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 2008-2017 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 <gnutls/abstract.h>
  47 #include <gnutls/crypto.h>
  48
  49 typedef struct tlsg_ctx {
  50         gnutls_certificate_credentials_t cred;
  51         gnutls_dh_params_t dh_params;
  52         unsigned long verify_depth;
  53         int refcount;
  54         int reqcert;
  55         gnutls_priority_t prios;
  56 #ifdef LDAP_R_COMPILE
  57         ldap_pvt_thread_mutex_t ref_mutex;
  58 #endif
  59 } tlsg_ctx;
  60
  61 typedef struct tlsg_session {
  62         gnutls_session_t session;
  63         tlsg_ctx *ctx;
  64         struct berval peer_der_dn;
  65 } tlsg_session;
  66
  67 static int tlsg_parse_ciphers( tlsg_ctx *ctx, char *suites );
  68 static int tlsg_cert_verify( tlsg_session *s );
  69
  70 #ifdef LDAP_R_COMPILE
  71
  72 static int
  73 tlsg_mutex_init( void **priv )
  74 {
  75         int err = 0;
  76         ldap_pvt_thread_mutex_t *lock = LDAP_MALLOC( sizeof( ldap_pvt_thread_mutex_t ));
  77
  78         if ( !lock )
  79                 err = ENOMEM;
  80         if ( !err ) {
  81                 err = ldap_pvt_thread_mutex_init( lock );
  82                 if ( err )
  83                         LDAP_FREE( lock );
  84                 else
  85                         *priv = lock;
  86         }
  87         return err;
  88 }
  89
  90 static int
  91 tlsg_mutex_destroy( void **lock )
  92 {
  93         int err = ldap_pvt_thread_mutex_destroy( *lock );
  94         LDAP_FREE( *lock );
  95         return err;
  96 }
  97
  98 static int
  99 tlsg_mutex_lock( void **lock )
 100 {
 101         return ldap_pvt_thread_mutex_lock( *lock );
 102 }
 103
 104 static int
 105 tlsg_mutex_unlock( void **lock )
 106 {
 107         return ldap_pvt_thread_mutex_unlock( *lock );
 108 }
 109
 110 static void
 111 tlsg_thr_init( void )
 112 {
 113         gnutls_global_set_mutex (tlsg_mutex_init,
 114                 tlsg_mutex_destroy,
 115                 tlsg_mutex_lock,
 116                 tlsg_mutex_unlock);
 117 }
 118 #endif /* LDAP_R_COMPILE */
 119
 120 /*
 121  * Initialize TLS subsystem. Should be called only once.
 122  */
 123 static int
 124 tlsg_init( void )
 125 {
 126         gnutls_global_init();
 127         return 0;
 128 }
 129
 130 /*
 131  * Tear down the TLS subsystem. Should only be called once.
 132  */
 133 static void
 134 tlsg_destroy( void )
 135 {
 136         gnutls_global_deinit();
 137 }
 138
 139 static tls_ctx *
 140 tlsg_ctx_new ( struct ldapoptions *lo )
 141 {
 142         tlsg_ctx *ctx;
 143
 144         ctx = ber_memcalloc ( 1, sizeof (*ctx) );
 145         if ( ctx ) {
 146                 if ( gnutls_certificate_allocate_credentials( &ctx->cred )) {
 147                         ber_memfree( ctx );
 148                         return NULL;
 149                 }
 150                 ctx->refcount = 1;
 151                 gnutls_priority_init( &ctx->prios, "NORMAL", NULL );
 152 #ifdef LDAP_R_COMPILE
 153                 ldap_pvt_thread_mutex_init( &ctx->ref_mutex );
 154 #endif
 155         }
 156         return (tls_ctx *)ctx;
 157 }
 158
 159 static void
 160 tlsg_ctx_ref( tls_ctx *ctx )
 161 {
 162         tlsg_ctx *c = (tlsg_ctx *)ctx;
 163         LDAP_MUTEX_LOCK( &c->ref_mutex );
 164         c->refcount++;
 165         LDAP_MUTEX_UNLOCK( &c->ref_mutex );
 166 }
 167
 168 static void
 169 tlsg_ctx_free ( tls_ctx *ctx )
 170 {
 171         tlsg_ctx *c = (tlsg_ctx *)ctx;
 172         int refcount;
 173
 174         if ( !c ) return;
 175
 176         LDAP_MUTEX_LOCK( &c->ref_mutex );
 177         refcount = --c->refcount;
 178         LDAP_MUTEX_UNLOCK( &c->ref_mutex );
 179         if ( refcount )
 180                 return;
 181         gnutls_priority_deinit( c->prios );
 182         gnutls_certificate_free_credentials( c->cred );
 183         if ( c->dh_params )
 184                 gnutls_dh_params_deinit( c->dh_params );
 185         ber_memfree ( c );
 186 }
 187
 188 static int
 189 tlsg_getfile( const char *path, gnutls_datum_t *buf )
 190 {
 191         int rc = -1, fd;
 192         struct stat st;
 193
 194         fd = open( path, O_RDONLY );
 195         if ( fd >= 0 && fstat( fd, &st ) == 0 ) {
 196                 buf->size = st.st_size;
 197                 buf->data = LDAP_MALLOC( st.st_size + 1 );
 198                 if ( buf->data ) {
 199                         rc = read( fd, buf->data, st.st_size );
 200                         close( fd );
 201                         if ( rc < st.st_size )
 202                                 rc = -1;
 203                         else
 204                                 rc = 0;
 205                 }
 206         }
 207         return rc;
 208 }
 209
 210 /* This is the GnuTLS default */
 211 #define VERIFY_DEPTH    6
 212
 213 /*
 214  * initialize a new TLS context
 215  */
 216 static int
 217 tlsg_ctx_init( struct ldapoptions *lo, struct ldaptls *lt, int is_server )
 218 {
 219         tlsg_ctx *ctx = lo->ldo_tls_ctx;
 220         int rc;
 221
 222         if ( lo->ldo_tls_ciphersuite &&
 223                 tlsg_parse_ciphers( ctx, lt->lt_ciphersuite )) {
 224                 Debug( LDAP_DEBUG_ANY,
 225                            "TLS: could not set cipher list %s.\n",
 226                            lo->ldo_tls_ciphersuite, 0, 0 );
 227                 return -1;
 228         }
 229
 230         if (lo->ldo_tls_cacertdir != NULL) {
 231                 Debug( LDAP_DEBUG_ANY,
 232                        "TLS: warning: cacertdir not implemented for gnutls\n",
 233                        NULL, NULL, NULL );
 234         }
 235
 236         if (lo->ldo_tls_cacertfile != NULL) {
 237                 rc = gnutls_certificate_set_x509_trust_file(
 238                         ctx->cred,
 239                         lt->lt_cacertfile,
 240                         GNUTLS_X509_FMT_PEM );
 241                 if ( rc < 0 ) return -1;
 242         }
 243         if (lo->ldo_tls_cacert.bv_val != NULL ) {
 244                 gnutls_datum_t buf;
 245                 buf.data = (unsigned char *)lo->ldo_tls_cacert.bv_val;
 246                 buf.size = lo->ldo_tls_cacert.bv_len;
 247                 rc = gnutls_certificate_set_x509_trust_mem(
 248                         ctx->cred,
 249                         &buf,
 250                         GNUTLS_X509_FMT_DER );
 251                 if ( rc < 0 ) return -1;
 252         }
 253
 254         if (( lo->ldo_tls_certfile && lo->ldo_tls_keyfile ) ||
 255                 ( lo->ldo_tls_cert.bv_val && lo->ldo_tls_key.bv_val )) {
 256                 gnutls_x509_privkey_t key;
 257                 gnutls_datum_t buf;
 258                 gnutls_x509_crt_t certs[VERIFY_DEPTH];
 259                 unsigned int max = VERIFY_DEPTH;
 260
 261                 rc = gnutls_x509_privkey_init( &key );
 262                 if ( rc ) return -1;
 263
 264                 /* OpenSSL builds the cert chain for us, but GnuTLS
 265                  * expects it to be present in the certfile. If it's
 266                  * not, we have to build it ourselves. So we have to
 267                  * do some special checks here...
 268                  */
 269                 if ( lo->ldo_tls_key.bv_val ) {
 270                         buf.data = (unsigned char *)lo->ldo_tls_key.bv_val;
 271                         buf.size = lo->ldo_tls_key.bv_len;
 272                         rc = gnutls_x509_privkey_import( key, &buf,
 273                                 GNUTLS_X509_FMT_DER );
 274                 } else {
 275                         rc = tlsg_getfile( lt->lt_keyfile, &buf );
 276                         if ( rc ) return -1;
 277                         rc = gnutls_x509_privkey_import( key, &buf,
 278                                 GNUTLS_X509_FMT_PEM );
 279                         LDAP_FREE( buf.data );
 280                 }
 281                 if ( rc < 0 ) return rc;
 282
 283                 if ( lo->ldo_tls_cert.bv_val ) {
 284                         buf.data = (unsigned char *)lo->ldo_tls_cert.bv_val;
 285                         buf.size = lo->ldo_tls_cert.bv_len;
 286                         rc = gnutls_x509_crt_list_import( certs, &max, &buf,
 287                                 GNUTLS_X509_FMT_DER, 0 );
 288                 } else {
 289                         rc = tlsg_getfile( lt->lt_certfile, &buf );
 290                         if ( rc ) return -1;
 291                         rc = gnutls_x509_crt_list_import( certs, &max, &buf,
 292                                 GNUTLS_X509_FMT_PEM, 0 );
 293                         LDAP_FREE( buf.data );
 294                 }
 295                 if ( rc < 0 ) return rc;
 296
 297                 /* If there's only one cert and it's not self-signed,
 298                  * then we have to build the cert chain.
 299                  */
 300                 if ( max == 1 && !gnutls_x509_crt_check_issuer( certs[0], certs[0] )) {
 301                         unsigned int i;
 302                         for ( i = 1; i<VERIFY_DEPTH; i++ ) {
 303                                 if ( gnutls_certificate_get_issuer( ctx->cred, certs[i-1], &certs[i], 0 ))
 304                                         break;
 305                                 max++;
 306                                 /* If this CA is self-signed, we're done */
 307                                 if ( gnutls_x509_crt_check_issuer( certs[i], certs[i] ))
 308                                         break;
 309                         }
 310                 }
 311                 rc = gnutls_certificate_set_x509_key( ctx->cred, certs, max, key );
 312                 if ( rc ) return -1;
 313         } else if (( lo->ldo_tls_certfile || lo->ldo_tls_keyfile )) {
 314                 Debug( LDAP_DEBUG_ANY,
 315                        "TLS: only one of certfile and keyfile specified\n",
 316                        NULL, NULL, NULL );
 317                 return -1;
 318         } else if (( lo->ldo_tls_cert.bv_val || lo->ldo_tls_key.bv_val )) {
 319                 Debug( LDAP_DEBUG_ANY,
 320                        "TLS: only one of cert and key specified\n",
 321                        NULL, NULL, NULL );
 322                 return -1;
 323         }
 324
 325         if ( lo->ldo_tls_crlfile ) {
 326                 rc = gnutls_certificate_set_x509_crl_file(
 327                         ctx->cred,
 328                         lt->lt_crlfile,
 329                         GNUTLS_X509_FMT_PEM );
 330                 if ( rc < 0 ) return -1;
 331                 rc = 0;
 332         }
 333
 334         /* FIXME: ITS#5992 - this should be configurable,
 335          * and V1 CA certs should be phased out ASAP.
 336          */
 337         gnutls_certificate_set_verify_flags( ctx->cred,
 338                 GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT );
 339
 340         if ( is_server && lo->ldo_tls_dhfile ) {
 341                 gnutls_datum_t buf;
 342                 rc = tlsg_getfile( lo->ldo_tls_dhfile, &buf );
 343                 if ( rc ) return -1;
 344                 rc = gnutls_dh_params_init( &ctx->dh_params );
 345                 if ( rc == 0 )
 346                         rc = gnutls_dh_params_import_pkcs3( ctx->dh_params, &buf,
 347                                 GNUTLS_X509_FMT_PEM );
 348                 LDAP_FREE( buf.data );
 349                 if ( rc ) return -1;
 350                 gnutls_certificate_set_dh_params( ctx->cred, ctx->dh_params );
 351         }
 352
 353         ctx->reqcert = lo->ldo_tls_require_cert;
 354
 355         return 0;
 356 }
 357
 358 static tls_session *
 359 tlsg_session_new ( tls_ctx * ctx, int is_server )
 360 {
 361         tlsg_ctx *c = (tlsg_ctx *)ctx;
 362         tlsg_session *session;
 363
 364         session = ber_memcalloc ( 1, sizeof (*session) );
 365         if ( !session )
 366                 return NULL;
 367
 368         session->ctx = c;
 369         gnutls_init( &session->session, is_server ? GNUTLS_SERVER : GNUTLS_CLIENT );
 370         gnutls_priority_set( session->session, c->prios );
 371         if ( c->cred )
 372                 gnutls_credentials_set( session->session, GNUTLS_CRD_CERTIFICATE, c->cred );
 373
 374         if ( is_server ) {
 375                 int flag = 0;
 376                 if ( c->reqcert ) {
 377                         flag = GNUTLS_CERT_REQUEST;
 378                         if ( c->reqcert == LDAP_OPT_X_TLS_DEMAND ||
 379                                 c->reqcert == LDAP_OPT_X_TLS_HARD )
 380                                 flag = GNUTLS_CERT_REQUIRE;
 381                         gnutls_certificate_server_set_request( session->session, flag );
 382                 }
 383         }
 384         return (tls_session *)session;
 385 }
 386
 387 static int
 388 tlsg_session_accept( tls_session *session )
 389 {
 390         tlsg_session *s = (tlsg_session *)session;
 391         int rc;
 392
 393         for ( rc = gnutls_handshake ( s->session );
 394               rc == GNUTLS_E_INTERRUPTED || rc == GNUTLS_E_AGAIN;
 395               rc = gnutls_handshake ( s->session ) );
 396         if ( rc == 0 && s->ctx->reqcert != LDAP_OPT_X_TLS_NEVER ) {
 397                 const gnutls_datum_t *peer_cert_list;
 398                 unsigned int list_size;
 399
 400                 peer_cert_list = gnutls_certificate_get_peers( s->session,
 401                                                 &list_size );
 402                 if ( !peer_cert_list && s->ctx->reqcert == LDAP_OPT_X_TLS_TRY )
 403                         rc = 0;
 404                 else {
 405                         rc = tlsg_cert_verify( s );
 406                         if ( rc && s->ctx->reqcert == LDAP_OPT_X_TLS_ALLOW )
 407                                 rc = 0;
 408                 }
 409         }
 410         return rc;
 411 }
 412
 413 static int
 414 tlsg_session_connect( LDAP *ld, tls_session *session )
 415 {
 416         return tlsg_session_accept( session);
 417 }
 418
 419 static int
 420 tlsg_session_upflags( Sockbuf *sb, tls_session *session, int rc )
 421 {
 422         tlsg_session *s = (tlsg_session *)session;
 423
 424         if ( rc != GNUTLS_E_INTERRUPTED && rc != GNUTLS_E_AGAIN )
 425                 return 0;
 426
 427         switch (gnutls_record_get_direction (s->session)) {
 428         case 0:
 429                 sb->sb_trans_needs_read = 1;
 430                 return 1;
 431         case 1:
 432                 sb->sb_trans_needs_write = 1;
 433                 return 1;
 434         }
 435         return 0;
 436 }
 437
 438 static char *
 439 tlsg_session_errmsg( tls_session *sess, int rc, char *buf, size_t len )
 440 {
 441         return (char *)gnutls_strerror( rc );
 442 }
 443
 444 static void
 445 tlsg_x509_cert_dn( struct berval *cert, struct berval *dn, int get_subject )
 446 {
 447         BerElementBuffer berbuf;
 448         BerElement *ber = (BerElement *)&berbuf;
 449         ber_tag_t tag;
 450         ber_len_t len;
 451         ber_int_t i;
 452
 453         ber_init2( ber, cert, LBER_USE_DER );
 454         tag = ber_skip_tag( ber, &len );        /* Sequence */
 455         tag = ber_skip_tag( ber, &len );        /* Sequence */
 456         tag = ber_peek_tag( ber, &len );        /* Context + Constructed (version) */
 457         if ( tag == 0xa0 ) {    /* Version is optional */
 458                 tag = ber_skip_tag( ber, &len );
 459                 tag = ber_get_int( ber, &i );   /* Int: Version */
 460         }
 461         tag = ber_skip_tag( ber, &len );        /* Int: Serial (can be longer than ber_int_t) */
 462         ber_skip_data( ber, len );
 463         tag = ber_skip_tag( ber, &len );        /* Sequence: Signature */
 464         ber_skip_data( ber, len );
 465         if ( !get_subject ) {
 466                 tag = ber_peek_tag( ber, &len );        /* Sequence: Issuer DN */
 467         } else {
 468                 tag = ber_skip_tag( ber, &len );
 469                 ber_skip_data( ber, len );
 470                 tag = ber_skip_tag( ber, &len );        /* Sequence: Validity */
 471                 ber_skip_data( ber, len );
 472                 tag = ber_peek_tag( ber, &len );        /* Sequence: Subject DN */
 473         }
 474         len = ber_ptrlen( ber );
 475         dn->bv_val = cert->bv_val + len;
 476         dn->bv_len = cert->bv_len - len;
 477 }
 478
 479 static int
 480 tlsg_session_my_dn( tls_session *session, struct berval *der_dn )
 481 {
 482         tlsg_session *s = (tlsg_session *)session;
 483         const gnutls_datum_t *x;
 484         struct berval bv;
 485
 486         x = gnutls_certificate_get_ours( s->session );
 487
 488         if (!x) return LDAP_INVALID_CREDENTIALS;
 489
 490         bv.bv_val = (char *) x->data;
 491         bv.bv_len = x->size;
 492
 493         tlsg_x509_cert_dn( &bv, der_dn, 1 );
 494         return 0;
 495 }
 496
 497 static int
 498 tlsg_session_peer_dn( tls_session *session, struct berval *der_dn )
 499 {
 500         tlsg_session *s = (tlsg_session *)session;
 501         if ( !s->peer_der_dn.bv_val ) {
 502                 const gnutls_datum_t *peer_cert_list;
 503                 unsigned int list_size;
 504                 struct berval bv;
 505
 506                 peer_cert_list = gnutls_certificate_get_peers( s->session,
 507                                                         &list_size );
 508                 if ( !peer_cert_list ) return LDAP_INVALID_CREDENTIALS;
 509
 510                 bv.bv_len = peer_cert_list->size;
 511                 bv.bv_val = (char *) peer_cert_list->data;
 512
 513                 tlsg_x509_cert_dn( &bv, &s->peer_der_dn, 1 );
 514         }
 515         *der_dn = s->peer_der_dn;
 516         return 0;
 517 }
 518
 519 /* what kind of hostname were we given? */
 520 #define IS_DNS  0
 521 #define IS_IP4  1
 522 #define IS_IP6  2
 523
 524 #define CN_OID  "2.5.4.3"
 525
 526 static int
 527 tlsg_session_chkhost( LDAP *ld, tls_session *session, const char *name_in )
 528 {
 529         tlsg_session *s = (tlsg_session *)session;
 530         int i, ret;
 531         const gnutls_datum_t *peer_cert_list;
 532         unsigned int list_size;
 533         char altname[NI_MAXHOST];
 534         size_t altnamesize;
 535
 536         gnutls_x509_crt_t cert;
 537         const char *name;
 538         char *ptr;
 539         char *domain = NULL;
 540 #ifdef LDAP_PF_INET6
 541         struct in6_addr addr;
 542 #else
 543         struct in_addr addr;
 544 #endif
 545         int len1 = 0, len2 = 0;
 546         int ntype = IS_DNS;
 547
 548         if( ldap_int_hostname &&
 549                 ( !name_in || !strcasecmp( name_in, "localhost" ) ) )
 550         {
 551                 name = ldap_int_hostname;
 552         } else {
 553                 name = name_in;
 554         }
 555
 556         peer_cert_list = gnutls_certificate_get_peers( s->session,
 557                                                 &list_size );
 558         if ( !peer_cert_list ) {
 559                 Debug( LDAP_DEBUG_ANY,
 560                         "TLS: unable to get peer certificate.\n",
 561                         0, 0, 0 );
 562                 /* If this was a fatal condition, things would have
 563                  * aborted long before now.
 564                  */
 565                 return LDAP_SUCCESS;
 566         }
 567         ret = gnutls_x509_crt_init( &cert );
 568         if ( ret < 0 )
 569                 return LDAP_LOCAL_ERROR;
 570         ret = gnutls_x509_crt_import( cert, peer_cert_list, GNUTLS_X509_FMT_DER );
 571         if ( ret ) {
 572                 gnutls_x509_crt_deinit( cert );
 573                 return LDAP_LOCAL_ERROR;
 574         }
 575
 576 #ifdef LDAP_PF_INET6
 577         if (inet_pton(AF_INET6, name, &addr)) {
 578                 ntype = IS_IP6;
 579         } else
 580 #endif
 581         if ((ptr = strrchr(name, '.')) && isdigit((unsigned char)ptr[1])) {
 582                 if (inet_aton(name, (struct in_addr *)&addr)) ntype = IS_IP4;
 583         }
 584
 585         if (ntype == IS_DNS) {
 586                 len1 = strlen(name);
 587                 domain = strchr(name, '.');
 588                 if (domain) {
 589                         len2 = len1 - (domain-name);
 590                 }
 591         }
 592
 593         for ( i=0, ret=0; ret >= 0; i++ ) {
 594                 altnamesize = sizeof(altname);
 595                 ret = gnutls_x509_crt_get_subject_alt_name( cert, i,
 596                         altname, &altnamesize, NULL );
 597                 if ( ret < 0 ) break;
 598
 599                 /* ignore empty */
 600                 if ( altnamesize == 0 ) continue;
 601
 602                 if ( ret == GNUTLS_SAN_DNSNAME ) {
 603                         if (ntype != IS_DNS) continue;
 604
 605                         /* Is this an exact match? */
 606                         if ((len1 == altnamesize) && !strncasecmp(name, altname, len1)) {
 607                                 break;
 608                         }
 609
 610                         /* Is this a wildcard match? */
 611                         if (domain && (altname[0] == '*') && (altname[1] == '.') &&
 612                                 (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2))
 613                         {
 614                                 break;
 615                         }
 616                 } else if ( ret == GNUTLS_SAN_IPADDRESS ) {
 617                         if (ntype == IS_DNS) continue;
 618
 619 #ifdef LDAP_PF_INET6
 620                         if (ntype == IS_IP6 && altnamesize != sizeof(struct in6_addr)) {
 621                                 continue;
 622                         } else
 623 #endif
 624                         if (ntype == IS_IP4 && altnamesize != sizeof(struct in_addr)) {
 625                                 continue;
 626                         }
 627                         if (!memcmp(altname, &addr, altnamesize)) {
 628                                 break;
 629                         }
 630                 }
 631         }
 632         if ( ret >= 0 ) {
 633                 ret = LDAP_SUCCESS;
 634         } else {
 635                 /* find the last CN */
 636                 i=0;
 637                 do {
 638                         altnamesize = 0;
 639                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 640                                 i, 1, altname, &altnamesize );
 641                         if ( ret == GNUTLS_E_SHORT_MEMORY_BUFFER )
 642                                 i++;
 643                         else
 644                                 break;
 645                 } while ( 1 );
 646
 647                 if ( i ) {
 648                         altnamesize = sizeof(altname);
 649                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 650                                 i-1, 0, altname, &altnamesize );
 651                 }
 652
 653                 if ( ret < 0 ) {
 654                         Debug( LDAP_DEBUG_ANY,
 655                                 "TLS: unable to get common name from peer certificate.\n",
 656                                 0, 0, 0 );
 657                         ret = LDAP_CONNECT_ERROR;
 658                         if ( ld->ld_error ) {
 659                                 LDAP_FREE( ld->ld_error );
 660                         }
 661                         ld->ld_error = LDAP_STRDUP(
 662                                 _("TLS: unable to get CN from peer certificate"));
 663
 664                 } else {
 665                         ret = LDAP_LOCAL_ERROR;
 666                         if ( !len1 ) len1 = strlen( name );
 667                         if ( len1 == altnamesize && strncasecmp(name, altname, altnamesize) == 0 ) {
 668                                 ret = LDAP_SUCCESS;
 669
 670                         } else if (( altname[0] == '*' ) && ( altname[1] == '.' )) {
 671                                         /* Is this a wildcard match? */
 672                                 if( domain &&
 673                                         (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2)) {
 674                                         ret = LDAP_SUCCESS;
 675                                 }
 676                         }
 677                 }
 678
 679                 if( ret == LDAP_LOCAL_ERROR ) {
 680                         altname[altnamesize] = '\0';
 681                         Debug( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
 682                                 "common name in certificate (%s).\n",
 683                                 name, altname, 0 );
 684                         ret = LDAP_CONNECT_ERROR;
 685                         if ( ld->ld_error ) {
 686                                 LDAP_FREE( ld->ld_error );
 687                         }
 688                         ld->ld_error = LDAP_STRDUP(
 689                                 _("TLS: hostname does not match CN in peer certificate"));
 690                 }
 691         }
 692         gnutls_x509_crt_deinit( cert );
 693         return ret;
 694 }
 695
 696 static int
 697 tlsg_session_strength( tls_session *session )
 698 {
 699         tlsg_session *s = (tlsg_session *)session;
 700         gnutls_cipher_algorithm_t c;
 701
 702         c = gnutls_cipher_get( s->session );
 703         return gnutls_cipher_get_key_size( c ) * 8;
 704 }
 705
 706 static int
 707 tlsg_session_unique( tls_session *sess, struct berval *buf, int is_server)
 708 {
 709         tlsg_session *s = (tlsg_session *)sess;
 710         gnutls_datum_t cb;
 711         int rc;
 712
 713         rc = gnutls_session_channel_binding( s->session, GNUTLS_CB_TLS_UNIQUE, &cb );
 714         if ( rc == 0 ) {
 715                 int len = cb.size;
 716                 if ( len > buf->bv_len )
 717                         len = buf->bv_len;
 718                 buf->bv_len = len;
 719                 memcpy( buf->bv_val, cb.data, len );
 720                 return len;
 721         }
 722         return 0;
 723 }
 724
 725 static const char *
 726 tlsg_session_version( tls_session *sess )
 727 {
 728         tlsg_session *s = (tlsg_session *)sess;
 729         return gnutls_protocol_get_name(gnutls_protocol_get_version( s->session ));
 730 }
 731
 732 static const char *
 733 tlsg_session_cipher( tls_session *sess )
 734 {
 735         tlsg_session *s = (tlsg_session *)sess;
 736         return gnutls_cipher_get_name(gnutls_cipher_get( s->session ));
 737 }
 738
 739 static int
 740 tlsg_session_peercert( tls_session *sess, struct berval *der )
 741 {
 742         tlsg_session *s = (tlsg_session *)sess;
 743         const gnutls_datum_t *peer_cert_list;
 744         unsigned int list_size;
 745
 746         peer_cert_list = gnutls_certificate_get_peers( s->session, &list_size );
 747         if (!peer_cert_list)
 748                 return -1;
 749         der->bv_len = peer_cert_list[0].size;
 750         der->bv_val = LDAP_MALLOC( der->bv_len );
 751         if (!der->bv_val)
 752                 return -1;
 753         memcpy(der->bv_val, peer_cert_list[0].data, der->bv_len);
 754         return 0;
 755 }
 756
 757 static int
 758 tlsg_session_pinning( LDAP *ld, tls_session *sess, char *hashalg, struct berval *hash )
 759 {
 760         tlsg_session *s = (tlsg_session *)sess;
 761         const gnutls_datum_t *cert_list;
 762         unsigned int cert_list_size = 0;
 763         gnutls_x509_crt_t crt;
 764         gnutls_pubkey_t pubkey;
 765         gnutls_datum_t key = {};
 766         gnutls_digest_algorithm_t alg;
 767         struct berval keyhash;
 768         size_t len;
 769         int rc = -1;
 770
 771         if ( hashalg ) {
 772                 alg = gnutls_digest_get_id( hashalg );
 773                 if ( alg == GNUTLS_DIG_UNKNOWN ) {
 774                         Debug( LDAP_DEBUG_ANY, "tlsg_session_pinning: "
 775                                         "unknown hashing algorithm for GnuTLS: '%s'\n",
 776                                         hashalg, 0, 0 );
 777                         return rc;
 778                 }
 779         }
 780
 781         cert_list = gnutls_certificate_get_peers( s->session, &cert_list_size );
 782         if ( cert_list_size == 0 ) {
 783                 return rc;
 784         }
 785
 786         if ( gnutls_x509_crt_init( &crt ) < 0 ) {
 787                 return rc;
 788         }
 789
 790         if ( gnutls_x509_crt_import( crt, &cert_list[0], GNUTLS_X509_FMT_DER ) ) {
 791                 goto done;
 792         }
 793
 794         if ( gnutls_pubkey_init( &pubkey ) ) {
 795                 goto done;
 796         }
 797
 798         if ( gnutls_pubkey_import_x509( pubkey, crt, 0 ) < 0 ) {
 799                 goto done;
 800         }
 801
 802         gnutls_pubkey_export( pubkey, GNUTLS_X509_FMT_DER, key.data, &len );
 803         if ( len <= 0 ) {
 804                 goto done;
 805         }
 806
 807         key.data = LDAP_MALLOC( len );
 808         if ( !key.data ) {
 809                 goto done;
 810         }
 811
 812         key.size = len;
 813
 814         if ( gnutls_pubkey_export( pubkey, GNUTLS_X509_FMT_DER,
 815                                 key.data, &len ) < 0 ) {
 816                 goto done;
 817         }
 818
 819         if ( hashalg ) {
 820                 keyhash.bv_len = gnutls_hash_get_len( alg );
 821                 keyhash.bv_val = LDAP_MALLOC( keyhash.bv_len );
 822                 if ( !keyhash.bv_val || gnutls_fingerprint( alg, &key,
 823                                         keyhash.bv_val, &keyhash.bv_len ) < 0 ) {
 824                         goto done;
 825                 }
 826         } else {
 827                 keyhash.bv_val = (char *)key.data;
 828                 keyhash.bv_len = key.size;
 829         }
 830
 831         if ( ber_bvcmp( hash, &keyhash ) ) {
 832                 rc = LDAP_CONNECT_ERROR;
 833                 Debug( LDAP_DEBUG_ANY, "tlsg_session_pinning: "
 834                                 "public key hash does not match provided pin.\n", 0, 0, 0 );
 835                 if ( ld->ld_error ) {
 836                         LDAP_FREE( ld->ld_error );
 837                 }
 838                 ld->ld_error = LDAP_STRDUP(
 839                         _("TLS: public key hash does not match provided pin"));
 840         } else {
 841                 rc = LDAP_SUCCESS;
 842         }
 843
 844 done:
 845         if ( pubkey ) {
 846                 gnutls_pubkey_deinit( pubkey );
 847         }
 848         if ( crt ) {
 849                 gnutls_x509_crt_deinit( crt );
 850         }
 851         if ( keyhash.bv_val != (char *)key.data ) {
 852                 LDAP_FREE( keyhash.bv_val );
 853         }
 854         if ( key.data ) {
 855                 LDAP_FREE( key.data );
 856         }
 857         return rc;
 858 }
 859
 860 /* suites is a string of colon-separated cipher suite names. */
 861 static int
 862 tlsg_parse_ciphers( tlsg_ctx *ctx, char *suites )
 863 {
 864         const char *err;
 865         int rc = gnutls_priority_init( &ctx->prios, suites, &err );
 866         if ( rc )
 867                 ctx->prios = NULL;
 868         return rc;
 869 }
 870
 871 /*
 872  * TLS support for LBER Sockbufs
 873  */
 874
 875 struct tls_data {
 876         tlsg_session            *session;
 877         Sockbuf_IO_Desc         *sbiod;
 878 };
 879
 880 static ssize_t
 881 tlsg_recv( gnutls_transport_ptr_t ptr, void *buf, size_t len )
 882 {
 883         struct tls_data         *p;
 884
 885         if ( buf == NULL || len <= 0 ) return 0;
 886
 887         p = (struct tls_data *)ptr;
 888
 889         if ( p == NULL || p->sbiod == NULL ) {
 890                 return 0;
 891         }
 892
 893         return LBER_SBIOD_READ_NEXT( p->sbiod, buf, len );
 894 }
 895
 896 static ssize_t
 897 tlsg_send( gnutls_transport_ptr_t ptr, const void *buf, size_t len )
 898 {
 899         struct tls_data         *p;
 900
 901         if ( buf == NULL || len <= 0 ) return 0;
 902
 903         p = (struct tls_data *)ptr;
 904
 905         if ( p == NULL || p->sbiod == NULL ) {
 906                 return 0;
 907         }
 908
 909         return LBER_SBIOD_WRITE_NEXT( p->sbiod, (char *)buf, len );
 910 }
 911
 912 static int
 913 tlsg_sb_setup( Sockbuf_IO_Desc *sbiod, void *arg )
 914 {
 915         struct tls_data         *p;
 916         tlsg_session    *session = arg;
 917
 918         assert( sbiod != NULL );
 919
 920         p = LBER_MALLOC( sizeof( *p ) );
 921         if ( p == NULL ) {
 922                 return -1;
 923         }
 924
 925         gnutls_transport_set_ptr( session->session, (gnutls_transport_ptr_t)p );
 926         gnutls_transport_set_pull_function( session->session, tlsg_recv );
 927         gnutls_transport_set_push_function( session->session, tlsg_send );
 928         p->session = session;
 929         p->sbiod = sbiod;
 930         sbiod->sbiod_pvt = p;
 931         return 0;
 932 }
 933
 934 static int
 935 tlsg_sb_remove( Sockbuf_IO_Desc *sbiod )
 936 {
 937         struct tls_data         *p;
 938
 939         assert( sbiod != NULL );
 940         assert( sbiod->sbiod_pvt != NULL );
 941
 942         p = (struct tls_data *)sbiod->sbiod_pvt;
 943         gnutls_deinit ( p->session->session );
 944         LBER_FREE( p->session );
 945         LBER_FREE( sbiod->sbiod_pvt );
 946         sbiod->sbiod_pvt = NULL;
 947         return 0;
 948 }
 949
 950 static int
 951 tlsg_sb_close( Sockbuf_IO_Desc *sbiod )
 952 {
 953         struct tls_data         *p;
 954
 955         assert( sbiod != NULL );
 956         assert( sbiod->sbiod_pvt != NULL );
 957
 958         p = (struct tls_data *)sbiod->sbiod_pvt;
 959         gnutls_bye ( p->session->session, GNUTLS_SHUT_WR );
 960         return 0;
 961 }
 962
 963 static int
 964 tlsg_sb_ctrl( Sockbuf_IO_Desc *sbiod, int opt, void *arg )
 965 {
 966         struct tls_data         *p;
 967
 968         assert( sbiod != NULL );
 969         assert( sbiod->sbiod_pvt != NULL );
 970
 971         p = (struct tls_data *)sbiod->sbiod_pvt;
 972
 973         if ( opt == LBER_SB_OPT_GET_SSL ) {
 974                 *((tlsg_session **)arg) = p->session;
 975                 return 1;
 976
 977         } else if ( opt == LBER_SB_OPT_DATA_READY ) {
 978                 if( gnutls_record_check_pending( p->session->session ) > 0 ) {
 979                         return 1;
 980                 }
 981         }
 982
 983         return LBER_SBIOD_CTRL_NEXT( sbiod, opt, arg );
 984 }
 985
 986 static ber_slen_t
 987 tlsg_sb_read( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
 988 {
 989         struct tls_data         *p;
 990         ber_slen_t              ret;
 991
 992         assert( sbiod != NULL );
 993         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
 994
 995         p = (struct tls_data *)sbiod->sbiod_pvt;
 996
 997         ret = gnutls_record_recv ( p->session->session, buf, len );
 998         switch (ret) {
 999         case GNUTLS_E_INTERRUPTED:
1000         case GNUTLS_E_AGAIN:
1001                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
1002                 sock_errset(EWOULDBLOCK);
1003                 ret = 0;
1004                 break;
1005         case GNUTLS_E_REHANDSHAKE:
1006                 for ( ret = gnutls_handshake ( p->session->session );
1007                       ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN;
1008                       ret = gnutls_handshake ( p->session->session ) );
1009                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
1010                 ret = 0;
1011                 break;
1012         default:
1013                 sbiod->sbiod_sb->sb_trans_needs_read = 0;
1014         }
1015         return ret;
1016 }
1017
1018 static ber_slen_t
1019 tlsg_sb_write( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
1020 {
1021         struct tls_data         *p;
1022         ber_slen_t              ret;
1023
1024         assert( sbiod != NULL );
1025         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
1026
1027         p = (struct tls_data *)sbiod->sbiod_pvt;
1028
1029         ret = gnutls_record_send ( p->session->session, (char *)buf, len );
1030
1031         if ( ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN ) {
1032                 sbiod->sbiod_sb->sb_trans_needs_write = 1;
1033                 sock_errset(EWOULDBLOCK);
1034                 ret = 0;
1035         } else {
1036                 sbiod->sbiod_sb->sb_trans_needs_write = 0;
1037         }
1038         return ret;
1039 }
1040
1041 static Sockbuf_IO tlsg_sbio =
1042 {
1043         tlsg_sb_setup,          /* sbi_setup */
1044         tlsg_sb_remove,         /* sbi_remove */
1045         tlsg_sb_ctrl,           /* sbi_ctrl */
1046         tlsg_sb_read,           /* sbi_read */
1047         tlsg_sb_write,          /* sbi_write */
1048         tlsg_sb_close           /* sbi_close */
1049 };
1050
1051 /* Certs are not automatically varified during the handshake */
1052 static int
1053 tlsg_cert_verify( tlsg_session *ssl )
1054 {
1055         unsigned int status = 0;
1056         int err;
1057         time_t now = time(0);
1058         time_t peertime;
1059
1060         err = gnutls_certificate_verify_peers2( ssl->session, &status );
1061         if ( err < 0 ) {
1062                 Debug( LDAP_DEBUG_ANY,"TLS: gnutls_certificate_verify_peers2 failed %d\n",
1063                         err,0,0 );
1064                 return -1;
1065         }
1066         if ( status ) {
1067                 Debug( LDAP_DEBUG_TRACE,"TLS: peer cert untrusted or revoked (0x%x)\n",
1068                         status, 0,0 );
1069                 return -1;
1070         }
1071         peertime = gnutls_certificate_expiration_time_peers( ssl->session );
1072         if ( peertime == (time_t) -1 ) {
1073                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_expiration_time_peers failed\n",
1074                         0, 0, 0 );
1075                 return -1;
1076         }
1077         if ( peertime < now ) {
1078                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate is expired\n",
1079                         0, 0, 0 );
1080                 return -1;
1081         }
1082         peertime = gnutls_certificate_activation_time_peers( ssl->session );
1083         if ( peertime == (time_t) -1 ) {
1084                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_activation_time_peers failed\n",
1085                         0, 0, 0 );
1086                 return -1;
1087         }
1088         if ( peertime > now ) {
1089                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate not yet active\n",
1090                         0, 0, 0 );
1091                 return -1;
1092         }
1093         return 0;
1094 }
1095
1096 tls_impl ldap_int_tls_impl = {
1097         "GnuTLS",
1098
1099         tlsg_init,
1100         tlsg_destroy,
1101
1102         tlsg_ctx_new,
1103         tlsg_ctx_ref,
1104         tlsg_ctx_free,
1105         tlsg_ctx_init,
1106
1107         tlsg_session_new,
1108         tlsg_session_connect,
1109         tlsg_session_accept,
1110         tlsg_session_upflags,
1111         tlsg_session_errmsg,
1112         tlsg_session_my_dn,
1113         tlsg_session_peer_dn,
1114         tlsg_session_chkhost,
1115         tlsg_session_strength,
1116         tlsg_session_unique,
1117         tlsg_session_version,
1118         tlsg_session_cipher,
1119         tlsg_session_peercert,
1120         tlsg_session_pinning,
1121
1122         &tlsg_sbio,
1123
1124 #ifdef LDAP_R_COMPILE
1125         tlsg_thr_init,
1126 #else
1127         NULL,
1128 #endif
1129
1130         0
1131 };
1132
1133 #endif /* HAVE_GNUTLS */