* tramp.texi (Multi-hops): Introduce `tramp-restricted-shell-hosts-alist'.
[emacs/old-mirror.git] / src / gnutls.c
blob9c96379ff7ed85ad33974d572d908574683ff87a
1 /* GnuTLS glue for GNU Emacs.
2 Copyright (C) 2010-2012 Free Software Foundation, Inc.
4 This file is part of GNU Emacs.
6 GNU Emacs is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 GNU Emacs is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
19 #include <config.h>
20 #include <errno.h>
21 #include <setjmp.h>
23 #include "lisp.h"
24 #include "process.h"
26 #ifdef HAVE_GNUTLS
27 #include <gnutls/gnutls.h>
29 #ifdef WINDOWSNT
30 #include <windows.h>
31 #include "w32.h"
32 #endif
34 static int
35 emacs_gnutls_handle_error (gnutls_session_t, int err);
37 static Lisp_Object Qgnutls_dll;
38 static Lisp_Object Qgnutls_code;
39 static Lisp_Object Qgnutls_anon, Qgnutls_x509pki;
40 static Lisp_Object Qgnutls_e_interrupted, Qgnutls_e_again,
41 Qgnutls_e_invalid_session, Qgnutls_e_not_ready_for_handshake;
42 static int gnutls_global_initialized;
44 /* The following are for the property list of `gnutls-boot'. */
45 static Lisp_Object QCgnutls_bootprop_priority;
46 static Lisp_Object QCgnutls_bootprop_trustfiles;
47 static Lisp_Object QCgnutls_bootprop_keylist;
48 static Lisp_Object QCgnutls_bootprop_crlfiles;
49 static Lisp_Object QCgnutls_bootprop_callbacks;
50 static Lisp_Object QCgnutls_bootprop_loglevel;
51 static Lisp_Object QCgnutls_bootprop_hostname;
52 static Lisp_Object QCgnutls_bootprop_min_prime_bits;
53 static Lisp_Object QCgnutls_bootprop_verify_flags;
54 static Lisp_Object QCgnutls_bootprop_verify_hostname_error;
56 /* Callback keys for `gnutls-boot'. Unused currently. */
57 static Lisp_Object QCgnutls_bootprop_callbacks_verify;
59 static void gnutls_log_function (int, const char *);
60 static void gnutls_log_function2 (int, const char*, const char*);
63 #ifdef WINDOWSNT
65 /* Macro for defining functions that will be loaded from the GnuTLS DLL. */
66 #define DEF_GNUTLS_FN(rettype,func,args) static rettype (FAR CDECL *fn_##func)args
68 /* Macro for loading GnuTLS functions from the library. */
69 #define LOAD_GNUTLS_FN(lib,func) { \
70 fn_##func = (void *) GetProcAddress (lib, #func); \
71 if (!fn_##func) return 0; \
74 DEF_GNUTLS_FN (gnutls_alert_description_t, gnutls_alert_get,
75 (gnutls_session_t));
76 DEF_GNUTLS_FN (const char *, gnutls_alert_get_name,
77 (gnutls_alert_description_t));
78 DEF_GNUTLS_FN (int, gnutls_alert_send_appropriate, (gnutls_session_t, int));
79 DEF_GNUTLS_FN (int, gnutls_anon_allocate_client_credentials,
80 (gnutls_anon_client_credentials_t *));
81 DEF_GNUTLS_FN (void, gnutls_anon_free_client_credentials,
82 (gnutls_anon_client_credentials_t));
83 DEF_GNUTLS_FN (int, gnutls_bye, (gnutls_session_t, gnutls_close_request_t));
84 DEF_GNUTLS_FN (int, gnutls_certificate_allocate_credentials,
85 (gnutls_certificate_credentials_t *));
86 DEF_GNUTLS_FN (void, gnutls_certificate_free_credentials,
87 (gnutls_certificate_credentials_t));
88 DEF_GNUTLS_FN (const gnutls_datum_t *, gnutls_certificate_get_peers,
89 (gnutls_session_t, unsigned int *));
90 DEF_GNUTLS_FN (void, gnutls_certificate_set_verify_flags,
91 (gnutls_certificate_credentials_t, unsigned int));
92 DEF_GNUTLS_FN (int, gnutls_certificate_set_x509_crl_file,
93 (gnutls_certificate_credentials_t, const char *,
94 gnutls_x509_crt_fmt_t));
95 DEF_GNUTLS_FN (int, gnutls_certificate_set_x509_key_file,
96 (gnutls_certificate_credentials_t, const char *, const char *,
97 gnutls_x509_crt_fmt_t));
98 DEF_GNUTLS_FN (int, gnutls_certificate_set_x509_trust_file,
99 (gnutls_certificate_credentials_t, const char *,
100 gnutls_x509_crt_fmt_t));
101 DEF_GNUTLS_FN (gnutls_certificate_type_t, gnutls_certificate_type_get,
102 (gnutls_session_t));
103 DEF_GNUTLS_FN (int, gnutls_certificate_verify_peers2,
104 (gnutls_session_t, unsigned int *));
105 DEF_GNUTLS_FN (int, gnutls_credentials_set,
106 (gnutls_session_t, gnutls_credentials_type_t, void *));
107 DEF_GNUTLS_FN (void, gnutls_deinit, (gnutls_session_t));
108 DEF_GNUTLS_FN (void, gnutls_dh_set_prime_bits,
109 (gnutls_session_t, unsigned int));
110 DEF_GNUTLS_FN (int, gnutls_error_is_fatal, (int));
111 DEF_GNUTLS_FN (int, gnutls_global_init, (void));
112 DEF_GNUTLS_FN (void, gnutls_global_set_log_function, (gnutls_log_func));
113 DEF_GNUTLS_FN (void, gnutls_global_set_log_level, (int));
114 DEF_GNUTLS_FN (void, gnutls_global_set_mem_functions,
115 (gnutls_alloc_function, gnutls_alloc_function,
116 gnutls_is_secure_function, gnutls_realloc_function,
117 gnutls_free_function));
118 DEF_GNUTLS_FN (int, gnutls_handshake, (gnutls_session_t));
119 DEF_GNUTLS_FN (int, gnutls_init, (gnutls_session_t *, gnutls_connection_end_t));
120 DEF_GNUTLS_FN (int, gnutls_priority_set_direct,
121 (gnutls_session_t, const char *, const char **));
122 DEF_GNUTLS_FN (size_t, gnutls_record_check_pending, (gnutls_session_t));
123 DEF_GNUTLS_FN (ssize_t, gnutls_record_recv, (gnutls_session_t, void *, size_t));
124 DEF_GNUTLS_FN (ssize_t, gnutls_record_send,
125 (gnutls_session_t, const void *, size_t));
126 DEF_GNUTLS_FN (const char *, gnutls_strerror, (int));
127 DEF_GNUTLS_FN (void, gnutls_transport_set_errno, (gnutls_session_t, int));
128 DEF_GNUTLS_FN (const char *, gnutls_check_version, (const char *));
129 DEF_GNUTLS_FN (void, gnutls_transport_set_lowat, (gnutls_session_t, int));
130 DEF_GNUTLS_FN (void, gnutls_transport_set_ptr2,
131 (gnutls_session_t, gnutls_transport_ptr_t,
132 gnutls_transport_ptr_t));
133 DEF_GNUTLS_FN (void, gnutls_transport_set_pull_function,
134 (gnutls_session_t, gnutls_pull_func));
135 DEF_GNUTLS_FN (void, gnutls_transport_set_push_function,
136 (gnutls_session_t, gnutls_push_func));
137 DEF_GNUTLS_FN (int, gnutls_x509_crt_check_hostname,
138 (gnutls_x509_crt_t, const char *));
139 DEF_GNUTLS_FN (void, gnutls_x509_crt_deinit, (gnutls_x509_crt_t));
140 DEF_GNUTLS_FN (int, gnutls_x509_crt_import,
141 (gnutls_x509_crt_t, const gnutls_datum_t *,
142 gnutls_x509_crt_fmt_t));
143 DEF_GNUTLS_FN (int, gnutls_x509_crt_init, (gnutls_x509_crt_t *));
145 static int
146 init_gnutls_functions (Lisp_Object libraries)
148 HMODULE library;
149 int max_log_level = 1;
151 if (!(library = w32_delayed_load (libraries, Qgnutls_dll)))
153 GNUTLS_LOG (1, max_log_level, "GnuTLS library not found");
154 return 0;
157 LOAD_GNUTLS_FN (library, gnutls_alert_get);
158 LOAD_GNUTLS_FN (library, gnutls_alert_get_name);
159 LOAD_GNUTLS_FN (library, gnutls_alert_send_appropriate);
160 LOAD_GNUTLS_FN (library, gnutls_anon_allocate_client_credentials);
161 LOAD_GNUTLS_FN (library, gnutls_anon_free_client_credentials);
162 LOAD_GNUTLS_FN (library, gnutls_bye);
163 LOAD_GNUTLS_FN (library, gnutls_certificate_allocate_credentials);
164 LOAD_GNUTLS_FN (library, gnutls_certificate_free_credentials);
165 LOAD_GNUTLS_FN (library, gnutls_certificate_get_peers);
166 LOAD_GNUTLS_FN (library, gnutls_certificate_set_verify_flags);
167 LOAD_GNUTLS_FN (library, gnutls_certificate_set_x509_crl_file);
168 LOAD_GNUTLS_FN (library, gnutls_certificate_set_x509_key_file);
169 LOAD_GNUTLS_FN (library, gnutls_certificate_set_x509_trust_file);
170 LOAD_GNUTLS_FN (library, gnutls_certificate_type_get);
171 LOAD_GNUTLS_FN (library, gnutls_certificate_verify_peers2);
172 LOAD_GNUTLS_FN (library, gnutls_credentials_set);
173 LOAD_GNUTLS_FN (library, gnutls_deinit);
174 LOAD_GNUTLS_FN (library, gnutls_dh_set_prime_bits);
175 LOAD_GNUTLS_FN (library, gnutls_error_is_fatal);
176 LOAD_GNUTLS_FN (library, gnutls_global_init);
177 LOAD_GNUTLS_FN (library, gnutls_global_set_log_function);
178 LOAD_GNUTLS_FN (library, gnutls_global_set_log_level);
179 LOAD_GNUTLS_FN (library, gnutls_global_set_mem_functions);
180 LOAD_GNUTLS_FN (library, gnutls_handshake);
181 LOAD_GNUTLS_FN (library, gnutls_init);
182 LOAD_GNUTLS_FN (library, gnutls_priority_set_direct);
183 LOAD_GNUTLS_FN (library, gnutls_record_check_pending);
184 LOAD_GNUTLS_FN (library, gnutls_record_recv);
185 LOAD_GNUTLS_FN (library, gnutls_record_send);
186 LOAD_GNUTLS_FN (library, gnutls_strerror);
187 LOAD_GNUTLS_FN (library, gnutls_transport_set_errno);
188 LOAD_GNUTLS_FN (library, gnutls_check_version);
189 /* We don't need to call gnutls_transport_set_lowat in GnuTLS 2.11.1
190 and later, and the function was removed entirely in 3.0.0. */
191 if (!fn_gnutls_check_version ("2.11.1"))
192 LOAD_GNUTLS_FN (library, gnutls_transport_set_lowat);
193 LOAD_GNUTLS_FN (library, gnutls_transport_set_ptr2);
194 LOAD_GNUTLS_FN (library, gnutls_transport_set_pull_function);
195 LOAD_GNUTLS_FN (library, gnutls_transport_set_push_function);
196 LOAD_GNUTLS_FN (library, gnutls_x509_crt_check_hostname);
197 LOAD_GNUTLS_FN (library, gnutls_x509_crt_deinit);
198 LOAD_GNUTLS_FN (library, gnutls_x509_crt_import);
199 LOAD_GNUTLS_FN (library, gnutls_x509_crt_init);
201 max_log_level = global_gnutls_log_level;
204 Lisp_Object name = CAR_SAFE (Fget (Qgnutls_dll, QCloaded_from));
205 GNUTLS_LOG2 (1, max_log_level, "GnuTLS library loaded:",
206 STRINGP (name) ? (const char *) SDATA (name) : "unknown");
209 return 1;
212 #else /* !WINDOWSNT */
214 #define fn_gnutls_alert_get gnutls_alert_get
215 #define fn_gnutls_alert_get_name gnutls_alert_get_name
216 #define fn_gnutls_alert_send_appropriate gnutls_alert_send_appropriate
217 #define fn_gnutls_anon_allocate_client_credentials gnutls_anon_allocate_client_credentials
218 #define fn_gnutls_anon_free_client_credentials gnutls_anon_free_client_credentials
219 #define fn_gnutls_bye gnutls_bye
220 #define fn_gnutls_certificate_allocate_credentials gnutls_certificate_allocate_credentials
221 #define fn_gnutls_certificate_free_credentials gnutls_certificate_free_credentials
222 #define fn_gnutls_certificate_get_peers gnutls_certificate_get_peers
223 #define fn_gnutls_certificate_set_verify_flags gnutls_certificate_set_verify_flags
224 #define fn_gnutls_certificate_set_x509_crl_file gnutls_certificate_set_x509_crl_file
225 #define fn_gnutls_certificate_set_x509_key_file gnutls_certificate_set_x509_key_file
226 #define fn_gnutls_certificate_set_x509_trust_file gnutls_certificate_set_x509_trust_file
227 #define fn_gnutls_certificate_type_get gnutls_certificate_type_get
228 #define fn_gnutls_certificate_verify_peers2 gnutls_certificate_verify_peers2
229 #define fn_gnutls_credentials_set gnutls_credentials_set
230 #define fn_gnutls_deinit gnutls_deinit
231 #define fn_gnutls_dh_set_prime_bits gnutls_dh_set_prime_bits
232 #define fn_gnutls_error_is_fatal gnutls_error_is_fatal
233 #define fn_gnutls_global_init gnutls_global_init
234 #define fn_gnutls_global_set_log_function gnutls_global_set_log_function
235 #define fn_gnutls_global_set_log_level gnutls_global_set_log_level
236 #define fn_gnutls_global_set_mem_functions gnutls_global_set_mem_functions
237 #define fn_gnutls_handshake gnutls_handshake
238 #define fn_gnutls_init gnutls_init
239 #define fn_gnutls_priority_set_direct gnutls_priority_set_direct
240 #define fn_gnutls_record_check_pending gnutls_record_check_pending
241 #define fn_gnutls_record_recv gnutls_record_recv
242 #define fn_gnutls_record_send gnutls_record_send
243 #define fn_gnutls_strerror gnutls_strerror
244 #define fn_gnutls_transport_set_errno gnutls_transport_set_errno
245 #define fn_gnutls_transport_set_ptr2 gnutls_transport_set_ptr2
246 #define fn_gnutls_x509_crt_check_hostname gnutls_x509_crt_check_hostname
247 #define fn_gnutls_x509_crt_deinit gnutls_x509_crt_deinit
248 #define fn_gnutls_x509_crt_import gnutls_x509_crt_import
249 #define fn_gnutls_x509_crt_init gnutls_x509_crt_init
251 #endif /* !WINDOWSNT */
254 /* Function to log a simple message. */
255 static void
256 gnutls_log_function (int level, const char* string)
258 message ("gnutls.c: [%d] %s", level, string);
261 /* Function to log a message and a string. */
262 static void
263 gnutls_log_function2 (int level, const char* string, const char* extra)
265 message ("gnutls.c: [%d] %s %s", level, string, extra);
268 /* Function to log a message and an integer. */
269 static void
270 gnutls_log_function2i (int level, const char* string, int extra)
272 message ("gnutls.c: [%d] %s %d", level, string, extra);
275 static int
276 emacs_gnutls_handshake (struct Lisp_Process *proc)
278 gnutls_session_t state = proc->gnutls_state;
279 int ret;
281 if (proc->gnutls_initstage < GNUTLS_STAGE_HANDSHAKE_CANDO)
282 return -1;
284 if (proc->gnutls_initstage < GNUTLS_STAGE_TRANSPORT_POINTERS_SET)
286 #ifdef WINDOWSNT
287 /* On W32 we cannot transfer socket handles between different runtime
288 libraries, so we tell GnuTLS to use our special push/pull
289 functions. */
290 fn_gnutls_transport_set_ptr2 (state,
291 (gnutls_transport_ptr_t) proc,
292 (gnutls_transport_ptr_t) proc);
293 fn_gnutls_transport_set_push_function (state, &emacs_gnutls_push);
294 fn_gnutls_transport_set_pull_function (state, &emacs_gnutls_pull);
296 /* For non blocking sockets or other custom made pull/push
297 functions the gnutls_transport_set_lowat must be called, with
298 a zero low water mark value. (GnuTLS 2.10.4 documentation)
300 (Note: this is probably not strictly necessary as the lowat
301 value is only used when no custom pull/push functions are
302 set.) */
303 /* According to GnuTLS NEWS file, lowat level has been set to
304 zero by default in version 2.11.1, and the function
305 gnutls_transport_set_lowat was removed from the library in
306 version 2.99.0. */
307 if (!fn_gnutls_check_version ("2.11.1"))
308 fn_gnutls_transport_set_lowat (state, 0);
309 #else
310 /* This is how GnuTLS takes sockets: as file descriptors passed
311 in. For an Emacs process socket, infd and outfd are the
312 same but we use this two-argument version for clarity. */
313 fn_gnutls_transport_set_ptr2 (state,
314 (gnutls_transport_ptr_t) (long) proc->infd,
315 (gnutls_transport_ptr_t) (long) proc->outfd);
316 #endif
318 proc->gnutls_initstage = GNUTLS_STAGE_TRANSPORT_POINTERS_SET;
323 ret = fn_gnutls_handshake (state);
324 emacs_gnutls_handle_error (state, ret);
325 QUIT;
327 while (ret < 0 && fn_gnutls_error_is_fatal (ret) == 0);
329 proc->gnutls_initstage = GNUTLS_STAGE_HANDSHAKE_TRIED;
331 if (ret == GNUTLS_E_SUCCESS)
333 /* Here we're finally done. */
334 proc->gnutls_initstage = GNUTLS_STAGE_READY;
336 else
338 fn_gnutls_alert_send_appropriate (state, ret);
340 return ret;
344 emacs_gnutls_record_check_pending (gnutls_session_t state)
346 return fn_gnutls_record_check_pending (state);
349 void
350 emacs_gnutls_transport_set_errno (gnutls_session_t state, int err)
352 fn_gnutls_transport_set_errno (state, err);
355 ptrdiff_t
356 emacs_gnutls_write (struct Lisp_Process *proc, const char *buf, ptrdiff_t nbyte)
358 ssize_t rtnval = 0;
359 ptrdiff_t bytes_written;
360 gnutls_session_t state = proc->gnutls_state;
362 if (proc->gnutls_initstage != GNUTLS_STAGE_READY)
364 #ifdef EWOULDBLOCK
365 errno = EWOULDBLOCK;
366 #endif
367 #ifdef EAGAIN
368 errno = EAGAIN;
369 #endif
370 return 0;
373 bytes_written = 0;
375 while (nbyte > 0)
377 rtnval = fn_gnutls_record_send (state, buf, nbyte);
379 if (rtnval < 0)
381 if (rtnval == GNUTLS_E_INTERRUPTED)
382 continue;
383 else
385 /* If we get GNUTLS_E_AGAIN, then set errno
386 appropriately so that send_process retries the
387 correct way instead of erroring out. */
388 if (rtnval == GNUTLS_E_AGAIN)
390 #ifdef EWOULDBLOCK
391 errno = EWOULDBLOCK;
392 #endif
393 #ifdef EAGAIN
394 errno = EAGAIN;
395 #endif
397 break;
401 buf += rtnval;
402 nbyte -= rtnval;
403 bytes_written += rtnval;
406 emacs_gnutls_handle_error (state, rtnval);
407 return (bytes_written);
410 ptrdiff_t
411 emacs_gnutls_read (struct Lisp_Process *proc, char *buf, ptrdiff_t nbyte)
413 ssize_t rtnval;
414 gnutls_session_t state = proc->gnutls_state;
416 int log_level = proc->gnutls_log_level;
418 if (proc->gnutls_initstage != GNUTLS_STAGE_READY)
420 /* If the handshake count is under the limit, try the handshake
421 again and increment the handshake count. This count is kept
422 per process (connection), not globally. */
423 if (proc->gnutls_handshakes_tried < GNUTLS_EMACS_HANDSHAKES_LIMIT)
425 proc->gnutls_handshakes_tried++;
426 emacs_gnutls_handshake (proc);
427 GNUTLS_LOG2i (5, log_level, "Retried handshake",
428 proc->gnutls_handshakes_tried);
429 return -1;
432 GNUTLS_LOG (2, log_level, "Giving up on handshake; resetting retries");
433 proc->gnutls_handshakes_tried = 0;
434 return 0;
436 rtnval = fn_gnutls_record_recv (state, buf, nbyte);
437 if (rtnval >= 0)
438 return rtnval;
439 else if (rtnval == GNUTLS_E_UNEXPECTED_PACKET_LENGTH)
440 /* The peer closed the connection. */
441 return 0;
442 else if (emacs_gnutls_handle_error (state, rtnval) == 0)
443 /* non-fatal error */
444 return -1;
445 else {
446 /* a fatal error occurred */
447 return 0;
451 /* report a GnuTLS error to the user.
452 Returns zero if the error code was successfully handled. */
453 static int
454 emacs_gnutls_handle_error (gnutls_session_t session, int err)
456 int max_log_level = 0;
458 int ret;
459 const char *str;
461 /* TODO: use a Lisp_Object generated by gnutls_make_error? */
462 if (err >= 0)
463 return 0;
465 max_log_level = global_gnutls_log_level;
467 /* TODO: use gnutls-error-fatalp and gnutls-error-string. */
469 str = fn_gnutls_strerror (err);
470 if (!str)
471 str = "unknown";
473 if (fn_gnutls_error_is_fatal (err))
475 ret = err;
476 GNUTLS_LOG2 (0, max_log_level, "fatal error:", str);
478 else
480 ret = 0;
481 GNUTLS_LOG2 (1, max_log_level, "non-fatal error:", str);
482 /* TODO: EAGAIN AKA Qgnutls_e_again should be level 2. */
485 if (err == GNUTLS_E_WARNING_ALERT_RECEIVED
486 || err == GNUTLS_E_FATAL_ALERT_RECEIVED)
488 int alert = fn_gnutls_alert_get (session);
489 int level = (err == GNUTLS_E_FATAL_ALERT_RECEIVED) ? 0 : 1;
490 str = fn_gnutls_alert_get_name (alert);
491 if (!str)
492 str = "unknown";
494 GNUTLS_LOG2 (level, max_log_level, "Received alert: ", str);
496 return ret;
499 /* convert an integer error to a Lisp_Object; it will be either a
500 known symbol like `gnutls_e_interrupted' and `gnutls_e_again' or
501 simply the integer value of the error. GNUTLS_E_SUCCESS is mapped
502 to Qt. */
503 static Lisp_Object
504 gnutls_make_error (int err)
506 switch (err)
508 case GNUTLS_E_SUCCESS:
509 return Qt;
510 case GNUTLS_E_AGAIN:
511 return Qgnutls_e_again;
512 case GNUTLS_E_INTERRUPTED:
513 return Qgnutls_e_interrupted;
514 case GNUTLS_E_INVALID_SESSION:
515 return Qgnutls_e_invalid_session;
518 return make_number (err);
521 Lisp_Object
522 emacs_gnutls_deinit (Lisp_Object proc)
524 int log_level;
526 CHECK_PROCESS (proc);
528 if (XPROCESS (proc)->gnutls_p == 0)
529 return Qnil;
531 log_level = XPROCESS (proc)->gnutls_log_level;
533 if (XPROCESS (proc)->gnutls_x509_cred)
535 GNUTLS_LOG (2, log_level, "Deallocating x509 credentials");
536 fn_gnutls_certificate_free_credentials (XPROCESS (proc)->gnutls_x509_cred);
537 XPROCESS (proc)->gnutls_x509_cred = NULL;
540 if (XPROCESS (proc)->gnutls_anon_cred)
542 GNUTLS_LOG (2, log_level, "Deallocating anon credentials");
543 fn_gnutls_anon_free_client_credentials (XPROCESS (proc)->gnutls_anon_cred);
544 XPROCESS (proc)->gnutls_anon_cred = NULL;
547 if (XPROCESS (proc)->gnutls_state)
549 fn_gnutls_deinit (XPROCESS (proc)->gnutls_state);
550 XPROCESS (proc)->gnutls_state = NULL;
551 if (GNUTLS_INITSTAGE (proc) >= GNUTLS_STAGE_INIT)
552 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_INIT - 1;
555 XPROCESS (proc)->gnutls_p = 0;
556 return Qt;
559 DEFUN ("gnutls-get-initstage", Fgnutls_get_initstage, Sgnutls_get_initstage, 1, 1, 0,
560 doc: /* Return the GnuTLS init stage of process PROC.
561 See also `gnutls-boot'. */)
562 (Lisp_Object proc)
564 CHECK_PROCESS (proc);
566 return make_number (GNUTLS_INITSTAGE (proc));
569 DEFUN ("gnutls-errorp", Fgnutls_errorp, Sgnutls_errorp, 1, 1, 0,
570 doc: /* Return t if ERROR indicates a GnuTLS problem.
571 ERROR is an integer or a symbol with an integer `gnutls-code' property.
572 usage: (gnutls-errorp ERROR) */)
573 (Lisp_Object err)
575 if (EQ (err, Qt)) return Qnil;
577 return Qt;
580 DEFUN ("gnutls-error-fatalp", Fgnutls_error_fatalp, Sgnutls_error_fatalp, 1, 1, 0,
581 doc: /* Check if ERROR is fatal.
582 ERROR is an integer or a symbol with an integer `gnutls-code' property.
583 usage: (gnutls-error-fatalp ERROR) */)
584 (Lisp_Object err)
586 Lisp_Object code;
588 if (EQ (err, Qt)) return Qnil;
590 if (SYMBOLP (err))
592 code = Fget (err, Qgnutls_code);
593 if (NUMBERP (code))
595 err = code;
597 else
599 error ("Symbol has no numeric gnutls-code property");
603 if (! TYPE_RANGED_INTEGERP (int, err))
604 error ("Not an error symbol or code");
606 if (0 == fn_gnutls_error_is_fatal (XINT (err)))
607 return Qnil;
609 return Qt;
612 DEFUN ("gnutls-error-string", Fgnutls_error_string, Sgnutls_error_string, 1, 1, 0,
613 doc: /* Return a description of ERROR.
614 ERROR is an integer or a symbol with an integer `gnutls-code' property.
615 usage: (gnutls-error-string ERROR) */)
616 (Lisp_Object err)
618 Lisp_Object code;
620 if (EQ (err, Qt)) return build_string ("Not an error");
622 if (SYMBOLP (err))
624 code = Fget (err, Qgnutls_code);
625 if (NUMBERP (code))
627 err = code;
629 else
631 return build_string ("Symbol has no numeric gnutls-code property");
635 if (! TYPE_RANGED_INTEGERP (int, err))
636 return build_string ("Not an error symbol or code");
638 return build_string (fn_gnutls_strerror (XINT (err)));
641 DEFUN ("gnutls-deinit", Fgnutls_deinit, Sgnutls_deinit, 1, 1, 0,
642 doc: /* Deallocate GnuTLS resources associated with process PROC.
643 See also `gnutls-init'. */)
644 (Lisp_Object proc)
646 return emacs_gnutls_deinit (proc);
649 DEFUN ("gnutls-available-p", Fgnutls_available_p, Sgnutls_available_p, 0, 0, 0,
650 doc: /* Return t if GnuTLS is available in this instance of Emacs. */)
651 (void)
653 #ifdef WINDOWSNT
654 Lisp_Object found = Fassq (Qgnutls_dll, Vlibrary_cache);
655 if (CONSP (found))
656 return XCDR (found);
657 else
659 Lisp_Object status;
660 status = init_gnutls_functions (Vdynamic_library_alist) ? Qt : Qnil;
661 Vlibrary_cache = Fcons (Fcons (Qgnutls_dll, status), Vlibrary_cache);
662 return status;
664 #else
665 return Qt;
666 #endif
670 /* Initializes global GnuTLS state to defaults.
671 Call `gnutls-global-deinit' when GnuTLS usage is no longer needed.
672 Returns zero on success. */
673 static Lisp_Object
674 emacs_gnutls_global_init (void)
676 int ret = GNUTLS_E_SUCCESS;
678 if (!gnutls_global_initialized)
680 fn_gnutls_global_set_mem_functions (xmalloc, xmalloc, NULL,
681 xrealloc, xfree);
682 ret = fn_gnutls_global_init ();
684 gnutls_global_initialized = 1;
686 return gnutls_make_error (ret);
689 #if 0
690 /* Deinitializes global GnuTLS state.
691 See also `gnutls-global-init'. */
692 static Lisp_Object
693 emacs_gnutls_global_deinit (void)
695 if (gnutls_global_initialized)
696 gnutls_global_deinit ();
698 gnutls_global_initialized = 0;
700 return gnutls_make_error (GNUTLS_E_SUCCESS);
702 #endif
704 DEFUN ("gnutls-boot", Fgnutls_boot, Sgnutls_boot, 3, 3, 0,
705 doc: /* Initialize GnuTLS client for process PROC with TYPE+PROPLIST.
706 Currently only client mode is supported. Return a success/failure
707 value you can check with `gnutls-errorp'.
709 TYPE is a symbol, either `gnutls-anon' or `gnutls-x509pki'.
710 PROPLIST is a property list with the following keys:
712 :hostname is a string naming the remote host.
714 :priority is a GnuTLS priority string, defaults to "NORMAL".
716 :trustfiles is a list of PEM-encoded trust files for `gnutls-x509pki'.
718 :crlfiles is a list of PEM-encoded CRL lists for `gnutls-x509pki'.
720 :keylist is an alist of PEM-encoded key files and PEM-encoded
721 certificates for `gnutls-x509pki'.
723 :callbacks is an alist of callback functions, see below.
725 :loglevel is the debug level requested from GnuTLS, try 4.
727 :verify-flags is a bitset as per GnuTLS'
728 gnutls_certificate_set_verify_flags.
730 :verify-hostname-error, if non-nil, makes a hostname mismatch an
731 error. Otherwise it will be just a warning.
733 :min-prime-bits is the minimum accepted number of bits the client will
734 accept in Diffie-Hellman key exchange.
736 The debug level will be set for this process AND globally for GnuTLS.
737 So if you set it higher or lower at any point, it affects global
738 debugging.
740 Note that the priority is set on the client. The server does not use
741 the protocols's priority except for disabling protocols that were not
742 specified.
744 Processes must be initialized with this function before other GnuTLS
745 functions are used. This function allocates resources which can only
746 be deallocated by calling `gnutls-deinit' or by calling it again.
748 The callbacks alist can have a `verify' key, associated with a
749 verification function (UNUSED).
751 Each authentication type may need additional information in order to
752 work. For X.509 PKI (`gnutls-x509pki'), you probably need at least
753 one trustfile (usually a CA bundle). */)
754 (Lisp_Object proc, Lisp_Object type, Lisp_Object proplist)
756 int ret = GNUTLS_E_SUCCESS;
757 int max_log_level = 0;
759 gnutls_session_t state;
760 gnutls_certificate_credentials_t x509_cred = NULL;
761 gnutls_anon_client_credentials_t anon_cred = NULL;
762 Lisp_Object global_init;
763 char const *priority_string_ptr = "NORMAL"; /* default priority string. */
764 unsigned int peer_verification;
765 char* c_hostname;
767 /* Placeholders for the property list elements. */
768 Lisp_Object priority_string;
769 Lisp_Object trustfiles;
770 Lisp_Object crlfiles;
771 Lisp_Object keylist;
772 /* Lisp_Object callbacks; */
773 Lisp_Object loglevel;
774 Lisp_Object hostname;
775 /* Lisp_Object verify_error; */
776 Lisp_Object verify_hostname_error;
777 Lisp_Object prime_bits;
779 CHECK_PROCESS (proc);
780 CHECK_SYMBOL (type);
781 CHECK_LIST (proplist);
783 if (NILP (Fgnutls_available_p ()))
785 error ("GnuTLS not available");
786 return gnutls_make_error (GNUTLS_EMACS_ERROR_NOT_LOADED);
789 if (!EQ (type, Qgnutls_x509pki) && !EQ (type, Qgnutls_anon))
791 error ("Invalid GnuTLS credential type");
792 return gnutls_make_error (GNUTLS_EMACS_ERROR_INVALID_TYPE);
795 hostname = Fplist_get (proplist, QCgnutls_bootprop_hostname);
796 priority_string = Fplist_get (proplist, QCgnutls_bootprop_priority);
797 trustfiles = Fplist_get (proplist, QCgnutls_bootprop_trustfiles);
798 keylist = Fplist_get (proplist, QCgnutls_bootprop_keylist);
799 crlfiles = Fplist_get (proplist, QCgnutls_bootprop_crlfiles);
800 loglevel = Fplist_get (proplist, QCgnutls_bootprop_loglevel);
801 verify_hostname_error = Fplist_get (proplist, QCgnutls_bootprop_verify_hostname_error);
802 prime_bits = Fplist_get (proplist, QCgnutls_bootprop_min_prime_bits);
804 if (!STRINGP (hostname))
805 error ("gnutls-boot: invalid :hostname parameter");
806 c_hostname = SSDATA (hostname);
808 state = XPROCESS (proc)->gnutls_state;
809 XPROCESS (proc)->gnutls_p = 1;
811 if (TYPE_RANGED_INTEGERP (int, loglevel))
813 fn_gnutls_global_set_log_function (gnutls_log_function);
814 fn_gnutls_global_set_log_level (XINT (loglevel));
815 max_log_level = XINT (loglevel);
816 XPROCESS (proc)->gnutls_log_level = max_log_level;
819 /* always initialize globals. */
820 global_init = emacs_gnutls_global_init ();
821 if (! NILP (Fgnutls_errorp (global_init)))
822 return global_init;
824 /* Before allocating new credentials, deallocate any credentials
825 that PROC might already have. */
826 emacs_gnutls_deinit (proc);
828 /* Mark PROC as a GnuTLS process. */
829 XPROCESS (proc)->gnutls_p = 1;
830 XPROCESS (proc)->gnutls_state = NULL;
831 XPROCESS (proc)->gnutls_x509_cred = NULL;
832 XPROCESS (proc)->gnutls_anon_cred = NULL;
833 XPROCESS (proc)->gnutls_cred_type = type;
834 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_EMPTY;
836 GNUTLS_LOG (1, max_log_level, "allocating credentials");
837 if (EQ (type, Qgnutls_x509pki))
839 Lisp_Object verify_flags;
840 unsigned int gnutls_verify_flags = GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT;
842 GNUTLS_LOG (2, max_log_level, "allocating x509 credentials");
843 fn_gnutls_certificate_allocate_credentials (&x509_cred);
844 XPROCESS (proc)->gnutls_x509_cred = x509_cred;
846 verify_flags = Fplist_get (proplist, QCgnutls_bootprop_verify_flags);
847 if (NUMBERP (verify_flags))
849 gnutls_verify_flags = XINT (verify_flags);
850 GNUTLS_LOG (2, max_log_level, "setting verification flags");
852 else if (NILP (verify_flags))
853 GNUTLS_LOG (2, max_log_level, "using default verification flags");
854 else
855 GNUTLS_LOG (2, max_log_level, "ignoring invalid verify-flags");
857 fn_gnutls_certificate_set_verify_flags (x509_cred, gnutls_verify_flags);
859 else /* Qgnutls_anon: */
861 GNUTLS_LOG (2, max_log_level, "allocating anon credentials");
862 fn_gnutls_anon_allocate_client_credentials (&anon_cred);
863 XPROCESS (proc)->gnutls_anon_cred = anon_cred;
866 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_CRED_ALLOC;
868 if (EQ (type, Qgnutls_x509pki))
870 /* TODO: GNUTLS_X509_FMT_DER is also an option. */
871 int file_format = GNUTLS_X509_FMT_PEM;
872 Lisp_Object tail;
874 for (tail = trustfiles; !NILP (tail); tail = Fcdr (tail))
876 Lisp_Object trustfile = Fcar (tail);
877 if (STRINGP (trustfile))
879 GNUTLS_LOG2 (1, max_log_level, "setting the trustfile: ",
880 SSDATA (trustfile));
881 ret = fn_gnutls_certificate_set_x509_trust_file
882 (x509_cred,
883 SSDATA (trustfile),
884 file_format);
886 if (ret < GNUTLS_E_SUCCESS)
887 return gnutls_make_error (ret);
889 else
891 emacs_gnutls_deinit (proc);
892 error ("Invalid trustfile");
896 for (tail = crlfiles; !NILP (tail); tail = Fcdr (tail))
898 Lisp_Object crlfile = Fcar (tail);
899 if (STRINGP (crlfile))
901 GNUTLS_LOG2 (1, max_log_level, "setting the CRL file: ",
902 SSDATA (crlfile));
903 ret = fn_gnutls_certificate_set_x509_crl_file
904 (x509_cred, SSDATA (crlfile), file_format);
906 if (ret < GNUTLS_E_SUCCESS)
907 return gnutls_make_error (ret);
909 else
911 emacs_gnutls_deinit (proc);
912 error ("Invalid CRL file");
916 for (tail = keylist; !NILP (tail); tail = Fcdr (tail))
918 Lisp_Object keyfile = Fcar (Fcar (tail));
919 Lisp_Object certfile = Fcar (Fcdr (tail));
920 if (STRINGP (keyfile) && STRINGP (certfile))
922 GNUTLS_LOG2 (1, max_log_level, "setting the client key file: ",
923 SSDATA (keyfile));
924 GNUTLS_LOG2 (1, max_log_level, "setting the client cert file: ",
925 SSDATA (certfile));
926 ret = fn_gnutls_certificate_set_x509_key_file
927 (x509_cred, SSDATA (certfile), SSDATA (keyfile), file_format);
929 if (ret < GNUTLS_E_SUCCESS)
930 return gnutls_make_error (ret);
932 else
934 emacs_gnutls_deinit (proc);
935 error (STRINGP (keyfile) ? "Invalid client cert file"
936 : "Invalid client key file");
941 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_FILES;
942 GNUTLS_LOG (1, max_log_level, "gnutls callbacks");
943 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_CALLBACKS;
945 /* Call gnutls_init here: */
947 GNUTLS_LOG (1, max_log_level, "gnutls_init");
948 ret = fn_gnutls_init (&state, GNUTLS_CLIENT);
949 XPROCESS (proc)->gnutls_state = state;
950 if (ret < GNUTLS_E_SUCCESS)
951 return gnutls_make_error (ret);
952 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_INIT;
954 if (STRINGP (priority_string))
956 priority_string_ptr = SSDATA (priority_string);
957 GNUTLS_LOG2 (1, max_log_level, "got non-default priority string:",
958 priority_string_ptr);
960 else
962 GNUTLS_LOG2 (1, max_log_level, "using default priority string:",
963 priority_string_ptr);
966 GNUTLS_LOG (1, max_log_level, "setting the priority string");
967 ret = fn_gnutls_priority_set_direct (state,
968 priority_string_ptr,
969 NULL);
970 if (ret < GNUTLS_E_SUCCESS)
971 return gnutls_make_error (ret);
973 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_PRIORITY;
975 if (INTEGERP (prime_bits))
976 fn_gnutls_dh_set_prime_bits (state, XUINT (prime_bits));
978 ret = EQ (type, Qgnutls_x509pki)
979 ? fn_gnutls_credentials_set (state, GNUTLS_CRD_CERTIFICATE, x509_cred)
980 : fn_gnutls_credentials_set (state, GNUTLS_CRD_ANON, anon_cred);
981 if (ret < GNUTLS_E_SUCCESS)
982 return gnutls_make_error (ret);
984 GNUTLS_INITSTAGE (proc) = GNUTLS_STAGE_CRED_SET;
985 ret = emacs_gnutls_handshake (XPROCESS (proc));
986 if (ret < GNUTLS_E_SUCCESS)
987 return gnutls_make_error (ret);
989 /* Now verify the peer, following
990 http://www.gnu.org/software/gnutls/manual/html_node/Verifying-peer_0027s-certificate.html.
991 The peer should present at least one certificate in the chain; do a
992 check of the certificate's hostname with
993 gnutls_x509_crt_check_hostname() against :hostname. */
995 ret = fn_gnutls_certificate_verify_peers2 (state, &peer_verification);
996 if (ret < GNUTLS_E_SUCCESS)
997 return gnutls_make_error (ret);
999 if (XINT (loglevel) > 0 && peer_verification & GNUTLS_CERT_INVALID)
1000 message ("%s certificate could not be verified.", c_hostname);
1002 if (peer_verification & GNUTLS_CERT_REVOKED)
1003 GNUTLS_LOG2 (1, max_log_level, "certificate was revoked (CRL):",
1004 c_hostname);
1006 if (peer_verification & GNUTLS_CERT_SIGNER_NOT_FOUND)
1007 GNUTLS_LOG2 (1, max_log_level, "certificate signer was not found:",
1008 c_hostname);
1010 if (peer_verification & GNUTLS_CERT_SIGNER_NOT_CA)
1011 GNUTLS_LOG2 (1, max_log_level, "certificate signer is not a CA:",
1012 c_hostname);
1014 if (peer_verification & GNUTLS_CERT_INSECURE_ALGORITHM)
1015 GNUTLS_LOG2 (1, max_log_level,
1016 "certificate was signed with an insecure algorithm:",
1017 c_hostname);
1019 if (peer_verification & GNUTLS_CERT_NOT_ACTIVATED)
1020 GNUTLS_LOG2 (1, max_log_level, "certificate is not yet activated:",
1021 c_hostname);
1023 if (peer_verification & GNUTLS_CERT_EXPIRED)
1024 GNUTLS_LOG2 (1, max_log_level, "certificate has expired:",
1025 c_hostname);
1027 if (peer_verification != 0)
1029 if (NILP (verify_hostname_error))
1030 GNUTLS_LOG2 (1, max_log_level, "certificate validation failed:",
1031 c_hostname);
1032 else
1034 emacs_gnutls_deinit (proc);
1035 error ("Certificate validation failed %s, verification code %d",
1036 c_hostname, peer_verification);
1040 /* Up to here the process is the same for X.509 certificates and
1041 OpenPGP keys. From now on X.509 certificates are assumed. This
1042 can be easily extended to work with openpgp keys as well. */
1043 if (fn_gnutls_certificate_type_get (state) == GNUTLS_CRT_X509)
1045 gnutls_x509_crt_t gnutls_verify_cert;
1046 const gnutls_datum_t *gnutls_verify_cert_list;
1047 unsigned int gnutls_verify_cert_list_size;
1049 ret = fn_gnutls_x509_crt_init (&gnutls_verify_cert);
1050 if (ret < GNUTLS_E_SUCCESS)
1051 return gnutls_make_error (ret);
1053 gnutls_verify_cert_list =
1054 fn_gnutls_certificate_get_peers (state, &gnutls_verify_cert_list_size);
1056 if (gnutls_verify_cert_list == NULL)
1058 fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
1059 emacs_gnutls_deinit (proc);
1060 error ("No x509 certificate was found\n");
1063 /* We only check the first certificate in the given chain. */
1064 ret = fn_gnutls_x509_crt_import (gnutls_verify_cert,
1065 &gnutls_verify_cert_list[0],
1066 GNUTLS_X509_FMT_DER);
1068 if (ret < GNUTLS_E_SUCCESS)
1070 fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
1071 return gnutls_make_error (ret);
1074 if (!fn_gnutls_x509_crt_check_hostname (gnutls_verify_cert, c_hostname))
1076 if (NILP (verify_hostname_error))
1077 GNUTLS_LOG2 (1, max_log_level, "x509 certificate does not match:",
1078 c_hostname);
1079 else
1081 fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
1082 emacs_gnutls_deinit (proc);
1083 error ("The x509 certificate does not match \"%s\"", c_hostname);
1086 fn_gnutls_x509_crt_deinit (gnutls_verify_cert);
1089 return gnutls_make_error (ret);
1092 DEFUN ("gnutls-bye", Fgnutls_bye,
1093 Sgnutls_bye, 2, 2, 0,
1094 doc: /* Terminate current GnuTLS connection for process PROC.
1095 The connection should have been initiated using `gnutls-handshake'.
1097 If CONT is not nil the TLS connection gets terminated and further
1098 receives and sends will be disallowed. If the return value is zero you
1099 may continue using the connection. If CONT is nil, GnuTLS actually
1100 sends an alert containing a close request and waits for the peer to
1101 reply with the same message. In order to reuse the connection you
1102 should wait for an EOF from the peer.
1104 This function may also return `gnutls-e-again', or
1105 `gnutls-e-interrupted'. */)
1106 (Lisp_Object proc, Lisp_Object cont)
1108 gnutls_session_t state;
1109 int ret;
1111 CHECK_PROCESS (proc);
1113 state = XPROCESS (proc)->gnutls_state;
1115 ret = fn_gnutls_bye (state,
1116 NILP (cont) ? GNUTLS_SHUT_RDWR : GNUTLS_SHUT_WR);
1118 return gnutls_make_error (ret);
1121 void
1122 syms_of_gnutls (void)
1124 gnutls_global_initialized = 0;
1126 DEFSYM (Qgnutls_dll, "gnutls");
1127 DEFSYM (Qgnutls_code, "gnutls-code");
1128 DEFSYM (Qgnutls_anon, "gnutls-anon");
1129 DEFSYM (Qgnutls_x509pki, "gnutls-x509pki");
1130 DEFSYM (QCgnutls_bootprop_hostname, ":hostname");
1131 DEFSYM (QCgnutls_bootprop_priority, ":priority");
1132 DEFSYM (QCgnutls_bootprop_trustfiles, ":trustfiles");
1133 DEFSYM (QCgnutls_bootprop_keylist, ":keylist");
1134 DEFSYM (QCgnutls_bootprop_crlfiles, ":crlfiles");
1135 DEFSYM (QCgnutls_bootprop_callbacks, ":callbacks");
1136 DEFSYM (QCgnutls_bootprop_callbacks_verify, "verify");
1137 DEFSYM (QCgnutls_bootprop_min_prime_bits, ":min-prime-bits");
1138 DEFSYM (QCgnutls_bootprop_loglevel, ":loglevel");
1139 DEFSYM (QCgnutls_bootprop_verify_flags, ":verify-flags");
1140 DEFSYM (QCgnutls_bootprop_verify_hostname_error, ":verify-hostname-error");
1142 DEFSYM (Qgnutls_e_interrupted, "gnutls-e-interrupted");
1143 Fput (Qgnutls_e_interrupted, Qgnutls_code,
1144 make_number (GNUTLS_E_INTERRUPTED));
1146 DEFSYM (Qgnutls_e_again, "gnutls-e-again");
1147 Fput (Qgnutls_e_again, Qgnutls_code,
1148 make_number (GNUTLS_E_AGAIN));
1150 DEFSYM (Qgnutls_e_invalid_session, "gnutls-e-invalid-session");
1151 Fput (Qgnutls_e_invalid_session, Qgnutls_code,
1152 make_number (GNUTLS_E_INVALID_SESSION));
1154 DEFSYM (Qgnutls_e_not_ready_for_handshake, "gnutls-e-not-ready-for-handshake");
1155 Fput (Qgnutls_e_not_ready_for_handshake, Qgnutls_code,
1156 make_number (GNUTLS_E_APPLICATION_ERROR_MIN));
1158 defsubr (&Sgnutls_get_initstage);
1159 defsubr (&Sgnutls_errorp);
1160 defsubr (&Sgnutls_error_fatalp);
1161 defsubr (&Sgnutls_error_string);
1162 defsubr (&Sgnutls_boot);
1163 defsubr (&Sgnutls_deinit);
1164 defsubr (&Sgnutls_bye);
1165 defsubr (&Sgnutls_available_p);
1167 DEFVAR_INT ("gnutls-log-level", global_gnutls_log_level,
1168 doc: /* Logging level used by the GnuTLS functions.
1169 Set this larger than 0 to get debug output in the *Messages* buffer.
1170 1 is for important messages, 2 is for debug data, and higher numbers
1171 are as per the GnuTLS logging conventions. */);
1172 global_gnutls_log_level = 0;
1175 #endif /* HAVE_GNUTLS */