GNUnet  0.10.x
socks.c
Go to the documentation of this file.
1 /*
2  This file is part of GNUnet.
3  Copyright (C) 2009-2013 GNUnet e.V.
4 
5  GNUnet is free software: you can redistribute it and/or modify it
6  under the terms of the GNU Affero General Public License as published
7  by the Free Software Foundation, either version 3 of the License,
8  or (at your option) any later version.
9 
10  GNUnet is distributed in the hope that it will be useful, but
11  WITHOUT ANY WARRANTY; without even the implied warranty of
12  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  Affero General Public License for more details.
14 
15  You should have received a copy of the GNU Affero General Public License
16  along with this program. If not, see <http://www.gnu.org/licenses/>.
17 
18  SPDX-License-Identifier: AGPL3.0-or-later
19  */
20 
28 #include "platform.h"
29 #include "gnunet_util_lib.h"
30 
31 
32 #define LOG(kind, ...) GNUNET_log_from(kind, "util-socks", __VA_ARGS__)
33 
34 #define LOG_STRERROR(kind, syscall) \
35  GNUNET_log_from_strerror(kind, "util-socks", syscall)
36 
37 
38 /* SOCKS5 authentication methods */
39 #define SOCKS5_AUTH_REJECT 0xFF /* No acceptable auth method */
40 #define SOCKS5_AUTH_NOAUTH 0x00 /* without authentication */
41 #define SOCKS5_AUTH_GSSAPI 0x01 /* GSSAPI */
42 #define SOCKS5_AUTH_USERPASS 0x02 /* User/Password */
43 #define SOCKS5_AUTH_CHAP 0x03 /* Challenge-Handshake Auth Proto. */
44 #define SOCKS5_AUTH_EAP 0x05 /* Extensible Authentication Proto. */
45 #define SOCKS5_AUTH_MAF 0x08 /* Multi-Authentication Framework */
46 
47 
48 /* SOCKS5 connection responces */
49 #define SOCKS5_REP_SUCCEEDED 0x00 /* succeeded */
50 #define SOCKS5_REP_FAIL 0x01 /* general SOCKS serer failure */
51 #define SOCKS5_REP_NALLOWED 0x02 /* connection not allowed by ruleset */
52 #define SOCKS5_REP_NUNREACH 0x03 /* Network unreachable */
53 #define SOCKS5_REP_HUNREACH 0x04 /* Host unreachable */
54 #define SOCKS5_REP_REFUSED 0x05 /* connection refused */
55 #define SOCKS5_REP_EXPIRED 0x06 /* TTL expired */
56 #define SOCKS5_REP_CNOTSUP 0x07 /* Command not supported */
57 #define SOCKS5_REP_ANOTSUP 0x08 /* Address not supported */
58 #define SOCKS5_REP_INVADDR 0x09 /* Inalid address */
59 
60 const char *
62 {
63  switch (rep)
64  {
66  return "succeeded";
67 
68  case SOCKS5_REP_FAIL:
69  return "general SOCKS server failure";
70 
72  return "connection not allowed by ruleset";
73 
75  return "Network unreachable";
76 
78  return "Host unreachable";
79 
80  case SOCKS5_REP_REFUSED:
81  return "connection refused";
82 
83  case SOCKS5_REP_EXPIRED:
84  return "TTL expired";
85 
86  case SOCKS5_REP_CNOTSUP:
87  return "Command not supported";
88 
89  case SOCKS5_REP_ANOTSUP:
90  return "Address not supported";
91 
92  case SOCKS5_REP_INVADDR:
93  return "Invalid address";
94 
95  default:
96  return NULL;
97  }
98 };
99 
100 
110 unsigned char *
111 SOCK5_proto_string(unsigned char *b, const char *s)
112 {
113  size_t l = strlen(s);
114 
115  if (l > 255)
116  {
118  "SOCKS5 cannot handle hostnames, usernames, or passwords over 255 bytes, truncating.\n");
119  l = 255;
120  }
121  *(b++) = (unsigned char)l;
122  memcpy(b, s, l);
123  return b + l;
124 }
125 
126 
127 #define SOCKS5_step_greet 0
128 #define SOCKS5_step_auth 1
129 #define SOCKS5_step_cmd 2
130 #define SOCKS5_step_done 3
131 
140 
145 
150 
154  int step;
155 
159  unsigned char outbuf[1024];
160 
164  unsigned char *(outstep[4]);
165 
169  unsigned char inbuf[1024];
170 
174  unsigned char *instart;
175  unsigned char *inend;
176 };
177 
178 
179 /* Regitering prototypes */
180 
181 void
182 register_reciever(struct GNUNET_SOCKS_Handshake *ih, int want);
183 
184 /* In fact, the client sends first rule in GNUnet suggests one could take
185  * large mac read sizes without fear of screwing up the proxied protocol,
186  * but we make a proper SOCKS5 client. */
187 #define register_reciever_wants(ih) ((SOCKS5_step_cmd == ih->step) ? 10 : 2)
188 
189 
192 
193 
201 void
203 {
205 }
206 
207 
213 void
215 {
216  unsigned char *b = ih->instart;
217  size_t available = ih->inend - b;
218 
219  int want = register_reciever_wants(ih);
220 
221  if (available < want)
222  {
223  register_reciever(ih, want - available);
224  return;
225  }
226  GNUNET_assert(SOCKS5_step_done > ih->step && ih->step >= 0);
227  switch (ih->step)
228  {
229  case SOCKS5_step_greet: /* SOCKS5 server's greeting */
230  if (b[0] != 5)
231  {
232  LOG(GNUNET_ERROR_TYPE_ERROR, "Not a SOCKS5 server\n");
233  GNUNET_assert(0);
234  }
235  switch (b[1])
236  {
237  case SOCKS5_AUTH_NOAUTH:
238  ih->step = SOCKS5_step_cmd; /* no authentication to do */
239  break;
240 
242  ih->step = SOCKS5_step_auth;
243  break;
244 
245  case SOCKS5_AUTH_REJECT:
246  LOG(GNUNET_ERROR_TYPE_ERROR, "No authentication method accepted\n");
247  return;
248 
249  default:
251  "Not a SOCKS5 server / Nonsensical authentication\n");
252  return;
253  }
254  b += 2;
255  break;
256 
257  case SOCKS5_step_auth: /* SOCKS5 server's responce to authentication */
258  if (b[1] != 0)
259  {
260  LOG(GNUNET_ERROR_TYPE_ERROR, "SOCKS5 authentication failed\n");
261  GNUNET_assert(0);
262  }
263  ih->step = SOCKS5_step_cmd;
264  b += 2;
265  break;
266 
267  case SOCKS5_step_cmd: /* SOCKS5 server's responce to command */
268  if (b[0] != 5)
269  {
270  LOG(GNUNET_ERROR_TYPE_ERROR, "SOCKS5 protocol error\n");
271  GNUNET_assert(0);
272  }
273  if (0 != b[1])
274  {
276  "SOCKS5 connection error : %s\n",
277  SOCKS5_REP_names(b[1]));
278  return;
279  }
280  b += 3;
281  /* There is no reason to verify host and port afaik. */
282  switch (*(b++))
283  {
284  case 1: /* IPv4 */
285  b += sizeof(struct in_addr); /* 4 */
286  break;
287 
288  case 4: /* IPv6 */
289  b += sizeof(struct in6_addr); /* 16 */
290  break;
291 
292  case 3: /* hostname */
293  b += *b;
294  break;
295  }
296  b += 2; /* port */
297  if (b > ih->inend)
298  {
299  register_reciever(ih, b - ih->inend);
300  return;
301  }
302  ih->step = SOCKS5_step_done;
304  "SOCKS5 server : %s\n",
305  SOCKS5_REP_names(b[1]));
306  ih->instart = b;
308  return;
309 
310  case SOCKS5_step_done:
311  GNUNET_assert(0);
312  }
313  ih->instart = b;
314  /* Do not reschedule the sender unless we're done reading.
315  * I imagine this lets us avoid ever cancelling the transmit handle. */
316  register_sender(ih);
317 }
318 
319 
327 void
328 reciever(void *cls,
329  const void *buf,
330  size_t available,
331  const struct sockaddr *addr,
332  socklen_t addrlen,
333  int errCode)
334 {
335  struct GNUNET_SOCKS_Handshake *ih = cls;
336 
337  GNUNET_assert(&ih->inend[available] < &ih->inbuf[1024]);
338  GNUNET_memcpy(ih->inend, buf, available);
339  ih->inend += available;
341 }
342 
343 
351 void
353 {
355  want,
357  &reciever,
358  ih);
359 }
360 
361 
370 size_t
371 transmit_ready(void *cls, size_t size, void *buf)
372 {
373  struct GNUNET_SOCKS_Handshake *ih = cls;
374 
375  /* connection.c has many routines that call us with buf == NULL :
376  * signal_transmit_error() - DNS, etc. active
377  * connect_fail_continuation()
378  * connect_probe_continuation() - timeout
379  * try_connect_using_address() - DNS failure/timeout
380  * transmit_timeout() - retry failed?
381  * GNUNET_CONNECTION_notify_transmit_ready() can schedule :
382  * transmit_timeout() - DNS still working
383  * connect_error() - DNS done but no socket?
384  * transmit_ready() - scheduler shutdown or timeout, or signal_transmit_error()
385  * We'd need to dig into the scheduler to guess at the reason, as
386  * connection.c tells us nothing itself, but mostly its timouts.
387  * Initially, we'll simply ignore this and leave massive timeouts, but
388  * maybe that should change for error handling pruposes. It appears that
389  * successful operations, including DNS resolution, do not use this. */
390  if (NULL == buf)
391  {
392  if (0 == ih->step)
393  {
395  "Timeout contacting SOCKS server, retrying indefinitely, but probably hopeless.\n");
396  register_sender(ih);
397  }
398  else
399  {
401  "Timeout during mid SOCKS handshake (step %u), probably not a SOCKS server.\n",
402  ih->step);
403  GNUNET_break(0);
404  }
405  return 0;
406  }
407 
408  GNUNET_assert((1024 >= size) && (size > 0));
409  GNUNET_assert((SOCKS5_step_done > ih->step) && (ih->step >= 0));
410  unsigned char *b = ih->outstep[ih->step];
411  unsigned char *e = ih->outstep[ih->step + 1];
412  GNUNET_assert(e <= &ih->outbuf[1024]);
413  unsigned int l = e - b;
414  GNUNET_assert(size >= l);
415  GNUNET_memcpy(buf, b, l);
417  return l;
418 }
419 
420 
430 {
432 
434  GNUNET_assert(ih->step >= 0);
435  if (0 == ih->step)
437  unsigned char *b = ih->outstep[ih->step];
438  unsigned char *e = ih->outstep[ih->step + 1];
439  GNUNET_assert(ih->outbuf <= b && b < e && e < &ih->outbuf[1024]);
441  e - b,
442  timeout,
444  ih);
445  return ih->th;
446 }
447 
448 
458 struct GNUNET_SOCKS_Handshake *
459 GNUNET_SOCKS_init_handshake(const char *user, const char *pass)
460 {
461  struct GNUNET_SOCKS_Handshake *ih =
463  unsigned char *b = ih->outbuf;
464 
465  ih->outstep[SOCKS5_step_greet] = b;
466  *(b++) = 5; /* SOCKS5 */
467  unsigned char *n = b++;
468  *n = 1; /* Number of authentication methods */
469  /* We support no authentication even when requesting authentication,
470  * but this appears harmless, given the way that Tor uses authentication.
471  * And some SOCKS5 servers might require this. */
472  *(b++) = SOCKS5_AUTH_NOAUTH;
473  if (NULL != user)
474  {
475  *(b++) = SOCKS5_AUTH_USERPASS;
476  (*n)++;
477  }
478  /* There is no apperent reason to support authentication methods beyond
479  * username and password since afaik Tor does not support them. */
480 
481  /* We authenticate with an empty username and password if the server demands
482  * them but we do not have any. */
483  if (user == NULL)
484  user = "";
485  if (pass == NULL)
486  pass = "";
487 
488  ih->outstep[SOCKS5_step_auth] = b;
489  *(b++) = 1; /* subnegotiation ver.: 1 */
490  b = SOCK5_proto_string(b, user);
491  b = SOCK5_proto_string(b, pass);
492 
493  ih->outstep[SOCKS5_step_cmd] = b;
494 
495  ih->inend = ih->instart = ih->inbuf;
496 
497  return ih;
498 }
499 
500 
507 struct GNUNET_SOCKS_Handshake *
509 {
510  return GNUNET_SOCKS_init_handshake(NULL, NULL);
511 }
512 
513 
522 void
524  const char *host,
525  uint16_t port)
526 {
527  union {
528  struct in_addr in4;
529  struct in6_addr in6;
530  } ia;
531  unsigned char *b = ih->outstep[SOCKS5_step_cmd];
532 
533  *(b++) = 5; /* SOCKS5 */
534  *(b++) = 1; /* Establish a TCP/IP stream */
535  *(b++) = 0; /* reserved */
536 
537  /* Specify destination */
538  if (1 == inet_pton(AF_INET, host, &ia.in4))
539  {
540  *(b++) = 1; /* IPv4 */
541  GNUNET_memcpy(b, &ia.in4, sizeof(struct in_addr));
542  b += sizeof(struct in_addr); /* 4 */
543  }
544  else if (1 == inet_pton(AF_INET6, host, &ia.in6))
545  {
546  *(b++) = 4; /* IPv6 */
547  GNUNET_memcpy(b, &ia.in6, sizeof(struct in6_addr));
548  b += sizeof(struct in6_addr); /* 16 */
549  }
550  else
551  {
552  *(b++) = 3; /* hostname */
553  b = SOCK5_proto_string(b, host);
554  }
555 
556  /* Specify port */
557  *(uint16_t *)b = htons(port);
558  b += 2;
559 
560  ih->outstep[SOCKS5_step_done] = b;
561 }
562 
563 
573  struct GNUNET_CONNECTION_Handle *c)
574 {
575  ih->socks5_connection = c;
577  register_sender(ih);
578 
579  return ih->target_connection;
580 }
581 
582 
591 int
593  const struct GNUNET_CONFIGURATION_Handle *cfg)
594 {
595  return GNUNET_CONFIGURATION_have_value(cfg, service_name, "SOCKSPORT") ||
596  GNUNET_CONFIGURATION_have_value(cfg, service_name, "SOCKSHOST");
597 }
598 
599 
610  const struct GNUNET_CONFIGURATION_Handle *cfg)
611 {
612  struct GNUNET_SOCKS_Handshake *ih;
613  struct GNUNET_CONNECTION_Handle *socks5; /* *proxied */
614  char *host0;
615  char *host1;
616  char *user;
617  char *pass;
618  unsigned long long port0;
619  unsigned long long port1;
620 
621  if (GNUNET_YES != GNUNET_SOCKS_check_service(service_name, cfg))
622  return NULL;
624  service_name,
625  "SOCKSPORT",
626  &port0))
627  port0 = 9050;
628  /* A typical Tor client should usually try port 9150 for the TBB too, but
629  * GNUnet can probably assume a system Tor installation. */
630  if (port0 > 65535 || port0 <= 0)
631  {
633  _(
634  "Attempting to use invalid port %d as SOCKS proxy for service `%s'.\n"),
635  port0,
636  service_name);
637  return NULL;
638  }
640  service_name,
641  "PORT",
642  &port1)) ||
643  (port1 > 65535) || (port1 <= 0) ||
645  service_name,
646  "HOSTNAME",
647  &host1)))
648  {
650  _(
651  "Attempting to proxy service `%s' to invalid port %d or hostname.\n"),
652  service_name,
653  port1);
654  return NULL;
655  }
656  /* Appeared to still work after host0 corrupted, so either test case is broken, or
657  this whole routine is not being called. */
659  service_name,
660  "SOCKSHOST",
661  &host0))
662  host0 = NULL;
664  (host0 != NULL) ? host0
665  : "127.0.0.1",
666  port0);
667  GNUNET_free_non_null(host0);
668 
669  /* Sets to NULL if they do not exist */
671  service_name,
672  "SOCKSUSER",
673  &user);
675  service_name,
676  "SOCKSPASS",
677  &pass);
678  ih = GNUNET_SOCKS_init_handshake(user, pass);
679  GNUNET_free_non_null(user);
680  GNUNET_free_non_null(pass);
681 
682  GNUNET_SOCKS_set_handshake_destination(ih, host1, port1);
683  GNUNET_free(host1);
684  return GNUNET_SOCKS_run_handshake(ih, socks5);
685 }
686 
687 /* socks.c */
#define SOCKS5_AUTH_NOAUTH
Definition: socks.c:40
struct GNUNET_CONNECTION_Handle * GNUNET_CONNECTION_create_from_connect(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *hostname, uint16_t port)
Create a connection handle by (asynchronously) connecting to a host.
unsigned char outbuf[1024]
Precomputed SOCKS5 handshake ouput buffer.
Definition: socks.c:159
#define SOCKS5_REP_EXPIRED
Definition: socks.c:55
int GNUNET_CONFIGURATION_get_value_number(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option, unsigned long long *number)
Get a configuration value that should be a number.
#define SOCKS5_REP_FAIL
Definition: socks.c:50
#define SOCKS5_REP_NALLOWED
Definition: socks.c:51
#define GNUNET_TIME_UNIT_MINUTES
One minute.
void GNUNET_CONNECTION_acivate_proxied(struct GNUNET_CONNECTION_Handle *proxied)
Activate proxied connection and destroy initial proxy handshake connection.
#define SOCKS5_step_done
Definition: socks.c:130
#define GNUNET_assert(cond)
Use this for fatal errors that cannot be handled.
unsigned char * inend
Definition: socks.c:175
#define GNUNET_memcpy(dst, src, n)
Call memcpy() but check for n being 0 first.
static struct Experiment * e
#define SOCKS5_AUTH_USERPASS
Definition: socks.c:42
#define GNUNET_OK
Named constants for return values.
Definition: gnunet_common.h:75
#define GNUNET_free_non_null(ptr)
Free the memory pointed to by ptr if ptr is not NULL.
#define GNUNET_new(type)
Allocate a struct or union of the given type.
#define SOCKS5_REP_REFUSED
Definition: socks.c:54
#define GNUNET_break(cond)
Use this for internal assertion violations that are not fatal (can be handled) but should not occur...
#define SOCKS5_step_cmd
Definition: socks.c:129
#define _(String)
GNU gettext support macro.
Definition: platform.h:181
static struct LoggingHandle * l
#define SOCKS5_REP_NUNREACH
Definition: socks.c:52
#define register_reciever_wants(ih)
Definition: socks.c:187
#define SOCKS5_step_greet
Definition: socks.c:127
struct GNUNET_SOCKS_Handshake * GNUNET_SOCKS_init_handshake_noauth()
Initialize a SOCKS5 handshake without authentication, thereby possibly sharing a Tor circuit with ano...
Definition: socks.c:508
struct GNUNET_CONNECTION_TransmitHandle * register_sender(struct GNUNET_SOCKS_Handshake *ih)
Register SOCKS5 handshake sender.
Definition: socks.c:429
void GNUNET_SOCKS_set_handshake_destination(struct GNUNET_SOCKS_Handshake *ih, const char *host, uint16_t port)
Build request that the SOCKS5 proxy open a TCP/IP stream to the given host and port.
Definition: socks.c:523
struct GNUNET_TIME_Relative GNUNET_TIME_relative_get_minute_(void)
Return relative time of 1 minute.
Definition: time.c:195
int GNUNET_CONFIGURATION_have_value(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option)
Test if we have a value for a particular option.
struct GNUNET_CONNECTION_Handle * GNUNET_SOCKS_do_connect(const char *service_name, const struct GNUNET_CONFIGURATION_Handle *cfg)
Try to connect to a service configured to use a SOCKS5 proxy.
Definition: socks.c:609
static char * service_name
Option -s: service name (hash to get service descriptor)
Definition: gnunet-vpn.c:51
static char buf[2048]
int GNUNET_CONNECTION_receive(struct GNUNET_CONNECTION_Handle *connection, size_t max, struct GNUNET_TIME_Relative timeout, GNUNET_CONNECTION_Receiver receiver, void *receiver_cls)
Receive data from the given connection.
struct GNUNET_TIME_Relative GNUNET_TIME_relative_multiply(struct GNUNET_TIME_Relative rel, unsigned long long factor)
Multiply relative time by a given factor.
Definition: time.c:440
struct GNUNET_CONNECTION_Handle * target_connection
Connection handle initially returned to client.
Definition: socks.c:144
void SOCKS5_handshake_done(struct GNUNET_SOCKS_Handshake *ih)
Conclude the SOCKS5 handshake successfully.
Definition: socks.c:202
int step
Our stage in the SOCKS5 handshake.
Definition: socks.c:154
#define SOCKS5_REP_ANOTSUP
Definition: socks.c:57
void SOCKS5_handshake_step(struct GNUNET_SOCKS_Handshake *ih)
Read one step in the SOCKS5 handshake.
Definition: socks.c:214
int GNUNET_CONFIGURATION_get_value_string(const struct GNUNET_CONFIGURATION_Handle *cfg, const char *section, const char *option, char **value)
Get a configuration value that should be a string.
static struct GNUNET_CONFIGURATION_Handle * cfg
Our configuration.
Definition: gnunet-arm.c:104
static unsigned int size
Size of the "table".
Definition: peer.c:66
unsigned char * outstep[4]
Pointers delineating protoocol steps in the outbut buffer.
Definition: socks.c:164
int GNUNET_SOCKS_check_service(const char *service_name, const struct GNUNET_CONFIGURATION_Handle *cfg)
Check if a SOCKS proxy is required by a service.
Definition: socks.c:592
void register_reciever(struct GNUNET_SOCKS_Handshake *ih, int want)
Register callback to read from the SOCKS5 proxy.
Definition: socks.c:352
#define LOG(kind,...)
Definition: socks.c:32
const char * SOCKS5_REP_names(int rep)
Definition: socks.c:61
#define SOCKS5_REP_SUCCEEDED
Definition: socks.c:49
unsigned char * SOCK5_proto_string(unsigned char *b, const char *s)
Encode a string for the SOCKS5 protocol by prefixing it a byte stating its length and stripping the t...
Definition: socks.c:111
unsigned char inbuf[1024]
SOCKS5 handshake input buffer.
Definition: socks.c:169
struct GNUNET_CONNECTION_TransmitHandle * th
Transmission handle on socks5_connection.
Definition: socks.c:149
static uint16_t port
Port number.
Definition: gnunet-bcd.c:81
size_t transmit_ready(void *cls, size_t size, void *buf)
Register SOCKS5 handshake sender.
Definition: socks.c:371
configuration data
Definition: configuration.c:83
struct GNUNET_CONNECTION_TransmitHandle * GNUNET_CONNECTION_notify_transmit_ready(struct GNUNET_CONNECTION_Handle *connection, size_t size, struct GNUNET_TIME_Relative timeout, GNUNET_CONNECTION_TransmitReadyNotify notify, void *notify_cls)
Ask the connection to call us once the specified number of bytes are free in the transmission buffer...
#define SOCKS5_AUTH_REJECT
Definition: socks.c:39
unsigned char * instart
Pointers delimiting the current step in the input buffer.
Definition: socks.c:174
struct GNUNET_CONNECTION_Handle * GNUNET_CONNECTION_create_proxied_from_handshake(struct GNUNET_CONNECTION_Handle *cph)
Create a connection to be proxied using a given connection.
struct GNUNET_CONNECTION_Handle * GNUNET_SOCKS_run_handshake(struct GNUNET_SOCKS_Handshake *ih, struct GNUNET_CONNECTION_Handle *c)
Run a SOCKS5 handshake on an open but unused TCP connection.
Definition: socks.c:572
#define GNUNET_YES
Definition: gnunet_common.h:77
struct GNUNET_CONNECTION_Handle * socks5_connection
Connection handle used for SOCKS5.
Definition: socks.c:139
#define SOCKS5_REP_HUNREACH
Definition: socks.c:53
State of the SOCKS5 handshake.
Definition: socks.c:135
handle for a network connection
#define SOCKS5_step_auth
Definition: socks.c:128
#define SOCKS5_REP_INVADDR
Definition: socks.c:58
void reciever(void *cls, const void *buf, size_t available, const struct sockaddr *addr, socklen_t addrlen, int errCode)
Callback to read from the SOCKS5 proxy.
Definition: socks.c:328
#define SOCKS5_REP_CNOTSUP
Definition: socks.c:56
#define GNUNET_free(ptr)
Wrapper around free.
Time for relative time used by GNUnet, in microseconds.
struct GNUNET_SOCKS_Handshake * GNUNET_SOCKS_init_handshake(const char *user, const char *pass)
Initialize a SOCKS5 handshake for authentication via username and password.
Definition: socks.c:459