- WTF?! Do not use non-existant vlc_closedir_wrapper
[vlc.git] / modules / misc / gnutls.c
1 /*****************************************************************************
2  * gnutls.c
3  *****************************************************************************
4  * Copyright (C) 2004-2006 Rémi Denis-Courmont
5  * $Id$
6  *
7  * Authors: Rémi Denis-Courmont <rem # videolan.org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22  *****************************************************************************/
23
24 /*****************************************************************************
25  * Preamble
26  *****************************************************************************/
27
28 #include <vlc/vlc.h>
29 #include <stdlib.h>
30 #include <errno.h>
31 #include <time.h>
32
33 #include <sys/types.h>
34 #include <errno.h>
35 #ifdef HAVE_DIRENT_H
36 # include <dirent.h>
37 #endif
38 #ifdef HAVE_SYS_STAT_H
39 # include <sys/stat.h>
40 # ifdef HAVE_UNISTD_H
41 #  include <unistd.h>
42 # endif
43 #endif
44
45
46 #include "vlc_tls.h"
47 #include <vlc_charset.h>
48
49 #include <gcrypt.h>
50 #include <gnutls/gnutls.h>
51 #include <gnutls/x509.h>
52
53 #define DH_BITS             1024
54 #define CACHE_EXPIRATION    3600
55 #define CACHE_SIZE          64
56
57 /*****************************************************************************
58  * Module descriptor
59  *****************************************************************************/
60 static int  Open ( vlc_object_t * );
61 static void Close( vlc_object_t * );
62
63 #define DH_BITS_TEXT N_("Diffie-Hellman prime bits")
64 #define DH_BITS_LONGTEXT N_( \
65     "This allows you to modify the Diffie-Hellman prime's number of bits, " \
66     "used for TLS or SSL-based server-side encryption. This is generally " \
67     "not needed." )
68
69 #define CACHE_EXPIRATION_TEXT N_("Expiration time for resumed TLS sessions")
70 #define CACHE_EXPIRATION_LONGTEXT N_( \
71     "It is possible to cache the resumed TLS sessions. This is the expiration "\
72     "time of the sessions stored in this cache, in seconds." )
73
74 #define CACHE_SIZE_TEXT N_("Number of resumed TLS sessions")
75 #define CACHE_SIZE_LONGTEXT N_( \
76     "This is the maximum number of resumed TLS sessions that " \
77     "the cache will hold." )
78
79 #define CHECK_CERT_TEXT N_("Check TLS/SSL server certificate validity")
80 #define CHECK_CERT_LONGTEXT N_( \
81     "This ensures that the server certificate is valid " \
82     "(i.e. signed by an approved Certification Authority)." )
83
84 #define CHECK_HOSTNAME_TEXT N_("Check TLS/SSL server hostname in certificate")
85 #define CHECK_HOSTNAME_LONGTEXT N_( \
86     "This ensures that the server hostname in certificate matches the " \
87     "requested host name." )
88
89 vlc_module_begin();
90     set_shortname( "GnuTLS" );
91     set_description( _("GnuTLS TLS encryption layer") );
92     set_capability( "tls", 1 );
93     set_callbacks( Open, Close );
94     set_category( CAT_ADVANCED );
95     set_subcategory( SUBCAT_ADVANCED_MISC );
96
97     add_bool( "tls-check-cert", VLC_TRUE, NULL, CHECK_CERT_TEXT,
98               CHECK_CERT_LONGTEXT, VLC_FALSE );
99     add_bool( "tls-check-hostname", VLC_TRUE, NULL, CHECK_HOSTNAME_TEXT,
100               CHECK_HOSTNAME_LONGTEXT, VLC_FALSE );
101
102     add_integer( "gnutls-dh-bits", DH_BITS, NULL, DH_BITS_TEXT,
103                  DH_BITS_LONGTEXT, VLC_TRUE );
104     add_integer( "gnutls-cache-expiration", CACHE_EXPIRATION, NULL,
105                  CACHE_EXPIRATION_TEXT, CACHE_EXPIRATION_LONGTEXT, VLC_TRUE );
106     add_integer( "gnutls-cache-size", CACHE_SIZE, NULL, CACHE_SIZE_TEXT,
107                  CACHE_SIZE_LONGTEXT, VLC_TRUE );
108 vlc_module_end();
109
110
111 #define MAX_SESSION_ID    32
112 #define MAX_SESSION_DATA  1024
113
114 typedef struct saved_session_t
115 {
116     char id[MAX_SESSION_ID];
117     char data[MAX_SESSION_DATA];
118
119     unsigned i_idlen;
120     unsigned i_datalen;
121 } saved_session_t;
122
123
124 typedef struct tls_server_sys_t
125 {
126     gnutls_certificate_credentials  x509_cred;
127     gnutls_dh_params                dh_params;
128
129     struct saved_session_t          *p_cache;
130     struct saved_session_t          *p_store;
131     int                             i_cache_size;
132     vlc_mutex_t                     cache_lock;
133
134     int                             (*pf_handshake2)( tls_session_t * );
135 } tls_server_sys_t;
136
137
138 typedef struct tls_session_sys_t
139 {
140     gnutls_session  session;
141     char            *psz_hostname;
142     vlc_bool_t      b_handshaked;
143 } tls_session_sys_t;
144
145
146 typedef struct tls_client_sys_t
147 {
148     struct tls_session_sys_t       session;
149     gnutls_certificate_credentials x509_cred;
150 } tls_client_sys_t;
151
152
153 static int gnutls_Error (vlc_object_t *obj, int val)
154 {
155     switch (val)
156     {
157         case GNUTLS_E_AGAIN:
158 #if ! defined(WIN32)
159             errno = EAGAIN;
160             break;
161 #endif
162             /* WinSock does not return EAGAIN, return EINTR instead */
163
164         case GNUTLS_E_INTERRUPTED:
165 #if defined(WIN32)
166             WSASetLastError(WSAEINTR);
167 #else
168             errno = EINTR;
169 #endif
170             break;
171
172         default:
173             msg_Err (obj, "%s", gnutls_strerror (val));
174 #ifdef DEBUG
175             if (!gnutls_error_is_fatal (val))
176                 msg_Err (obj, "Error above should be handled");
177 #endif
178 #if defined(WIN32)
179             WSASetLastError(WSAECONNRESET);
180 #else
181             errno = ECONNRESET;
182 #endif
183     }
184     return -1;
185 }
186
187
188 /**
189  * Sends data through a TLS session.
190  */
191 static int
192 gnutls_Send( void *p_session, const void *buf, int i_length )
193 {
194     int val;
195     tls_session_sys_t *p_sys;
196
197     p_sys = (tls_session_sys_t *)(((tls_session_t *)p_session)->p_sys);
198
199     val = gnutls_record_send( p_sys->session, buf, i_length );
200     return (val < 0) ? gnutls_Error ((vlc_object_t *)p_session, val) : val;
201 }
202
203
204 /**
205  * Receives data through a TLS session.
206  */
207 static int
208 gnutls_Recv( void *p_session, void *buf, int i_length )
209 {
210     int val;
211     tls_session_sys_t *p_sys;
212
213     p_sys = (tls_session_sys_t *)(((tls_session_t *)p_session)->p_sys);
214
215     val = gnutls_record_recv( p_sys->session, buf, i_length );
216     return (val < 0) ? gnutls_Error ((vlc_object_t *)p_session, val) : val;
217 }
218
219
220 /*****************************************************************************
221  * tls_Session(Continue)?Handshake:
222  *****************************************************************************
223  * Establishes TLS session with a peer through socket <fd>.
224  * Returns -1 on error (you need not and must not call tls_SessionClose)
225  * 0 on succesful handshake completion, 1 if more would-be blocking recv is
226  * needed, 2 if more would-be blocking send is required.
227  *****************************************************************************/
228 static int
229 gnutls_ContinueHandshake( tls_session_t *p_session)
230 {
231     tls_session_sys_t *p_sys;
232     int val;
233
234     p_sys = (tls_session_sys_t *)(p_session->p_sys);
235
236 #ifdef WIN32
237     WSASetLastError( 0 );
238 #endif
239     val = gnutls_handshake( p_sys->session );
240     if( ( val == GNUTLS_E_AGAIN ) || ( val == GNUTLS_E_INTERRUPTED ) )
241         return 1 + gnutls_record_get_direction( p_sys->session );
242
243     if( val < 0 )
244     {
245 #ifdef WIN32
246         msg_Dbg( p_session, "Winsock error %d", WSAGetLastError( ) );
247 #endif
248         msg_Err( p_session, "TLS handshake error: %s",
249                  gnutls_strerror( val ) );
250         p_session->pf_close( p_session );
251         return -1;
252     }
253
254     p_sys->b_handshaked = VLC_TRUE;
255     return 0;
256 }
257
258
259 typedef struct
260 {
261     int flag;
262     const char *msg;
263 } error_msg_t;
264
265 static const error_msg_t cert_errors[] =
266 {
267     { GNUTLS_CERT_INVALID,
268         "Certificate could not be verified" },
269     { GNUTLS_CERT_REVOKED,
270         "Certificate was revoked" },
271     { GNUTLS_CERT_SIGNER_NOT_FOUND,
272         "Certificate's signer was not found" },
273     { GNUTLS_CERT_SIGNER_NOT_CA,
274         "Certificate's signer is not a CA" },
275     { GNUTLS_CERT_INSECURE_ALGORITHM,
276         "Insecure certificate signature algorithm" },
277     { 0, NULL }
278 };
279
280
281 static int
282 gnutls_HandshakeAndValidate( tls_session_t *session )
283 {
284     int val = gnutls_ContinueHandshake( session );
285     if( val )
286         return val;
287
288     tls_session_sys_t *p_sys = (tls_session_sys_t *)(session->p_sys);
289
290     /* certificates chain verification */
291     unsigned status;
292     val = gnutls_certificate_verify_peers2( p_sys->session, &status );
293
294     if( val )
295     {
296         msg_Err( session, "Certificate verification failed: %s",
297                  gnutls_strerror( val ) );
298         goto error;
299     }
300
301     if( status )
302     {
303         msg_Err( session, "TLS session: access denied" );
304         for( const error_msg_t *e = cert_errors; e->flag; e++ )
305         {
306             if( status & e->flag )
307             {
308                 msg_Err( session, e->msg );
309                 status &= ~e->flag;
310             }
311         }
312
313         if( status )
314             msg_Err( session,
315                      "unknown certificate error (you found a bug in VLC)" );
316
317         goto error;
318     }
319
320     /* certificate (host)name verification */
321     const gnutls_datum *data = gnutls_certificate_get_peers( p_sys->session,
322                                                              &(size_t){ 0 } );
323     if( data == NULL )
324     {
325         msg_Err( session, "Peer certificate not available" );
326         goto error;
327     }
328
329     gnutls_x509_crt cert;
330     val = gnutls_x509_crt_init( &cert );
331     if( val )
332     {
333         msg_Err( session, "x509 fatal error: %s", gnutls_strerror( val ) );
334         goto error;
335     }
336
337     val = gnutls_x509_crt_import( cert, data, GNUTLS_X509_FMT_DER );
338     if( val )
339     {
340         msg_Err( session, "Certificate import error: %s",
341                  gnutls_strerror( val ) );
342         gnutls_x509_crt_deinit( cert );
343         goto crt_error;
344     }
345
346     if( p_sys->psz_hostname != NULL )
347     {
348         if ( !gnutls_x509_crt_check_hostname( cert, p_sys->psz_hostname ) )
349         {
350             msg_Err( session, "Certificate does not match \"%s\"",
351                      p_sys->psz_hostname );
352             goto crt_error;
353         }
354     }
355     else
356         msg_Warn( session, "Certificate and hostname were not verified" );
357
358     if( gnutls_x509_crt_get_expiration_time( cert ) < time( NULL ) )
359     {
360         msg_Err( session, "Certificate expired" );
361         goto crt_error;
362     }
363
364     if( gnutls_x509_crt_get_activation_time( cert ) > time ( NULL ) )
365     {
366         msg_Err( session, "Certificate not yet valid" );
367         goto crt_error;
368     }
369
370     gnutls_x509_crt_deinit( cert );
371     msg_Dbg( session, "TLS/x509 certificate verified" );
372     return 0;
373
374 crt_error:
375     gnutls_x509_crt_deinit( cert );
376 error:
377     session->pf_close( session );
378     return -1;
379 }
380
381 /**
382  * Starts negociation of a TLS session.
383  *
384  * @param fd stream socket already connected with the peer.
385  * @param psz_hostname if not NULL, hostname to mention as a Server Name.
386  *
387  * @return -1 on error (you need not and must not call tls_SessionClose),
388  * 0 on succesful handshake completion, 1 if more would-be blocking recv is
389  * needed, 2 if more would-be blocking send is required.
390  */
391 static int
392 gnutls_BeginHandshake( tls_session_t *p_session, int fd,
393                        const char *psz_hostname )
394 {
395     tls_session_sys_t *p_sys;
396
397     p_sys = (tls_session_sys_t *)(p_session->p_sys);
398
399     gnutls_transport_set_ptr (p_sys->session, (gnutls_transport_ptr)(intptr_t)fd);
400
401     if( psz_hostname != NULL )
402     {
403         gnutls_server_name_set( p_sys->session, GNUTLS_NAME_DNS, psz_hostname,
404                                 strlen( psz_hostname ) );
405         if (var_CreateGetBool (p_session, "tls-check-hostname"))
406         {
407             p_sys->psz_hostname = strdup( psz_hostname );
408             if( p_sys->psz_hostname == NULL )
409             {
410                 p_session->pf_close( p_session );
411                 return -1;
412             }
413         }
414     }
415
416     return p_session->pf_handshake2( p_session );
417 }
418
419 /**
420  * Terminates TLS session and releases session data.
421  * You still have to close the socket yourself.
422  */
423 static void
424 gnutls_SessionClose( tls_session_t *p_session )
425 {
426     tls_session_sys_t *p_sys;
427
428     p_sys = (tls_session_sys_t *)(p_session->p_sys);
429
430     if( p_sys->b_handshaked == VLC_TRUE )
431         gnutls_bye( p_sys->session, GNUTLS_SHUT_WR );
432     gnutls_deinit( p_sys->session );
433
434     if( p_sys->psz_hostname != NULL )
435         free( p_sys->psz_hostname );
436
437     vlc_object_detach( p_session );
438     vlc_object_destroy( p_session );
439
440     free( p_sys );
441 }
442
443
444 typedef int (*tls_prio_func) (gnutls_session_t, const int *);
445
446 static int
447 gnutls_SetPriority (vlc_object_t *restrict obj, const char *restrict name,
448                     tls_prio_func func, gnutls_session_t session,
449                     const int *restrict values)
450 {
451     int val = func (session, values);
452     if (val < 0)
453     {
454         msg_Err (obj, "cannot set %s priorities: %s", name,
455                  gnutls_strerror (val));
456         return VLC_EGENERIC;
457     }
458     return VLC_SUCCESS;
459 }
460
461
462 static int
463 gnutls_SessionPrioritize (vlc_object_t *obj, gnutls_session_t session)
464 {
465     /* Note that ordering matters (on the client side) */
466     static const int protos[] =
467     {
468         GNUTLS_TLS1_1,
469         GNUTLS_TLS1_0,
470         GNUTLS_SSL3,
471         0
472     };
473     static const int comps[] =
474     {
475         GNUTLS_COMP_DEFLATE,
476         GNUTLS_COMP_NULL,
477         0
478     };
479     static const int macs[] =
480     {
481         GNUTLS_MAC_SHA1,
482         GNUTLS_MAC_RMD160, // RIPEMD
483         GNUTLS_MAC_MD5,
484         //GNUTLS_MAC_MD2,
485         //GNUTLS_MAC_NULL,
486         0
487     };
488     static const int ciphers[] =
489     {
490         GNUTLS_CIPHER_AES_256_CBC,
491         GNUTLS_CIPHER_AES_128_CBC,
492         GNUTLS_CIPHER_3DES_CBC,
493         GNUTLS_CIPHER_ARCFOUR_128,
494         //GNUTLS_CIPHER_DES_CBC,
495         //GNUTLS_CIPHER_ARCFOUR_40,
496         //GNUTLS_CIPHER_RC2_40_CBC,
497         //GNUTLS_CIPHER_NULL,
498         0
499     };
500     static const int kx[] =
501     {
502         GNUTLS_KX_DHE_RSA,
503         GNUTLS_KX_DHE_DSS,
504         GNUTLS_KX_RSA,
505         //GNUTLS_KX_RSA_EXPORT,
506         //GNUTLS_KX_DHE_PSK, TODO
507         //GNUTLS_KX_PSK,     TODO
508         //GNUTLS_KX_SRP_RSA, TODO
509         //GNUTLS_KX_SRP_DSS, TODO
510         //GNUTLS_KX_SRP,     TODO
511         //GNUTLS_KX_ANON_DH,
512         0
513     };
514     static const int cert_types[] =
515     {
516         GNUTLS_CRT_X509,
517         //GNUTLS_CRT_OPENPGP, TODO
518         0
519     };
520
521     int val = gnutls_set_default_priority (session);
522     if (val < 0)
523     {
524         msg_Err (obj, "cannot set default TLS priorities: %s",
525                  gnutls_strerror (val));
526         return VLC_EGENERIC;
527     }
528
529     if (gnutls_SetPriority (obj, "protocols",
530                             gnutls_protocol_set_priority, session, protos)
531      || gnutls_SetPriority (obj, "compression algorithms",
532                             gnutls_compression_set_priority, session, comps)
533      || gnutls_SetPriority (obj, "MAC algorithms",
534                             gnutls_mac_set_priority, session, macs)
535      || gnutls_SetPriority (obj, "ciphers",
536                             gnutls_cipher_set_priority, session, ciphers)
537      || gnutls_SetPriority (obj, "key exchange algorithms",
538                             gnutls_kx_set_priority, session, kx)
539      || gnutls_SetPriority (obj, "certificate types",
540                             gnutls_certificate_type_set_priority, session,
541                             cert_types))
542         return VLC_EGENERIC;
543
544     return VLC_SUCCESS;
545 }
546
547
548 static void
549 gnutls_ClientDelete( tls_session_t *p_session )
550 {
551     /* On the client-side, credentials are re-allocated per session */
552     gnutls_certificate_credentials x509_cred =
553                         ((tls_client_sys_t *)(p_session->p_sys))->x509_cred;
554
555     gnutls_SessionClose( p_session );
556
557     /* credentials must be free'd *after* gnutls_deinit() */
558     gnutls_certificate_free_credentials( x509_cred );
559 }
560
561
562 static int
563 gnutls_Addx509File( vlc_object_t *p_this,
564                     gnutls_certificate_credentials cred,
565                     const char *psz_path, vlc_bool_t b_priv );
566
567 static int
568 gnutls_Addx509Directory( vlc_object_t *p_this,
569                          gnutls_certificate_credentials cred,
570                          const char *psz_dirname,
571                          vlc_bool_t b_priv )
572 {
573     DIR* dir;
574
575     if( *psz_dirname == '\0' )
576         psz_dirname = ".";
577
578     dir = utf8_opendir( psz_dirname );
579     if( dir == NULL )
580     {
581         msg_Warn( p_this, "cannot open directory (%s): %s", psz_dirname,
582                   strerror( errno ) );
583         return VLC_EGENERIC;
584     }
585 #ifdef S_ISLNK
586     else
587     {
588         struct stat st1, st2;
589         int fd = dirfd( dir );
590
591         /*
592          * Gets stats for the directory path, checks that it is not a
593          * symbolic link (to avoid possibly infinite recursion), and verifies
594          * that the inode is still the same, to avoid TOCTOU race condition.
595          */
596         if( ( fd == -1)
597          || fstat( fd, &st1 ) || utf8_lstat( psz_dirname, &st2 )
598          || S_ISLNK( st2.st_mode ) || ( st1.st_ino != st2.st_ino ) )
599         {
600             closedir( dir );
601             return VLC_EGENERIC;
602         }
603     }
604 #endif
605
606     for (;;)
607     {
608         char *ent = utf8_readdir (dir);
609         if (ent == NULL)
610             break;
611
612         if ((strcmp (ent, ".") == 0) || (strcmp (ent, "..") == 0))
613             continue;
614
615         char path[strlen (psz_dirname) + strlen (ent) + 2];
616         sprintf (path, "%s"DIR_SEP"%s", psz_dirname, ent);
617         free (ent);
618
619         gnutls_Addx509File( p_this, cred, path, b_priv );
620     }
621
622     closedir( dir );
623     return VLC_SUCCESS;
624 }
625
626
627 static int
628 gnutls_Addx509File( vlc_object_t *p_this,
629                     gnutls_certificate_credentials cred,
630                     const char *psz_path, vlc_bool_t b_priv )
631 {
632     struct stat st;
633
634     if( utf8_stat( psz_path, &st ) == 0 )
635     {
636         if( S_ISREG( st.st_mode ) )
637         {
638             char *psz_localname = ToLocale( psz_path );
639             int i = b_priv
640                     ? gnutls_certificate_set_x509_key_file( cred,
641                     psz_localname,  psz_localname, GNUTLS_X509_FMT_PEM )
642                 : gnutls_certificate_set_x509_trust_file( cred,
643                         psz_localname, GNUTLS_X509_FMT_PEM );
644             LocaleFree( psz_localname );
645
646             if( i < 0 )
647             {
648                 msg_Warn( p_this, "cannot add x509 credentials (%s): %s",
649                           psz_path, gnutls_strerror( i ) );
650                 return VLC_EGENERIC;
651             }
652             else
653             {
654                 msg_Dbg( p_this, "added x509 credentials (%s)",
655                          psz_path );
656                 return VLC_SUCCESS;
657             }
658         }
659         else if( S_ISDIR( st.st_mode ) )
660         {
661             msg_Dbg( p_this,
662                      "looking recursively for x509 credentials in %s",
663                      psz_path );
664             return gnutls_Addx509Directory( p_this, cred, psz_path, b_priv);
665         }
666     }
667     else
668         msg_Warn( p_this, "cannot add x509 credentials (%s): %s",
669                   psz_path, strerror( errno ) );
670     return VLC_EGENERIC;
671 }
672
673
674 /**
675  * Initializes a client-side TLS session.
676  */
677 static tls_session_t *
678 gnutls_ClientCreate( tls_t *p_tls )
679 {
680     tls_session_t *p_session = NULL;
681     tls_client_sys_t *p_sys = NULL;
682     int i_val;
683
684     p_sys = (tls_client_sys_t *)malloc( sizeof(struct tls_client_sys_t) );
685     if( p_sys == NULL )
686         return NULL;
687
688     p_session = (struct tls_session_t *)vlc_object_create ( p_tls, sizeof(struct tls_session_t) );
689     if( p_session == NULL )
690     {
691         free( p_sys );
692         return NULL;
693     }
694
695     p_session->p_sys = p_sys;
696     p_session->sock.p_sys = p_session;
697     p_session->sock.pf_send = gnutls_Send;
698     p_session->sock.pf_recv = gnutls_Recv;
699     p_session->pf_handshake = gnutls_BeginHandshake;
700     p_session->pf_close = gnutls_ClientDelete;
701
702     p_sys->session.b_handshaked = VLC_FALSE;
703     p_sys->session.psz_hostname = NULL;
704
705     vlc_object_attach( p_session, p_tls );
706
707     const char *homedir = p_tls->p_libvlc->psz_homedir,
708                *datadir = config_GetDataDir ((vlc_object_t *)p_session);
709     size_t l1 = strlen (homedir), l2 = strlen (datadir);
710     char path[((l1 > l2) ? l1 : l2) + sizeof ("/"CONFIG_DIR"/ssl/private")];
711     //                              > sizeof ("/"CONFIG_DIR"/ssl/certs")
712     //                              > sizeof ("/ca-certificates.crt")
713
714     i_val = gnutls_certificate_allocate_credentials( &p_sys->x509_cred );
715     if( i_val != 0 )
716     {
717         msg_Err( p_tls, "cannot allocate X509 credentials: %s",
718                  gnutls_strerror( i_val ) );
719         goto error;
720     }
721
722     if (var_CreateGetBool (p_tls, "tls-check-cert"))
723     {
724         sprintf (path, "%s/"CONFIG_DIR"/ssl/certs", homedir);
725         gnutls_Addx509Directory ((vlc_object_t *)p_session,
726                                   p_sys->x509_cred, path, VLC_FALSE);
727
728         sprintf (path, "%s/ca-certificates.crt", datadir);
729         gnutls_Addx509File ((vlc_object_t *)p_session,
730                             p_sys->x509_cred, path, VLC_FALSE);
731         p_session->pf_handshake2 = gnutls_HandshakeAndValidate;
732     }
733     else
734         p_session->pf_handshake2 = gnutls_ContinueHandshake;
735
736     sprintf (path, "%s/"CONFIG_DIR"/ssl/private", homedir);
737     gnutls_Addx509Directory ((vlc_object_t *)p_session, p_sys->x509_cred,
738                              path, VLC_TRUE);
739
740     i_val = gnutls_init( &p_sys->session.session, GNUTLS_CLIENT );
741     if( i_val != 0 )
742     {
743         msg_Err( p_tls, "cannot initialize TLS session: %s",
744                  gnutls_strerror( i_val ) );
745         gnutls_certificate_free_credentials( p_sys->x509_cred );
746         goto error;
747     }
748
749     if (gnutls_SessionPrioritize (VLC_OBJECT (p_session),
750                                   p_sys->session.session))
751         goto s_error;
752
753     i_val = gnutls_credentials_set( p_sys->session.session,
754                                     GNUTLS_CRD_CERTIFICATE,
755                                     p_sys->x509_cred );
756     if( i_val < 0 )
757     {
758         msg_Err( p_tls, "cannot set TLS session credentials: %s",
759                  gnutls_strerror( i_val ) );
760         goto s_error;
761     }
762
763     return p_session;
764
765 s_error:
766     gnutls_deinit( p_sys->session.session );
767     gnutls_certificate_free_credentials( p_sys->x509_cred );
768
769 error:
770     vlc_object_detach( p_session );
771     vlc_object_destroy( p_session );
772     free( p_sys );
773
774     return NULL;
775 }
776
777
778 /**
779  * TLS session resumption callbacks (server-side)
780  */
781 static int cb_store( void *p_server, gnutls_datum key, gnutls_datum data )
782 {
783     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
784
785     if( ( p_sys->i_cache_size == 0 )
786      || ( key.size > MAX_SESSION_ID )
787      || ( data.size > MAX_SESSION_DATA ) )
788         return -1;
789
790     vlc_mutex_lock( &p_sys->cache_lock );
791
792     memcpy( p_sys->p_store->id, key.data, key.size);
793     memcpy( p_sys->p_store->data, data.data, data.size );
794     p_sys->p_store->i_idlen = key.size;
795     p_sys->p_store->i_datalen = data.size;
796
797     p_sys->p_store++;
798     if( ( p_sys->p_store - p_sys->p_cache ) == p_sys->i_cache_size )
799         p_sys->p_store = p_sys->p_cache;
800
801     vlc_mutex_unlock( &p_sys->cache_lock );
802
803     return 0;
804 }
805
806
807 static const gnutls_datum err_datum = { NULL, 0 };
808
809 static gnutls_datum cb_fetch( void *p_server, gnutls_datum key )
810 {
811     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
812     saved_session_t *p_session, *p_end;
813
814     p_session = p_sys->p_cache;
815     p_end = p_session + p_sys->i_cache_size;
816
817     vlc_mutex_lock( &p_sys->cache_lock );
818
819     while( p_session < p_end )
820     {
821         if( ( p_session->i_idlen == key.size )
822          && !memcmp( p_session->id, key.data, key.size ) )
823         {
824             gnutls_datum data;
825
826             data.size = p_session->i_datalen;
827
828             data.data = gnutls_malloc( data.size );
829             if( data.data == NULL )
830             {
831                 vlc_mutex_unlock( &p_sys->cache_lock );
832                 return err_datum;
833             }
834
835             memcpy( data.data, p_session->data, data.size );
836             vlc_mutex_unlock( &p_sys->cache_lock );
837             return data;
838         }
839         p_session++;
840     }
841
842     vlc_mutex_unlock( &p_sys->cache_lock );
843
844     return err_datum;
845 }
846
847
848 static int cb_delete( void *p_server, gnutls_datum key )
849 {
850     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
851     saved_session_t *p_session, *p_end;
852
853     p_session = p_sys->p_cache;
854     p_end = p_session + p_sys->i_cache_size;
855
856     vlc_mutex_lock( &p_sys->cache_lock );
857
858     while( p_session < p_end )
859     {
860         if( ( p_session->i_idlen == key.size )
861          && !memcmp( p_session->id, key.data, key.size ) )
862         {
863             p_session->i_datalen = p_session->i_idlen = 0;
864             vlc_mutex_unlock( &p_sys->cache_lock );
865             return 0;
866         }
867         p_session++;
868     }
869
870     vlc_mutex_unlock( &p_sys->cache_lock );
871
872     return -1;
873 }
874
875
876 /**
877  * Initializes a server-side TLS session.
878  */
879 static tls_session_t *
880 gnutls_ServerSessionPrepare( tls_server_t *p_server )
881 {
882     tls_session_t *p_session;
883     tls_server_sys_t *p_server_sys;
884     gnutls_session session;
885     int i_val;
886
887     p_session = vlc_object_create( p_server, sizeof (struct tls_session_t) );
888     if( p_session == NULL )
889         return NULL;
890
891     p_session->p_sys = malloc( sizeof(struct tls_session_sys_t) );
892     if( p_session->p_sys == NULL )
893     {
894         vlc_object_destroy( p_session );
895         return NULL;
896     }
897
898     vlc_object_attach( p_session, p_server );
899
900     p_server_sys = (tls_server_sys_t *)p_server->p_sys;
901     p_session->sock.p_sys = p_session;
902     p_session->sock.pf_send = gnutls_Send;
903     p_session->sock.pf_recv = gnutls_Recv;
904     p_session->pf_handshake = gnutls_BeginHandshake;
905     p_session->pf_handshake2 = p_server_sys->pf_handshake2;
906     p_session->pf_close = gnutls_SessionClose;
907
908     ((tls_session_sys_t *)p_session->p_sys)->b_handshaked = VLC_FALSE;
909     ((tls_session_sys_t *)p_session->p_sys)->psz_hostname = NULL;
910
911     i_val = gnutls_init( &session, GNUTLS_SERVER );
912     if( i_val != 0 )
913     {
914         msg_Err( p_server, "cannot initialize TLS session: %s",
915                  gnutls_strerror( i_val ) );
916         goto error;
917     }
918
919     ((tls_session_sys_t *)p_session->p_sys)->session = session;
920
921     if (gnutls_SessionPrioritize (VLC_OBJECT (p_session), session))
922     {
923         gnutls_deinit( session );
924         goto error;
925     }
926
927     i_val = gnutls_credentials_set( session, GNUTLS_CRD_CERTIFICATE,
928                                     p_server_sys->x509_cred );
929     if( i_val < 0 )
930     {
931         msg_Err( p_server, "cannot set TLS session credentials: %s",
932                  gnutls_strerror( i_val ) );
933         gnutls_deinit( session );
934         goto error;
935     }
936
937     if( p_session->pf_handshake2 == gnutls_HandshakeAndValidate )
938         gnutls_certificate_server_set_request( session, GNUTLS_CERT_REQUIRE );
939
940     i_val = config_GetInt (p_server, "gnutls-dh-bits");
941     gnutls_dh_set_prime_bits (session, i_val);
942
943     /* Session resumption support */
944     i_val = config_GetInt (p_server, "gnutls-cache-expiration");
945     gnutls_db_set_cache_expiration (session, i_val);
946     gnutls_db_set_retrieve_function( session, cb_fetch );
947     gnutls_db_set_remove_function( session, cb_delete );
948     gnutls_db_set_store_function( session, cb_store );
949     gnutls_db_set_ptr( session, p_server );
950
951     return p_session;
952
953 error:
954     free( p_session->p_sys );
955     vlc_object_detach( p_session );
956     vlc_object_destroy( p_session );
957     return NULL;
958 }
959
960
961 /**
962  * Releases data allocated with tls_ServerCreate().
963  */
964 static void
965 gnutls_ServerDelete( tls_server_t *p_server )
966 {
967     tls_server_sys_t *p_sys;
968     p_sys = (tls_server_sys_t *)p_server->p_sys;
969
970     vlc_mutex_destroy( &p_sys->cache_lock );
971     free( p_sys->p_cache );
972
973     vlc_object_detach( p_server );
974     vlc_object_destroy( p_server );
975
976     /* all sessions depending on the server are now deinitialized */
977     gnutls_certificate_free_credentials( p_sys->x509_cred );
978     gnutls_dh_params_deinit( p_sys->dh_params );
979     free( p_sys );
980 }
981
982
983 /**
984  * Adds one or more certificate authorities.
985  *
986  * @param psz_ca_path (Unicode) path to an x509 certificates list.
987  *
988  * @return -1 on error, 0 on success.
989  *****************************************************************************/
990 static int
991 gnutls_ServerAddCA( tls_server_t *p_server, const char *psz_ca_path )
992 {
993     tls_server_sys_t *p_sys;
994     char *psz_local_path;
995     int val;
996
997     p_sys = (tls_server_sys_t *)(p_server->p_sys);
998
999     psz_local_path = ToLocale( psz_ca_path );
1000     val = gnutls_certificate_set_x509_trust_file( p_sys->x509_cred,
1001                                                   psz_local_path,
1002                                                   GNUTLS_X509_FMT_PEM );
1003     LocaleFree( psz_local_path );
1004     if( val < 0 )
1005     {
1006         msg_Err( p_server, "cannot add trusted CA (%s): %s", psz_ca_path,
1007                  gnutls_strerror( val ) );
1008         return VLC_EGENERIC;
1009     }
1010     msg_Dbg( p_server, " %d trusted CA added (%s)", val, psz_ca_path );
1011
1012     /* enables peer's certificate verification */
1013     p_sys->pf_handshake2 = gnutls_HandshakeAndValidate;
1014
1015     return VLC_SUCCESS;
1016 }
1017
1018
1019 /**
1020  * Adds a certificates revocation list to be sent to TLS clients.
1021  *
1022  * @param psz_crl_path (Unicode) path of the CRL file.
1023  *
1024  * @return -1 on error, 0 on success.
1025  */
1026 static int
1027 gnutls_ServerAddCRL( tls_server_t *p_server, const char *psz_crl_path )
1028 {
1029     int val;
1030     char *psz_local_path = ToLocale( psz_crl_path );
1031
1032     val = gnutls_certificate_set_x509_crl_file( ((tls_server_sys_t *)
1033                                                 (p_server->p_sys))->x509_cred,
1034                                                 psz_local_path,
1035                                                 GNUTLS_X509_FMT_PEM );
1036     LocaleFree( psz_crl_path );
1037     if( val < 0 )
1038     {
1039         msg_Err( p_server, "cannot add CRL (%s): %s", psz_crl_path,
1040                  gnutls_strerror( val ) );
1041         return VLC_EGENERIC;
1042     }
1043     msg_Dbg( p_server, "%d CRL added (%s)", val, psz_crl_path );
1044     return VLC_SUCCESS;
1045 }
1046
1047
1048 /**
1049  * Allocates a whole server's TLS credentials.
1050  *
1051  * @return NULL on error.
1052  */
1053 static tls_server_t *
1054 gnutls_ServerCreate( tls_t *p_tls, const char *psz_cert_path,
1055                      const char *psz_key_path )
1056 {
1057     tls_server_t *p_server;
1058     tls_server_sys_t *p_sys;
1059     char *psz_local_key, *psz_local_cert;
1060     int val;
1061
1062     msg_Dbg( p_tls, "creating TLS server" );
1063
1064     p_sys = (tls_server_sys_t *)malloc( sizeof(struct tls_server_sys_t) );
1065     if( p_sys == NULL )
1066         return NULL;
1067
1068     p_sys->i_cache_size = config_GetInt (p_tls, "gnutls-cache-size");
1069     p_sys->p_cache = (struct saved_session_t *)calloc( p_sys->i_cache_size,
1070                                            sizeof( struct saved_session_t ) );
1071     if( p_sys->p_cache == NULL )
1072     {
1073         free( p_sys );
1074         return NULL;
1075     }
1076     p_sys->p_store = p_sys->p_cache;
1077
1078     p_server = vlc_object_create( p_tls, sizeof(struct tls_server_t) );
1079     if( p_server == NULL )
1080     {
1081         free( p_sys->p_cache );
1082         free( p_sys );
1083         return NULL;
1084     }
1085
1086     vlc_object_attach( p_server, p_tls );
1087
1088     p_server->p_sys = p_sys;
1089     p_server->pf_delete = gnutls_ServerDelete;
1090     p_server->pf_add_CA = gnutls_ServerAddCA;
1091     p_server->pf_add_CRL = gnutls_ServerAddCRL;
1092     p_server->pf_session_prepare = gnutls_ServerSessionPrepare;
1093
1094     /* No certificate validation by default */
1095     p_sys->pf_handshake2 = gnutls_ContinueHandshake;
1096
1097     vlc_mutex_init( p_server, &p_sys->cache_lock );
1098
1099     /* Sets server's credentials */
1100     val = gnutls_certificate_allocate_credentials( &p_sys->x509_cred );
1101     if( val != 0 )
1102     {
1103         msg_Err( p_server, "cannot allocate X509 credentials: %s",
1104                  gnutls_strerror( val ) );
1105         goto error;
1106     }
1107
1108     psz_local_cert = ToLocale( psz_cert_path );
1109     psz_local_key = ToLocale( psz_key_path );
1110     val = gnutls_certificate_set_x509_key_file( p_sys->x509_cred,
1111                                                 psz_local_cert, psz_local_key,
1112                                                 GNUTLS_X509_FMT_PEM );
1113     LocaleFree( psz_cert_path );
1114     LocaleFree( psz_key_path );
1115     if( val < 0 )
1116     {
1117         msg_Err( p_server, "cannot set certificate chain or private key: %s",
1118                  gnutls_strerror( val ) );
1119         gnutls_certificate_free_credentials( p_sys->x509_cred );
1120         goto error;
1121     }
1122
1123     /* FIXME:
1124      * - regenerate these regularly
1125      * - support other ciper suites
1126      */
1127     val = gnutls_dh_params_init( &p_sys->dh_params );
1128     if( val >= 0 )
1129     {
1130         msg_Dbg( p_server, "computing Diffie Hellman ciphers parameters" );
1131         val = gnutls_dh_params_generate2( p_sys->dh_params,
1132                                           config_GetInt( p_tls, "gnutls-dh-bits" ) );
1133     }
1134     if( val < 0 )
1135     {
1136         msg_Err( p_server, "cannot initialize DH cipher suites: %s",
1137                  gnutls_strerror( val ) );
1138         gnutls_certificate_free_credentials( p_sys->x509_cred );
1139         goto error;
1140     }
1141     msg_Dbg( p_server, "ciphers parameters computed" );
1142
1143     gnutls_certificate_set_dh_params( p_sys->x509_cred, p_sys->dh_params);
1144
1145     return p_server;
1146
1147 error:
1148     vlc_mutex_destroy( &p_sys->cache_lock );
1149     vlc_object_detach( p_server );
1150     vlc_object_destroy( p_server );
1151     free( p_sys );
1152     return NULL;
1153 }
1154
1155
1156 #ifdef LIBVLC_USE_PTHREAD
1157 GCRY_THREAD_OPTION_PTHREAD_IMPL;
1158 # define gcry_threads_vlc gcry_threads_pthread
1159 #else
1160 /**
1161  * gcrypt thread option VLC implementation
1162  */
1163
1164 # define NEED_THREAD_CONTEXT 1
1165 static vlc_object_t *__p_gcry_data;
1166
1167 static int gcry_vlc_mutex_init( void **p_sys )
1168 {
1169     int i_val;
1170     vlc_mutex_t *p_lock = (vlc_mutex_t *)malloc( sizeof( vlc_mutex_t ) );
1171
1172     if( p_lock == NULL)
1173         return ENOMEM;
1174
1175     i_val = vlc_mutex_init( __p_gcry_data, p_lock );
1176     if( i_val )
1177         free( p_lock );
1178     else
1179         *p_sys = p_lock;
1180     return i_val;
1181 }
1182
1183 static int gcry_vlc_mutex_destroy( void **p_sys )
1184 {
1185     int i_val;
1186     vlc_mutex_t *p_lock = (vlc_mutex_t *)*p_sys;
1187
1188     i_val = vlc_mutex_destroy( p_lock );
1189     free( p_lock );
1190     return i_val;
1191 }
1192
1193 static int gcry_vlc_mutex_lock( void **p_sys )
1194 {
1195     return vlc_mutex_lock( (vlc_mutex_t *)*p_sys );
1196 }
1197
1198 static int gcry_vlc_mutex_unlock( void **lock )
1199 {
1200     return vlc_mutex_unlock( (vlc_mutex_t *)*lock );
1201 }
1202
1203 static struct gcry_thread_cbs gcry_threads_vlc =
1204 {
1205     GCRY_THREAD_OPTION_USER,
1206     NULL,
1207     gcry_vlc_mutex_init,
1208     gcry_vlc_mutex_destroy,
1209     gcry_vlc_mutex_lock,
1210     gcry_vlc_mutex_unlock
1211 };
1212 #endif
1213
1214
1215 /*****************************************************************************
1216  * Module initialization
1217  *****************************************************************************/
1218 static int
1219 Open( vlc_object_t *p_this )
1220 {
1221     tls_t *p_tls = (tls_t *)p_this;
1222
1223     vlc_value_t lock, count;
1224
1225     var_Create( p_this->p_libvlc_global, "gnutls_mutex", VLC_VAR_MUTEX );
1226     var_Get( p_this->p_libvlc_global, "gnutls_mutex", &lock );
1227     vlc_mutex_lock( lock.p_address );
1228
1229     /* Initialize GnuTLS only once */
1230     var_Create( p_this->p_libvlc_global, "gnutls_count", VLC_VAR_INTEGER );
1231     var_Get( p_this->p_libvlc_global, "gnutls_count", &count);
1232
1233     if( count.i_int == 0)
1234     {
1235 #ifdef NEED_THREAD_CONTEXT
1236         __p_gcry_data = VLC_OBJECT( p_this->p_libvlc );
1237 #endif
1238
1239         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_vlc);
1240         if( gnutls_global_init( ) )
1241         {
1242             msg_Warn( p_this, "cannot initialize GnuTLS" );
1243             vlc_mutex_unlock( lock.p_address );
1244             return VLC_EGENERIC;
1245         }
1246
1247         const char *psz_version = gnutls_check_version( "1.2.9" );
1248         if( psz_version == NULL )
1249         {
1250             gnutls_global_deinit( );
1251             vlc_mutex_unlock( lock.p_address );
1252             msg_Err( p_this, "unsupported GnuTLS version" );
1253             return VLC_EGENERIC;
1254         }
1255         msg_Dbg( p_this, "GnuTLS v%s initialized", psz_version );
1256     }
1257
1258     count.i_int++;
1259     var_Set( p_this->p_libvlc_global, "gnutls_count", count);
1260     vlc_mutex_unlock( lock.p_address );
1261
1262     p_tls->pf_server_create = gnutls_ServerCreate;
1263     p_tls->pf_client_create = gnutls_ClientCreate;
1264     return VLC_SUCCESS;
1265 }
1266
1267
1268 /*****************************************************************************
1269  * Module deinitialization
1270  *****************************************************************************/
1271 static void
1272 Close( vlc_object_t *p_this )
1273 {
1274     /*tls_t *p_tls = (tls_t *)p_this;
1275     tls_sys_t *p_sys = (tls_sys_t *)(p_this->p_sys);*/
1276
1277     vlc_value_t lock, count;
1278
1279     var_Create( p_this->p_libvlc_global, "gnutls_mutex", VLC_VAR_MUTEX );
1280     var_Get( p_this->p_libvlc_global, "gnutls_mutex", &lock );
1281     vlc_mutex_lock( lock.p_address );
1282
1283     var_Create( p_this->p_libvlc_global, "gnutls_count", VLC_VAR_INTEGER );
1284     var_Get( p_this->p_libvlc_global, "gnutls_count", &count);
1285     count.i_int--;
1286     var_Set( p_this->p_libvlc_global, "gnutls_count", count);
1287
1288     if( count.i_int == 0 )
1289     {
1290         gnutls_global_deinit( );
1291         msg_Dbg( p_this, "GnuTLS deinitialized" );
1292     }
1293
1294     vlc_mutex_unlock( lock.p_address );
1295 }