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