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