git.sur5r.net Git - openldap/blob - libraries/libldap/tls_g.c

   1 /* tls_g.c - Handle tls/ssl using GNUTLS. */
   2 /* $OpenLDAP$ */
   3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   4  *
   5  * Copyright 2008-2013 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16 /* ACKNOWLEDGEMENTS: GNUTLS support written by Howard Chu and
  17  * Emily Backes; sponsored by The Written Word (thewrittenword.com)
  18  * and Stanford University (stanford.edu).
  19  */
  20
  21 #include "portable.h"
  22
  23 #ifdef HAVE_GNUTLS
  24
  25 #include "ldap_config.h"
  26
  27 #include <stdio.h>
  28
  29 #include <ac/stdlib.h>
  30 #include <ac/errno.h>
  31 #include <ac/socket.h>
  32 #include <ac/string.h>
  33 #include <ac/ctype.h>
  34 #include <ac/time.h>
  35 #include <ac/unistd.h>
  36 #include <ac/param.h>
  37 #include <ac/dirent.h>
  38 #include <sys/stat.h>
  39 #include <fcntl.h>
  40
  41 #include "ldap-int.h"
  42 #include "ldap-tls.h"
  43
  44 #include <gnutls/gnutls.h>
  45 #include <gnutls/x509.h>
  46 #include <gcrypt.h>
  47
  48 #if LIBGNUTLS_VERSION_NUMBER >= 0x020200
  49 #define HAVE_CIPHERSUITES       1
  50 /* This is a kludge. gcrypt 1.4.x has support. Recent GnuTLS requires gcrypt 1.4.x
  51  * but that dependency isn't reflected in their configure script, resulting in
  52  * build errors on older gcrypt. So, if they have a working build environment,
  53  * assume gcrypt is new enough.
  54  */
  55 #define HAVE_GCRYPT_RAND        1
  56 #else
  57 #undef HAVE_CIPHERSUITES
  58 #undef HAVE_GCRYPT_RAND
  59 #endif
  60
  61 #ifndef HAVE_CIPHERSUITES
  62 /* Versions prior to 2.2.0 didn't handle cipher suites, so we had to
  63  * kludge them ourselves.
  64  */
  65 typedef struct tls_cipher_suite {
  66         const char *name;
  67         gnutls_kx_algorithm_t kx;
  68         gnutls_cipher_algorithm_t cipher;
  69         gnutls_mac_algorithm_t mac;
  70         gnutls_protocol_t version;
  71 } tls_cipher_suite;
  72 #endif
  73
  74 typedef struct tlsg_ctx {
  75         struct ldapoptions *lo;
  76         gnutls_certificate_credentials_t cred;
  77         gnutls_dh_params_t dh_params;
  78         unsigned long verify_depth;
  79         int refcount;
  80 #ifdef HAVE_CIPHERSUITES
  81         gnutls_priority_t prios;
  82 #else
  83         int *kx_list;
  84         int *cipher_list;
  85         int *mac_list;
  86 #endif
  87 #ifdef LDAP_R_COMPILE
  88         ldap_pvt_thread_mutex_t ref_mutex;
  89 #endif
  90 } tlsg_ctx;
  91
  92 typedef struct tlsg_session {
  93         gnutls_session_t session;
  94         tlsg_ctx *ctx;
  95         struct berval peer_der_dn;
  96 } tlsg_session;
  97
  98 #ifndef HAVE_CIPHERSUITES
  99 static tls_cipher_suite *tlsg_ciphers;
 100 static int tlsg_n_ciphers;
 101 #endif
 102
 103 static int tlsg_parse_ciphers( tlsg_ctx *ctx, char *suites );
 104 static int tlsg_cert_verify( tlsg_session *s );
 105
 106 #ifdef LDAP_R_COMPILE
 107
 108 static int
 109 tlsg_mutex_init( void **priv )
 110 {
 111         int err = 0;
 112         ldap_pvt_thread_mutex_t *lock = LDAP_MALLOC( sizeof( ldap_pvt_thread_mutex_t ));
 113
 114         if ( !lock )
 115                 err = ENOMEM;
 116         if ( !err ) {
 117                 err = ldap_pvt_thread_mutex_init( lock );
 118                 if ( err )
 119                         LDAP_FREE( lock );
 120                 else
 121                         *priv = lock;
 122         }
 123         return err;
 124 }
 125
 126 static int
 127 tlsg_mutex_destroy( void **lock )
 128 {
 129         int err = ldap_pvt_thread_mutex_destroy( *lock );
 130         LDAP_FREE( *lock );
 131         return err;
 132 }
 133
 134 static int
 135 tlsg_mutex_lock( void **lock )
 136 {
 137         return ldap_pvt_thread_mutex_lock( *lock );
 138 }
 139
 140 static int
 141 tlsg_mutex_unlock( void **lock )
 142 {
 143         return ldap_pvt_thread_mutex_unlock( *lock );
 144 }
 145
 146 static struct gcry_thread_cbs tlsg_thread_cbs = {
 147         GCRY_THREAD_OPTION_USER,
 148         NULL,
 149         tlsg_mutex_init,
 150         tlsg_mutex_destroy,
 151         tlsg_mutex_lock,
 152         tlsg_mutex_unlock,
 153         NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
 154 };
 155
 156 static void
 157 tlsg_thr_init( void )
 158 {
 159         gcry_control (GCRYCTL_SET_THREAD_CBS, &tlsg_thread_cbs);
 160 }
 161 #endif /* LDAP_R_COMPILE */
 162
 163 /*
 164  * Initialize TLS subsystem. Should be called only once.
 165  */
 166 static int
 167 tlsg_init( void )
 168 {
 169 #ifdef HAVE_GCRYPT_RAND
 170         struct ldapoptions *lo = LDAP_INT_GLOBAL_OPT();
 171         if ( lo->ldo_tls_randfile &&
 172                 gcry_control( GCRYCTL_SET_RNDEGD_SOCKET, lo->ldo_tls_randfile )) {
 173                 Debug( LDAP_DEBUG_ANY,
 174                 "TLS: gcry_control GCRYCTL_SET_RNDEGD_SOCKET failed\n",
 175                 0, 0, 0);
 176                 return -1;
 177         }
 178 #endif
 179
 180         gnutls_global_init();
 181
 182 #ifndef HAVE_CIPHERSUITES
 183         /* GNUtls cipher suite handling: The library ought to parse suite
 184          * names for us, but it doesn't. It will return a list of suite names
 185          * that it supports, so we can do parsing ourselves. It ought to tell
 186          * us how long the list is, but it doesn't do that either, so we just
 187          * have to count it manually...
 188          */
 189         {
 190                 int i = 0;
 191                 tls_cipher_suite *ptr, tmp;
 192                 char cs_id[2];
 193
 194                 while ( gnutls_cipher_suite_info( i, cs_id, &tmp.kx, &tmp.cipher,
 195                         &tmp.mac, &tmp.version ))
 196                         i++;
 197                 tlsg_n_ciphers = i;
 198
 199                 /* Store a copy */
 200                 tlsg_ciphers = LDAP_MALLOC(tlsg_n_ciphers * sizeof(tls_cipher_suite));
 201                 if ( !tlsg_ciphers )
 202                         return -1;
 203                 for ( i=0; i<tlsg_n_ciphers; i++ ) {
 204                         tlsg_ciphers[i].name = gnutls_cipher_suite_info( i, cs_id,
 205                                 &tlsg_ciphers[i].kx, &tlsg_ciphers[i].cipher, &tlsg_ciphers[i].mac,
 206                                 &tlsg_ciphers[i].version );
 207                 }
 208         }
 209 #endif
 210         return 0;
 211 }
 212
 213 /*
 214  * Tear down the TLS subsystem. Should only be called once.
 215  */
 216 static void
 217 tlsg_destroy( void )
 218 {
 219 #ifndef HAVE_CIPHERSUITES
 220         LDAP_FREE( tlsg_ciphers );
 221         tlsg_ciphers = NULL;
 222         tlsg_n_ciphers = 0;
 223 #endif
 224         gnutls_global_deinit();
 225 }
 226
 227 static tls_ctx *
 228 tlsg_ctx_new ( struct ldapoptions *lo )
 229 {
 230         tlsg_ctx *ctx;
 231
 232         ctx = ber_memcalloc ( 1, sizeof (*ctx) );
 233         if ( ctx ) {
 234                 ctx->lo = lo;
 235                 if ( gnutls_certificate_allocate_credentials( &ctx->cred )) {
 236                         ber_memfree( ctx );
 237                         return NULL;
 238                 }
 239                 ctx->refcount = 1;
 240 #ifdef HAVE_CIPHERSUITES
 241                 gnutls_priority_init( &ctx->prios, "NORMAL", NULL );
 242 #endif
 243 #ifdef LDAP_R_COMPILE
 244                 ldap_pvt_thread_mutex_init( &ctx->ref_mutex );
 245 #endif
 246         }
 247         return (tls_ctx *)ctx;
 248 }
 249
 250 static void
 251 tlsg_ctx_ref( tls_ctx *ctx )
 252 {
 253         tlsg_ctx *c = (tlsg_ctx *)ctx;
 254         LDAP_MUTEX_LOCK( &c->ref_mutex );
 255         c->refcount++;
 256         LDAP_MUTEX_UNLOCK( &c->ref_mutex );
 257 }
 258
 259 static void
 260 tlsg_ctx_free ( tls_ctx *ctx )
 261 {
 262         tlsg_ctx *c = (tlsg_ctx *)ctx;
 263         int refcount;
 264
 265         if ( !c ) return;
 266
 267         LDAP_MUTEX_LOCK( &c->ref_mutex );
 268         refcount = --c->refcount;
 269         LDAP_MUTEX_UNLOCK( &c->ref_mutex );
 270         if ( refcount )
 271                 return;
 272 #ifdef HAVE_CIPHERSUITES
 273         gnutls_priority_deinit( c->prios );
 274 #else
 275         LDAP_FREE( c->kx_list );
 276 #endif
 277         gnutls_certificate_free_credentials( c->cred );
 278         if ( c->dh_params )
 279                 gnutls_dh_params_deinit( c->dh_params );
 280         ber_memfree ( c );
 281 }
 282
 283 static int
 284 tlsg_getfile( const char *path, gnutls_datum_t *buf )
 285 {
 286         int rc = -1, fd;
 287         struct stat st;
 288
 289         fd = open( path, O_RDONLY );
 290         if ( fd >= 0 && fstat( fd, &st ) == 0 ) {
 291                 buf->size = st.st_size;
 292                 buf->data = LDAP_MALLOC( st.st_size + 1 );
 293                 if ( buf->data ) {
 294                         rc = read( fd, buf->data, st.st_size );
 295                         close( fd );
 296                         if ( rc < st.st_size )
 297                                 rc = -1;
 298                         else
 299                                 rc = 0;
 300                 }
 301         }
 302         return rc;
 303 }
 304
 305 /* This is the GnuTLS default */
 306 #define VERIFY_DEPTH    6
 307
 308 /*
 309  * initialize a new TLS context
 310  */
 311 static int
 312 tlsg_ctx_init( struct ldapoptions *lo, struct ldaptls *lt, int is_server )
 313 {
 314         tlsg_ctx *ctx = lo->ldo_tls_ctx;
 315         int rc;
 316
 317         if ( lo->ldo_tls_ciphersuite &&
 318                 tlsg_parse_ciphers( ctx, lt->lt_ciphersuite )) {
 319                 Debug( LDAP_DEBUG_ANY,
 320                            "TLS: could not set cipher list %s.\n",
 321                            lo->ldo_tls_ciphersuite, 0, 0 );
 322                 return -1;
 323         }
 324
 325         if (lo->ldo_tls_cacertdir != NULL) {
 326                 Debug( LDAP_DEBUG_ANY,
 327                        "TLS: warning: cacertdir not implemented for gnutls\n",
 328                        NULL, NULL, NULL );
 329         }
 330
 331         if (lo->ldo_tls_cacertfile != NULL) {
 332                 rc = gnutls_certificate_set_x509_trust_file(
 333                         ctx->cred,
 334                         lt->lt_cacertfile,
 335                         GNUTLS_X509_FMT_PEM );
 336                 if ( rc < 0 ) return -1;
 337         }
 338
 339         if ( lo->ldo_tls_certfile && lo->ldo_tls_keyfile ) {
 340                 gnutls_x509_privkey_t key;
 341                 gnutls_datum_t buf;
 342                 gnutls_x509_crt_t certs[VERIFY_DEPTH];
 343                 unsigned int max = VERIFY_DEPTH;
 344
 345                 rc = gnutls_x509_privkey_init( &key );
 346                 if ( rc ) return -1;
 347
 348                 /* OpenSSL builds the cert chain for us, but GnuTLS
 349                  * expects it to be present in the certfile. If it's
 350                  * not, we have to build it ourselves. So we have to
 351                  * do some special checks here...
 352                  */
 353                 rc = tlsg_getfile( lt->lt_keyfile, &buf );
 354                 if ( rc ) return -1;
 355                 rc = gnutls_x509_privkey_import( key, &buf,
 356                         GNUTLS_X509_FMT_PEM );
 357                 LDAP_FREE( buf.data );
 358                 if ( rc < 0 ) return rc;
 359
 360                 rc = tlsg_getfile( lt->lt_certfile, &buf );
 361                 if ( rc ) return -1;
 362                 rc = gnutls_x509_crt_list_import( certs, &max, &buf,
 363                         GNUTLS_X509_FMT_PEM, 0 );
 364                 LDAP_FREE( buf.data );
 365                 if ( rc < 0 ) return rc;
 366
 367                 /* If there's only one cert and it's not self-signed,
 368                  * then we have to build the cert chain.
 369                  */
 370                 if ( max == 1 && !gnutls_x509_crt_check_issuer( certs[0], certs[0] )) {
 371 #if GNUTLS_VERSION_NUMBER >= 0x020c00
 372                         unsigned int i;
 373                         for ( i = 1; i<VERIFY_DEPTH; i++ ) {
 374                                 if ( gnutls_certificate_get_issuer( ctx->cred, certs[i-1], &certs[i], 0 ))
 375                                         break;
 376                                 max++;
 377                                 /* If this CA is self-signed, we're done */
 378                                 if ( gnutls_x509_crt_check_issuer( certs[i], certs[i] ))
 379                                         break;
 380                         }
 381 #else
 382                         gnutls_x509_crt_t *cas;
 383                         unsigned int i, j, ncas;
 384
 385                         gnutls_certificate_get_x509_cas( ctx->cred, &cas, &ncas );
 386                         for ( i = 1; i<VERIFY_DEPTH; i++ ) {
 387                                 for ( j = 0; j<ncas; j++ ) {
 388                                         if ( gnutls_x509_crt_check_issuer( certs[i-1], cas[j] )) {
 389                                                 certs[i] = cas[j];
 390                                                 max++;
 391                                                 /* If this CA is self-signed, we're done */
 392                                                 if ( gnutls_x509_crt_check_issuer( cas[j], cas[j] ))
 393                                                         j = ncas;
 394                                                 break;
 395                                         }
 396                                 }
 397                                 /* only continue if we found a CA and it was not self-signed */
 398                                 if ( j == ncas )
 399                                         break;
 400                         }
 401 #endif
 402                 }
 403                 rc = gnutls_certificate_set_x509_key( ctx->cred, certs, max, key );
 404                 if ( rc ) return -1;
 405         } else if ( lo->ldo_tls_certfile || lo->ldo_tls_keyfile ) {
 406                 Debug( LDAP_DEBUG_ANY,
 407                        "TLS: only one of certfile and keyfile specified\n",
 408                        NULL, NULL, NULL );
 409                 return -1;
 410         }
 411
 412         if ( lo->ldo_tls_crlfile ) {
 413                 rc = gnutls_certificate_set_x509_crl_file(
 414                         ctx->cred,
 415                         lt->lt_crlfile,
 416                         GNUTLS_X509_FMT_PEM );
 417                 if ( rc < 0 ) return -1;
 418                 rc = 0;
 419         }
 420
 421         /* FIXME: ITS#5992 - this should be configurable,
 422          * and V1 CA certs should be phased out ASAP.
 423          */
 424         gnutls_certificate_set_verify_flags( ctx->cred,
 425                 GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT );
 426
 427         if ( is_server && lo->ldo_tls_dhfile ) {
 428                 gnutls_datum_t buf;
 429                 rc = tlsg_getfile( lo->ldo_tls_dhfile, &buf );
 430                 if ( rc ) return -1;
 431                 rc = gnutls_dh_params_init( &ctx->dh_params );
 432                 if ( rc == 0 )
 433                         rc = gnutls_dh_params_import_pkcs3( ctx->dh_params, &buf,
 434                                 GNUTLS_X509_FMT_PEM );
 435                 LDAP_FREE( buf.data );
 436                 if ( rc ) return -1;
 437                 gnutls_certificate_set_dh_params( ctx->cred, ctx->dh_params );
 438         }
 439         return 0;
 440 }
 441
 442 static tls_session *
 443 tlsg_session_new ( tls_ctx * ctx, int is_server )
 444 {
 445         tlsg_ctx *c = (tlsg_ctx *)ctx;
 446         tlsg_session *session;
 447
 448         session = ber_memcalloc ( 1, sizeof (*session) );
 449         if ( !session )
 450                 return NULL;
 451
 452         session->ctx = c;
 453         gnutls_init( &session->session, is_server ? GNUTLS_SERVER : GNUTLS_CLIENT );
 454 #ifdef HAVE_CIPHERSUITES
 455         gnutls_priority_set( session->session, c->prios );
 456 #else
 457         gnutls_set_default_priority( session->session );
 458         if ( c->kx_list ) {
 459                 gnutls_kx_set_priority( session->session, c->kx_list );
 460                 gnutls_cipher_set_priority( session->session, c->cipher_list );
 461                 gnutls_mac_set_priority( session->session, c->mac_list );
 462         }
 463 #endif
 464         if ( c->cred )
 465                 gnutls_credentials_set( session->session, GNUTLS_CRD_CERTIFICATE, c->cred );
 466
 467         if ( is_server ) {
 468                 int flag = 0;
 469                 if ( c->lo->ldo_tls_require_cert ) {
 470                         flag = GNUTLS_CERT_REQUEST;
 471                         if ( c->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_DEMAND ||
 472                                 c->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_HARD )
 473                                 flag = GNUTLS_CERT_REQUIRE;
 474                         gnutls_certificate_server_set_request( session->session, flag );
 475                 }
 476         }
 477         return (tls_session *)session;
 478 }
 479
 480 static int
 481 tlsg_session_accept( tls_session *session )
 482 {
 483         tlsg_session *s = (tlsg_session *)session;
 484         int rc;
 485
 486         rc = gnutls_handshake( s->session );
 487         if ( rc == 0 && s->ctx->lo->ldo_tls_require_cert != LDAP_OPT_X_TLS_NEVER ) {
 488                 const gnutls_datum_t *peer_cert_list;
 489                 unsigned int list_size;
 490
 491                 peer_cert_list = gnutls_certificate_get_peers( s->session,
 492                                                 &list_size );
 493                 if ( !peer_cert_list && s->ctx->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_TRY )
 494                         rc = 0;
 495                 else {
 496                         rc = tlsg_cert_verify( s );
 497                         if ( rc && s->ctx->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_ALLOW )
 498                                 rc = 0;
 499                 }
 500         }
 501         return rc;
 502 }
 503
 504 static int
 505 tlsg_session_connect( LDAP *ld, tls_session *session )
 506 {
 507         return tlsg_session_accept( session);
 508 }
 509
 510 static int
 511 tlsg_session_upflags( Sockbuf *sb, tls_session *session, int rc )
 512 {
 513         tlsg_session *s = (tlsg_session *)session;
 514
 515         if ( rc != GNUTLS_E_INTERRUPTED && rc != GNUTLS_E_AGAIN )
 516                 return 0;
 517
 518         switch (gnutls_record_get_direction (s->session)) {
 519         case 0:
 520                 sb->sb_trans_needs_read = 1;
 521                 return 1;
 522         case 1:
 523                 sb->sb_trans_needs_write = 1;
 524                 return 1;
 525         }
 526         return 0;
 527 }
 528
 529 static char *
 530 tlsg_session_errmsg( tls_session *sess, int rc, char *buf, size_t len )
 531 {
 532         return (char *)gnutls_strerror( rc );
 533 }
 534
 535 static void
 536 tlsg_x509_cert_dn( struct berval *cert, struct berval *dn, int get_subject )
 537 {
 538         BerElementBuffer berbuf;
 539         BerElement *ber = (BerElement *)&berbuf;
 540         ber_tag_t tag;
 541         ber_len_t len;
 542         ber_int_t i;
 543
 544         ber_init2( ber, cert, LBER_USE_DER );
 545         tag = ber_skip_tag( ber, &len );        /* Sequence */
 546         tag = ber_skip_tag( ber, &len );        /* Sequence */
 547         tag = ber_peek_tag( ber, &len );        /* Context + Constructed (version) */
 548         if ( tag == 0xa0 ) {    /* Version is optional */
 549                 tag = ber_skip_tag( ber, &len );
 550                 tag = ber_get_int( ber, &i );   /* Int: Version */
 551         }
 552         tag = ber_skip_tag( ber, &len );        /* Int: Serial (can be longer than ber_int_t) */
 553         ber_skip_data( ber, len );
 554         tag = ber_skip_tag( ber, &len );        /* Sequence: Signature */
 555         ber_skip_data( ber, len );
 556         if ( !get_subject ) {
 557                 tag = ber_peek_tag( ber, &len );        /* Sequence: Issuer DN */
 558         } else {
 559                 tag = ber_skip_tag( ber, &len );
 560                 ber_skip_data( ber, len );
 561                 tag = ber_skip_tag( ber, &len );        /* Sequence: Validity */
 562                 ber_skip_data( ber, len );
 563                 tag = ber_peek_tag( ber, &len );        /* Sequence: Subject DN */
 564         }
 565         len = ber_ptrlen( ber );
 566         dn->bv_val = cert->bv_val + len;
 567         dn->bv_len = cert->bv_len - len;
 568 }
 569
 570 static int
 571 tlsg_session_my_dn( tls_session *session, struct berval *der_dn )
 572 {
 573         tlsg_session *s = (tlsg_session *)session;
 574         const gnutls_datum_t *x;
 575         struct berval bv;
 576
 577         x = gnutls_certificate_get_ours( s->session );
 578
 579         if (!x) return LDAP_INVALID_CREDENTIALS;
 580
 581         bv.bv_val = (char *) x->data;
 582         bv.bv_len = x->size;
 583
 584         tlsg_x509_cert_dn( &bv, der_dn, 1 );
 585         return 0;
 586 }
 587
 588 static int
 589 tlsg_session_peer_dn( tls_session *session, struct berval *der_dn )
 590 {
 591         tlsg_session *s = (tlsg_session *)session;
 592         if ( !s->peer_der_dn.bv_val ) {
 593                 const gnutls_datum_t *peer_cert_list;
 594                 unsigned int list_size;
 595                 struct berval bv;
 596
 597                 peer_cert_list = gnutls_certificate_get_peers( s->session,
 598                                                         &list_size );
 599                 if ( !peer_cert_list ) return LDAP_INVALID_CREDENTIALS;
 600
 601                 bv.bv_len = peer_cert_list->size;
 602                 bv.bv_val = (char *) peer_cert_list->data;
 603
 604                 tlsg_x509_cert_dn( &bv, &s->peer_der_dn, 1 );
 605         }
 606         *der_dn = s->peer_der_dn;
 607         return 0;
 608 }
 609
 610 /* what kind of hostname were we given? */
 611 #define IS_DNS  0
 612 #define IS_IP4  1
 613 #define IS_IP6  2
 614
 615 #define CN_OID  "2.5.4.3"
 616
 617 static int
 618 tlsg_session_chkhost( LDAP *ld, tls_session *session, const char *name_in )
 619 {
 620         tlsg_session *s = (tlsg_session *)session;
 621         int i, ret;
 622         const gnutls_datum_t *peer_cert_list;
 623         unsigned int list_size;
 624         char altname[NI_MAXHOST];
 625         size_t altnamesize;
 626
 627         gnutls_x509_crt_t cert;
 628         const char *name;
 629         char *ptr;
 630         char *domain = NULL;
 631 #ifdef LDAP_PF_INET6
 632         struct in6_addr addr;
 633 #else
 634         struct in_addr addr;
 635 #endif
 636         int len1 = 0, len2 = 0;
 637         int ntype = IS_DNS;
 638
 639         if( ldap_int_hostname &&
 640                 ( !name_in || !strcasecmp( name_in, "localhost" ) ) )
 641         {
 642                 name = ldap_int_hostname;
 643         } else {
 644                 name = name_in;
 645         }
 646
 647         peer_cert_list = gnutls_certificate_get_peers( s->session,
 648                                                 &list_size );
 649         if ( !peer_cert_list ) {
 650                 Debug( LDAP_DEBUG_ANY,
 651                         "TLS: unable to get peer certificate.\n",
 652                         0, 0, 0 );
 653                 /* If this was a fatal condition, things would have
 654                  * aborted long before now.
 655                  */
 656                 return LDAP_SUCCESS;
 657         }
 658         ret = gnutls_x509_crt_init( &cert );
 659         if ( ret < 0 )
 660                 return LDAP_LOCAL_ERROR;
 661         ret = gnutls_x509_crt_import( cert, peer_cert_list, GNUTLS_X509_FMT_DER );
 662         if ( ret ) {
 663                 gnutls_x509_crt_deinit( cert );
 664                 return LDAP_LOCAL_ERROR;
 665         }
 666
 667 #ifdef LDAP_PF_INET6
 668         if (inet_pton(AF_INET6, name, &addr)) {
 669                 ntype = IS_IP6;
 670         } else
 671 #endif
 672         if ((ptr = strrchr(name, '.')) && isdigit((unsigned char)ptr[1])) {
 673                 if (inet_aton(name, (struct in_addr *)&addr)) ntype = IS_IP4;
 674         }
 675
 676         if (ntype == IS_DNS) {
 677                 len1 = strlen(name);
 678                 domain = strchr(name, '.');
 679                 if (domain) {
 680                         len2 = len1 - (domain-name);
 681                 }
 682         }
 683
 684         for ( i=0, ret=0; ret >= 0; i++ ) {
 685                 altnamesize = sizeof(altname);
 686                 ret = gnutls_x509_crt_get_subject_alt_name( cert, i,
 687                         altname, &altnamesize, NULL );
 688                 if ( ret < 0 ) break;
 689
 690                 /* ignore empty */
 691                 if ( altnamesize == 0 ) continue;
 692
 693                 if ( ret == GNUTLS_SAN_DNSNAME ) {
 694                         if (ntype != IS_DNS) continue;
 695
 696                         /* Is this an exact match? */
 697                         if ((len1 == altnamesize) && !strncasecmp(name, altname, len1)) {
 698                                 break;
 699                         }
 700
 701                         /* Is this a wildcard match? */
 702                         if (domain && (altname[0] == '*') && (altname[1] == '.') &&
 703                                 (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2))
 704                         {
 705                                 break;
 706                         }
 707                 } else if ( ret == GNUTLS_SAN_IPADDRESS ) {
 708                         if (ntype == IS_DNS) continue;
 709
 710 #ifdef LDAP_PF_INET6
 711                         if (ntype == IS_IP6 && altnamesize != sizeof(struct in6_addr)) {
 712                                 continue;
 713                         } else
 714 #endif
 715                         if (ntype == IS_IP4 && altnamesize != sizeof(struct in_addr)) {
 716                                 continue;
 717                         }
 718                         if (!memcmp(altname, &addr, altnamesize)) {
 719                                 break;
 720                         }
 721                 }
 722         }
 723         if ( ret >= 0 ) {
 724                 ret = LDAP_SUCCESS;
 725         } else {
 726                 /* find the last CN */
 727                 i=0;
 728                 do {
 729                         altnamesize = 0;
 730                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 731                                 i, 1, altname, &altnamesize );
 732                         if ( ret == GNUTLS_E_SHORT_MEMORY_BUFFER )
 733                                 i++;
 734                         else
 735                                 break;
 736                 } while ( 1 );
 737
 738                 if ( i ) {
 739                         altnamesize = sizeof(altname);
 740                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 741                                 i-1, 0, altname, &altnamesize );
 742                 }
 743
 744                 if ( ret < 0 ) {
 745                         Debug( LDAP_DEBUG_ANY,
 746                                 "TLS: unable to get common name from peer certificate.\n",
 747                                 0, 0, 0 );
 748                         ret = LDAP_CONNECT_ERROR;
 749                         if ( ld->ld_error ) {
 750                                 LDAP_FREE( ld->ld_error );
 751                         }
 752                         ld->ld_error = LDAP_STRDUP(
 753                                 _("TLS: unable to get CN from peer certificate"));
 754
 755                 } else {
 756                         ret = LDAP_LOCAL_ERROR;
 757                         if ( !len1 ) len1 = strlen( name );
 758                         if ( len1 == altnamesize && strncasecmp(name, altname, altnamesize) == 0 ) {
 759                                 ret = LDAP_SUCCESS;
 760
 761                         } else if (( altname[0] == '*' ) && ( altname[1] == '.' )) {
 762                                         /* Is this a wildcard match? */
 763                                 if( domain &&
 764                                         (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2)) {
 765                                         ret = LDAP_SUCCESS;
 766                                 }
 767                         }
 768                 }
 769
 770                 if( ret == LDAP_LOCAL_ERROR ) {
 771                         altname[altnamesize] = '\0';
 772                         Debug( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
 773                                 "common name in certificate (%s).\n",
 774                                 name, altname, 0 );
 775                         ret = LDAP_CONNECT_ERROR;
 776                         if ( ld->ld_error ) {
 777                                 LDAP_FREE( ld->ld_error );
 778                         }
 779                         ld->ld_error = LDAP_STRDUP(
 780                                 _("TLS: hostname does not match CN in peer certificate"));
 781                 }
 782         }
 783         gnutls_x509_crt_deinit( cert );
 784         return ret;
 785 }
 786
 787 static int
 788 tlsg_session_strength( tls_session *session )
 789 {
 790         tlsg_session *s = (tlsg_session *)session;
 791         gnutls_cipher_algorithm_t c;
 792
 793         c = gnutls_cipher_get( s->session );
 794         return gnutls_cipher_get_key_size( c ) * 8;
 795 }
 796
 797 static int
 798 tlsg_session_unique( tls_session *sess, struct berval *buf, int is_server)
 799 {
 800 /* channel bindings added in 2.12.0 */
 801 #if GNUTLS_VERSION_NUMBER >= 0x020c00
 802         tlsg_session *s = (tlsg_session *)sess;
 803         gnutls_datum_t cb;
 804         int rc;
 805
 806         rc = gnutls_session_channel_binding( s->session, GNUTLS_CB_TLS_UNIQUE, &cb );
 807         if ( rc == 0 ) {
 808                 int len = cb.size;
 809                 if ( len > buf->bv_len )
 810                         len = buf->bv_len;
 811                 buf->bv_len = len;
 812                 memcpy( buf->bv_val, cb.data, len );
 813                 return len;
 814         }
 815 #endif
 816         return 0;
 817 }
 818
 819 static const char *
 820 tlsg_session_version( tls_session *sess )
 821 {
 822         tlsg_session *s = (tlsg_session *)sess;
 823         return gnutls_protocol_get_name(gnutls_protocol_get_version( s->session ));
 824 }
 825
 826 static const char *
 827 tlsg_session_cipher( tls_session *sess )
 828 {
 829         tlsg_session *s = (tlsg_session *)sess;
 830         return gnutls_cipher_get_name(gnutls_cipher_get( s->session ));
 831 }
 832
 833 static int
 834 tlsg_session_peercert( tls_session *sess, struct berval *der )
 835 {
 836         tlsg_session *s = (tlsg_session *)sess;
 837         const gnutls_datum_t *peer_cert_list;
 838         unsigned int list_size;
 839
 840         peer_cert_list = gnutls_certificate_get_peers( s->session, &list_size );
 841         if (!peer_cert_list)
 842                 return -1;
 843         der->bv_len = peer_cert_list[0].size;
 844         der->bv_val = LDAP_MALLOC( der->bv_len );
 845         if (!der->bv_val)
 846                 return -1;
 847         memcpy(der->bv_val, peer_cert_list[0].data, der->bv_len);
 848         return 0;
 849 }
 850
 851 /* suites is a string of colon-separated cipher suite names. */
 852 static int
 853 tlsg_parse_ciphers( tlsg_ctx *ctx, char *suites )
 854 {
 855 #ifdef HAVE_CIPHERSUITES
 856         const char *err;
 857         int rc = gnutls_priority_init( &ctx->prios, suites, &err );
 858         if ( rc )
 859                 ctx->prios = NULL;
 860         return rc;
 861 #else
 862         char *ptr, *end;
 863         int i, j, len, num;
 864         int *list, nkx = 0, ncipher = 0, nmac = 0;
 865         int *kx, *cipher, *mac;
 866
 867         num = 0;
 868         ptr = suites;
 869         do {
 870                 end = strchr(ptr, ':');
 871                 if ( end )
 872                         len = end - ptr;
 873                 else
 874                         len = strlen(ptr);
 875                 for (i=0; i<tlsg_n_ciphers; i++) {
 876                         if ( !strncasecmp( tlsg_ciphers[i].name, ptr, len )) {
 877                                 num++;
 878                                 break;
 879                         }
 880                 }
 881                 if ( i == tlsg_n_ciphers ) {
 882                         /* unrecognized cipher suite */
 883                         return -1;
 884                 }
 885                 ptr += len + 1;
 886         } while (end);
 887
 888         /* Space for all 3 lists */
 889         list = LDAP_MALLOC( (num+1) * sizeof(int) * 3 );
 890         if ( !list )
 891                 return -1;
 892         kx = list;
 893         cipher = kx+num+1;
 894         mac = cipher+num+1;
 895
 896         ptr = suites;
 897         do {
 898                 end = strchr(ptr, ':');
 899                 if ( end )
 900                         len = end - ptr;
 901                 else
 902                         len = strlen(ptr);
 903                 for (i=0; i<tlsg_n_ciphers; i++) {
 904                         /* For each cipher suite, insert its algorithms into
 905                          * their respective priority lists. Make sure they
 906                          * only appear once in each list.
 907                          */
 908                         if ( !strncasecmp( tlsg_ciphers[i].name, ptr, len )) {
 909                                 for (j=0; j<nkx; j++)
 910                                         if ( kx[j] == tlsg_ciphers[i].kx )
 911                                                 break;
 912                                 if ( j == nkx )
 913                                         kx[nkx++] = tlsg_ciphers[i].kx;
 914                                 for (j=0; j<ncipher; j++)
 915                                         if ( cipher[j] == tlsg_ciphers[i].cipher )
 916                                                 break;
 917                                 if ( j == ncipher )
 918                                         cipher[ncipher++] = tlsg_ciphers[i].cipher;
 919                                 for (j=0; j<nmac; j++)
 920                                         if ( mac[j] == tlsg_ciphers[i].mac )
 921                                                 break;
 922                                 if ( j == nmac )
 923                                         mac[nmac++] = tlsg_ciphers[i].mac;
 924                                 break;
 925                         }
 926                 }
 927                 ptr += len + 1;
 928         } while (end);
 929         kx[nkx] = 0;
 930         cipher[ncipher] = 0;
 931         mac[nmac] = 0;
 932         ctx->kx_list = kx;
 933         ctx->cipher_list = cipher;
 934         ctx->mac_list = mac;
 935         return 0;
 936 #endif
 937 }
 938
 939 /*
 940  * TLS support for LBER Sockbufs
 941  */
 942
 943 struct tls_data {
 944         tlsg_session            *session;
 945         Sockbuf_IO_Desc         *sbiod;
 946 };
 947
 948 static ssize_t
 949 tlsg_recv( gnutls_transport_ptr_t ptr, void *buf, size_t len )
 950 {
 951         struct tls_data         *p;
 952
 953         if ( buf == NULL || len <= 0 ) return 0;
 954
 955         p = (struct tls_data *)ptr;
 956
 957         if ( p == NULL || p->sbiod == NULL ) {
 958                 return 0;
 959         }
 960
 961         return LBER_SBIOD_READ_NEXT( p->sbiod, buf, len );
 962 }
 963
 964 static ssize_t
 965 tlsg_send( gnutls_transport_ptr_t ptr, const void *buf, size_t len )
 966 {
 967         struct tls_data         *p;
 968
 969         if ( buf == NULL || len <= 0 ) return 0;
 970
 971         p = (struct tls_data *)ptr;
 972
 973         if ( p == NULL || p->sbiod == NULL ) {
 974                 return 0;
 975         }
 976
 977         return LBER_SBIOD_WRITE_NEXT( p->sbiod, (char *)buf, len );
 978 }
 979
 980 static int
 981 tlsg_sb_setup( Sockbuf_IO_Desc *sbiod, void *arg )
 982 {
 983         struct tls_data         *p;
 984         tlsg_session    *session = arg;
 985
 986         assert( sbiod != NULL );
 987
 988         p = LBER_MALLOC( sizeof( *p ) );
 989         if ( p == NULL ) {
 990                 return -1;
 991         }
 992
 993         gnutls_transport_set_ptr( session->session, (gnutls_transport_ptr)p );
 994         gnutls_transport_set_pull_function( session->session, tlsg_recv );
 995         gnutls_transport_set_push_function( session->session, tlsg_send );
 996         p->session = session;
 997         p->sbiod = sbiod;
 998         sbiod->sbiod_pvt = p;
 999         return 0;
1000 }
1001
1002 static int
1003 tlsg_sb_remove( Sockbuf_IO_Desc *sbiod )
1004 {
1005         struct tls_data         *p;
1006
1007         assert( sbiod != NULL );
1008         assert( sbiod->sbiod_pvt != NULL );
1009
1010         p = (struct tls_data *)sbiod->sbiod_pvt;
1011         gnutls_deinit ( p->session->session );
1012         LBER_FREE( p->session );
1013         LBER_FREE( sbiod->sbiod_pvt );
1014         sbiod->sbiod_pvt = NULL;
1015         return 0;
1016 }
1017
1018 static int
1019 tlsg_sb_close( Sockbuf_IO_Desc *sbiod )
1020 {
1021         struct tls_data         *p;
1022
1023         assert( sbiod != NULL );
1024         assert( sbiod->sbiod_pvt != NULL );
1025
1026         p = (struct tls_data *)sbiod->sbiod_pvt;
1027         gnutls_bye ( p->session->session, GNUTLS_SHUT_WR );
1028         return 0;
1029 }
1030
1031 static int
1032 tlsg_sb_ctrl( Sockbuf_IO_Desc *sbiod, int opt, void *arg )
1033 {
1034         struct tls_data         *p;
1035
1036         assert( sbiod != NULL );
1037         assert( sbiod->sbiod_pvt != NULL );
1038
1039         p = (struct tls_data *)sbiod->sbiod_pvt;
1040
1041         if ( opt == LBER_SB_OPT_GET_SSL ) {
1042                 *((tlsg_session **)arg) = p->session;
1043                 return 1;
1044
1045         } else if ( opt == LBER_SB_OPT_DATA_READY ) {
1046                 if( gnutls_record_check_pending( p->session->session ) > 0 ) {
1047                         return 1;
1048                 }
1049         }
1050
1051         return LBER_SBIOD_CTRL_NEXT( sbiod, opt, arg );
1052 }
1053
1054 static ber_slen_t
1055 tlsg_sb_read( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
1056 {
1057         struct tls_data         *p;
1058         ber_slen_t              ret;
1059
1060         assert( sbiod != NULL );
1061         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
1062
1063         p = (struct tls_data *)sbiod->sbiod_pvt;
1064
1065         ret = gnutls_record_recv ( p->session->session, buf, len );
1066         switch (ret) {
1067         case GNUTLS_E_INTERRUPTED:
1068         case GNUTLS_E_AGAIN:
1069                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
1070                 sock_errset(EWOULDBLOCK);
1071                 ret = 0;
1072                 break;
1073         case GNUTLS_E_REHANDSHAKE:
1074                 for ( ret = gnutls_handshake ( p->session->session );
1075                       ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN;
1076                       ret = gnutls_handshake ( p->session->session ) );
1077                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
1078                 ret = 0;
1079                 break;
1080         default:
1081                 sbiod->sbiod_sb->sb_trans_needs_read = 0;
1082         }
1083         return ret;
1084 }
1085
1086 static ber_slen_t
1087 tlsg_sb_write( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
1088 {
1089         struct tls_data         *p;
1090         ber_slen_t              ret;
1091
1092         assert( sbiod != NULL );
1093         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
1094
1095         p = (struct tls_data *)sbiod->sbiod_pvt;
1096
1097         ret = gnutls_record_send ( p->session->session, (char *)buf, len );
1098
1099         if ( ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN ) {
1100                 sbiod->sbiod_sb->sb_trans_needs_write = 1;
1101                 sock_errset(EWOULDBLOCK);
1102                 ret = 0;
1103         } else {
1104                 sbiod->sbiod_sb->sb_trans_needs_write = 0;
1105         }
1106         return ret;
1107 }
1108
1109 static Sockbuf_IO tlsg_sbio =
1110 {
1111         tlsg_sb_setup,          /* sbi_setup */
1112         tlsg_sb_remove,         /* sbi_remove */
1113         tlsg_sb_ctrl,           /* sbi_ctrl */
1114         tlsg_sb_read,           /* sbi_read */
1115         tlsg_sb_write,          /* sbi_write */
1116         tlsg_sb_close           /* sbi_close */
1117 };
1118
1119 /* Certs are not automatically varified during the handshake */
1120 static int
1121 tlsg_cert_verify( tlsg_session *ssl )
1122 {
1123         unsigned int status = 0;
1124         int err;
1125         time_t now = time(0);
1126         time_t peertime;
1127
1128         err = gnutls_certificate_verify_peers2( ssl->session, &status );
1129         if ( err < 0 ) {
1130                 Debug( LDAP_DEBUG_ANY,"TLS: gnutls_certificate_verify_peers2 failed %d\n",
1131                         err,0,0 );
1132                 return -1;
1133         }
1134         if ( status ) {
1135                 Debug( LDAP_DEBUG_TRACE,"TLS: peer cert untrusted or revoked (0x%x)\n",
1136                         status, 0,0 );
1137                 return -1;
1138         }
1139         peertime = gnutls_certificate_expiration_time_peers( ssl->session );
1140         if ( peertime == (time_t) -1 ) {
1141                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_expiration_time_peers failed\n",
1142                         0, 0, 0 );
1143                 return -1;
1144         }
1145         if ( peertime < now ) {
1146                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate is expired\n",
1147                         0, 0, 0 );
1148                 return -1;
1149         }
1150         peertime = gnutls_certificate_activation_time_peers( ssl->session );
1151         if ( peertime == (time_t) -1 ) {
1152                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_activation_time_peers failed\n",
1153                         0, 0, 0 );
1154                 return -1;
1155         }
1156         if ( peertime > now ) {
1157                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate not yet active\n",
1158                         0, 0, 0 );
1159                 return -1;
1160         }
1161         return 0;
1162 }
1163
1164 tls_impl ldap_int_tls_impl = {
1165         "GnuTLS",
1166
1167         tlsg_init,
1168         tlsg_destroy,
1169
1170         tlsg_ctx_new,
1171         tlsg_ctx_ref,
1172         tlsg_ctx_free,
1173         tlsg_ctx_init,
1174
1175         tlsg_session_new,
1176         tlsg_session_connect,
1177         tlsg_session_accept,
1178         tlsg_session_upflags,
1179         tlsg_session_errmsg,
1180         tlsg_session_my_dn,
1181         tlsg_session_peer_dn,
1182         tlsg_session_chkhost,
1183         tlsg_session_strength,
1184         tlsg_session_unique,
1185         tlsg_session_version,
1186         tlsg_session_cipher,
1187         tlsg_session_peercert,
1188
1189         &tlsg_sbio,
1190
1191 #ifdef LDAP_R_COMPILE
1192         tlsg_thr_init,
1193 #else
1194         NULL,
1195 #endif
1196
1197         0
1198 };
1199
1200 #endif /* HAVE_GNUTLS */