1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 2009, 2011, Markus Moeller, <markus_moeller (at) compuserve.com> 9 * Copyright (C) 2012 - 2015, 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 http://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 #include "curl_printf.h" 36 #include "curl_memory.h" 37 /* The last #include file should be: */ 38 #include "memdebug.h" 39 40 static gss_ctx_id_t gss_context = GSS_C_NO_CONTEXT; 41 42 /* 43 * Helper GSS-API error functions. 44 */ 45 static int check_gss_err(struct SessionHandle *data, 46 OM_uint32 major_status, 47 OM_uint32 minor_status, 48 const char* function) 49 { 50 if(GSS_ERROR(major_status)) { 51 OM_uint32 maj_stat, min_stat; 52 OM_uint32 msg_ctx = 0; 53 gss_buffer_desc status_string; 54 char buf[1024]; 55 size_t len; 56 57 len = 0; 58 msg_ctx = 0; 59 while(!msg_ctx) { 60 /* convert major status code (GSS-API error) to text */ 61 maj_stat = gss_display_status(&min_stat, major_status, 62 GSS_C_GSS_CODE, 63 GSS_C_NULL_OID, 64 &msg_ctx, &status_string); 65 if(maj_stat == GSS_S_COMPLETE) { 66 if(sizeof(buf) > len + status_string.length + 1) { 67 strcpy(buf+len, (char*) status_string.value); 68 len += status_string.length; 69 } 70 gss_release_buffer(&min_stat, &status_string); 71 break; 72 } 73 gss_release_buffer(&min_stat, &status_string); 74 } 75 if(sizeof(buf) > len + 3) { 76 strcpy(buf+len, ".\n"); 77 len += 2; 78 } 79 msg_ctx = 0; 80 while(!msg_ctx) { 81 /* convert minor status code (underlying routine error) to text */ 82 maj_stat = gss_display_status(&min_stat, minor_status, 83 GSS_C_MECH_CODE, 84 GSS_C_NULL_OID, 85 &msg_ctx, &status_string); 86 if(maj_stat == GSS_S_COMPLETE) { 87 if(sizeof(buf) > len + status_string.length) 88 strcpy(buf+len, (char*) status_string.value); 89 gss_release_buffer(&min_stat, &status_string); 90 break; 91 } 92 gss_release_buffer(&min_stat, &status_string); 93 } 94 failf(data, "GSS-API error: %s failed:\n%s", function, buf); 95 return 1; 96 } 97 98 return 0; 99 } 100 101 CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex, 102 struct connectdata *conn) 103 { 104 struct SessionHandle *data = conn->data; 105 curl_socket_t sock = conn->sock[sockindex]; 106 CURLcode code; 107 ssize_t actualread; 108 ssize_t written; 109 int result; 110 OM_uint32 gss_major_status, gss_minor_status, gss_status; 111 OM_uint32 gss_ret_flags; 112 int gss_conf_state, gss_enc; 113 gss_buffer_desc service = GSS_C_EMPTY_BUFFER; 114 gss_buffer_desc gss_send_token = GSS_C_EMPTY_BUFFER; 115 gss_buffer_desc gss_recv_token = GSS_C_EMPTY_BUFFER; 116 gss_buffer_desc gss_w_token = GSS_C_EMPTY_BUFFER; 117 gss_buffer_desc* gss_token = GSS_C_NO_BUFFER; 118 gss_name_t server = GSS_C_NO_NAME; 119 gss_name_t gss_client_name = GSS_C_NO_NAME; 120 unsigned short us_length; 121 char *user=NULL; 122 unsigned char socksreq[4]; /* room for GSS-API exchange header only */ 123 char *serviceptr = data->set.str[STRING_SOCKS5_GSSAPI_SERVICE]; 124 125 /* GSS-API request looks like 126 * +----+------+-----+----------------+ 127 * |VER | MTYP | LEN | TOKEN | 128 * +----+------+----------------------+ 129 * | 1 | 1 | 2 | up to 2^16 - 1 | 130 * +----+------+-----+----------------+ 131 */ 132 133 /* prepare service name */ 134 if(strchr(serviceptr, '/')) { 135 service.value = malloc(strlen(serviceptr)); 136 if(!service.value) 137 return CURLE_OUT_OF_MEMORY; 138 service.length = strlen(serviceptr); 139 memcpy(service.value, serviceptr, service.length); 140 141 gss_major_status = gss_import_name(&gss_minor_status, &service, 142 (gss_OID) GSS_C_NULL_OID, &server); 143 } 144 else { 145 service.value = malloc(strlen(serviceptr) +strlen(conn->proxy.name)+2); 146 if(!service.value) 147 return CURLE_OUT_OF_MEMORY; 148 service.length = strlen(serviceptr) +strlen(conn->proxy.name)+1; 149 snprintf(service.value, service.length+1, "%s@%s", 150 serviceptr, conn->proxy.name); 151 152 gss_major_status = gss_import_name(&gss_minor_status, &service, 153 GSS_C_NT_HOSTBASED_SERVICE, &server); 154 } 155 156 gss_release_buffer(&gss_status, &service); /* clear allocated memory */ 157 158 if(check_gss_err(data, gss_major_status, 159 gss_minor_status, "gss_import_name()")) { 160 failf(data, "Failed to create service name."); 161 gss_release_name(&gss_status, &server); 162 return CURLE_COULDNT_CONNECT; 163 } 164 165 /* As long as we need to keep sending some context info, and there's no */ 166 /* errors, keep sending it... */ 167 for(;;) { 168 gss_major_status = Curl_gss_init_sec_context(data, 169 &gss_minor_status, 170 &gss_context, 171 server, 172 &Curl_krb5_mech_oid, 173 NULL, 174 gss_token, 175 &gss_send_token, 176 TRUE, 177 &gss_ret_flags); 178 179 if(gss_token != GSS_C_NO_BUFFER) 180 gss_release_buffer(&gss_status, &gss_recv_token); 181 if(check_gss_err(data, gss_major_status, 182 gss_minor_status, "gss_init_sec_context")) { 183 gss_release_name(&gss_status, &server); 184 gss_release_buffer(&gss_status, &gss_recv_token); 185 gss_release_buffer(&gss_status, &gss_send_token); 186 gss_delete_sec_context(&gss_status, &gss_context, NULL); 187 failf(data, "Failed to initial GSS-API token."); 188 return CURLE_COULDNT_CONNECT; 189 } 190 191 if(gss_send_token.length != 0) { 192 socksreq[0] = 1; /* GSS-API subnegotiation version */ 193 socksreq[1] = 1; /* authentication message type */ 194 us_length = htons((short)gss_send_token.length); 195 memcpy(socksreq+2, &us_length, sizeof(short)); 196 197 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written); 198 if(code || (4 != written)) { 199 failf(data, "Failed to send GSS-API authentication request."); 200 gss_release_name(&gss_status, &server); 201 gss_release_buffer(&gss_status, &gss_recv_token); 202 gss_release_buffer(&gss_status, &gss_send_token); 203 gss_delete_sec_context(&gss_status, &gss_context, NULL); 204 return CURLE_COULDNT_CONNECT; 205 } 206 207 code = Curl_write_plain(conn, sock, (char *)gss_send_token.value, 208 gss_send_token.length, &written); 209 210 if(code || ((ssize_t)gss_send_token.length != written)) { 211 failf(data, "Failed to send GSS-API authentication token."); 212 gss_release_name(&gss_status, &server); 213 gss_release_buffer(&gss_status, &gss_recv_token); 214 gss_release_buffer(&gss_status, &gss_send_token); 215 gss_delete_sec_context(&gss_status, &gss_context, NULL); 216 return CURLE_COULDNT_CONNECT; 217 } 218 219 } 220 221 gss_release_buffer(&gss_status, &gss_send_token); 222 gss_release_buffer(&gss_status, &gss_recv_token); 223 if(gss_major_status != GSS_S_CONTINUE_NEEDED) break; 224 225 /* analyse response */ 226 227 /* GSS-API response looks like 228 * +----+------+-----+----------------+ 229 * |VER | MTYP | LEN | TOKEN | 230 * +----+------+----------------------+ 231 * | 1 | 1 | 2 | up to 2^16 - 1 | 232 * +----+------+-----+----------------+ 233 */ 234 235 result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread); 236 if(result || (actualread != 4)) { 237 failf(data, "Failed to receive GSS-API authentication response."); 238 gss_release_name(&gss_status, &server); 239 gss_delete_sec_context(&gss_status, &gss_context, NULL); 240 return CURLE_COULDNT_CONNECT; 241 } 242 243 /* ignore the first (VER) byte */ 244 if(socksreq[1] == 255) { /* status / message type */ 245 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 246 socksreq[0], socksreq[1]); 247 gss_release_name(&gss_status, &server); 248 gss_delete_sec_context(&gss_status, &gss_context, NULL); 249 return CURLE_COULDNT_CONNECT; 250 } 251 252 if(socksreq[1] != 1) { /* status / messgae type */ 253 failf(data, "Invalid GSS-API authentication response type (%d %d).", 254 socksreq[0], socksreq[1]); 255 gss_release_name(&gss_status, &server); 256 gss_delete_sec_context(&gss_status, &gss_context, NULL); 257 return CURLE_COULDNT_CONNECT; 258 } 259 260 memcpy(&us_length, socksreq+2, sizeof(short)); 261 us_length = ntohs(us_length); 262 263 gss_recv_token.length=us_length; 264 gss_recv_token.value=malloc(us_length); 265 if(!gss_recv_token.value) { 266 failf(data, 267 "Could not allocate memory for GSS-API authentication " 268 "response token."); 269 gss_release_name(&gss_status, &server); 270 gss_delete_sec_context(&gss_status, &gss_context, NULL); 271 return CURLE_OUT_OF_MEMORY; 272 } 273 274 result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value, 275 gss_recv_token.length, &actualread); 276 277 if(result || (actualread != us_length)) { 278 failf(data, "Failed to receive GSS-API authentication token."); 279 gss_release_name(&gss_status, &server); 280 gss_release_buffer(&gss_status, &gss_recv_token); 281 gss_delete_sec_context(&gss_status, &gss_context, NULL); 282 return CURLE_COULDNT_CONNECT; 283 } 284 285 gss_token = &gss_recv_token; 286 } 287 288 gss_release_name(&gss_status, &server); 289 290 /* Everything is good so far, user was authenticated! */ 291 gss_major_status = gss_inquire_context (&gss_minor_status, gss_context, 292 &gss_client_name, NULL, NULL, NULL, 293 NULL, NULL, NULL); 294 if(check_gss_err(data, gss_major_status, 295 gss_minor_status, "gss_inquire_context")) { 296 gss_delete_sec_context(&gss_status, &gss_context, NULL); 297 gss_release_name(&gss_status, &gss_client_name); 298 failf(data, "Failed to determine user name."); 299 return CURLE_COULDNT_CONNECT; 300 } 301 gss_major_status = gss_display_name(&gss_minor_status, gss_client_name, 302 &gss_send_token, NULL); 303 if(check_gss_err(data, gss_major_status, 304 gss_minor_status, "gss_display_name")) { 305 gss_delete_sec_context(&gss_status, &gss_context, NULL); 306 gss_release_name(&gss_status, &gss_client_name); 307 gss_release_buffer(&gss_status, &gss_send_token); 308 failf(data, "Failed to determine user name."); 309 return CURLE_COULDNT_CONNECT; 310 } 311 user=malloc(gss_send_token.length+1); 312 if(!user) { 313 gss_delete_sec_context(&gss_status, &gss_context, NULL); 314 gss_release_name(&gss_status, &gss_client_name); 315 gss_release_buffer(&gss_status, &gss_send_token); 316 return CURLE_OUT_OF_MEMORY; 317 } 318 319 memcpy(user, gss_send_token.value, gss_send_token.length); 320 user[gss_send_token.length] = '\0'; 321 gss_release_name(&gss_status, &gss_client_name); 322 gss_release_buffer(&gss_status, &gss_send_token); 323 infof(data, "SOCKS5 server authencticated user %s with GSS-API.\n",user); 324 free(user); 325 user=NULL; 326 327 /* Do encryption */ 328 socksreq[0] = 1; /* GSS-API subnegotiation version */ 329 socksreq[1] = 2; /* encryption message type */ 330 331 gss_enc = 0; /* no data protection */ 332 /* do confidentiality protection if supported */ 333 if(gss_ret_flags & GSS_C_CONF_FLAG) 334 gss_enc = 2; 335 /* else do integrity protection */ 336 else if(gss_ret_flags & GSS_C_INTEG_FLAG) 337 gss_enc = 1; 338 339 infof(data, "SOCKS5 server supports GSS-API %s data protection.\n", 340 (gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality")); 341 /* force for the moment to no data protection */ 342 gss_enc = 0; 343 /* 344 * Sending the encryption type in clear seems wrong. It should be 345 * protected with gss_seal()/gss_wrap(). See RFC1961 extract below 346 * The NEC reference implementations on which this is based is 347 * therefore at fault 348 * 349 * +------+------+------+.......................+ 350 * + ver | mtyp | len | token | 351 * +------+------+------+.......................+ 352 * + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets | 353 * +------+------+------+.......................+ 354 * 355 * Where: 356 * 357 * - "ver" is the protocol version number, here 1 to represent the 358 * first version of the SOCKS/GSS-API protocol 359 * 360 * - "mtyp" is the message type, here 2 to represent a protection 361 * -level negotiation message 362 * 363 * - "len" is the length of the "token" field in octets 364 * 365 * - "token" is the GSS-API encapsulated protection level 366 * 367 * The token is produced by encapsulating an octet containing the 368 * required protection level using gss_seal()/gss_wrap() with conf_req 369 * set to FALSE. The token is verified using gss_unseal()/ 370 * gss_unwrap(). 371 * 372 */ 373 if(data->set.socks5_gssapi_nec) { 374 us_length = htons((short)1); 375 memcpy(socksreq+2, &us_length, sizeof(short)); 376 } 377 else { 378 gss_send_token.length = 1; 379 gss_send_token.value = malloc(1); 380 if(!gss_send_token.value) { 381 gss_delete_sec_context(&gss_status, &gss_context, NULL); 382 return CURLE_OUT_OF_MEMORY; 383 } 384 memcpy(gss_send_token.value, &gss_enc, 1); 385 386 gss_major_status = gss_wrap(&gss_minor_status, gss_context, 0, 387 GSS_C_QOP_DEFAULT, &gss_send_token, 388 &gss_conf_state, &gss_w_token); 389 390 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_wrap")) { 391 gss_release_buffer(&gss_status, &gss_send_token); 392 gss_release_buffer(&gss_status, &gss_w_token); 393 gss_delete_sec_context(&gss_status, &gss_context, NULL); 394 failf(data, "Failed to wrap GSS-API encryption value into token."); 395 return CURLE_COULDNT_CONNECT; 396 } 397 gss_release_buffer(&gss_status, &gss_send_token); 398 399 us_length = htons((short)gss_w_token.length); 400 memcpy(socksreq+2, &us_length, sizeof(short)); 401 } 402 403 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written); 404 if(code || (4 != written)) { 405 failf(data, "Failed to send GSS-API encryption request."); 406 gss_release_buffer(&gss_status, &gss_w_token); 407 gss_delete_sec_context(&gss_status, &gss_context, NULL); 408 return CURLE_COULDNT_CONNECT; 409 } 410 411 if(data->set.socks5_gssapi_nec) { 412 memcpy(socksreq, &gss_enc, 1); 413 code = Curl_write_plain(conn, sock, socksreq, 1, &written); 414 if(code || ( 1 != written)) { 415 failf(data, "Failed to send GSS-API encryption type."); 416 gss_delete_sec_context(&gss_status, &gss_context, NULL); 417 return CURLE_COULDNT_CONNECT; 418 } 419 } 420 else { 421 code = Curl_write_plain(conn, sock, (char *)gss_w_token.value, 422 gss_w_token.length, &written); 423 if(code || ((ssize_t)gss_w_token.length != written)) { 424 failf(data, "Failed to send GSS-API encryption type."); 425 gss_release_buffer(&gss_status, &gss_w_token); 426 gss_delete_sec_context(&gss_status, &gss_context, NULL); 427 return CURLE_COULDNT_CONNECT; 428 } 429 gss_release_buffer(&gss_status, &gss_w_token); 430 } 431 432 result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread); 433 if(result || (actualread != 4)) { 434 failf(data, "Failed to receive GSS-API encryption response."); 435 gss_delete_sec_context(&gss_status, &gss_context, NULL); 436 return CURLE_COULDNT_CONNECT; 437 } 438 439 /* ignore the first (VER) byte */ 440 if(socksreq[1] == 255) { /* status / message type */ 441 failf(data, "User was rejected by the SOCKS5 server (%d %d).", 442 socksreq[0], socksreq[1]); 443 gss_delete_sec_context(&gss_status, &gss_context, NULL); 444 return CURLE_COULDNT_CONNECT; 445 } 446 447 if(socksreq[1] != 2) { /* status / messgae type */ 448 failf(data, "Invalid GSS-API encryption response type (%d %d).", 449 socksreq[0], socksreq[1]); 450 gss_delete_sec_context(&gss_status, &gss_context, NULL); 451 return CURLE_COULDNT_CONNECT; 452 } 453 454 memcpy(&us_length, socksreq+2, sizeof(short)); 455 us_length = ntohs(us_length); 456 457 gss_recv_token.length= us_length; 458 gss_recv_token.value=malloc(gss_recv_token.length); 459 if(!gss_recv_token.value) { 460 gss_delete_sec_context(&gss_status, &gss_context, NULL); 461 return CURLE_OUT_OF_MEMORY; 462 } 463 result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value, 464 gss_recv_token.length, &actualread); 465 466 if(result || (actualread != us_length)) { 467 failf(data, "Failed to receive GSS-API encryptrion type."); 468 gss_release_buffer(&gss_status, &gss_recv_token); 469 gss_delete_sec_context(&gss_status, &gss_context, NULL); 470 return CURLE_COULDNT_CONNECT; 471 } 472 473 if(!data->set.socks5_gssapi_nec) { 474 gss_major_status = gss_unwrap(&gss_minor_status, gss_context, 475 &gss_recv_token, &gss_w_token, 476 0, GSS_C_QOP_DEFAULT); 477 478 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_unwrap")) { 479 gss_release_buffer(&gss_status, &gss_recv_token); 480 gss_release_buffer(&gss_status, &gss_w_token); 481 gss_delete_sec_context(&gss_status, &gss_context, NULL); 482 failf(data, "Failed to unwrap GSS-API encryption value into token."); 483 return CURLE_COULDNT_CONNECT; 484 } 485 gss_release_buffer(&gss_status, &gss_recv_token); 486 487 if(gss_w_token.length != 1) { 488 failf(data, "Invalid GSS-API encryption response length (%d).", 489 gss_w_token.length); 490 gss_release_buffer(&gss_status, &gss_w_token); 491 gss_delete_sec_context(&gss_status, &gss_context, NULL); 492 return CURLE_COULDNT_CONNECT; 493 } 494 495 memcpy(socksreq, gss_w_token.value, gss_w_token.length); 496 gss_release_buffer(&gss_status, &gss_w_token); 497 } 498 else { 499 if(gss_recv_token.length != 1) { 500 failf(data, "Invalid GSS-API encryption response length (%d).", 501 gss_recv_token.length); 502 gss_release_buffer(&gss_status, &gss_recv_token); 503 gss_delete_sec_context(&gss_status, &gss_context, NULL); 504 return CURLE_COULDNT_CONNECT; 505 } 506 507 memcpy(socksreq, gss_recv_token.value, gss_recv_token.length); 508 gss_release_buffer(&gss_status, &gss_recv_token); 509 } 510 511 infof(data, "SOCKS5 access with%s protection granted.\n", 512 (socksreq[0]==0)?"out GSS-API data": 513 ((socksreq[0]==1)?" GSS-API integrity":" GSS-API confidentiality")); 514 515 conn->socks5_gssapi_enctype = socksreq[0]; 516 if(socksreq[0] == 0) 517 gss_delete_sec_context(&gss_status, &gss_context, NULL); 518 519 return CURLE_OK; 520 } 521 522 #endif /* HAVE_GSSAPI && !CURL_DISABLE_PROXY */ 523
