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