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_obsolete_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  *                     and to be found in the server's certificate.
 379  *
 380  * @return -1 on error (you need not and must not call tls_SessionClose),
 381  * 0 on succesful handshake completion, 1 if more would-be blocking recv is
 382  * needed, 2 if more would-be blocking send is required.
 383  */
 384 static int
 385 gnutls_BeginHandshake( tls_session_t *p_session, int fd,
 386                        const char *psz_hostname )
 387 {
 388     tls_session_sys_t *p_sys;
 389
 390     p_sys = (tls_session_sys_t *)(p_session->p_sys);
 391
 392     gnutls_transport_set_ptr (p_sys->session, (gnutls_transport_ptr)(intptr_t)fd);
 393
 394     if( psz_hostname != NULL )
 395     {
 396         gnutls_server_name_set (p_sys->session, GNUTLS_NAME_DNS, psz_hostname,
 397                                 strlen (psz_hostname));
 398         p_sys->psz_hostname = strdup (psz_hostname);
 399         if (p_sys->psz_hostname == NULL)
 400         {
 401             p_session->pf_close (p_session);
 402             return -1;
 403         }
 404     }
 405
 406     return p_session->pf_handshake2( p_session );
 407 }
 408
 409 /**
 410  * Terminates TLS session and releases session data.
 411  * You still have to close the socket yourself.
 412  */
 413 static void
 414 gnutls_SessionClose( tls_session_t *p_session )
 415 {
 416     tls_session_sys_t *p_sys;
 417
 418     p_sys = (tls_session_sys_t *)(p_session->p_sys);
 419
 420     if( p_sys->b_handshaked == VLC_TRUE )
 421         gnutls_bye( p_sys->session, GNUTLS_SHUT_WR );
 422     gnutls_deinit( p_sys->session );
 423
 424     if( p_sys->psz_hostname != NULL )
 425         free( p_sys->psz_hostname );
 426
 427     vlc_object_detach( p_session );
 428     vlc_object_destroy( p_session );
 429
 430     free( p_sys );
 431 }
 432
 433
 434 typedef int (*tls_prio_func) (gnutls_session_t, const int *);
 435
 436 static int
 437 gnutls_SetPriority (vlc_object_t *restrict obj, const char *restrict name,
 438                     tls_prio_func func, gnutls_session_t session,
 439                     const int *restrict values)
 440 {
 441     int val = func (session, values);
 442     if (val < 0)
 443     {
 444         msg_Err (obj, "cannot set %s priorities: %s", name,
 445                  gnutls_strerror (val));
 446         return VLC_EGENERIC;
 447     }
 448     return VLC_SUCCESS;
 449 }
 450
 451
 452 static int
 453 gnutls_SessionPrioritize (vlc_object_t *obj, gnutls_session_t session)
 454 {
 455     /* Note that ordering matters (on the client side) */
 456     static const int protos[] =
 457     {
 458         GNUTLS_TLS1_1,
 459         GNUTLS_TLS1_0,
 460         GNUTLS_SSL3,
 461         0
 462     };
 463     static const int comps[] =
 464     {
 465         GNUTLS_COMP_DEFLATE,
 466         GNUTLS_COMP_NULL,
 467         0
 468     };
 469     static const int macs[] =
 470     {
 471         GNUTLS_MAC_SHA1,
 472         GNUTLS_MAC_RMD160, // RIPEMD
 473         GNUTLS_MAC_MD5,
 474         //GNUTLS_MAC_MD2,
 475         //GNUTLS_MAC_NULL,
 476         0
 477     };
 478     static const int ciphers[] =
 479     {
 480         GNUTLS_CIPHER_AES_256_CBC,
 481         GNUTLS_CIPHER_AES_128_CBC,
 482         GNUTLS_CIPHER_3DES_CBC,
 483         GNUTLS_CIPHER_ARCFOUR_128,
 484         //GNUTLS_CIPHER_DES_CBC,
 485         //GNUTLS_CIPHER_ARCFOUR_40,
 486         //GNUTLS_CIPHER_RC2_40_CBC,
 487         //GNUTLS_CIPHER_NULL,
 488         0
 489     };
 490     static const int kx[] =
 491     {
 492         GNUTLS_KX_DHE_RSA,
 493         GNUTLS_KX_DHE_DSS,
 494         GNUTLS_KX_RSA,
 495         //GNUTLS_KX_RSA_EXPORT,
 496         //GNUTLS_KX_DHE_PSK, TODO
 497         //GNUTLS_KX_PSK,     TODO
 498         //GNUTLS_KX_SRP_RSA, TODO
 499         //GNUTLS_KX_SRP_DSS, TODO
 500         //GNUTLS_KX_SRP,     TODO
 501         //GNUTLS_KX_ANON_DH,
 502         0
 503     };
 504     static const int cert_types[] =
 505     {
 506         GNUTLS_CRT_X509,
 507         //GNUTLS_CRT_OPENPGP, TODO
 508         0
 509     };
 510
 511     int val = gnutls_set_default_priority (session);
 512     if (val < 0)
 513     {
 514         msg_Err (obj, "cannot set default TLS priorities: %s",
 515                  gnutls_strerror (val));
 516         return VLC_EGENERIC;
 517     }
 518
 519     if (gnutls_SetPriority (obj, "protocols",
 520                             gnutls_protocol_set_priority, session, protos)
 521      || gnutls_SetPriority (obj, "compression algorithms",
 522                             gnutls_compression_set_priority, session, comps)
 523      || gnutls_SetPriority (obj, "MAC algorithms",
 524                             gnutls_mac_set_priority, session, macs)
 525      || gnutls_SetPriority (obj, "ciphers",
 526                             gnutls_cipher_set_priority, session, ciphers)
 527      || gnutls_SetPriority (obj, "key exchange algorithms",
 528                             gnutls_kx_set_priority, session, kx)
 529      || gnutls_SetPriority (obj, "certificate types",
 530                             gnutls_certificate_type_set_priority, session,
 531                             cert_types))
 532         return VLC_EGENERIC;
 533
 534     return VLC_SUCCESS;
 535 }
 536
 537
 538 static void
 539 gnutls_ClientDelete( tls_session_t *p_session )
 540 {
 541     /* On the client-side, credentials are re-allocated per session */
 542     gnutls_certificate_credentials x509_cred =
 543                         ((tls_client_sys_t *)(p_session->p_sys))->x509_cred;
 544
 545     gnutls_SessionClose( p_session );
 546
 547     /* credentials must be free'd *after* gnutls_deinit() */
 548     gnutls_certificate_free_credentials( x509_cred );
 549 }
 550
 551
 552 static int
 553 gnutls_Addx509File( vlc_object_t *p_this,
 554                     gnutls_certificate_credentials cred,
 555                     const char *psz_path, vlc_bool_t b_priv );
 556
 557 static int
 558 gnutls_Addx509Directory( vlc_object_t *p_this,
 559                          gnutls_certificate_credentials cred,
 560                          const char *psz_dirname,
 561                          vlc_bool_t b_priv )
 562 {
 563     DIR* dir;
 564
 565     if( *psz_dirname == '\0' )
 566         psz_dirname = ".";
 567
 568     dir = utf8_opendir( psz_dirname );
 569     if( dir == NULL )
 570     {
 571         msg_Warn( p_this, "cannot open directory (%s): %m", psz_dirname );
 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): %m", psz_path );
 658     return VLC_EGENERIC;
 659 }
 660
 661
 662 /**
 663  * Initializes a client-side TLS session.
 664  */
 665 static tls_session_t *
 666 gnutls_ClientCreate( tls_t *p_tls )
 667 {
 668     tls_session_t *p_session = NULL;
 669     tls_client_sys_t *p_sys = NULL;
 670     int i_val;
 671
 672     p_sys = (tls_client_sys_t *)malloc( sizeof(struct tls_client_sys_t) );
 673     if( p_sys == NULL )
 674         return NULL;
 675
 676     p_session = (struct tls_session_t *)vlc_object_create ( p_tls, sizeof(struct tls_session_t) );
 677     if( p_session == NULL )
 678     {
 679         free( p_sys );
 680         return NULL;
 681     }
 682
 683     p_session->p_sys = p_sys;
 684     p_session->sock.p_sys = p_session;
 685     p_session->sock.pf_send = gnutls_Send;
 686     p_session->sock.pf_recv = gnutls_Recv;
 687     p_session->pf_handshake = gnutls_BeginHandshake;
 688     p_session->pf_close = gnutls_ClientDelete;
 689
 690     p_sys->session.b_handshaked = VLC_FALSE;
 691     p_sys->session.psz_hostname = NULL;
 692
 693     vlc_object_attach( p_session, p_tls );
 694
 695     const char *homedir = p_tls->p_libvlc->psz_datadir,
 696                *datadir = config_GetDataDir ();
 697     size_t l1 = strlen (homedir), l2 = strlen (datadir);
 698     char path[((l1 > l2) ? l1 : l2) + sizeof ("/ssl/private")];
 699     //                              > sizeof ("/ssl/certs")
 700     //                              > sizeof ("/ca-certificates.crt")
 701
 702     i_val = gnutls_certificate_allocate_credentials( &p_sys->x509_cred );
 703     if( i_val != 0 )
 704     {
 705         msg_Err( p_tls, "cannot allocate X509 credentials: %s",
 706                  gnutls_strerror( i_val ) );
 707         goto error;
 708     }
 709
 710     if (var_CreateGetBool (p_tls, "tls-check-cert"))
 711     {
 712         sprintf (path, "%s/ssl/certs", homedir);
 713         gnutls_Addx509Directory ((vlc_object_t *)p_session,
 714                                   p_sys->x509_cred, path, VLC_FALSE);
 715
 716         sprintf (path, "%s/ca-certificates.crt", datadir);
 717         gnutls_Addx509File ((vlc_object_t *)p_session,
 718                             p_sys->x509_cred, path, VLC_FALSE);
 719         p_session->pf_handshake2 = gnutls_HandshakeAndValidate;
 720     }
 721     else
 722         p_session->pf_handshake2 = gnutls_ContinueHandshake;
 723
 724     sprintf (path, "%s/ssl/private", homedir);
 725     gnutls_Addx509Directory ((vlc_object_t *)p_session, p_sys->x509_cred,
 726                              path, VLC_TRUE);
 727
 728     i_val = gnutls_init( &p_sys->session.session, GNUTLS_CLIENT );
 729     if( i_val != 0 )
 730     {
 731         msg_Err( p_tls, "cannot initialize TLS session: %s",
 732                  gnutls_strerror( i_val ) );
 733         gnutls_certificate_free_credentials( p_sys->x509_cred );
 734         goto error;
 735     }
 736
 737     if (gnutls_SessionPrioritize (VLC_OBJECT (p_session),
 738                                   p_sys->session.session))
 739         goto s_error;
 740
 741     i_val = gnutls_credentials_set( p_sys->session.session,
 742                                     GNUTLS_CRD_CERTIFICATE,
 743                                     p_sys->x509_cred );
 744     if( i_val < 0 )
 745     {
 746         msg_Err( p_tls, "cannot set TLS session credentials: %s",
 747                  gnutls_strerror( i_val ) );
 748         goto s_error;
 749     }
 750
 751     return p_session;
 752
 753 s_error:
 754     gnutls_deinit( p_sys->session.session );
 755     gnutls_certificate_free_credentials( p_sys->x509_cred );
 756
 757 error:
 758     vlc_object_detach( p_session );
 759     vlc_object_destroy( p_session );
 760     free( p_sys );
 761
 762     return NULL;
 763 }
 764
 765
 766 /**
 767  * TLS session resumption callbacks (server-side)
 768  */
 769 static int cb_store( void *p_server, gnutls_datum key, gnutls_datum data )
 770 {
 771     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
 772
 773     if( ( p_sys->i_cache_size == 0 )
 774      || ( key.size > MAX_SESSION_ID )
 775      || ( data.size > MAX_SESSION_DATA ) )
 776         return -1;
 777
 778     vlc_mutex_lock( &p_sys->cache_lock );
 779
 780     memcpy( p_sys->p_store->id, key.data, key.size);
 781     memcpy( p_sys->p_store->data, data.data, data.size );
 782     p_sys->p_store->i_idlen = key.size;
 783     p_sys->p_store->i_datalen = data.size;
 784
 785     p_sys->p_store++;
 786     if( ( p_sys->p_store - p_sys->p_cache ) == p_sys->i_cache_size )
 787         p_sys->p_store = p_sys->p_cache;
 788
 789     vlc_mutex_unlock( &p_sys->cache_lock );
 790
 791     return 0;
 792 }
 793
 794
 795 static const gnutls_datum err_datum = { NULL, 0 };
 796
 797 static gnutls_datum cb_fetch( void *p_server, gnutls_datum key )
 798 {
 799     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
 800     saved_session_t *p_session, *p_end;
 801
 802     p_session = p_sys->p_cache;
 803     p_end = p_session + p_sys->i_cache_size;
 804
 805     vlc_mutex_lock( &p_sys->cache_lock );
 806
 807     while( p_session < p_end )
 808     {
 809         if( ( p_session->i_idlen == key.size )
 810          && !memcmp( p_session->id, key.data, key.size ) )
 811         {
 812             gnutls_datum data;
 813
 814             data.size = p_session->i_datalen;
 815
 816             data.data = gnutls_malloc( data.size );
 817             if( data.data == NULL )
 818             {
 819                 vlc_mutex_unlock( &p_sys->cache_lock );
 820                 return err_datum;
 821             }
 822
 823             memcpy( data.data, p_session->data, data.size );
 824             vlc_mutex_unlock( &p_sys->cache_lock );
 825             return data;
 826         }
 827         p_session++;
 828     }
 829
 830     vlc_mutex_unlock( &p_sys->cache_lock );
 831
 832     return err_datum;
 833 }
 834
 835
 836 static int cb_delete( void *p_server, gnutls_datum key )
 837 {
 838     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
 839     saved_session_t *p_session, *p_end;
 840
 841     p_session = p_sys->p_cache;
 842     p_end = p_session + p_sys->i_cache_size;
 843
 844     vlc_mutex_lock( &p_sys->cache_lock );
 845
 846     while( p_session < p_end )
 847     {
 848         if( ( p_session->i_idlen == key.size )
 849          && !memcmp( p_session->id, key.data, key.size ) )
 850         {
 851             p_session->i_datalen = p_session->i_idlen = 0;
 852             vlc_mutex_unlock( &p_sys->cache_lock );
 853             return 0;
 854         }
 855         p_session++;
 856     }
 857
 858     vlc_mutex_unlock( &p_sys->cache_lock );
 859
 860     return -1;
 861 }
 862
 863
 864 /**
 865  * Initializes a server-side TLS session.
 866  */
 867 static tls_session_t *
 868 gnutls_ServerSessionPrepare( tls_server_t *p_server )
 869 {
 870     tls_session_t *p_session;
 871     tls_server_sys_t *p_server_sys;
 872     gnutls_session session;
 873     int i_val;
 874
 875     p_session = vlc_object_create( p_server, sizeof (struct tls_session_t) );
 876     if( p_session == NULL )
 877         return NULL;
 878
 879     p_session->p_sys = malloc( sizeof(struct tls_session_sys_t) );
 880     if( p_session->p_sys == NULL )
 881     {
 882         vlc_object_destroy( p_session );
 883         return NULL;
 884     }
 885
 886     vlc_object_attach( p_session, p_server );
 887
 888     p_server_sys = (tls_server_sys_t *)p_server->p_sys;
 889     p_session->sock.p_sys = p_session;
 890     p_session->sock.pf_send = gnutls_Send;
 891     p_session->sock.pf_recv = gnutls_Recv;
 892     p_session->pf_handshake = gnutls_BeginHandshake;
 893     p_session->pf_handshake2 = p_server_sys->pf_handshake2;
 894     p_session->pf_close = gnutls_SessionClose;
 895
 896     ((tls_session_sys_t *)p_session->p_sys)->b_handshaked = VLC_FALSE;
 897     ((tls_session_sys_t *)p_session->p_sys)->psz_hostname = NULL;
 898
 899     i_val = gnutls_init( &session, GNUTLS_SERVER );
 900     if( i_val != 0 )
 901     {
 902         msg_Err( p_server, "cannot initialize TLS session: %s",
 903                  gnutls_strerror( i_val ) );
 904         goto error;
 905     }
 906
 907     ((tls_session_sys_t *)p_session->p_sys)->session = session;
 908
 909     if (gnutls_SessionPrioritize (VLC_OBJECT (p_session), session))
 910     {
 911         gnutls_deinit( session );
 912         goto error;
 913     }
 914
 915     i_val = gnutls_credentials_set( session, GNUTLS_CRD_CERTIFICATE,
 916                                     p_server_sys->x509_cred );
 917     if( i_val < 0 )
 918     {
 919         msg_Err( p_server, "cannot set TLS session credentials: %s",
 920                  gnutls_strerror( i_val ) );
 921         gnutls_deinit( session );
 922         goto error;
 923     }
 924
 925     if( p_session->pf_handshake2 == gnutls_HandshakeAndValidate )
 926         gnutls_certificate_server_set_request( session, GNUTLS_CERT_REQUIRE );
 927
 928     i_val = config_GetInt (p_server, "gnutls-dh-bits");
 929     gnutls_dh_set_prime_bits (session, i_val);
 930
 931     /* Session resumption support */
 932     i_val = config_GetInt (p_server, "gnutls-cache-expiration");
 933     gnutls_db_set_cache_expiration (session, i_val);
 934     gnutls_db_set_retrieve_function( session, cb_fetch );
 935     gnutls_db_set_remove_function( session, cb_delete );
 936     gnutls_db_set_store_function( session, cb_store );
 937     gnutls_db_set_ptr( session, p_server );
 938
 939     return p_session;
 940
 941 error:
 942     free( p_session->p_sys );
 943     vlc_object_detach( p_session );
 944     vlc_object_destroy( p_session );
 945     return NULL;
 946 }
 947
 948
 949 /**
 950  * Releases data allocated with tls_ServerCreate().
 951  */
 952 static void
 953 gnutls_ServerDelete( tls_server_t *p_server )
 954 {
 955     tls_server_sys_t *p_sys;
 956     p_sys = (tls_server_sys_t *)p_server->p_sys;
 957
 958     vlc_mutex_destroy( &p_sys->cache_lock );
 959     free( p_sys->p_cache );
 960
 961     vlc_object_detach( p_server );
 962     vlc_object_destroy( p_server );
 963
 964     /* all sessions depending on the server are now deinitialized */
 965     gnutls_certificate_free_credentials( p_sys->x509_cred );
 966     gnutls_dh_params_deinit( p_sys->dh_params );
 967     free( p_sys );
 968 }
 969
 970
 971 /**
 972  * Adds one or more certificate authorities.
 973  *
 974  * @param psz_ca_path (Unicode) path to an x509 certificates list.
 975  *
 976  * @return -1 on error, 0 on success.
 977  *****************************************************************************/
 978 static int
 979 gnutls_ServerAddCA( tls_server_t *p_server, const char *psz_ca_path )
 980 {
 981     tls_server_sys_t *p_sys;
 982     char *psz_local_path;
 983     int val;
 984
 985     p_sys = (tls_server_sys_t *)(p_server->p_sys);
 986
 987     psz_local_path = ToLocale( psz_ca_path );
 988     val = gnutls_certificate_set_x509_trust_file( p_sys->x509_cred,
 989                                                   psz_local_path,
 990                                                   GNUTLS_X509_FMT_PEM );
 991     LocaleFree( psz_local_path );
 992     if( val < 0 )
 993     {
 994         msg_Err( p_server, "cannot add trusted CA (%s): %s", psz_ca_path,
 995                  gnutls_strerror( val ) );
 996         return VLC_EGENERIC;
 997     }
 998     msg_Dbg( p_server, " %d trusted CA added (%s)", val, psz_ca_path );
 999
1000     /* enables peer's certificate verification */
1001     p_sys->pf_handshake2 = gnutls_HandshakeAndValidate;
1002
1003     return VLC_SUCCESS;
1004 }
1005
1006
1007 /**
1008  * Adds a certificates revocation list to be sent to TLS clients.
1009  *
1010  * @param psz_crl_path (Unicode) path of the CRL file.
1011  *
1012  * @return -1 on error, 0 on success.
1013  */
1014 static int
1015 gnutls_ServerAddCRL( tls_server_t *p_server, const char *psz_crl_path )
1016 {
1017     int val;
1018     char *psz_local_path = ToLocale( psz_crl_path );
1019
1020     val = gnutls_certificate_set_x509_crl_file( ((tls_server_sys_t *)
1021                                                 (p_server->p_sys))->x509_cred,
1022                                                 psz_local_path,
1023                                                 GNUTLS_X509_FMT_PEM );
1024     LocaleFree( psz_crl_path );
1025     if( val < 0 )
1026     {
1027         msg_Err( p_server, "cannot add CRL (%s): %s", psz_crl_path,
1028                  gnutls_strerror( val ) );
1029         return VLC_EGENERIC;
1030     }
1031     msg_Dbg( p_server, "%d CRL added (%s)", val, psz_crl_path );
1032     return VLC_SUCCESS;
1033 }
1034
1035
1036 /**
1037  * Allocates a whole server's TLS credentials.
1038  *
1039  * @return NULL on error.
1040  */
1041 static tls_server_t *
1042 gnutls_ServerCreate( tls_t *p_tls, const char *psz_cert_path,
1043                      const char *psz_key_path )
1044 {
1045     tls_server_t *p_server;
1046     tls_server_sys_t *p_sys;
1047     char *psz_local_key, *psz_local_cert;
1048     int val;
1049
1050     msg_Dbg( p_tls, "creating TLS server" );
1051
1052     p_sys = (tls_server_sys_t *)malloc( sizeof(struct tls_server_sys_t) );
1053     if( p_sys == NULL )
1054         return NULL;
1055
1056     p_sys->i_cache_size = config_GetInt (p_tls, "gnutls-cache-size");
1057     p_sys->p_cache = (struct saved_session_t *)calloc( p_sys->i_cache_size,
1058                                            sizeof( struct saved_session_t ) );
1059     if( p_sys->p_cache == NULL )
1060     {
1061         free( p_sys );
1062         return NULL;
1063     }
1064     p_sys->p_store = p_sys->p_cache;
1065
1066     p_server = vlc_object_create( p_tls, sizeof(struct tls_server_t) );
1067     if( p_server == NULL )
1068     {
1069         free( p_sys->p_cache );
1070         free( p_sys );
1071         return NULL;
1072     }
1073
1074     vlc_object_attach( p_server, p_tls );
1075
1076     p_server->p_sys = p_sys;
1077     p_server->pf_delete = gnutls_ServerDelete;
1078     p_server->pf_add_CA = gnutls_ServerAddCA;
1079     p_server->pf_add_CRL = gnutls_ServerAddCRL;
1080     p_server->pf_session_prepare = gnutls_ServerSessionPrepare;
1081
1082     /* No certificate validation by default */
1083     p_sys->pf_handshake2 = gnutls_ContinueHandshake;
1084
1085     vlc_mutex_init( p_server, &p_sys->cache_lock );
1086
1087     /* Sets server's credentials */
1088     val = gnutls_certificate_allocate_credentials( &p_sys->x509_cred );
1089     if( val != 0 )
1090     {
1091         msg_Err( p_server, "cannot allocate X509 credentials: %s",
1092                  gnutls_strerror( val ) );
1093         goto error;
1094     }
1095
1096     psz_local_cert = ToLocale( psz_cert_path );
1097     psz_local_key = ToLocale( psz_key_path );
1098     val = gnutls_certificate_set_x509_key_file( p_sys->x509_cred,
1099                                                 psz_local_cert, psz_local_key,
1100                                                 GNUTLS_X509_FMT_PEM );
1101     LocaleFree( psz_cert_path );
1102     LocaleFree( psz_key_path );
1103     if( val < 0 )
1104     {
1105         msg_Err( p_server, "cannot set certificate chain or private key: %s",
1106                  gnutls_strerror( val ) );
1107         gnutls_certificate_free_credentials( p_sys->x509_cred );
1108         goto error;
1109     }
1110
1111     /* FIXME:
1112      * - regenerate these regularly
1113      * - support other ciper suites
1114      */
1115     val = gnutls_dh_params_init( &p_sys->dh_params );
1116     if( val >= 0 )
1117     {
1118         msg_Dbg( p_server, "computing Diffie Hellman ciphers parameters" );
1119         val = gnutls_dh_params_generate2( p_sys->dh_params,
1120                                           config_GetInt( p_tls, "gnutls-dh-bits" ) );
1121     }
1122     if( val < 0 )
1123     {
1124         msg_Err( p_server, "cannot initialize DH cipher suites: %s",
1125                  gnutls_strerror( val ) );
1126         gnutls_certificate_free_credentials( p_sys->x509_cred );
1127         goto error;
1128     }
1129     msg_Dbg( p_server, "ciphers parameters computed" );
1130
1131     gnutls_certificate_set_dh_params( p_sys->x509_cred, p_sys->dh_params);
1132
1133     return p_server;
1134
1135 error:
1136     vlc_mutex_destroy( &p_sys->cache_lock );
1137     vlc_object_detach( p_server );
1138     vlc_object_destroy( p_server );
1139     free( p_sys );
1140     return NULL;
1141 }
1142
1143
1144 #ifdef LIBVLC_USE_PTHREAD
1145 GCRY_THREAD_OPTION_PTHREAD_IMPL;
1146 # define gcry_threads_vlc gcry_threads_pthread
1147 #else
1148 /**
1149  * gcrypt thread option VLC implementation
1150  */
1151
1152 # define NEED_THREAD_CONTEXT 1
1153 static vlc_object_t *__p_gcry_data;
1154
1155 static int gcry_vlc_mutex_init( void **p_sys )
1156 {
1157     int i_val;
1158     vlc_mutex_t *p_lock = (vlc_mutex_t *)malloc( sizeof( vlc_mutex_t ) );
1159
1160     if( p_lock == NULL)
1161         return ENOMEM;
1162
1163     i_val = vlc_mutex_init( __p_gcry_data, p_lock );
1164     if( i_val )
1165         free( p_lock );
1166     else
1167         *p_sys = p_lock;
1168     return i_val;
1169 }
1170
1171 static int gcry_vlc_mutex_destroy( void **p_sys )
1172 {
1173     int i_val;
1174     vlc_mutex_t *p_lock = (vlc_mutex_t *)*p_sys;
1175
1176     i_val = vlc_mutex_destroy( p_lock );
1177     free( p_lock );
1178     return i_val;
1179 }
1180
1181 static int gcry_vlc_mutex_lock( void **p_sys )
1182 {
1183     return vlc_mutex_lock( (vlc_mutex_t *)*p_sys );
1184 }
1185
1186 static int gcry_vlc_mutex_unlock( void **lock )
1187 {
1188     return vlc_mutex_unlock( (vlc_mutex_t *)*lock );
1189 }
1190
1191 static struct gcry_thread_cbs gcry_threads_vlc =
1192 {
1193     GCRY_THREAD_OPTION_USER,
1194     NULL,
1195     gcry_vlc_mutex_init,
1196     gcry_vlc_mutex_destroy,
1197     gcry_vlc_mutex_lock,
1198     gcry_vlc_mutex_unlock
1199 };
1200 #endif
1201
1202
1203 /*****************************************************************************
1204  * Module initialization
1205  *****************************************************************************/
1206 static unsigned refs = 0;
1207
1208 static int
1209 Open( vlc_object_t *p_this )
1210 {
1211     tls_t *p_tls = (tls_t *)p_this;
1212     vlc_mutex_t *lock;
1213
1214     lock = var_GetGlobalMutex( "gnutls_mutex" );
1215     vlc_mutex_lock( lock );
1216
1217     /* Initialize GnuTLS only once */
1218     if( refs == 0 )
1219     {
1220 #ifdef NEED_THREAD_CONTEXT
1221         __p_gcry_data = VLC_OBJECT( p_this->p_libvlc );
1222 #endif
1223
1224         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_vlc);
1225         if( gnutls_global_init( ) )
1226         {
1227             msg_Warn( p_this, "cannot initialize GnuTLS" );
1228             vlc_mutex_unlock( lock );
1229             return VLC_EGENERIC;
1230         }
1231
1232         const char *psz_version = gnutls_check_version( "1.2.9" );
1233         if( psz_version == NULL )
1234         {
1235             gnutls_global_deinit( );
1236             vlc_mutex_unlock( lock );
1237             msg_Err( p_this, "unsupported GnuTLS version" );
1238             return VLC_EGENERIC;
1239         }
1240         msg_Dbg( p_this, "GnuTLS v%s initialized", psz_version );
1241     }
1242
1243     refs++;
1244     vlc_mutex_unlock( lock );
1245
1246     p_tls->pf_server_create = gnutls_ServerCreate;
1247     p_tls->pf_client_create = gnutls_ClientCreate;
1248     return VLC_SUCCESS;
1249 }
1250
1251
1252 /*****************************************************************************
1253  * Module deinitialization
1254  *****************************************************************************/
1255 static void
1256 Close( vlc_object_t *p_this )
1257 {
1258     /*tls_t *p_tls = (tls_t *)p_this;
1259     tls_sys_t *p_sys = (tls_sys_t *)(p_this->p_sys);*/
1260
1261     vlc_mutex_t *lock;
1262
1263     lock = var_GetGlobalMutex( "gnutls_mutex" );
1264     vlc_mutex_lock( lock );
1265
1266     if( --refs == 0 )
1267     {
1268         gnutls_global_deinit( );
1269         msg_Dbg( p_this, "GnuTLS deinitialized" );
1270     }
1271
1272     vlc_mutex_unlock( lock );
1273 }