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 2008-2011 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  * Matt 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 #define DH_BITS (1024)
  49
  50 #if LIBGNUTLS_VERSION_NUMBER >= 0x020200
  51 #define HAVE_CIPHERSUITES       1
  52 /* This is a kludge. gcrypt 1.4.x has support. Recent GnuTLS requires gcrypt 1.4.x
  53  * but that dependency isn't reflected in their configure script, resulting in
  54  * build errors on older gcrypt. So, if they have a working build environment,
  55  * assume gcrypt is new enough.
  56  */
  57 #define HAVE_GCRYPT_RAND        1
  58 #else
  59 #undef HAVE_CIPHERSUITES
  60 #undef HAVE_GCRYPT_RAND
  61 #endif
  62
  63 #ifndef HAVE_CIPHERSUITES
  64 /* Versions prior to 2.2.0 didn't handle cipher suites, so we had to
  65  * kludge them ourselves.
  66  */
  67 typedef struct tls_cipher_suite {
  68         const char *name;
  69         gnutls_kx_algorithm_t kx;
  70         gnutls_cipher_algorithm_t cipher;
  71         gnutls_mac_algorithm_t mac;
  72         gnutls_protocol_t version;
  73 } tls_cipher_suite;
  74 #endif
  75
  76 typedef struct tlsg_ctx {
  77         struct ldapoptions *lo;
  78         gnutls_certificate_credentials_t cred;
  79         gnutls_dh_params_t dh_params;
  80         unsigned long verify_depth;
  81         int refcount;
  82 #ifdef HAVE_CIPHERSUITES
  83         gnutls_priority_t prios;
  84 #else
  85         int *kx_list;
  86         int *cipher_list;
  87         int *mac_list;
  88 #endif
  89 #ifdef LDAP_R_COMPILE
  90         ldap_pvt_thread_mutex_t ref_mutex;
  91 #endif
  92 } tlsg_ctx;
  93
  94 typedef struct tlsg_session {
  95         gnutls_session_t session;
  96         tlsg_ctx *ctx;
  97         struct berval peer_der_dn;
  98 } tlsg_session;
  99
 100 #ifndef HAVE_CIPHERSUITES
 101 static tls_cipher_suite *tlsg_ciphers;
 102 static int tlsg_n_ciphers;
 103 #endif
 104
 105 static int tlsg_parse_ciphers( tlsg_ctx *ctx, char *suites );
 106 static int tlsg_cert_verify( tlsg_session *s );
 107
 108 #ifdef LDAP_R_COMPILE
 109
 110 static int
 111 tlsg_mutex_init( void **priv )
 112 {
 113         int err = 0;
 114         ldap_pvt_thread_mutex_t *lock = LDAP_MALLOC( sizeof( ldap_pvt_thread_mutex_t ));
 115
 116         if ( !lock )
 117                 err = ENOMEM;
 118         if ( !err ) {
 119                 err = ldap_pvt_thread_mutex_init( lock );
 120                 if ( err )
 121                         LDAP_FREE( lock );
 122                 else
 123                         *priv = lock;
 124         }
 125         return err;
 126 }
 127
 128 static int
 129 tlsg_mutex_destroy( void **lock )
 130 {
 131         int err = ldap_pvt_thread_mutex_destroy( *lock );
 132         LDAP_FREE( *lock );
 133         return err;
 134 }
 135
 136 static int
 137 tlsg_mutex_lock( void **lock )
 138 {
 139         return ldap_pvt_thread_mutex_lock( *lock );
 140 }
 141
 142 static int
 143 tlsg_mutex_unlock( void **lock )
 144 {
 145         return ldap_pvt_thread_mutex_unlock( *lock );
 146 }
 147
 148 static struct gcry_thread_cbs tlsg_thread_cbs = {
 149         GCRY_THREAD_OPTION_USER,
 150         NULL,
 151         tlsg_mutex_init,
 152         tlsg_mutex_destroy,
 153         tlsg_mutex_lock,
 154         tlsg_mutex_unlock,
 155         NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL
 156 };
 157
 158 static void
 159 tlsg_thr_init( void )
 160 {
 161         gcry_control (GCRYCTL_SET_THREAD_CBS, &tlsg_thread_cbs);
 162 }
 163 #endif /* LDAP_R_COMPILE */
 164
 165 /*
 166  * Initialize TLS subsystem. Should be called only once.
 167  */
 168 static int
 169 tlsg_init( void )
 170 {
 171 #ifdef HAVE_GCRYPT_RAND
 172         struct ldapoptions *lo = LDAP_INT_GLOBAL_OPT();
 173         if ( lo->ldo_tls_randfile &&
 174                 gcry_control( GCRYCTL_SET_RNDEGD_SOCKET, lo->ldo_tls_randfile )) {
 175                 Debug( LDAP_DEBUG_ANY,
 176                 "TLS: gcry_control GCRYCTL_SET_RNDEGD_SOCKET failed\n",
 177                 0, 0, 0);
 178                 return -1;
 179         }
 180 #endif
 181
 182         gnutls_global_init();
 183
 184 #ifndef HAVE_CIPHERSUITES
 185         /* GNUtls cipher suite handling: The library ought to parse suite
 186          * names for us, but it doesn't. It will return a list of suite names
 187          * that it supports, so we can do parsing ourselves. It ought to tell
 188          * us how long the list is, but it doesn't do that either, so we just
 189          * have to count it manually...
 190          */
 191         {
 192                 int i = 0;
 193                 tls_cipher_suite *ptr, tmp;
 194                 char cs_id[2];
 195
 196                 while ( gnutls_cipher_suite_info( i, cs_id, &tmp.kx, &tmp.cipher,
 197                         &tmp.mac, &tmp.version ))
 198                         i++;
 199                 tlsg_n_ciphers = i;
 200
 201                 /* Store a copy */
 202                 tlsg_ciphers = LDAP_MALLOC(tlsg_n_ciphers * sizeof(tls_cipher_suite));
 203                 if ( !tlsg_ciphers )
 204                         return -1;
 205                 for ( i=0; i<tlsg_n_ciphers; i++ ) {
 206                         tlsg_ciphers[i].name = gnutls_cipher_suite_info( i, cs_id,
 207                                 &tlsg_ciphers[i].kx, &tlsg_ciphers[i].cipher, &tlsg_ciphers[i].mac,
 208                                 &tlsg_ciphers[i].version );
 209                 }
 210         }
 211 #endif
 212         return 0;
 213 }
 214
 215 /*
 216  * Tear down the TLS subsystem. Should only be called once.
 217  */
 218 static void
 219 tlsg_destroy( void )
 220 {
 221 #ifndef HAVE_CIPHERSUITES
 222         LDAP_FREE( tlsg_ciphers );
 223         tlsg_ciphers = NULL;
 224         tlsg_n_ciphers = 0;
 225 #endif
 226         gnutls_global_deinit();
 227 }
 228
 229 static tls_ctx *
 230 tlsg_ctx_new ( struct ldapoptions *lo )
 231 {
 232         tlsg_ctx *ctx;
 233
 234         ctx = ber_memcalloc ( 1, sizeof (*ctx) );
 235         if ( ctx ) {
 236                 ctx->lo = lo;
 237                 if ( gnutls_certificate_allocate_credentials( &ctx->cred )) {
 238                         ber_memfree( ctx );
 239                         return NULL;
 240                 }
 241                 ctx->refcount = 1;
 242 #ifdef HAVE_CIPHERSUITES
 243                 gnutls_priority_init( &ctx->prios, "NORMAL", NULL );
 244 #endif
 245 #ifdef LDAP_R_COMPILE
 246                 ldap_pvt_thread_mutex_init( &ctx->ref_mutex );
 247 #endif
 248         }
 249         return (tls_ctx *)ctx;
 250 }
 251
 252 static void
 253 tlsg_ctx_ref( tls_ctx *ctx )
 254 {
 255         tlsg_ctx *c = (tlsg_ctx *)ctx;
 256         LDAP_MUTEX_LOCK( &c->ref_mutex );
 257         c->refcount++;
 258         LDAP_MUTEX_UNLOCK( &c->ref_mutex );
 259 }
 260
 261 static void
 262 tlsg_ctx_free ( tls_ctx *ctx )
 263 {
 264         tlsg_ctx *c = (tlsg_ctx *)ctx;
 265         int refcount;
 266
 267         if ( !c ) return;
 268
 269         LDAP_MUTEX_LOCK( &c->ref_mutex );
 270         refcount = --c->refcount;
 271         LDAP_MUTEX_UNLOCK( &c->ref_mutex );
 272         if ( refcount )
 273                 return;
 274 #ifdef HAVE_CIPHERSUITES
 275         gnutls_priority_deinit( c->prios );
 276 #else
 277         LDAP_FREE( c->kx_list );
 278 #endif
 279         gnutls_certificate_free_credentials( c->cred );
 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                         gnutls_x509_crt_t *cas;
 372                         unsigned int i, j, ncas;
 373
 374                         gnutls_certificate_get_x509_cas( ctx->cred, &cas, &ncas );
 375                         for ( i = 1; i<VERIFY_DEPTH; i++ ) {
 376                                 for ( j = 0; j<ncas; j++ ) {
 377                                         if ( gnutls_x509_crt_check_issuer( certs[i-1], cas[j] )) {
 378                                                 certs[i] = cas[j];
 379                                                 max++;
 380                                                 /* If this CA is self-signed, we're done */
 381                                                 if ( gnutls_x509_crt_check_issuer( cas[j], cas[j] ))
 382                                                         j = ncas;
 383                                                 break;
 384                                         }
 385                                 }
 386                                 /* only continue if we found a CA and it was not self-signed */
 387                                 if ( j == ncas )
 388                                         break;
 389                         }
 390                 }
 391                 rc = gnutls_certificate_set_x509_key( ctx->cred, certs, max, key );
 392                 if ( rc ) return -1;
 393         } else if ( lo->ldo_tls_certfile || lo->ldo_tls_keyfile ) {
 394                 Debug( LDAP_DEBUG_ANY,
 395                        "TLS: only one of certfile and keyfile specified\n",
 396                        NULL, NULL, NULL );
 397                 return -1;
 398         }
 399
 400         if ( lo->ldo_tls_dhfile ) {
 401                 Debug( LDAP_DEBUG_ANY,
 402                        "TLS: warning: ignoring dhfile\n",
 403                        NULL, NULL, NULL );
 404         }
 405
 406         if ( lo->ldo_tls_crlfile ) {
 407                 rc = gnutls_certificate_set_x509_crl_file(
 408                         ctx->cred,
 409                         lt->lt_crlfile,
 410                         GNUTLS_X509_FMT_PEM );
 411                 if ( rc < 0 ) return -1;
 412                 rc = 0;
 413         }
 414
 415         /* FIXME: ITS#5992 - this should go be configurable,
 416          * and V1 CA certs should be phased out ASAP.
 417          */
 418         gnutls_certificate_set_verify_flags( ctx->cred,
 419                 GNUTLS_VERIFY_ALLOW_X509_V1_CA_CRT );
 420
 421         if ( is_server ) {
 422                 gnutls_dh_params_init(&ctx->dh_params);
 423                 gnutls_dh_params_generate2(ctx->dh_params, DH_BITS);
 424         }
 425         return 0;
 426 }
 427
 428 static tls_session *
 429 tlsg_session_new ( tls_ctx * ctx, int is_server )
 430 {
 431         tlsg_ctx *c = (tlsg_ctx *)ctx;
 432         tlsg_session *session;
 433
 434         session = ber_memcalloc ( 1, sizeof (*session) );
 435         if ( !session )
 436                 return NULL;
 437
 438         session->ctx = c;
 439         gnutls_init( &session->session, is_server ? GNUTLS_SERVER : GNUTLS_CLIENT );
 440 #ifdef HAVE_CIPHERSUITES
 441         gnutls_priority_set( session->session, c->prios );
 442 #else
 443         gnutls_set_default_priority( session->session );
 444         if ( c->kx_list ) {
 445                 gnutls_kx_set_priority( session->session, c->kx_list );
 446                 gnutls_cipher_set_priority( session->session, c->cipher_list );
 447                 gnutls_mac_set_priority( session->session, c->mac_list );
 448         }
 449 #endif
 450         if ( c->cred )
 451                 gnutls_credentials_set( session->session, GNUTLS_CRD_CERTIFICATE, c->cred );
 452
 453         if ( is_server ) {
 454                 int flag = 0;
 455                 if ( c->lo->ldo_tls_require_cert ) {
 456                         flag = GNUTLS_CERT_REQUEST;
 457                         if ( c->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_DEMAND ||
 458                                 c->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_HARD )
 459                                 flag = GNUTLS_CERT_REQUIRE;
 460                         gnutls_certificate_server_set_request( session->session, flag );
 461                 }
 462         }
 463         return (tls_session *)session;
 464 }
 465
 466 static int
 467 tlsg_session_accept( tls_session *session )
 468 {
 469         tlsg_session *s = (tlsg_session *)session;
 470         int rc;
 471
 472         rc = gnutls_handshake( s->session );
 473         if ( rc == 0 && s->ctx->lo->ldo_tls_require_cert != LDAP_OPT_X_TLS_NEVER ) {
 474                 const gnutls_datum_t *peer_cert_list;
 475                 unsigned int list_size;
 476
 477                 peer_cert_list = gnutls_certificate_get_peers( s->session,
 478                                                 &list_size );
 479                 if ( !peer_cert_list && s->ctx->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_TRY )
 480                         rc = 0;
 481                 else {
 482                         rc = tlsg_cert_verify( s );
 483                         if ( rc && s->ctx->lo->ldo_tls_require_cert == LDAP_OPT_X_TLS_ALLOW )
 484                                 rc = 0;
 485                 }
 486         }
 487         return rc;
 488 }
 489
 490 static int
 491 tlsg_session_connect( LDAP *ld, tls_session *session )
 492 {
 493         return tlsg_session_accept( session);
 494 }
 495
 496 static int
 497 tlsg_session_upflags( Sockbuf *sb, tls_session *session, int rc )
 498 {
 499         tlsg_session *s = (tlsg_session *)session;
 500
 501         if ( rc != GNUTLS_E_INTERRUPTED && rc != GNUTLS_E_AGAIN )
 502                 return 0;
 503
 504         switch (gnutls_record_get_direction (s->session)) {
 505         case 0:
 506                 sb->sb_trans_needs_read = 1;
 507                 return 1;
 508         case 1:
 509                 sb->sb_trans_needs_write = 1;
 510                 return 1;
 511         }
 512         return 0;
 513 }
 514
 515 static char *
 516 tlsg_session_errmsg( tls_session *sess, int rc, char *buf, size_t len )
 517 {
 518         return (char *)gnutls_strerror( rc );
 519 }
 520
 521 static void
 522 tlsg_x509_cert_dn( struct berval *cert, struct berval *dn, int get_subject )
 523 {
 524         BerElementBuffer berbuf;
 525         BerElement *ber = (BerElement *)&berbuf;
 526         ber_tag_t tag;
 527         ber_len_t len;
 528         ber_int_t i;
 529
 530         ber_init2( ber, cert, LBER_USE_DER );
 531         tag = ber_skip_tag( ber, &len );        /* Sequence */
 532         tag = ber_skip_tag( ber, &len );        /* Sequence */
 533         tag = ber_peek_tag( ber, &len );        /* Context + Constructed (version) */
 534         if ( tag == 0xa0 ) {    /* Version is optional */
 535                 tag = ber_skip_tag( ber, &len );
 536                 tag = ber_get_int( ber, &i );   /* Int: Version */
 537         }
 538         tag = ber_skip_tag( ber, &len );        /* Int: Serial (can be longer than ber_int_t) */
 539         ber_skip_data( ber, len );
 540         tag = ber_skip_tag( ber, &len );        /* Sequence: Signature */
 541         ber_skip_data( ber, len );
 542         if ( !get_subject ) {
 543                 tag = ber_peek_tag( ber, &len );        /* Sequence: Issuer DN */
 544         } else {
 545                 tag = ber_skip_tag( ber, &len );
 546                 ber_skip_data( ber, len );
 547                 tag = ber_skip_tag( ber, &len );        /* Sequence: Validity */
 548                 ber_skip_data( ber, len );
 549                 tag = ber_peek_tag( ber, &len );        /* Sequence: Subject DN */
 550         }
 551         len = ber_ptrlen( ber );
 552         dn->bv_val = cert->bv_val + len;
 553         dn->bv_len = cert->bv_len - len;
 554 }
 555
 556 static int
 557 tlsg_session_my_dn( tls_session *session, struct berval *der_dn )
 558 {
 559         tlsg_session *s = (tlsg_session *)session;
 560         const gnutls_datum_t *x;
 561         struct berval bv;
 562
 563         x = gnutls_certificate_get_ours( s->session );
 564
 565         if (!x) return LDAP_INVALID_CREDENTIALS;
 566
 567         bv.bv_val = (char *) x->data;
 568         bv.bv_len = x->size;
 569
 570         tlsg_x509_cert_dn( &bv, der_dn, 1 );
 571         return 0;
 572 }
 573
 574 static int
 575 tlsg_session_peer_dn( tls_session *session, struct berval *der_dn )
 576 {
 577         tlsg_session *s = (tlsg_session *)session;
 578         if ( !s->peer_der_dn.bv_val ) {
 579                 const gnutls_datum_t *peer_cert_list;
 580                 unsigned int list_size;
 581                 struct berval bv;
 582
 583                 peer_cert_list = gnutls_certificate_get_peers( s->session,
 584                                                         &list_size );
 585                 if ( !peer_cert_list ) return LDAP_INVALID_CREDENTIALS;
 586
 587                 bv.bv_len = peer_cert_list->size;
 588                 bv.bv_val = (char *) peer_cert_list->data;
 589
 590                 tlsg_x509_cert_dn( &bv, &s->peer_der_dn, 1 );
 591         }
 592         *der_dn = s->peer_der_dn;
 593         return 0;
 594 }
 595
 596 /* what kind of hostname were we given? */
 597 #define IS_DNS  0
 598 #define IS_IP4  1
 599 #define IS_IP6  2
 600
 601 #define CN_OID  "2.5.4.3"
 602
 603 static int
 604 tlsg_session_chkhost( LDAP *ld, tls_session *session, const char *name_in )
 605 {
 606         tlsg_session *s = (tlsg_session *)session;
 607         int i, ret;
 608         const gnutls_datum_t *peer_cert_list;
 609         unsigned int list_size;
 610         char altname[NI_MAXHOST];
 611         size_t altnamesize;
 612
 613         gnutls_x509_crt_t cert;
 614         const char *name;
 615         char *ptr;
 616         char *domain = NULL;
 617 #ifdef LDAP_PF_INET6
 618         struct in6_addr addr;
 619 #else
 620         struct in_addr addr;
 621 #endif
 622         int len1 = 0, len2 = 0;
 623         int ntype = IS_DNS;
 624
 625         if( ldap_int_hostname &&
 626                 ( !name_in || !strcasecmp( name_in, "localhost" ) ) )
 627         {
 628                 name = ldap_int_hostname;
 629         } else {
 630                 name = name_in;
 631         }
 632
 633         peer_cert_list = gnutls_certificate_get_peers( s->session,
 634                                                 &list_size );
 635         if ( !peer_cert_list ) {
 636                 Debug( LDAP_DEBUG_ANY,
 637                         "TLS: unable to get peer certificate.\n",
 638                         0, 0, 0 );
 639                 /* If this was a fatal condition, things would have
 640                  * aborted long before now.
 641                  */
 642                 return LDAP_SUCCESS;
 643         }
 644         ret = gnutls_x509_crt_init( &cert );
 645         if ( ret < 0 )
 646                 return LDAP_LOCAL_ERROR;
 647         ret = gnutls_x509_crt_import( cert, peer_cert_list, GNUTLS_X509_FMT_DER );
 648         if ( ret ) {
 649                 gnutls_x509_crt_deinit( cert );
 650                 return LDAP_LOCAL_ERROR;
 651         }
 652
 653 #ifdef LDAP_PF_INET6
 654         if (name[0] == '[' && strchr(name, ']')) {
 655                 char *n2 = ldap_strdup(name+1);
 656                 *strchr(n2, ']') = 0;
 657                 if (inet_pton(AF_INET6, n2, &addr))
 658                         ntype = IS_IP6;
 659                 LDAP_FREE(n2);
 660         } else
 661 #endif
 662         if ((ptr = strrchr(name, '.')) && isdigit((unsigned char)ptr[1])) {
 663                 if (inet_aton(name, (struct in_addr *)&addr)) ntype = IS_IP4;
 664         }
 665
 666         if (ntype == IS_DNS) {
 667                 len1 = strlen(name);
 668                 domain = strchr(name, '.');
 669                 if (domain) {
 670                         len2 = len1 - (domain-name);
 671                 }
 672         }
 673
 674         for ( i=0, ret=0; ret >= 0; i++ ) {
 675                 altnamesize = sizeof(altname);
 676                 ret = gnutls_x509_crt_get_subject_alt_name( cert, i,
 677                         altname, &altnamesize, NULL );
 678                 if ( ret < 0 ) break;
 679
 680                 /* ignore empty */
 681                 if ( altnamesize == 0 ) continue;
 682
 683                 if ( ret == GNUTLS_SAN_DNSNAME ) {
 684                         if (ntype != IS_DNS) continue;
 685
 686                         /* Is this an exact match? */
 687                         if ((len1 == altnamesize) && !strncasecmp(name, altname, len1)) {
 688                                 break;
 689                         }
 690
 691                         /* Is this a wildcard match? */
 692                         if (domain && (altname[0] == '*') && (altname[1] == '.') &&
 693                                 (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2))
 694                         {
 695                                 break;
 696                         }
 697                 } else if ( ret == GNUTLS_SAN_IPADDRESS ) {
 698                         if (ntype == IS_DNS) continue;
 699
 700 #ifdef LDAP_PF_INET6
 701                         if (ntype == IS_IP6 && altnamesize != sizeof(struct in6_addr)) {
 702                                 continue;
 703                         } else
 704 #endif
 705                         if (ntype == IS_IP4 && altnamesize != sizeof(struct in_addr)) {
 706                                 continue;
 707                         }
 708                         if (!memcmp(altname, &addr, altnamesize)) {
 709                                 break;
 710                         }
 711                 }
 712         }
 713         if ( ret >= 0 ) {
 714                 ret = LDAP_SUCCESS;
 715         } else {
 716                 /* find the last CN */
 717                 i=0;
 718                 do {
 719                         altnamesize = 0;
 720                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 721                                 i, 1, altname, &altnamesize );
 722                         if ( ret == GNUTLS_E_SHORT_MEMORY_BUFFER )
 723                                 i++;
 724                         else
 725                                 break;
 726                 } while ( 1 );
 727
 728                 if ( i ) {
 729                         altnamesize = sizeof(altname);
 730                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 731                                 i-1, 0, altname, &altnamesize );
 732                 }
 733
 734                 if ( ret < 0 ) {
 735                         Debug( LDAP_DEBUG_ANY,
 736                                 "TLS: unable to get common name from peer certificate.\n",
 737                                 0, 0, 0 );
 738                         ret = LDAP_CONNECT_ERROR;
 739                         if ( ld->ld_error ) {
 740                                 LDAP_FREE( ld->ld_error );
 741                         }
 742                         ld->ld_error = LDAP_STRDUP(
 743                                 _("TLS: unable to get CN from peer certificate"));
 744
 745                 } else {
 746                         ret = LDAP_LOCAL_ERROR;
 747                         if ( !len1 ) len1 = strlen( name );
 748                         if ( len1 == altnamesize && strncasecmp(name, altname, altnamesize) == 0 ) {
 749                                 ret = LDAP_SUCCESS;
 750
 751                         } else if (( altname[0] == '*' ) && ( altname[1] == '.' )) {
 752                                         /* Is this a wildcard match? */
 753                                 if( domain &&
 754                                         (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2)) {
 755                                         ret = LDAP_SUCCESS;
 756                                 }
 757                         }
 758                 }
 759
 760                 if( ret == LDAP_LOCAL_ERROR ) {
 761                         altname[altnamesize] = '\0';
 762                         Debug( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
 763                                 "common name in certificate (%s).\n",
 764                                 name, altname, 0 );
 765                         ret = LDAP_CONNECT_ERROR;
 766                         if ( ld->ld_error ) {
 767                                 LDAP_FREE( ld->ld_error );
 768                         }
 769                         ld->ld_error = LDAP_STRDUP(
 770                                 _("TLS: hostname does not match CN in peer certificate"));
 771                 }
 772         }
 773         gnutls_x509_crt_deinit( cert );
 774         return ret;
 775 }
 776
 777 static int
 778 tlsg_session_strength( tls_session *session )
 779 {
 780         tlsg_session *s = (tlsg_session *)session;
 781         gnutls_cipher_algorithm_t c;
 782
 783         c = gnutls_cipher_get( s->session );
 784         return gnutls_cipher_get_key_size( c ) * 8;
 785 }
 786
 787 /* suites is a string of colon-separated cipher suite names. */
 788 static int
 789 tlsg_parse_ciphers( tlsg_ctx *ctx, char *suites )
 790 {
 791 #ifdef HAVE_CIPHERSUITES
 792         const char *err;
 793         return gnutls_priority_init( &ctx->prios, suites, &err );
 794 #else
 795         char *ptr, *end;
 796         int i, j, len, num;
 797         int *list, nkx = 0, ncipher = 0, nmac = 0;
 798         int *kx, *cipher, *mac;
 799
 800         num = 0;
 801         ptr = suites;
 802         do {
 803                 end = strchr(ptr, ':');
 804                 if ( end )
 805                         len = end - ptr;
 806                 else
 807                         len = strlen(ptr);
 808                 for (i=0; i<tlsg_n_ciphers; i++) {
 809                         if ( !strncasecmp( tlsg_ciphers[i].name, ptr, len )) {
 810                                 num++;
 811                                 break;
 812                         }
 813                 }
 814                 if ( i == tlsg_n_ciphers ) {
 815                         /* unrecognized cipher suite */
 816                         return -1;
 817                 }
 818                 ptr += len + 1;
 819         } while (end);
 820
 821         /* Space for all 3 lists */
 822         list = LDAP_MALLOC( (num+1) * sizeof(int) * 3 );
 823         if ( !list )
 824                 return -1;
 825         kx = list;
 826         cipher = kx+num+1;
 827         mac = cipher+num+1;
 828
 829         ptr = suites;
 830         do {
 831                 end = strchr(ptr, ':');
 832                 if ( end )
 833                         len = end - ptr;
 834                 else
 835                         len = strlen(ptr);
 836                 for (i=0; i<tlsg_n_ciphers; i++) {
 837                         /* For each cipher suite, insert its algorithms into
 838                          * their respective priority lists. Make sure they
 839                          * only appear once in each list.
 840                          */
 841                         if ( !strncasecmp( tlsg_ciphers[i].name, ptr, len )) {
 842                                 for (j=0; j<nkx; j++)
 843                                         if ( kx[j] == tlsg_ciphers[i].kx )
 844                                                 break;
 845                                 if ( j == nkx )
 846                                         kx[nkx++] = tlsg_ciphers[i].kx;
 847                                 for (j=0; j<ncipher; j++)
 848                                         if ( cipher[j] == tlsg_ciphers[i].cipher )
 849                                                 break;
 850                                 if ( j == ncipher )
 851                                         cipher[ncipher++] = tlsg_ciphers[i].cipher;
 852                                 for (j=0; j<nmac; j++)
 853                                         if ( mac[j] == tlsg_ciphers[i].mac )
 854                                                 break;
 855                                 if ( j == nmac )
 856                                         mac[nmac++] = tlsg_ciphers[i].mac;
 857                                 break;
 858                         }
 859                 }
 860                 ptr += len + 1;
 861         } while (end);
 862         kx[nkx] = 0;
 863         cipher[ncipher] = 0;
 864         mac[nmac] = 0;
 865         ctx->kx_list = kx;
 866         ctx->cipher_list = cipher;
 867         ctx->mac_list = mac;
 868         return 0;
 869 #endif
 870 }
 871
 872 /*
 873  * TLS support for LBER Sockbufs
 874  */
 875
 876 struct tls_data {
 877         tlsg_session            *session;
 878         Sockbuf_IO_Desc         *sbiod;
 879 };
 880
 881 static ssize_t
 882 tlsg_recv( gnutls_transport_ptr_t ptr, void *buf, size_t len )
 883 {
 884         struct tls_data         *p;
 885
 886         if ( buf == NULL || len <= 0 ) return 0;
 887
 888         p = (struct tls_data *)ptr;
 889
 890         if ( p == NULL || p->sbiod == NULL ) {
 891                 return 0;
 892         }
 893
 894         return LBER_SBIOD_READ_NEXT( p->sbiod, buf, len );
 895 }
 896
 897 static ssize_t
 898 tlsg_send( gnutls_transport_ptr_t ptr, const void *buf, size_t len )
 899 {
 900         struct tls_data         *p;
 901
 902         if ( buf == NULL || len <= 0 ) return 0;
 903
 904         p = (struct tls_data *)ptr;
 905
 906         if ( p == NULL || p->sbiod == NULL ) {
 907                 return 0;
 908         }
 909
 910         return LBER_SBIOD_WRITE_NEXT( p->sbiod, (char *)buf, len );
 911 }
 912
 913 static int
 914 tlsg_sb_setup( Sockbuf_IO_Desc *sbiod, void *arg )
 915 {
 916         struct tls_data         *p;
 917         tlsg_session    *session = arg;
 918
 919         assert( sbiod != NULL );
 920
 921         p = LBER_MALLOC( sizeof( *p ) );
 922         if ( p == NULL ) {
 923                 return -1;
 924         }
 925
 926         gnutls_transport_set_ptr( session->session, (gnutls_transport_ptr)p );
 927         gnutls_transport_set_pull_function( session->session, tlsg_recv );
 928         gnutls_transport_set_push_function( session->session, tlsg_send );
 929         p->session = session;
 930         p->sbiod = sbiod;
 931         sbiod->sbiod_pvt = p;
 932         return 0;
 933 }
 934
 935 static int
 936 tlsg_sb_remove( Sockbuf_IO_Desc *sbiod )
 937 {
 938         struct tls_data         *p;
 939
 940         assert( sbiod != NULL );
 941         assert( sbiod->sbiod_pvt != NULL );
 942
 943         p = (struct tls_data *)sbiod->sbiod_pvt;
 944         gnutls_deinit ( p->session->session );
 945         LBER_FREE( p->session );
 946         LBER_FREE( sbiod->sbiod_pvt );
 947         sbiod->sbiod_pvt = NULL;
 948         return 0;
 949 }
 950
 951 static int
 952 tlsg_sb_close( Sockbuf_IO_Desc *sbiod )
 953 {
 954         struct tls_data         *p;
 955
 956         assert( sbiod != NULL );
 957         assert( sbiod->sbiod_pvt != NULL );
 958
 959         p = (struct tls_data *)sbiod->sbiod_pvt;
 960         gnutls_bye ( p->session->session, GNUTLS_SHUT_WR );
 961         return 0;
 962 }
 963
 964 static int
 965 tlsg_sb_ctrl( Sockbuf_IO_Desc *sbiod, int opt, void *arg )
 966 {
 967         struct tls_data         *p;
 968
 969         assert( sbiod != NULL );
 970         assert( sbiod->sbiod_pvt != NULL );
 971
 972         p = (struct tls_data *)sbiod->sbiod_pvt;
 973
 974         if ( opt == LBER_SB_OPT_GET_SSL ) {
 975                 *((tlsg_session **)arg) = p->session;
 976                 return 1;
 977
 978         } else if ( opt == LBER_SB_OPT_DATA_READY ) {
 979                 if( gnutls_record_check_pending( p->session->session ) > 0 ) {
 980                         return 1;
 981                 }
 982         }
 983
 984         return LBER_SBIOD_CTRL_NEXT( sbiod, opt, arg );
 985 }
 986
 987 static ber_slen_t
 988 tlsg_sb_read( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
 989 {
 990         struct tls_data         *p;
 991         ber_slen_t              ret;
 992
 993         assert( sbiod != NULL );
 994         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
 995
 996         p = (struct tls_data *)sbiod->sbiod_pvt;
 997
 998         ret = gnutls_record_recv ( p->session->session, buf, len );
 999         switch (ret) {
1000         case GNUTLS_E_INTERRUPTED:
1001         case GNUTLS_E_AGAIN:
1002                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
1003                 sock_errset(EWOULDBLOCK);
1004                 ret = 0;
1005                 break;
1006         case GNUTLS_E_REHANDSHAKE:
1007                 for ( ret = gnutls_handshake ( p->session->session );
1008                       ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN;
1009                       ret = gnutls_handshake ( p->session->session ) );
1010                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
1011                 ret = 0;
1012                 break;
1013         default:
1014                 sbiod->sbiod_sb->sb_trans_needs_read = 0;
1015         }
1016         return ret;
1017 }
1018
1019 static ber_slen_t
1020 tlsg_sb_write( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
1021 {
1022         struct tls_data         *p;
1023         ber_slen_t              ret;
1024
1025         assert( sbiod != NULL );
1026         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
1027
1028         p = (struct tls_data *)sbiod->sbiod_pvt;
1029
1030         ret = gnutls_record_send ( p->session->session, (char *)buf, len );
1031
1032         if ( ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN ) {
1033                 sbiod->sbiod_sb->sb_trans_needs_write = 1;
1034                 sock_errset(EWOULDBLOCK);
1035                 ret = 0;
1036         } else {
1037                 sbiod->sbiod_sb->sb_trans_needs_write = 0;
1038         }
1039         return ret;
1040 }
1041
1042 static Sockbuf_IO tlsg_sbio =
1043 {
1044         tlsg_sb_setup,          /* sbi_setup */
1045         tlsg_sb_remove,         /* sbi_remove */
1046         tlsg_sb_ctrl,           /* sbi_ctrl */
1047         tlsg_sb_read,           /* sbi_read */
1048         tlsg_sb_write,          /* sbi_write */
1049         tlsg_sb_close           /* sbi_close */
1050 };
1051
1052 /* Certs are not automatically varified during the handshake */
1053 static int
1054 tlsg_cert_verify( tlsg_session *ssl )
1055 {
1056         unsigned int status = 0;
1057         int err;
1058         time_t now = time(0);
1059         time_t peertime;
1060
1061         err = gnutls_certificate_verify_peers2( ssl->session, &status );
1062         if ( err < 0 ) {
1063                 Debug( LDAP_DEBUG_ANY,"TLS: gnutls_certificate_verify_peers2 failed %d\n",
1064                         err,0,0 );
1065                 return -1;
1066         }
1067         if ( status ) {
1068                 Debug( LDAP_DEBUG_TRACE,"TLS: peer cert untrusted or revoked (0x%x)\n",
1069                         status, 0,0 );
1070                 return -1;
1071         }
1072         peertime = gnutls_certificate_expiration_time_peers( ssl->session );
1073         if ( peertime == (time_t) -1 ) {
1074                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_expiration_time_peers failed\n",
1075                         0, 0, 0 );
1076                 return -1;
1077         }
1078         if ( peertime < now ) {
1079                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate is expired\n",
1080                         0, 0, 0 );
1081                 return -1;
1082         }
1083         peertime = gnutls_certificate_activation_time_peers( ssl->session );
1084         if ( peertime == (time_t) -1 ) {
1085                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_activation_time_peers failed\n",
1086                         0, 0, 0 );
1087                 return -1;
1088         }
1089         if ( peertime > now ) {
1090                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate not yet active\n",
1091                         0, 0, 0 );
1092                 return -1;
1093         }
1094         return 0;
1095 }
1096
1097 tls_impl ldap_int_tls_impl = {
1098         "GnuTLS",
1099
1100         tlsg_init,
1101         tlsg_destroy,
1102
1103         tlsg_ctx_new,
1104         tlsg_ctx_ref,
1105         tlsg_ctx_free,
1106         tlsg_ctx_init,
1107
1108         tlsg_session_new,
1109         tlsg_session_connect,
1110         tlsg_session_accept,
1111         tlsg_session_upflags,
1112         tlsg_session_errmsg,
1113         tlsg_session_my_dn,
1114         tlsg_session_peer_dn,
1115         tlsg_session_chkhost,
1116         tlsg_session_strength,
1117
1118         &tlsg_sbio,
1119
1120 #ifdef LDAP_R_COMPILE
1121         tlsg_thr_init,
1122 #else
1123         NULL,
1124 #endif
1125
1126         0
1127 };
1128
1129 #endif /* HAVE_GNUTLS */