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