1 /***************************************************************************
3 * Project ___| | | | _ \| |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
8 * Copyright (C) 2009, 2011, Markus Moeller, <markus_moeller@compuserve.com>
9 * Copyright (C) 2012 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
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.
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.
19 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
20 * KIND, either express or implied.
22 ***************************************************************************/
24 #include "curl_setup.h"
26 #if defined(HAVE_GSSAPI) && !defined(CURL_DISABLE_PROXY)
28 #include "curl_gssapi.h"
36 /* The last 3 #include files should be in this order */
37 #include "curl_printf.h"
38 #include "curl_memory.h"
41 static gss_ctx_id_t gss_context = GSS_C_NO_CONTEXT;
44 * Helper GSS-API error functions.
46 static int check_gss_err(struct Curl_easy *data,
47 OM_uint32 major_status,
48 OM_uint32 minor_status,
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;
61 /* convert major status code (GSS-API error) to text */
62 maj_stat = gss_display_status(&min_stat, major_status,
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;
71 gss_release_buffer(&min_stat, &status_string);
74 gss_release_buffer(&min_stat, &status_string);
76 if(sizeof(buf) > len + 3) {
77 strcpy(buf+len, ".\n");
82 /* convert minor status code (underlying routine error) to text */
83 maj_stat = gss_display_status(&min_stat, minor_status,
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);
93 gss_release_buffer(&min_stat, &status_string);
95 failf(data, "GSS-API error: %s failed:\n%s", function, buf);
102 CURLcode Curl_SOCKS5_gssapi_negotiate(int sockindex,
103 struct connectdata *conn)
105 struct Curl_easy *data = conn->data;
106 curl_socket_t sock = conn->sock[sockindex];
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;
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);
128 /* GSS-API request looks like
129 * +----+------+-----+----------------+
130 * |VER | MTYP | LEN | TOKEN |
131 * +----+------+----------------------+
132 * | 1 | 1 | 2 | up to 2^16 - 1 |
133 * +----+------+-----+----------------+
136 /* prepare service name */
137 if(strchr(serviceptr, '/')) {
138 service.length = serviceptr_length;
139 service.value = malloc(service.length);
141 return CURLE_OUT_OF_MEMORY;
142 memcpy(service.value, serviceptr, service.length);
144 gss_major_status = gss_import_name(&gss_minor_status, &service,
145 (gss_OID) GSS_C_NULL_OID, &server);
148 service.value = malloc(serviceptr_length +
149 strlen(conn->socks_proxy.host.name)+2);
151 return CURLE_OUT_OF_MEMORY;
152 service.length = serviceptr_length + strlen(conn->socks_proxy.host.name)+1;
153 snprintf(service.value, service.length+1, "%s@%s",
154 serviceptr, conn->socks_proxy.host.name);
156 gss_major_status = gss_import_name(&gss_minor_status, &service,
157 GSS_C_NT_HOSTBASED_SERVICE, &server);
160 gss_release_buffer(&gss_status, &service); /* clear allocated memory */
162 if(check_gss_err(data, gss_major_status,
163 gss_minor_status, "gss_import_name()")) {
164 failf(data, "Failed to create service name.");
165 gss_release_name(&gss_status, &server);
166 return CURLE_COULDNT_CONNECT;
169 /* As long as we need to keep sending some context info, and there's no */
170 /* errors, keep sending it... */
172 gss_major_status = Curl_gss_init_sec_context(data,
183 if(gss_token != GSS_C_NO_BUFFER)
184 gss_release_buffer(&gss_status, &gss_recv_token);
185 if(check_gss_err(data, gss_major_status,
186 gss_minor_status, "gss_init_sec_context")) {
187 gss_release_name(&gss_status, &server);
188 gss_release_buffer(&gss_status, &gss_recv_token);
189 gss_release_buffer(&gss_status, &gss_send_token);
190 gss_delete_sec_context(&gss_status, &gss_context, NULL);
191 failf(data, "Failed to initial GSS-API token.");
192 return CURLE_COULDNT_CONNECT;
195 if(gss_send_token.length != 0) {
196 socksreq[0] = 1; /* GSS-API subnegotiation version */
197 socksreq[1] = 1; /* authentication message type */
198 us_length = htons((short)gss_send_token.length);
199 memcpy(socksreq+2, &us_length, sizeof(short));
201 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
202 if(code || (4 != written)) {
203 failf(data, "Failed to send GSS-API authentication request.");
204 gss_release_name(&gss_status, &server);
205 gss_release_buffer(&gss_status, &gss_recv_token);
206 gss_release_buffer(&gss_status, &gss_send_token);
207 gss_delete_sec_context(&gss_status, &gss_context, NULL);
208 return CURLE_COULDNT_CONNECT;
211 code = Curl_write_plain(conn, sock, (char *)gss_send_token.value,
212 gss_send_token.length, &written);
214 if(code || ((ssize_t)gss_send_token.length != written)) {
215 failf(data, "Failed to send GSS-API authentication token.");
216 gss_release_name(&gss_status, &server);
217 gss_release_buffer(&gss_status, &gss_recv_token);
218 gss_release_buffer(&gss_status, &gss_send_token);
219 gss_delete_sec_context(&gss_status, &gss_context, NULL);
220 return CURLE_COULDNT_CONNECT;
225 gss_release_buffer(&gss_status, &gss_send_token);
226 gss_release_buffer(&gss_status, &gss_recv_token);
227 if(gss_major_status != GSS_S_CONTINUE_NEEDED) break;
229 /* analyse response */
231 /* GSS-API response looks like
232 * +----+------+-----+----------------+
233 * |VER | MTYP | LEN | TOKEN |
234 * +----+------+----------------------+
235 * | 1 | 1 | 2 | up to 2^16 - 1 |
236 * +----+------+-----+----------------+
239 result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread);
240 if(result || (actualread != 4)) {
241 failf(data, "Failed to receive GSS-API authentication response.");
242 gss_release_name(&gss_status, &server);
243 gss_delete_sec_context(&gss_status, &gss_context, NULL);
244 return CURLE_COULDNT_CONNECT;
247 /* ignore the first (VER) byte */
248 if(socksreq[1] == 255) { /* status / message type */
249 failf(data, "User was rejected by the SOCKS5 server (%d %d).",
250 socksreq[0], socksreq[1]);
251 gss_release_name(&gss_status, &server);
252 gss_delete_sec_context(&gss_status, &gss_context, NULL);
253 return CURLE_COULDNT_CONNECT;
256 if(socksreq[1] != 1) { /* status / messgae type */
257 failf(data, "Invalid GSS-API authentication response type (%d %d).",
258 socksreq[0], socksreq[1]);
259 gss_release_name(&gss_status, &server);
260 gss_delete_sec_context(&gss_status, &gss_context, NULL);
261 return CURLE_COULDNT_CONNECT;
264 memcpy(&us_length, socksreq+2, sizeof(short));
265 us_length = ntohs(us_length);
267 gss_recv_token.length=us_length;
268 gss_recv_token.value=malloc(us_length);
269 if(!gss_recv_token.value) {
271 "Could not allocate memory for GSS-API authentication "
273 gss_release_name(&gss_status, &server);
274 gss_delete_sec_context(&gss_status, &gss_context, NULL);
275 return CURLE_OUT_OF_MEMORY;
278 result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value,
279 gss_recv_token.length, &actualread);
281 if(result || (actualread != us_length)) {
282 failf(data, "Failed to receive GSS-API authentication token.");
283 gss_release_name(&gss_status, &server);
284 gss_release_buffer(&gss_status, &gss_recv_token);
285 gss_delete_sec_context(&gss_status, &gss_context, NULL);
286 return CURLE_COULDNT_CONNECT;
289 gss_token = &gss_recv_token;
292 gss_release_name(&gss_status, &server);
294 /* Everything is good so far, user was authenticated! */
295 gss_major_status = gss_inquire_context(&gss_minor_status, gss_context,
296 &gss_client_name, NULL, NULL, NULL,
298 if(check_gss_err(data, gss_major_status,
299 gss_minor_status, "gss_inquire_context")) {
300 gss_delete_sec_context(&gss_status, &gss_context, NULL);
301 gss_release_name(&gss_status, &gss_client_name);
302 failf(data, "Failed to determine user name.");
303 return CURLE_COULDNT_CONNECT;
305 gss_major_status = gss_display_name(&gss_minor_status, gss_client_name,
306 &gss_send_token, NULL);
307 if(check_gss_err(data, gss_major_status,
308 gss_minor_status, "gss_display_name")) {
309 gss_delete_sec_context(&gss_status, &gss_context, NULL);
310 gss_release_name(&gss_status, &gss_client_name);
311 gss_release_buffer(&gss_status, &gss_send_token);
312 failf(data, "Failed to determine user name.");
313 return CURLE_COULDNT_CONNECT;
315 user=malloc(gss_send_token.length+1);
317 gss_delete_sec_context(&gss_status, &gss_context, NULL);
318 gss_release_name(&gss_status, &gss_client_name);
319 gss_release_buffer(&gss_status, &gss_send_token);
320 return CURLE_OUT_OF_MEMORY;
323 memcpy(user, gss_send_token.value, gss_send_token.length);
324 user[gss_send_token.length] = '\0';
325 gss_release_name(&gss_status, &gss_client_name);
326 gss_release_buffer(&gss_status, &gss_send_token);
327 infof(data, "SOCKS5 server authencticated user %s with GSS-API.\n",user);
332 socksreq[0] = 1; /* GSS-API subnegotiation version */
333 socksreq[1] = 2; /* encryption message type */
335 gss_enc = 0; /* no data protection */
336 /* do confidentiality protection if supported */
337 if(gss_ret_flags & GSS_C_CONF_FLAG)
339 /* else do integrity protection */
340 else if(gss_ret_flags & GSS_C_INTEG_FLAG)
343 infof(data, "SOCKS5 server supports GSS-API %s data protection.\n",
344 (gss_enc==0)?"no":((gss_enc==1)?"integrity":"confidentiality"));
345 /* force for the moment to no data protection */
348 * Sending the encryption type in clear seems wrong. It should be
349 * protected with gss_seal()/gss_wrap(). See RFC1961 extract below
350 * The NEC reference implementations on which this is based is
353 * +------+------+------+.......................+
354 * + ver | mtyp | len | token |
355 * +------+------+------+.......................+
356 * + 0x01 | 0x02 | 0x02 | up to 2^16 - 1 octets |
357 * +------+------+------+.......................+
361 * - "ver" is the protocol version number, here 1 to represent the
362 * first version of the SOCKS/GSS-API protocol
364 * - "mtyp" is the message type, here 2 to represent a protection
365 * -level negotiation message
367 * - "len" is the length of the "token" field in octets
369 * - "token" is the GSS-API encapsulated protection level
371 * The token is produced by encapsulating an octet containing the
372 * required protection level using gss_seal()/gss_wrap() with conf_req
373 * set to FALSE. The token is verified using gss_unseal()/
377 if(data->set.socks5_gssapi_nec) {
378 us_length = htons((short)1);
379 memcpy(socksreq+2, &us_length, sizeof(short));
382 gss_send_token.length = 1;
383 gss_send_token.value = malloc(1);
384 if(!gss_send_token.value) {
385 gss_delete_sec_context(&gss_status, &gss_context, NULL);
386 return CURLE_OUT_OF_MEMORY;
388 memcpy(gss_send_token.value, &gss_enc, 1);
390 gss_major_status = gss_wrap(&gss_minor_status, gss_context, 0,
391 GSS_C_QOP_DEFAULT, &gss_send_token,
392 &gss_conf_state, &gss_w_token);
394 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_wrap")) {
395 gss_release_buffer(&gss_status, &gss_send_token);
396 gss_release_buffer(&gss_status, &gss_w_token);
397 gss_delete_sec_context(&gss_status, &gss_context, NULL);
398 failf(data, "Failed to wrap GSS-API encryption value into token.");
399 return CURLE_COULDNT_CONNECT;
401 gss_release_buffer(&gss_status, &gss_send_token);
403 us_length = htons((short)gss_w_token.length);
404 memcpy(socksreq+2, &us_length, sizeof(short));
407 code = Curl_write_plain(conn, sock, (char *)socksreq, 4, &written);
408 if(code || (4 != written)) {
409 failf(data, "Failed to send GSS-API encryption request.");
410 gss_release_buffer(&gss_status, &gss_w_token);
411 gss_delete_sec_context(&gss_status, &gss_context, NULL);
412 return CURLE_COULDNT_CONNECT;
415 if(data->set.socks5_gssapi_nec) {
416 memcpy(socksreq, &gss_enc, 1);
417 code = Curl_write_plain(conn, sock, socksreq, 1, &written);
418 if(code || ( 1 != written)) {
419 failf(data, "Failed to send GSS-API encryption type.");
420 gss_delete_sec_context(&gss_status, &gss_context, NULL);
421 return CURLE_COULDNT_CONNECT;
425 code = Curl_write_plain(conn, sock, (char *)gss_w_token.value,
426 gss_w_token.length, &written);
427 if(code || ((ssize_t)gss_w_token.length != written)) {
428 failf(data, "Failed to send GSS-API encryption type.");
429 gss_release_buffer(&gss_status, &gss_w_token);
430 gss_delete_sec_context(&gss_status, &gss_context, NULL);
431 return CURLE_COULDNT_CONNECT;
433 gss_release_buffer(&gss_status, &gss_w_token);
436 result=Curl_blockread_all(conn, sock, (char *)socksreq, 4, &actualread);
437 if(result || (actualread != 4)) {
438 failf(data, "Failed to receive GSS-API encryption response.");
439 gss_delete_sec_context(&gss_status, &gss_context, NULL);
440 return CURLE_COULDNT_CONNECT;
443 /* ignore the first (VER) byte */
444 if(socksreq[1] == 255) { /* status / message type */
445 failf(data, "User was rejected by the SOCKS5 server (%d %d).",
446 socksreq[0], socksreq[1]);
447 gss_delete_sec_context(&gss_status, &gss_context, NULL);
448 return CURLE_COULDNT_CONNECT;
451 if(socksreq[1] != 2) { /* status / messgae type */
452 failf(data, "Invalid GSS-API encryption response type (%d %d).",
453 socksreq[0], socksreq[1]);
454 gss_delete_sec_context(&gss_status, &gss_context, NULL);
455 return CURLE_COULDNT_CONNECT;
458 memcpy(&us_length, socksreq+2, sizeof(short));
459 us_length = ntohs(us_length);
461 gss_recv_token.length= us_length;
462 gss_recv_token.value=malloc(gss_recv_token.length);
463 if(!gss_recv_token.value) {
464 gss_delete_sec_context(&gss_status, &gss_context, NULL);
465 return CURLE_OUT_OF_MEMORY;
467 result=Curl_blockread_all(conn, sock, (char *)gss_recv_token.value,
468 gss_recv_token.length, &actualread);
470 if(result || (actualread != us_length)) {
471 failf(data, "Failed to receive GSS-API encryptrion type.");
472 gss_release_buffer(&gss_status, &gss_recv_token);
473 gss_delete_sec_context(&gss_status, &gss_context, NULL);
474 return CURLE_COULDNT_CONNECT;
477 if(!data->set.socks5_gssapi_nec) {
478 gss_major_status = gss_unwrap(&gss_minor_status, gss_context,
479 &gss_recv_token, &gss_w_token,
480 0, GSS_C_QOP_DEFAULT);
482 if(check_gss_err(data, gss_major_status, gss_minor_status, "gss_unwrap")) {
483 gss_release_buffer(&gss_status, &gss_recv_token);
484 gss_release_buffer(&gss_status, &gss_w_token);
485 gss_delete_sec_context(&gss_status, &gss_context, NULL);
486 failf(data, "Failed to unwrap GSS-API encryption value into token.");
487 return CURLE_COULDNT_CONNECT;
489 gss_release_buffer(&gss_status, &gss_recv_token);
491 if(gss_w_token.length != 1) {
492 failf(data, "Invalid GSS-API encryption response length (%d).",
494 gss_release_buffer(&gss_status, &gss_w_token);
495 gss_delete_sec_context(&gss_status, &gss_context, NULL);
496 return CURLE_COULDNT_CONNECT;
499 memcpy(socksreq, gss_w_token.value, gss_w_token.length);
500 gss_release_buffer(&gss_status, &gss_w_token);
503 if(gss_recv_token.length != 1) {
504 failf(data, "Invalid GSS-API encryption response length (%d).",
505 gss_recv_token.length);
506 gss_release_buffer(&gss_status, &gss_recv_token);
507 gss_delete_sec_context(&gss_status, &gss_context, NULL);
508 return CURLE_COULDNT_CONNECT;
511 memcpy(socksreq, gss_recv_token.value, gss_recv_token.length);
512 gss_release_buffer(&gss_status, &gss_recv_token);
515 infof(data, "SOCKS5 access with%s protection granted.\n",
516 (socksreq[0]==0)?"out GSS-API data":
517 ((socksreq[0]==1)?" GSS-API integrity":" GSS-API confidentiality"));
519 conn->socks5_gssapi_enctype = socksreq[0];
521 gss_delete_sec_context(&gss_status, &gss_context, NULL);
526 #endif /* HAVE_GSSAPI && !CURL_DISABLE_PROXY */