length = strlen(serviceptr); 141 memcpy(service.value, serviceptr, service.length); 142 143 gss_major_status = gss_import_name(&gss_minor_status, &service, 144 (gss_OID) GSS_C_NULL_OID, &server); 145 } 146 else { 147 service.value = malloc(strlen(serviceptr) +strlen(conn->proxy.name)+2); 148 if(!service.value) 149 return CURLE_OUT_OF_MEMORY; 150 service.length = strlen(serviceptr) +strlen(conn->proxy.name)+1; 151 snprintf(service.value, service.length+1, "%s@%s", 152 serviceptr, conn->proxy.name); 153 154 gss_major_status = gss_import_name(&gss_minor_status, &service, 155 GSS_C_NT_HOSTBASED_SERVICE, &server); 156 } 157 158 gss_release_buffer(&gss_status, &service); /* clear allocated memory */ 159 160 if(check_gss_err(data, gss_major_status, 161 gss_minor_status, "gss_import_name()")) { 162 failf(data, "Failed to create service name."); 163 gss_release_name(&gss_status, &server); 164 return CURLE_COULDNT_CONNECT; 165 } 166 167 /* As long as we need to keep sending some context info, and there's no */ 168 /* errors, keep sending it... */ 169 for(;;) { 170 gss_major_status = Curl_gss_init_sec_context(data, 171 &gss_minor_status, 172 &gss_context, 173 server, 174 &Curl_krb5_mech_oid, 175 NULL, 176 gss_token, 177 &gss_send_token, 178 TRUE, 179 &gss_ret_flags); 180 181 if(gss_token != GSS_C_NO_BUFFER) 182 gss_release_buffer(&gss_status, &gss_recv_token); 183 if(check_gss_err(data, gss_major_status, 184 gss_minor_status, "gss_init_sec_context")) { 185 gss_release_name(&gss_status, &server); 186 gss_release_buffer(&gss_status, &gss_recv_token); 187 gss_release_buffer(&gss_status, &gss_send_token); 188 gss_delete_sec_context(&gss_status, &gss_context, NULL); 189 failf(data, "Failed to initial GSS-API token."); 190 return CURLE_COULDNT_CONNECT; 191 } 192 193 if(gss_send_token.length != 0) { 194 socksreq[0] = 1; /* GSS-API subnegotiation version */ 195 socksreq[1] = 1; /* authentication message type */ 196 us_length = htons((short)gss_send_token.length); 197 memcpy(socksreq+2, &us_length, sizeof(short)); 198 199 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written); 200 if(code || (4 != written)) { 201 failf(data, "Failed to send GSS-API authentication request."); 202 gss_release_name(&gss_status, &server); 203 gss_release_buffer(&gss_status, &gss_recv_token); 204 gss_release_buffer(&gss_status, &gss_send_token); 205 gss_delete_sec_context(&gss_status, &gss_context, NULL); 206 return CURLE_COULDNT_CONNECT; 207 } 208 209 code = Curl_write_plain(conn, sock, (char *)gss_send_token.value, 210 gss_send_token.length, &written); 211 212 if(code || ((ssize_t)gss_send_token.length != written)) { 213 failf(data, "Failed to send GSS-API authentication token."); 214 gss_release_name(&gss_status, &server); 215 gss_release_buffer(&gss_status, &gss_recv_token); 216 gss_release_buffer(&gss_status, &gss_send_token); 217 gss_delete_sec_context(&gss_status, &gss_context, NULL); 218 return CURLE_COULDNT_CONNECT; 219 } 220 221 } 222 223 gss_release_buffer(&gss_status, &gss_send_token); 224 gss_release_buffer(&gss_status, &gss_recv_token); 225 if(gss_major_status != GSS_S_CONTINUE_NEEDED) break; 226 227 /* analyse response */ 228 229 /* GSS-API response looks like 230 * +----+------+-----+----------------+ 231 * |VER | MTYP | LEN | TOKEN | 232 * +----+------+----------------------+ 233 * | 1 | 1 | 2 | up to 2^16 - 1 | 234 * +----+------+-----+----------------+ 235 */ 236 237 result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread); 238 if(result || (actualread != 4)) { 239 failf(data, "Failed to receive GSS-API authentication response."); 240 gss_release_name(&gss_status, &server); 241 gss_delete_sec_context(&gss_status, &gss_context, NULL); 242 return CURLE_COULDNT_CONNECT; 243 } 244 245 /* ignore the first (VER) byte */ 246 if(socksreq[1] == 255) { /* status / message type */ 247 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 248 socksreq[0], socksreq[1]); 249 gss_release_name(&gss_status, &server); 250 gss_delete_sec_context(&gss_status, &gss_context, NULL); 251 return CURLE_COULDNT_CONNECT; 252 } 253 254 if(socksreq[1] != 1) { /* status / messgae type */ 255 failf(data, "Invalid GSS-API authentication response type (%d %d).", 256 socksreq[0], socksreq[1]); 257 gss_release_name(&gss_status, &server); 258 gss_delete_sec_context(&gss_status, &gss_context, NULL); 259 return CURLE_COULDNT_CONNECT; 260 } 261 262 memcpy(&us_length, socksreq+2, sizeof(short)); 263 us_length = ntohs(us_length); 264 265 gss_recv_token.length=us_length; 266 gss_recv_token.value=malloc(us_length); 267 if(!gss_recv_token.value) { 268 failf(data, 269 "Could not allocate memory for GSS-API authentication " 270 "response token."); 271 gss_release_name(&gss_status, &server); 272 gss_delete_sec_context(&gss_status, &gss_context, NULL); 273 return CURLE_OUT_OF_MEMORY; 274 } 275 276 result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value, 277 gss_recv_token.length, &actualread); 278 279 if(result || (actualread != us_length)) { 280 failf(data, "Failed to receive GSS-API authentication token."); 281 gss_release_name(&gss_status, &server); 282 gss_release_buffer(&gss_status, &gss_recv_token); 283 gss_delete_sec_context(&gss_status, &gss_context, NULL); 284 return CURLE_COULDNT_CONNECT; 285 } 286 287 gss_token = &gss_recv_token; 288 } 289 290 gss_release_name(&gss_status, &server); 291 292 /* Everything is good so far, user was authenticated! */ 293 gss_major_status = gss_inquire_context (&gss_minor_status, gss_context, 294 &gss_client_name, NULL, NULL, NULL, 295 NULL, NULL, NULL); 296 if(check_gss_err(data, gss_major_status, 297 gss_minor_status, "gss_inquire_context")) { 298 gss_delete_sec_context(&gss_status, &gss_context, NULL); 299 gss_release_name(&gss_status, &gss_client_name); 300 failf(data, "Failed to determine user name."); 301 return CURLE_COULDNT_CONNECT; 302 } 303 gss_major_status = gss_display_name(&gss_minor_status, gss_client_name, 304 &gss_send_token, NULL); 305 if(check_gss_err(data, gss_major_status, 306 gss_minor_status, "gss_display_name")) { 307 gss_delete_sec_context(&gss_status, &gss_context, NULL); 308 gss_release_name(&gss_status, &gss_client_name); 309 gss_release_buffer(&gss_status, &gss_send_token); 310 failf(data, "Failed to determine user name."); 311 return CURLE_COULDNT_CONNECT; 312 } 313 user=malloc(gss_send_token.length+1); 314 if(!user) { 315 gss_delete_sec_context(&gss_status, &gss_context, NULL); 316 gss_release_name(&gss_status, &gss_client_name); 317 gss_release_buffer(&gss_status, &gss_send_token); 318 return CURLE_OUT_OF_MEMORY; 319 } 320 321 memcpy(user, gss_send_token.value, gss_send_token.length); 322 user[gss_send_token.length] = '\0'; 323 gss_release_name(&gss_status, &gss_client_name); 324 gss_release_buffer(&gss_status, &gss_send_token); 325 infof(data, "SOCKS5 server authencticated user %s with GSS-API.\n",user); 326 free(user); 327 user=NULL; 328 329 /* Do encryption */ 330 socksreq[0] = 1; /* GSS-API subnegotiation version */ 331 socksreq[1] = 2; /* encryption message type */ 332 333 gss_enc = 0; /* no data protection */ 334 /* do confidentiality protection if supported */ 335 if(gss_ret_flags & GSS_C_CONF_FLAG) 336 gss_enc = 2; 337 /* else do integrity protection */ 338 else if(gss_ret_flags & GSS_C_INTEG_FLAG) 339 gss_enc = 1; 340 341 infof(data, "SOCKS5 server supports GSS-API %s data protection.\n", 342 (gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality")); 343 /* force for the moment to no data protection */ 344 gss_enc = 0; 345 /* 346 * Sending the encryption type in clear seems wrong. It should be 347 * protected with gss_seal()/gss_wrap(). See RFC1961 extract below 348 * The NEC reference implementations on which this is based is 349 * therefore at fault 350 * 351 * +------+------+------+.......................+ 352 * + ver | mtyp | len | token | 353 * +------+------+------+.......................+ 354 * + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets | 355 * +------+------+------+.......................+ 356 * 357 * Where: 358 * 359 * - "ver" is the protocol version number, here 1 to represent the 360 * first version of the SOCKS/GSS-API protocol 361 * 362 * - "mtyp" is the message type, here 2 to represent a protection 363 * -level negotiation message 364 * 365 * - "len" is the length of the "token" field in octets 366 * 367 * - "token" is the GSS-API encapsulated protection level 368 * 369 * The token is produced by encapsulating an octet containing the 370 * required protection level using gss_seal()/gss_wrap() with conf_req 371 * set to FALSE. The token is verified using gss_unseal()/ 372 * gss_unwrap(). 373 * 374 */ 375 if(data->set.socks5_gssapi_nec) { 376 us_length = htons((short)1); 377 memcpy(socksreq+2, &us_length, sizeof(short)); 378 } 379 else { 380 gss_send_token.length = 1; 381 gss_send_token.value = malloc(1); 382 if(!gss_send_token.value) { 383 gss_delete_sec_context(&gss_status, &gss_context, NULL); 384 return CURLE_OUT_OF_MEMORY; 385 } 386 memcpy(gss_send_token.value, &gss_enc, 1); 387 388 gss_major_status = gss_wrap(&gss_minor_status, gss_context, 0, 389 GSS_C_QOP_DEFAULT, &gss_send_token, 390 &gss_conf_state, &gss_w_token); 391 392 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_wrap")) { 393 gss_release_buffer(&gss_status, &gss_send_token); 394 gss_release_buffer(&gss_status, &gss_w_token); 395 gss_delete_sec_context(&gss_status, &gss_context, NULL); 396 failf(data, "Failed to wrap GSS-API encryption value into token."); 397 return CURLE_COULDNT_CONNECT; 398 } 399 gss_release_buffer(&gss_status, &gss_send_token); 400 401 us_length = htons((short)gss_w_token.length); 402 memcpy(socksreq+2, &us_length, sizeof(short)); 403 } 404 405 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written); 406 if(code || (4 != written)) { 407 failf(data, "Failed to send GSS-API encryption request."); 408 gss_release_buffer(&gss_status, &gss_w_token); 409 gss_delete_sec_context(&gss_status, &gss_context, NULL); 410 return CURLE_COULDNT_CONNECT; 411 } 412 413 if(data->set.socks5_gssapi_nec) { 414 memcpy(socksreq, &gss_enc, 1); 415 code = Curl_write_plain(conn, sock, socksreq, 1, &written); 416 if(code || ( 1 != written)) { 417 failf(data, "Failed to send GSS-API encryption type."); 418 gss_delete_sec_context(&gss_status, &gss_context, NULL); 419 return CURLE_COULDNT_CONNECT; 420 } 421 } 422 else { 423 code = Curl_write_plain(conn, sock, (char *)gss_w_token.value, 424 gss_w_token.length, &written); 425 if(code || ((ssize_t)gss_w_token.length != written)) { 426 failf(data, "Failed to send GSS-API encryption type."); 427 gss_release_buffer(&gss_status, &gss_w_token); 428 gss_delete_sec_context(&gss_status, &gss_context, NULL); 429 return CURLE_COULDNT_CONNECT; 430 } 431 gss_release_buffer(&gss_status, &gss_w_token); 432 } 433 434 result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread); 435 if(result || (actualread != 4)) { 436 failf(data, "Failed to receive GSS-API encryption response."); 437 gss_delete_sec_context(&gss_status, &gss_context, NULL); 438 return CURLE_COULDNT_CONNECT; 439 } 440 441 /* ignore the first (VER) byte */ 442 if(socksreq[1] == 255) { /* status / message type */ 443 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 444 socksreq[0], socksreq[1]); 445 gss_delete_sec_context(&gss_status, &gss_context, NULL); 446 return CURLE_COULDNT_CONNECT; 447 } 448 449 if(socksreq[1] != 2) { /* status / messgae type */ 450 failf(data, "Invalid GSS-API encryption response type (%d %d).", 451 socksreq[0], socksreq[1]); 452 gss_delete_sec_context(&gss_status, &gss_context, NULL); 453 return CURLE_COULDNT_CONNECT; 454 } 455 456 memcpy(&us_length, socksreq+2, sizeof(short)); 457 us_length = ntohs(us_length); 458 459 gss_recv_token.length= us_length; 460 gss_recv_token.value=malloc(gss_recv_token.length); 461 if(!gss_recv_token.value) { 462 gss_delete_sec_context(&gss_status, &gss_context, NULL); 463 return CURLE_OUT_OF_MEMORY; 464 } 465 result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value, 466 gss_recv_token.length, &actualread); 467 468 if(result || (actualread != us_length)) { 469 failf(data, "Failed to receive GSS-API encryptrion type."); 470 gss_release_buffer(&gss_status, &gss_recv_token); 471 gss_delete_sec_context(&gss_status, &gss_context, NULL); 472 return CURLE_COULDNT_CONNECT; 473 } 474 475 if(!data->set.socks5_gssapi_nec) { 476 gss_major_status = gss_unwrap(&gss_minor_status, gss_context, 477 &gss_recv_token, &gss_w_token, 478 0, GSS_C_QOP_DEFAULT); 479 480 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_unwrap")) { 481 gss_release_buffer(&gss_status, &gss_recv_token); 482 gss_release_buffer(&gss_status, &gss_w_token); 483 gss_delete_sec_context(&gss_status, &gss_context, NULL); 484 failf(data, "Failed to unwrap GSS-API encryption value into token."); 485 return CURLE_COULDNT_CONNECT; 486 } 487 gss_release_buffer(&gss_status, &gss_recv_token); 488 489 if(gss_w_token.length != 1) { 490 failf(data, "Invalid GSS-API encryption response length (%d).", 491 gss_w_token.length); 492 gss_release_buffer(&gss_status, &gss_w_token); 493 gss_delete_sec_context(&gss_status, &gss_context, NULL); 494 return CURLE_COULDNT_CONNECT; 495 } 496 497 memcpy(socksreq, gss_w_token.value, gss_w_token.length); 498 gss_release_buffer(&gss_status, &gss_w_token); 499 } 500 else { 501 if(gss_recv_token.length != 1) { 502 failf(data, "Invalid GSS-API encryption response length (%d).", 503 gss_recv_token.length); 504 gss_release_buffer(&gss_status, &gss_recv_token); 505 gss_delete_sec_context(&gss_status, &gss_context, NULL); 506 return CURLE_COULDNT_CONNECT; 507 } 508 509 memcpy(socksreq, gss_recv_token.value, gss_recv_token.length); 510 gss_release_buffer(&gss_status, &gss_recv_token); 511 } 512 513 infof(data, "SOCKS5 access with%s protection granted.\n", 514 (socksreq[0]==0)?"out GSS-API data": 515 ((socksreq[0]==1)?" GSS-API integrity":" GSS-API confidentiality")); 516 517 conn->socks5_gssapi_enctype = socksreq[0]; 518 if(socksreq[0] == 0) 519 gss_delete_sec_context(&gss_status, &gss_context, NULL); 520 521 return CURLE_OK; 522 } 523 524 #endif /* HAVE_GSSAPI && !CURL_DISABLE_PROXY */ 525
