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  * TODO:
  26  * - fix FIXMEs
  27  */
  28
  29
  30 /*****************************************************************************
  31  * Preamble
  32  *****************************************************************************/
  33 #include <stdlib.h>
  34 #include <errno.h>
  35 #include <vlc/vlc.h>
  36
  37 #include <sys/types.h>
  38 #include <errno.h>
  39 #ifdef HAVE_DIRENT_H
  40 # include <dirent.h>
  41 #endif
  42 #ifdef HAVE_SYS_STAT_H
  43 # include <sys/stat.h>
  44 # ifdef HAVE_UNISTD_H
  45 #  include <unistd.h>
  46 # endif
  47 #endif
  48
  49
  50 #include "vlc_tls.h"
  51 #include "charset.h"
  52
  53 #include <gcrypt.h>
  54 #include <gnutls/gnutls.h>
  55 #include <gnutls/x509.h>
  56
  57 #define DH_BITS             1024
  58 #define CACHE_EXPIRATION    3600
  59 #define CACHE_SIZE          64
  60
  61 /*****************************************************************************
  62  * Module descriptor
  63  *****************************************************************************/
  64 static int  Open ( vlc_object_t * );
  65 static void Close( vlc_object_t * );
  66
  67 #define DH_BITS_TEXT N_("Diffie-Hellman prime bits")
  68 #define DH_BITS_LONGTEXT N_( \
  69     "Allows you to modify the Diffie-Hellman prime's number of bits " \
  70     "(used for TLS or SSL-based server-side encryption)." )
  71
  72 #define CACHE_EXPIRATION_TEXT N_("Expiration time for resumed TLS sessions")
  73 #define CACHE_EXPIRATION_LONGTEXT N_( \
  74     "Defines the delay before resumed TLS sessions will be expired " \
  75     "(in seconds)." )
  76
  77 #define CACHE_SIZE_TEXT N_("Number of resumed TLS sessions")
  78 #define CACHE_SIZE_LONGTEXT N_( \
  79     "Allows you to modify the maximum number of resumed TLS sessions that " \
  80     "the cache will hold." )
  81
  82 #define CHECK_CERT_TEXT N_("Check TLS/SSL server certificate validity")
  83 #define CHECK_CERT_LONGTEXT N_( \
  84     "Ensures that server certificate is valid " \
  85     "(i.e. signed by an approved Certificate Authority)." )
  86
  87 #define CHECK_HOSTNAME_TEXT N_("Check TLS/SSL server hostname in certificate")
  88 #define CHECK_HOSTNAME_LONGTEXT N_( \
  89     "Ensures that server hostname in certificate match requested host name." )
  90
  91 #if defined (WIN32) || defined (UNDER_CE)
  92 # undef HOST_CA_PATH
  93 #else
  94 # define HOST_CA_PATH "/etc/ssl/certs/ca-certificates.crt"
  95 #endif
  96
  97 vlc_module_begin();
  98     set_shortname( "GnuTLS" );
  99     set_description( _("GnuTLS TLS encryption layer") );
 100     set_capability( "tls", 1 );
 101     set_callbacks( Open, Close );
 102     set_category( CAT_ADVANCED );
 103     set_subcategory( SUBCAT_ADVANCED_MISC );
 104
 105     add_bool( "tls-check-cert", VLC_TRUE, NULL, CHECK_CERT_TEXT,
 106               CHECK_CERT_LONGTEXT, VLC_FALSE );
 107     add_bool( "tls-check-hostname", VLC_TRUE, NULL, CHECK_HOSTNAME_TEXT,
 108               CHECK_HOSTNAME_LONGTEXT, VLC_FALSE );
 109
 110     add_integer( "gnutls-dh-bits", DH_BITS, NULL, DH_BITS_TEXT,
 111                  DH_BITS_LONGTEXT, VLC_TRUE );
 112     add_integer( "gnutls-cache-expiration", CACHE_EXPIRATION, NULL,
 113                  CACHE_EXPIRATION_TEXT, CACHE_EXPIRATION_LONGTEXT, VLC_TRUE );
 114     add_integer( "gnutls-cache-size", CACHE_SIZE, NULL, CACHE_SIZE_TEXT,
 115                  CACHE_SIZE_LONGTEXT, VLC_TRUE );
 116 vlc_module_end();
 117
 118
 119 #define MAX_SESSION_ID    32
 120 #define MAX_SESSION_DATA  1024
 121
 122 typedef struct saved_session_t
 123 {
 124     char id[MAX_SESSION_ID];
 125     char data[MAX_SESSION_DATA];
 126
 127     unsigned i_idlen;
 128     unsigned i_datalen;
 129 } saved_session_t;
 130
 131
 132 typedef struct tls_server_sys_t
 133 {
 134     gnutls_certificate_credentials  x509_cred;
 135     gnutls_dh_params                dh_params;
 136
 137     struct saved_session_t          *p_cache;
 138     struct saved_session_t          *p_store;
 139     int                             i_cache_size;
 140     vlc_mutex_t                     cache_lock;
 141
 142     int                             (*pf_handshake2)( tls_session_t * );
 143 } tls_server_sys_t;
 144
 145
 146 typedef struct tls_session_sys_t
 147 {
 148     gnutls_session  session;
 149     char            *psz_hostname;
 150     vlc_bool_t      b_handshaked;
 151 } tls_session_sys_t;
 152
 153
 154 typedef struct tls_client_sys_t
 155 {
 156     struct tls_session_sys_t       session;
 157     gnutls_certificate_credentials x509_cred;
 158 } tls_client_sys_t;
 159
 160
 161 static int
 162 _get_Int( vlc_object_t *p_this, const char *var )
 163 {
 164     vlc_value_t value;
 165
 166     if( var_Get( p_this, var, &value ) != VLC_SUCCESS )
 167     {
 168         var_Create( p_this, var, VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
 169         var_Get( p_this, var, &value );
 170     }
 171
 172     return value.i_int;
 173 }
 174
 175 static int
 176 _get_Bool( vlc_object_t *p_this, const char *var )
 177 {
 178     vlc_value_t value;
 179
 180     if( var_Get( p_this, var, &value ) != VLC_SUCCESS )
 181     {
 182         var_Create( p_this, var, VLC_VAR_BOOL | VLC_VAR_DOINHERIT );
 183         var_Get( p_this, var, &value );
 184     }
 185
 186     return value.b_bool;
 187 }
 188
 189 #define get_Int( a, b ) _get_Int( (vlc_object_t *)(a), (b) )
 190 #define get_Bool( a, b ) _get_Bool( (vlc_object_t *)(a), (b) )
 191
 192
 193 /*****************************************************************************
 194  * tls_Send:
 195  *****************************************************************************
 196  * Sends data through a TLS session.
 197  *****************************************************************************/
 198 static int
 199 gnutls_Send( void *p_session, const void *buf, int i_length )
 200 {
 201     int val;
 202     tls_session_sys_t *p_sys;
 203
 204     p_sys = (tls_session_sys_t *)(((tls_session_t *)p_session)->p_sys);
 205
 206     val = gnutls_record_send( p_sys->session, buf, i_length );
 207     /* TODO: handle fatal error */
 208     return val < 0 ? -1 : val;
 209 }
 210
 211
 212 /*****************************************************************************
 213  * tls_Recv:
 214  *****************************************************************************
 215  * Receives data through a TLS session.
 216  *****************************************************************************/
 217 static int
 218 gnutls_Recv( void *p_session, void *buf, int i_length )
 219 {
 220     int val;
 221     tls_session_sys_t *p_sys;
 222
 223     p_sys = (tls_session_sys_t *)(((tls_session_t *)p_session)->p_sys);
 224
 225     val = gnutls_record_recv( p_sys->session, buf, i_length );
 226     /* TODO: handle fatal error */
 227     return val < 0 ? -1 : val;
 228 }
 229
 230
 231 /*****************************************************************************
 232  * tls_Session(Continue)?Handshake:
 233  *****************************************************************************
 234  * Establishes TLS session with a peer through socket <fd>.
 235  * Returns -1 on error (you need not and must not call tls_SessionClose)
 236  * 0 on succesful handshake completion, 1 if more would-be blocking recv is
 237  * needed, 2 if more would-be blocking send is required.
 238  *****************************************************************************/
 239 static int
 240 gnutls_ContinueHandshake( tls_session_t *p_session)
 241 {
 242     tls_session_sys_t *p_sys;
 243     int val;
 244
 245     p_sys = (tls_session_sys_t *)(p_session->p_sys);
 246
 247      /* TODO: handle fatal error */
 248     val = gnutls_handshake( p_sys->session );
 249     if( ( val == GNUTLS_E_AGAIN ) || ( val == GNUTLS_E_INTERRUPTED ) )
 250         return 1 + gnutls_record_get_direction( p_sys->session );
 251
 252     if( val < 0 )
 253     {
 254         msg_Err( p_session, "TLS handshake failed: %s",
 255                  gnutls_strerror( val ) );
 256         p_session->pf_close( p_session );
 257         return -1;
 258     }
 259
 260     p_sys->b_handshaked = VLC_TRUE;
 261     return 0;
 262 }
 263
 264 static int
 265 gnutls_VerifyHostname( vlc_object_t *p_this, gnutls_session session,
 266                        const char *psz_hostname )
 267 {
 268     const gnutls_datum *p_data;
 269     gnutls_x509_crt cert;
 270     unsigned status;
 271     int val;
 272
 273     /* certificate (host)name verification */
 274     p_data = gnutls_certificate_get_peers( session, &status );
 275     if( p_data == NULL )
 276     {
 277         msg_Err( p_this, "TLS peer certificate not available" );
 278         return -1;
 279     }
 280
 281     val = gnutls_x509_crt_init( &cert );
 282     if( val )
 283     {
 284         msg_Err( p_this, "x509 fatal error: %s", gnutls_strerror( val ) );
 285         return -1;
 286     }
 287
 288     val = gnutls_x509_crt_import( cert, p_data, GNUTLS_X509_FMT_DER );
 289     if( val )
 290     {
 291         msg_Err( p_this, "x509 certificate import error: %s",
 292                 gnutls_strerror( val ) );
 293         gnutls_x509_crt_deinit( cert );
 294         return -1;
 295     }
 296
 297     if( gnutls_x509_crt_check_hostname( cert, psz_hostname ) == 0 )
 298     {
 299         msg_Err( p_this, "x509 certificate does not match \"%s\"",
 300                 psz_hostname );
 301         gnutls_x509_crt_deinit( cert );
 302         return -1;
 303     }
 304
 305     gnutls_x509_crt_deinit( cert );
 306     msg_Dbg( p_this, "x509 hostname matches %s", psz_hostname );
 307     return 0;
 308 }
 309
 310 static int
 311 gnutls_HandshakeAndValidate( tls_session_t *p_session )
 312 {
 313     int val;
 314
 315     val = gnutls_ContinueHandshake( p_session );
 316     if( val == 0 )
 317     {
 318         unsigned status;
 319         tls_session_sys_t *p_sys;
 320
 321         p_sys = (tls_session_sys_t *)(p_session->p_sys);
 322         /* certificates chain verification */
 323         val = gnutls_certificate_verify_peers2( p_sys->session, &status );
 324
 325         if( val )
 326         {
 327             msg_Err( p_session, "TLS certificate verification failed: %s",
 328                      gnutls_strerror( val ) );
 329             p_session->pf_close( p_session );
 330             return -1;
 331         }
 332
 333         if( status )
 334         {
 335             msg_Warn( p_session, "TLS session: access denied" );
 336             if( status & GNUTLS_CERT_INVALID )
 337                 msg_Dbg( p_session, "certificate could not be verified" );
 338             if( status & GNUTLS_CERT_REVOKED )
 339                 msg_Dbg( p_session, "certificate was revoked" );
 340             if( status & GNUTLS_CERT_SIGNER_NOT_FOUND )
 341                 msg_Dbg( p_session, "certificate's signer was not found" );
 342             if( status & GNUTLS_CERT_SIGNER_NOT_CA )
 343                 msg_Dbg( p_session, "certificate's signer is not a CA" );
 344             p_session->pf_close( p_session );
 345             return -1;
 346         }
 347
 348         msg_Dbg( p_session, "TLS certificate verified" );
 349         if( ( p_sys->psz_hostname != NULL )
 350          && gnutls_VerifyHostname( (vlc_object_t *)p_session, p_sys->session,
 351                                    p_sys->psz_hostname ) )
 352         {
 353             p_session->pf_close( p_session );
 354             return -1;
 355         }
 356         return 0;
 357     }
 358
 359     return val;
 360 }
 361
 362 static int
 363 gnutls_BeginHandshake( tls_session_t *p_session, int fd,
 364                          const char *psz_hostname )
 365 {
 366     tls_session_sys_t *p_sys;
 367
 368     p_sys = (tls_session_sys_t *)(p_session->p_sys);
 369
 370     gnutls_transport_set_ptr (p_sys->session, (gnutls_transport_ptr)(intptr_t)fd);
 371
 372     if( psz_hostname != NULL )
 373     {
 374         gnutls_server_name_set( p_sys->session, GNUTLS_NAME_DNS, psz_hostname,
 375                                 strlen( psz_hostname ) );
 376         if( get_Bool( p_session, "tls-check-hostname" ) )
 377         {
 378             p_sys->psz_hostname = strdup( psz_hostname );
 379             if( p_sys->psz_hostname == NULL )
 380             {
 381                 p_session->pf_close( p_session );
 382                 return -1;
 383             }
 384         }
 385     }
 386
 387     return p_session->pf_handshake2( p_session );
 388 }
 389
 390 /*****************************************************************************
 391  * tls_SessionClose:
 392  *****************************************************************************
 393  * Terminates TLS session and releases session data.
 394  *****************************************************************************/
 395 static void
 396 gnutls_SessionClose( tls_session_t *p_session )
 397 {
 398     tls_session_sys_t *p_sys;
 399
 400     p_sys = (tls_session_sys_t *)(p_session->p_sys);
 401
 402     if( p_sys->b_handshaked == VLC_TRUE )
 403         gnutls_bye( p_sys->session, GNUTLS_SHUT_WR );
 404     gnutls_deinit( p_sys->session );
 405
 406     if( p_sys->psz_hostname != NULL )
 407         free( p_sys->psz_hostname );
 408
 409     vlc_object_detach( p_session );
 410     vlc_object_destroy( p_session );
 411
 412     free( p_sys );
 413 }
 414
 415 static void
 416 gnutls_ClientDelete( tls_session_t *p_session )
 417 {
 418     /* On the client-side, credentials are re-allocated per session */
 419     gnutls_certificate_credentials x509_cred =
 420                         ((tls_client_sys_t *)(p_session->p_sys))->x509_cred;
 421
 422     gnutls_SessionClose( p_session );
 423
 424     /* credentials must be free'd *after* gnutls_deinit() */
 425     gnutls_certificate_free_credentials( x509_cred );
 426 }
 427
 428
 429 static int
 430 gnutls_Addx509File( vlc_object_t *p_this,
 431                     gnutls_certificate_credentials cred,
 432                     const char *psz_path, vlc_bool_t b_priv );
 433
 434 static int
 435 gnutls_Addx509Directory( vlc_object_t *p_this,
 436                          gnutls_certificate_credentials cred,
 437                          const char *psz_dirname,
 438                          vlc_bool_t b_priv )
 439 {
 440     DIR* dir;
 441     const char *psz_dirent;
 442
 443     if( *psz_dirname == '\0' )
 444         psz_dirname = ".";
 445
 446     dir = utf8_opendir( psz_dirname );
 447     if( dir == NULL )
 448     {
 449         msg_Warn( p_this, "Cannot open directory (%s): %s", psz_dirname,
 450                   strerror( errno ) );
 451         return VLC_EGENERIC;
 452     }
 453 #ifdef S_ISLNK
 454     else
 455     {
 456         struct stat st1, st2;
 457         int fd = dirfd( dir );
 458
 459         /*
 460          * Gets stats for the directory path, checks that it is not a
 461          * symbolic link (to avoid possibly infinite recursion), and verifies
 462          * that the inode is still the same, to avoid TOCTOU race condition.
 463          */
 464         if( ( fd == -1)
 465          || fstat( fd, &st1 ) || utf8_lstat( psz_dirname, &st2 )
 466          || S_ISLNK( st2.st_mode ) || ( st1.st_ino != st2.st_ino ) )
 467         {
 468             closedir( dir );
 469             return VLC_EGENERIC;
 470         }
 471     }
 472 #endif
 473
 474     while( ( psz_dirent = utf8_readdir( dir ) ) != NULL )
 475     {
 476         char *psz_filename;
 477         int check;
 478
 479         if( ( strcmp( ".", psz_dirent ) == 0 )
 480          || ( strcmp( "..", psz_dirent ) == 0 ) )
 481             continue;
 482
 483         check = asprintf( &psz_filename, "%s/%s", psz_dirname,
 484                               psz_dirent );
 485         LocaleFree( psz_dirent );
 486         if( check == -1 )
 487             continue;
 488
 489         gnutls_Addx509File( p_this, cred, psz_filename, b_priv );
 490         free( psz_filename );
 491     }
 492
 493     closedir( dir );
 494     return VLC_SUCCESS;
 495 }
 496
 497
 498 static int
 499 gnutls_Addx509File( vlc_object_t *p_this,
 500                     gnutls_certificate_credentials cred,
 501                     const char *psz_path, vlc_bool_t b_priv )
 502 {
 503     struct stat st;
 504
 505     if( utf8_stat( psz_path, &st ) == 0 )
 506     {
 507         if( S_ISREG( st.st_mode ) )
 508         {
 509             char *psz_localname = ToLocale( psz_path );
 510             int i = b_priv
 511                     ? gnutls_certificate_set_x509_key_file( cred,
 512                     psz_localname,  psz_localname, GNUTLS_X509_FMT_PEM )
 513                 : gnutls_certificate_set_x509_trust_file( cred,
 514                         psz_localname, GNUTLS_X509_FMT_PEM );
 515             LocaleFree( psz_localname );
 516
 517             if( i < 0 )
 518             {
 519                 msg_Warn( p_this, "Cannot add x509 credentials (%s): %s",
 520                           psz_path, gnutls_strerror( i ) );
 521                 return VLC_EGENERIC;
 522             }
 523             else
 524             {
 525                 msg_Dbg( p_this, "Added x509 credentials (%s)",
 526                          psz_path );
 527                 return VLC_SUCCESS;
 528             }
 529         }
 530         else if( S_ISDIR( st.st_mode ) )
 531         {
 532             msg_Dbg( p_this,
 533                      "Looking recursively for x509 credentials in %s",
 534                      psz_path );
 535             return gnutls_Addx509Directory( p_this, cred, psz_path, b_priv);
 536         }
 537     }
 538     return VLC_EGENERIC;
 539 }
 540
 541
 542 /*****************************************************************************
 543  * tls_ClientCreate:
 544  *****************************************************************************
 545  * Initializes client-side TLS session data.
 546  *****************************************************************************/
 547 static tls_session_t *
 548 gnutls_ClientCreate( tls_t *p_tls )
 549 {
 550     tls_session_t *p_session = NULL;
 551     tls_client_sys_t *p_sys = NULL;
 552     int i_val;
 553     const int cert_type_priority[3] =
 554     {
 555         GNUTLS_CRT_X509,
 556         0
 557     };
 558
 559     p_sys = (tls_client_sys_t *)malloc( sizeof(struct tls_client_sys_t) );
 560     if( p_sys == NULL )
 561         return NULL;
 562
 563     p_session = (struct tls_session_t *)vlc_object_create ( p_tls, sizeof(struct tls_session_t) );
 564     if( p_session == NULL )
 565     {
 566         free( p_sys );
 567         return NULL;
 568     }
 569
 570     p_session->p_sys = p_sys;
 571     p_session->sock.p_sys = p_session;
 572     p_session->sock.pf_send = gnutls_Send;
 573     p_session->sock.pf_recv = gnutls_Recv;
 574     p_session->pf_handshake = gnutls_BeginHandshake;
 575     p_session->pf_close = gnutls_ClientDelete;
 576
 577     p_sys->session.b_handshaked = VLC_FALSE;
 578     p_sys->session.psz_hostname = NULL;
 579
 580     vlc_object_attach( p_session, p_tls );
 581
 582     i_val = gnutls_certificate_allocate_credentials( &p_sys->x509_cred );
 583     if( i_val != 0 )
 584     {
 585         msg_Err( p_tls, "Cannot allocate X509 credentials: %s",
 586                  gnutls_strerror( i_val ) );
 587         goto error;
 588     }
 589
 590     if( get_Bool( p_tls, "tls-check-cert" ) )
 591     {
 592         char *psz_path;
 593
 594         if( asprintf( &psz_path, "%s/"CONFIG_DIR"/ssl/certs",
 595                       p_tls->p_vlc->psz_homedir ) == -1 )
 596         {
 597             gnutls_certificate_free_credentials( p_sys->x509_cred );
 598             goto error;
 599         }
 600
 601         gnutls_Addx509Directory( (vlc_object_t *)p_session, p_sys->x509_cred,
 602                                  psz_path, VLC_FALSE );
 603 #ifdef HOST_CA_PATH
 604         gnutls_Addx509File( (vlc_object_t *)p_session, p_sys->x509_cred,
 605                             HOST_CA_PATH, VLC_FALSE );
 606 #endif
 607
 608         free( psz_path );
 609         p_session->pf_handshake2 = gnutls_HandshakeAndValidate;
 610     }
 611     else
 612         p_session->pf_handshake2 = gnutls_ContinueHandshake;
 613
 614     {
 615         char *psz_path;
 616
 617         if( asprintf( &psz_path, "%s/"CONFIG_DIR"/ssl/private",
 618                       p_tls->p_vlc->psz_homedir ) == -1 )
 619         {
 620             gnutls_certificate_free_credentials( p_sys->x509_cred );
 621             goto error;
 622         }
 623
 624         gnutls_Addx509Directory( (vlc_object_t *)p_session, p_sys->x509_cred,
 625                                  psz_path, VLC_TRUE );
 626
 627         free( psz_path );
 628     }
 629
 630     i_val = gnutls_init( &p_sys->session.session, GNUTLS_CLIENT );
 631     if( i_val != 0 )
 632     {
 633         msg_Err( p_tls, "Cannot initialize TLS session: %s",
 634                  gnutls_strerror( i_val ) );
 635         gnutls_certificate_free_credentials( p_sys->x509_cred );
 636         goto error;
 637     }
 638
 639     i_val = gnutls_set_default_priority( p_sys->session.session );
 640     if( i_val < 0 )
 641     {
 642         msg_Err( p_tls, "Cannot set ciphers priorities: %s",
 643                  gnutls_strerror( i_val ) );
 644         gnutls_deinit( p_sys->session.session );
 645         gnutls_certificate_free_credentials( p_sys->x509_cred );
 646         goto error;
 647     }
 648
 649     i_val = gnutls_certificate_type_set_priority( p_sys->session.session,
 650                                                   cert_type_priority );
 651     if( i_val < 0 )
 652     {
 653         msg_Err( p_tls, "Cannot set certificate type priorities: %s",
 654                  gnutls_strerror( i_val ) );
 655         gnutls_deinit( p_sys->session.session );
 656         gnutls_certificate_free_credentials( p_sys->x509_cred );
 657         goto error;
 658     }
 659
 660     i_val = gnutls_credentials_set( p_sys->session.session,
 661                                     GNUTLS_CRD_CERTIFICATE,
 662                                     p_sys->x509_cred );
 663     if( i_val < 0 )
 664     {
 665         msg_Err( p_tls, "Cannot set TLS session credentials: %s",
 666                  gnutls_strerror( i_val ) );
 667         gnutls_deinit( p_sys->session.session );
 668         gnutls_certificate_free_credentials( p_sys->x509_cred );
 669         goto error;
 670     }
 671
 672     return p_session;
 673
 674 error:
 675     vlc_object_detach( p_session );
 676     vlc_object_destroy( p_session );
 677     free( p_sys );
 678
 679     return NULL;
 680 }
 681
 682
 683 /*****************************************************************************
 684  * TLS session resumption callbacks
 685  *****************************************************************************/
 686 static int cb_store( void *p_server, gnutls_datum key, gnutls_datum data )
 687 {
 688     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
 689
 690     if( ( p_sys->i_cache_size == 0 )
 691      || ( key.size > MAX_SESSION_ID )
 692      || ( data.size > MAX_SESSION_DATA ) )
 693         return -1;
 694
 695     vlc_mutex_lock( &p_sys->cache_lock );
 696
 697     memcpy( p_sys->p_store->id, key.data, key.size);
 698     memcpy( p_sys->p_store->data, data.data, data.size );
 699     p_sys->p_store->i_idlen = key.size;
 700     p_sys->p_store->i_datalen = data.size;
 701
 702     p_sys->p_store++;
 703     if( ( p_sys->p_store - p_sys->p_cache ) == p_sys->i_cache_size )
 704         p_sys->p_store = p_sys->p_cache;
 705
 706     vlc_mutex_unlock( &p_sys->cache_lock );
 707
 708     return 0;
 709 }
 710
 711
 712 static const gnutls_datum err_datum = { NULL, 0 };
 713
 714 static gnutls_datum cb_fetch( void *p_server, gnutls_datum key )
 715 {
 716     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
 717     saved_session_t *p_session, *p_end;
 718
 719     p_session = p_sys->p_cache;
 720     p_end = p_session + p_sys->i_cache_size;
 721
 722     vlc_mutex_lock( &p_sys->cache_lock );
 723
 724     while( p_session < p_end )
 725     {
 726         if( ( p_session->i_idlen == key.size )
 727          && !memcmp( p_session->id, key.data, key.size ) )
 728         {
 729             gnutls_datum data;
 730
 731             data.size = p_session->i_datalen;
 732
 733             data.data = gnutls_malloc( data.size );
 734             if( data.data == NULL )
 735             {
 736                 vlc_mutex_unlock( &p_sys->cache_lock );
 737                 return err_datum;
 738             }
 739
 740             memcpy( data.data, p_session->data, data.size );
 741             vlc_mutex_unlock( &p_sys->cache_lock );
 742             return data;
 743         }
 744         p_session++;
 745     }
 746
 747     vlc_mutex_unlock( &p_sys->cache_lock );
 748
 749     return err_datum;
 750 }
 751
 752
 753 static int cb_delete( void *p_server, gnutls_datum key )
 754 {
 755     tls_server_sys_t *p_sys = ((tls_server_t *)p_server)->p_sys;
 756     saved_session_t *p_session, *p_end;
 757
 758     p_session = p_sys->p_cache;
 759     p_end = p_session + p_sys->i_cache_size;
 760
 761     vlc_mutex_lock( &p_sys->cache_lock );
 762
 763     while( p_session < p_end )
 764     {
 765         if( ( p_session->i_idlen == key.size )
 766          && !memcmp( p_session->id, key.data, key.size ) )
 767         {
 768             p_session->i_datalen = p_session->i_idlen = 0;
 769             vlc_mutex_unlock( &p_sys->cache_lock );
 770             return 0;
 771         }
 772         p_session++;
 773     }
 774
 775     vlc_mutex_unlock( &p_sys->cache_lock );
 776
 777     return -1;
 778 }
 779
 780
 781 /*****************************************************************************
 782  * tls_ServerSessionPrepare:
 783  *****************************************************************************
 784  * Initializes server-side TLS session data.
 785  *****************************************************************************/
 786 static tls_session_t *
 787 gnutls_ServerSessionPrepare( tls_server_t *p_server )
 788 {
 789     tls_session_t *p_session;
 790     tls_server_sys_t *p_server_sys;
 791     gnutls_session session;
 792     int i_val;
 793
 794     p_session = vlc_object_create( p_server, sizeof (struct tls_session_t) );
 795     if( p_session == NULL )
 796         return NULL;
 797
 798     p_session->p_sys = malloc( sizeof(struct tls_session_sys_t) );
 799     if( p_session->p_sys == NULL )
 800     {
 801         vlc_object_destroy( p_session );
 802         return NULL;
 803     }
 804
 805     vlc_object_attach( p_session, p_server );
 806
 807     p_server_sys = (tls_server_sys_t *)p_server->p_sys;
 808     p_session->sock.p_sys = p_session;
 809     p_session->sock.pf_send = gnutls_Send;
 810     p_session->sock.pf_recv = gnutls_Recv;
 811     p_session->pf_handshake = gnutls_BeginHandshake;
 812     p_session->pf_handshake2 = p_server_sys->pf_handshake2;
 813     p_session->pf_close = gnutls_SessionClose;
 814
 815     ((tls_session_sys_t *)p_session->p_sys)->b_handshaked = VLC_FALSE;
 816     ((tls_session_sys_t *)p_session->p_sys)->psz_hostname = NULL;
 817
 818     i_val = gnutls_init( &session, GNUTLS_SERVER );
 819     if( i_val != 0 )
 820     {
 821         msg_Err( p_server, "Cannot initialize TLS session: %s",
 822                  gnutls_strerror( i_val ) );
 823         goto error;
 824     }
 825
 826     ((tls_session_sys_t *)p_session->p_sys)->session = session;
 827
 828     i_val = gnutls_set_default_priority( session );
 829     if( i_val < 0 )
 830     {
 831         msg_Err( p_server, "Cannot set ciphers priorities: %s",
 832                  gnutls_strerror( i_val ) );
 833         gnutls_deinit( session );
 834         goto error;
 835     }
 836
 837     i_val = gnutls_credentials_set( session, GNUTLS_CRD_CERTIFICATE,
 838                                     p_server_sys->x509_cred );
 839     if( i_val < 0 )
 840     {
 841         msg_Err( p_server, "Cannot set TLS session credentials: %s",
 842                  gnutls_strerror( i_val ) );
 843         gnutls_deinit( session );
 844         goto error;
 845     }
 846
 847     if( p_session->pf_handshake2 == gnutls_HandshakeAndValidate )
 848         gnutls_certificate_server_set_request( session, GNUTLS_CERT_REQUIRE );
 849
 850     gnutls_dh_set_prime_bits( session, get_Int( p_server, "gnutls-dh-bits" ) );
 851
 852     /* Session resumption support */
 853     gnutls_db_set_cache_expiration( session, get_Int( p_server,
 854                                     "gnutls-cache-expiration" ) );
 855     gnutls_db_set_retrieve_function( session, cb_fetch );
 856     gnutls_db_set_remove_function( session, cb_delete );
 857     gnutls_db_set_store_function( session, cb_store );
 858     gnutls_db_set_ptr( session, p_server );
 859
 860     return p_session;
 861
 862 error:
 863     free( p_session->p_sys );
 864     vlc_object_detach( p_session );
 865     vlc_object_destroy( p_session );
 866     return NULL;
 867 }
 868
 869
 870 /*****************************************************************************
 871  * tls_ServerDelete:
 872  *****************************************************************************
 873  * Releases data allocated with tls_ServerCreate.
 874  *****************************************************************************/
 875 static void
 876 gnutls_ServerDelete( tls_server_t *p_server )
 877 {
 878     tls_server_sys_t *p_sys;
 879     p_sys = (tls_server_sys_t *)p_server->p_sys;
 880
 881     vlc_mutex_destroy( &p_sys->cache_lock );
 882     free( p_sys->p_cache );
 883
 884     vlc_object_detach( p_server );
 885     vlc_object_destroy( p_server );
 886
 887     /* all sessions depending on the server are now deinitialized */
 888     gnutls_certificate_free_credentials( p_sys->x509_cred );
 889     gnutls_dh_params_deinit( p_sys->dh_params );
 890     free( p_sys );
 891 }
 892
 893
 894 /*****************************************************************************
 895  * tls_ServerAddCA:
 896  *****************************************************************************
 897  * Adds one or more certificate authorities.
 898  * Returns -1 on error, 0 on success.
 899  *****************************************************************************/
 900 static int
 901 gnutls_ServerAddCA( tls_server_t *p_server, const char *psz_ca_path )
 902 {
 903     tls_server_sys_t *p_sys;
 904     char *psz_local_path;
 905     int val;
 906
 907     p_sys = (tls_server_sys_t *)(p_server->p_sys);
 908
 909     psz_local_path = ToLocale( psz_ca_path );
 910     val = gnutls_certificate_set_x509_trust_file( p_sys->x509_cred,
 911                                                   psz_local_path,
 912                                                   GNUTLS_X509_FMT_PEM );
 913     LocaleFree( psz_local_path );
 914     if( val < 0 )
 915     {
 916         msg_Err( p_server, "Cannot add trusted CA (%s): %s", psz_ca_path,
 917                  gnutls_strerror( val ) );
 918         return VLC_EGENERIC;
 919     }
 920     msg_Dbg( p_server, " %d trusted CA added (%s)", val, psz_ca_path );
 921
 922     /* enables peer's certificate verification */
 923     p_sys->pf_handshake2 = gnutls_HandshakeAndValidate;
 924
 925     return VLC_SUCCESS;
 926 }
 927
 928
 929 /*****************************************************************************
 930  * tls_ServerAddCRL:
 931  *****************************************************************************
 932  * Adds a certificates revocation list to be sent to TLS clients.
 933  * Returns -1 on error, 0 on success.
 934  *****************************************************************************/
 935 static int
 936 gnutls_ServerAddCRL( tls_server_t *p_server, const char *psz_crl_path )
 937 {
 938     int val;
 939     char *psz_local_path = ToLocale( psz_crl_path );
 940
 941     val = gnutls_certificate_set_x509_crl_file( ((tls_server_sys_t *)
 942                                                 (p_server->p_sys))->x509_cred,
 943                                                 psz_local_path,
 944                                                 GNUTLS_X509_FMT_PEM );
 945     LocaleFree( psz_crl_path );
 946     if( val < 0 )
 947     {
 948         msg_Err( p_server, "Cannot add CRL (%s): %s", psz_crl_path,
 949                  gnutls_strerror( val ) );
 950         return VLC_EGENERIC;
 951     }
 952     msg_Dbg( p_server, "%d CRL added (%s)", val, psz_crl_path );
 953     return VLC_SUCCESS;
 954 }
 955
 956
 957 /*****************************************************************************
 958  * tls_ServerCreate:
 959  *****************************************************************************
 960  * Allocates a whole server's TLS credentials.
 961  * Returns NULL on error.
 962  *****************************************************************************/
 963 static tls_server_t *
 964 gnutls_ServerCreate( tls_t *p_tls, const char *psz_cert_path,
 965                      const char *psz_key_path )
 966 {
 967     tls_server_t *p_server;
 968     tls_server_sys_t *p_sys;
 969     char *psz_local_key, *psz_local_cert;
 970     int val;
 971
 972     msg_Dbg( p_tls, "Creating TLS server" );
 973
 974     p_sys = (tls_server_sys_t *)malloc( sizeof(struct tls_server_sys_t) );
 975     if( p_sys == NULL )
 976         return NULL;
 977
 978     p_sys->i_cache_size = get_Int( p_tls, "gnutls-cache-size" );
 979     p_sys->p_cache = (struct saved_session_t *)calloc( p_sys->i_cache_size,
 980                                            sizeof( struct saved_session_t ) );
 981     if( p_sys->p_cache == NULL )
 982     {
 983         free( p_sys );
 984         return NULL;
 985     }
 986     p_sys->p_store = p_sys->p_cache;
 987
 988     p_server = vlc_object_create( p_tls, sizeof(struct tls_server_t) );
 989     if( p_server == NULL )
 990     {
 991         free( p_sys->p_cache );
 992         free( p_sys );
 993         return NULL;
 994     }
 995
 996     vlc_object_attach( p_server, p_tls );
 997
 998     p_server->p_sys = p_sys;
 999     p_server->pf_delete = gnutls_ServerDelete;
1000     p_server->pf_add_CA = gnutls_ServerAddCA;
1001     p_server->pf_add_CRL = gnutls_ServerAddCRL;
1002     p_server->pf_session_prepare = gnutls_ServerSessionPrepare;
1003
1004     /* No certificate validation by default */
1005     p_sys->pf_handshake2 = gnutls_ContinueHandshake;
1006
1007     /* FIXME: check for errors */
1008     vlc_mutex_init( p_server, &p_sys->cache_lock );
1009
1010     /* Sets server's credentials */
1011     val = gnutls_certificate_allocate_credentials( &p_sys->x509_cred );
1012     if( val != 0 )
1013     {
1014         msg_Err( p_server, "Cannot allocate X509 credentials: %s",
1015                  gnutls_strerror( val ) );
1016         goto error;
1017     }
1018
1019     psz_local_cert = ToLocale( psz_cert_path );
1020     psz_local_key = ToLocale( psz_key_path );
1021     val = gnutls_certificate_set_x509_key_file( p_sys->x509_cred,
1022                                                 psz_local_cert, psz_local_key,
1023                                                 GNUTLS_X509_FMT_PEM );
1024     LocaleFree( psz_cert_path );
1025     LocaleFree( psz_key_path );
1026     if( val < 0 )
1027     {
1028         msg_Err( p_server, "Cannot set certificate chain or private key: %s",
1029                  gnutls_strerror( val ) );
1030         gnutls_certificate_free_credentials( p_sys->x509_cred );
1031         goto error;
1032     }
1033
1034     /* FIXME:
1035      * - regenerate these regularly
1036      * - support other ciper suites
1037      */
1038     val = gnutls_dh_params_init( &p_sys->dh_params );
1039     if( val >= 0 )
1040     {
1041         msg_Dbg( p_server, "Computing Diffie Hellman ciphers parameters" );
1042         val = gnutls_dh_params_generate2( p_sys->dh_params,
1043                                           get_Int( p_tls, "gnutls-dh-bits" ) );
1044     }
1045     if( val < 0 )
1046     {
1047         msg_Err( p_server, "Cannot initialize DH cipher suites: %s",
1048                  gnutls_strerror( val ) );
1049         gnutls_certificate_free_credentials( p_sys->x509_cred );
1050         goto error;
1051     }
1052     msg_Dbg( p_server, "Ciphers parameters computed" );
1053
1054     gnutls_certificate_set_dh_params( p_sys->x509_cred, p_sys->dh_params);
1055
1056     return p_server;
1057
1058 error:
1059     vlc_mutex_destroy( &p_sys->cache_lock );
1060     vlc_object_detach( p_server );
1061     vlc_object_destroy( p_server );
1062     free( p_sys );
1063     return NULL;
1064 }
1065
1066
1067 /*****************************************************************************
1068  * gcrypt thread option VLC implementation:
1069  *****************************************************************************/
1070 vlc_object_t *__p_gcry_data;
1071
1072 static int gcry_vlc_mutex_init( void **p_sys )
1073 {
1074     int i_val;
1075     vlc_mutex_t *p_lock = (vlc_mutex_t *)malloc( sizeof( vlc_mutex_t ) );
1076
1077     if( p_lock == NULL)
1078         return ENOMEM;
1079
1080     i_val = vlc_mutex_init( __p_gcry_data, p_lock );
1081     if( i_val )
1082         free( p_lock );
1083     else
1084         *p_sys = p_lock;
1085     return i_val;
1086 }
1087
1088 static int gcry_vlc_mutex_destroy( void **p_sys )
1089 {
1090     int i_val;
1091     vlc_mutex_t *p_lock = (vlc_mutex_t *)*p_sys;
1092
1093     i_val = vlc_mutex_destroy( p_lock );
1094     free( p_lock );
1095     return i_val;
1096 }
1097
1098 static int gcry_vlc_mutex_lock( void **p_sys )
1099 {
1100     return vlc_mutex_lock( (vlc_mutex_t *)*p_sys );
1101 }
1102
1103 static int gcry_vlc_mutex_unlock( void **lock )
1104 {
1105     return vlc_mutex_unlock( (vlc_mutex_t *)*lock );
1106 }
1107
1108 static struct gcry_thread_cbs gcry_threads_vlc =
1109 {
1110     GCRY_THREAD_OPTION_USER,
1111     NULL,
1112     gcry_vlc_mutex_init,
1113     gcry_vlc_mutex_destroy,
1114     gcry_vlc_mutex_lock,
1115     gcry_vlc_mutex_unlock
1116 };
1117
1118
1119 /*****************************************************************************
1120  * Module initialization
1121  *****************************************************************************/
1122 static int
1123 Open( vlc_object_t *p_this )
1124 {
1125     tls_t *p_tls = (tls_t *)p_this;
1126
1127     vlc_value_t lock, count;
1128
1129     var_Create( p_this->p_libvlc, "gnutls_mutex", VLC_VAR_MUTEX );
1130     var_Get( p_this->p_libvlc, "gnutls_mutex", &lock );
1131     vlc_mutex_lock( lock.p_address );
1132
1133     /* Initialize GnuTLS only once */
1134     var_Create( p_this->p_libvlc, "gnutls_count", VLC_VAR_INTEGER );
1135     var_Get( p_this->p_libvlc, "gnutls_count", &count);
1136
1137     if( count.i_int == 0)
1138     {
1139         const char *psz_version;
1140
1141         __p_gcry_data = VLC_OBJECT( p_this->p_vlc );
1142
1143         gcry_control (GCRYCTL_SET_THREAD_CBS, &gcry_threads_vlc);
1144         if( gnutls_global_init( ) )
1145         {
1146             msg_Warn( p_this, "cannot initialize GnuTLS" );
1147             vlc_mutex_unlock( lock.p_address );
1148             return VLC_EGENERIC;
1149         }
1150         /*
1151          * FIXME: in fact, we currently depends on 1.0.17, but it breaks on
1152          * Debian which as a patched 1.0.16 (which we can use).
1153          */
1154         psz_version = gnutls_check_version( "1.0.16" );
1155         if( psz_version == NULL )
1156         {
1157             gnutls_global_deinit( );
1158             vlc_mutex_unlock( lock.p_address );
1159             msg_Err( p_this, "unsupported GnuTLS version" );
1160             return VLC_EGENERIC;
1161         }
1162         msg_Dbg( p_this, "GnuTLS v%s initialized", psz_version );
1163     }
1164
1165     count.i_int++;
1166     var_Set( p_this->p_libvlc, "gnutls_count", count);
1167     vlc_mutex_unlock( lock.p_address );
1168
1169     p_tls->pf_server_create = gnutls_ServerCreate;
1170     p_tls->pf_client_create = gnutls_ClientCreate;
1171     return VLC_SUCCESS;
1172 }
1173
1174
1175 /*****************************************************************************
1176  * Module deinitialization
1177  *****************************************************************************/
1178 static void
1179 Close( vlc_object_t *p_this )
1180 {
1181     /*tls_t *p_tls = (tls_t *)p_this;
1182     tls_sys_t *p_sys = (tls_sys_t *)(p_this->p_sys);*/
1183
1184     vlc_value_t lock, count;
1185
1186     var_Create( p_this->p_libvlc, "gnutls_mutex", VLC_VAR_MUTEX );
1187     var_Get( p_this->p_libvlc, "gnutls_mutex", &lock );
1188     vlc_mutex_lock( lock.p_address );
1189
1190     var_Create( p_this->p_libvlc, "gnutls_count", VLC_VAR_INTEGER );
1191     var_Get( p_this->p_libvlc, "gnutls_count", &count);
1192     count.i_int--;
1193     var_Set( p_this->p_libvlc, "gnutls_count", count);
1194
1195     if( count.i_int == 0 )
1196     {
1197         gnutls_global_deinit( );
1198         msg_Dbg( p_this, "GnuTLS deinitialized" );
1199     }
1200
1201     vlc_mutex_unlock( lock.p_address );
1202 }