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 2008-2012 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16 /* ACKNOWLEDGEMENTS: GNUTLS support written by Howard Chu and
  17  * Emily Backes; sponsored by The Written Word (thewrittenword.com)
  18  * and Stanford University (stanford.edu).
  19  */
  20
  21 #include "portable.h"
  22
  23 #ifdef HAVE_GNUTLS
  24
  25 #include "ldap_config.h"
  26
  27 #include <stdio.h>
  28
  29 #include <ac/stdlib.h>
  30 #include <ac/errno.h>
  31 #include <ac/socket.h>
  32 #include <ac/string.h>
  33 #include <ac/ctype.h>
  34 #include <ac/time.h>
  35 #include <ac/unistd.h>
  36 #include <ac/param.h>
  37 #include <ac/dirent.h>
  38 #include <sys/stat.h>
  39 #include <fcntl.h>
  40
  41 #include "ldap-int.h"
  42 #include "ldap-tls.h"
  43
  44 #include <gnutls/gnutls.h>
  45 #include <gnutls/x509.h>
  46 #include <gcrypt.h>
  47
  48 #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 (inet_pton(AF_INET6, name, &addr)) {
 655                 ntype = IS_IP6;
 656         } else
 657 #endif
 658         if ((ptr = strrchr(name, '.')) && isdigit((unsigned char)ptr[1])) {
 659                 if (inet_aton(name, (struct in_addr *)&addr)) ntype = IS_IP4;
 660         }
 661
 662         if (ntype == IS_DNS) {
 663                 len1 = strlen(name);
 664                 domain = strchr(name, '.');
 665                 if (domain) {
 666                         len2 = len1 - (domain-name);
 667                 }
 668         }
 669
 670         for ( i=0, ret=0; ret >= 0; i++ ) {
 671                 altnamesize = sizeof(altname);
 672                 ret = gnutls_x509_crt_get_subject_alt_name( cert, i,
 673                         altname, &altnamesize, NULL );
 674                 if ( ret < 0 ) break;
 675
 676                 /* ignore empty */
 677                 if ( altnamesize == 0 ) continue;
 678
 679                 if ( ret == GNUTLS_SAN_DNSNAME ) {
 680                         if (ntype != IS_DNS) continue;
 681
 682                         /* Is this an exact match? */
 683                         if ((len1 == altnamesize) && !strncasecmp(name, altname, len1)) {
 684                                 break;
 685                         }
 686
 687                         /* Is this a wildcard match? */
 688                         if (domain && (altname[0] == '*') && (altname[1] == '.') &&
 689                                 (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2))
 690                         {
 691                                 break;
 692                         }
 693                 } else if ( ret == GNUTLS_SAN_IPADDRESS ) {
 694                         if (ntype == IS_DNS) continue;
 695
 696 #ifdef LDAP_PF_INET6
 697                         if (ntype == IS_IP6 && altnamesize != sizeof(struct in6_addr)) {
 698                                 continue;
 699                         } else
 700 #endif
 701                         if (ntype == IS_IP4 && altnamesize != sizeof(struct in_addr)) {
 702                                 continue;
 703                         }
 704                         if (!memcmp(altname, &addr, altnamesize)) {
 705                                 break;
 706                         }
 707                 }
 708         }
 709         if ( ret >= 0 ) {
 710                 ret = LDAP_SUCCESS;
 711         } else {
 712                 /* find the last CN */
 713                 i=0;
 714                 do {
 715                         altnamesize = 0;
 716                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 717                                 i, 1, altname, &altnamesize );
 718                         if ( ret == GNUTLS_E_SHORT_MEMORY_BUFFER )
 719                                 i++;
 720                         else
 721                                 break;
 722                 } while ( 1 );
 723
 724                 if ( i ) {
 725                         altnamesize = sizeof(altname);
 726                         ret = gnutls_x509_crt_get_dn_by_oid( cert, CN_OID,
 727                                 i-1, 0, altname, &altnamesize );
 728                 }
 729
 730                 if ( ret < 0 ) {
 731                         Debug( LDAP_DEBUG_ANY,
 732                                 "TLS: unable to get common name from peer certificate.\n",
 733                                 0, 0, 0 );
 734                         ret = LDAP_CONNECT_ERROR;
 735                         if ( ld->ld_error ) {
 736                                 LDAP_FREE( ld->ld_error );
 737                         }
 738                         ld->ld_error = LDAP_STRDUP(
 739                                 _("TLS: unable to get CN from peer certificate"));
 740
 741                 } else {
 742                         ret = LDAP_LOCAL_ERROR;
 743                         if ( !len1 ) len1 = strlen( name );
 744                         if ( len1 == altnamesize && strncasecmp(name, altname, altnamesize) == 0 ) {
 745                                 ret = LDAP_SUCCESS;
 746
 747                         } else if (( altname[0] == '*' ) && ( altname[1] == '.' )) {
 748                                         /* Is this a wildcard match? */
 749                                 if( domain &&
 750                                         (len2 == altnamesize-1) && !strncasecmp(domain, &altname[1], len2)) {
 751                                         ret = LDAP_SUCCESS;
 752                                 }
 753                         }
 754                 }
 755
 756                 if( ret == LDAP_LOCAL_ERROR ) {
 757                         altname[altnamesize] = '\0';
 758                         Debug( LDAP_DEBUG_ANY, "TLS: hostname (%s) does not match "
 759                                 "common name in certificate (%s).\n",
 760                                 name, altname, 0 );
 761                         ret = LDAP_CONNECT_ERROR;
 762                         if ( ld->ld_error ) {
 763                                 LDAP_FREE( ld->ld_error );
 764                         }
 765                         ld->ld_error = LDAP_STRDUP(
 766                                 _("TLS: hostname does not match CN in peer certificate"));
 767                 }
 768         }
 769         gnutls_x509_crt_deinit( cert );
 770         return ret;
 771 }
 772
 773 static int
 774 tlsg_session_strength( tls_session *session )
 775 {
 776         tlsg_session *s = (tlsg_session *)session;
 777         gnutls_cipher_algorithm_t c;
 778
 779         c = gnutls_cipher_get( s->session );
 780         return gnutls_cipher_get_key_size( c ) * 8;
 781 }
 782
 783 /* suites is a string of colon-separated cipher suite names. */
 784 static int
 785 tlsg_parse_ciphers( tlsg_ctx *ctx, char *suites )
 786 {
 787 #ifdef HAVE_CIPHERSUITES
 788         const char *err;
 789         return gnutls_priority_init( &ctx->prios, suites, &err );
 790 #else
 791         char *ptr, *end;
 792         int i, j, len, num;
 793         int *list, nkx = 0, ncipher = 0, nmac = 0;
 794         int *kx, *cipher, *mac;
 795
 796         num = 0;
 797         ptr = suites;
 798         do {
 799                 end = strchr(ptr, ':');
 800                 if ( end )
 801                         len = end - ptr;
 802                 else
 803                         len = strlen(ptr);
 804                 for (i=0; i<tlsg_n_ciphers; i++) {
 805                         if ( !strncasecmp( tlsg_ciphers[i].name, ptr, len )) {
 806                                 num++;
 807                                 break;
 808                         }
 809                 }
 810                 if ( i == tlsg_n_ciphers ) {
 811                         /* unrecognized cipher suite */
 812                         return -1;
 813                 }
 814                 ptr += len + 1;
 815         } while (end);
 816
 817         /* Space for all 3 lists */
 818         list = LDAP_MALLOC( (num+1) * sizeof(int) * 3 );
 819         if ( !list )
 820                 return -1;
 821         kx = list;
 822         cipher = kx+num+1;
 823         mac = cipher+num+1;
 824
 825         ptr = suites;
 826         do {
 827                 end = strchr(ptr, ':');
 828                 if ( end )
 829                         len = end - ptr;
 830                 else
 831                         len = strlen(ptr);
 832                 for (i=0; i<tlsg_n_ciphers; i++) {
 833                         /* For each cipher suite, insert its algorithms into
 834                          * their respective priority lists. Make sure they
 835                          * only appear once in each list.
 836                          */
 837                         if ( !strncasecmp( tlsg_ciphers[i].name, ptr, len )) {
 838                                 for (j=0; j<nkx; j++)
 839                                         if ( kx[j] == tlsg_ciphers[i].kx )
 840                                                 break;
 841                                 if ( j == nkx )
 842                                         kx[nkx++] = tlsg_ciphers[i].kx;
 843                                 for (j=0; j<ncipher; j++)
 844                                         if ( cipher[j] == tlsg_ciphers[i].cipher )
 845                                                 break;
 846                                 if ( j == ncipher )
 847                                         cipher[ncipher++] = tlsg_ciphers[i].cipher;
 848                                 for (j=0; j<nmac; j++)
 849                                         if ( mac[j] == tlsg_ciphers[i].mac )
 850                                                 break;
 851                                 if ( j == nmac )
 852                                         mac[nmac++] = tlsg_ciphers[i].mac;
 853                                 break;
 854                         }
 855                 }
 856                 ptr += len + 1;
 857         } while (end);
 858         kx[nkx] = 0;
 859         cipher[ncipher] = 0;
 860         mac[nmac] = 0;
 861         ctx->kx_list = kx;
 862         ctx->cipher_list = cipher;
 863         ctx->mac_list = mac;
 864         return 0;
 865 #endif
 866 }
 867
 868 /*
 869  * TLS support for LBER Sockbufs
 870  */
 871
 872 struct tls_data {
 873         tlsg_session            *session;
 874         Sockbuf_IO_Desc         *sbiod;
 875 };
 876
 877 static ssize_t
 878 tlsg_recv( gnutls_transport_ptr_t ptr, void *buf, size_t len )
 879 {
 880         struct tls_data         *p;
 881
 882         if ( buf == NULL || len <= 0 ) return 0;
 883
 884         p = (struct tls_data *)ptr;
 885
 886         if ( p == NULL || p->sbiod == NULL ) {
 887                 return 0;
 888         }
 889
 890         return LBER_SBIOD_READ_NEXT( p->sbiod, buf, len );
 891 }
 892
 893 static ssize_t
 894 tlsg_send( gnutls_transport_ptr_t ptr, const void *buf, size_t len )
 895 {
 896         struct tls_data         *p;
 897
 898         if ( buf == NULL || len <= 0 ) return 0;
 899
 900         p = (struct tls_data *)ptr;
 901
 902         if ( p == NULL || p->sbiod == NULL ) {
 903                 return 0;
 904         }
 905
 906         return LBER_SBIOD_WRITE_NEXT( p->sbiod, (char *)buf, len );
 907 }
 908
 909 static int
 910 tlsg_sb_setup( Sockbuf_IO_Desc *sbiod, void *arg )
 911 {
 912         struct tls_data         *p;
 913         tlsg_session    *session = arg;
 914
 915         assert( sbiod != NULL );
 916
 917         p = LBER_MALLOC( sizeof( *p ) );
 918         if ( p == NULL ) {
 919                 return -1;
 920         }
 921
 922         gnutls_transport_set_ptr( session->session, (gnutls_transport_ptr)p );
 923         gnutls_transport_set_pull_function( session->session, tlsg_recv );
 924         gnutls_transport_set_push_function( session->session, tlsg_send );
 925         p->session = session;
 926         p->sbiod = sbiod;
 927         sbiod->sbiod_pvt = p;
 928         return 0;
 929 }
 930
 931 static int
 932 tlsg_sb_remove( Sockbuf_IO_Desc *sbiod )
 933 {
 934         struct tls_data         *p;
 935
 936         assert( sbiod != NULL );
 937         assert( sbiod->sbiod_pvt != NULL );
 938
 939         p = (struct tls_data *)sbiod->sbiod_pvt;
 940         gnutls_deinit ( p->session->session );
 941         LBER_FREE( p->session );
 942         LBER_FREE( sbiod->sbiod_pvt );
 943         sbiod->sbiod_pvt = NULL;
 944         return 0;
 945 }
 946
 947 static int
 948 tlsg_sb_close( Sockbuf_IO_Desc *sbiod )
 949 {
 950         struct tls_data         *p;
 951
 952         assert( sbiod != NULL );
 953         assert( sbiod->sbiod_pvt != NULL );
 954
 955         p = (struct tls_data *)sbiod->sbiod_pvt;
 956         gnutls_bye ( p->session->session, GNUTLS_SHUT_WR );
 957         return 0;
 958 }
 959
 960 static int
 961 tlsg_sb_ctrl( Sockbuf_IO_Desc *sbiod, int opt, void *arg )
 962 {
 963         struct tls_data         *p;
 964
 965         assert( sbiod != NULL );
 966         assert( sbiod->sbiod_pvt != NULL );
 967
 968         p = (struct tls_data *)sbiod->sbiod_pvt;
 969
 970         if ( opt == LBER_SB_OPT_GET_SSL ) {
 971                 *((tlsg_session **)arg) = p->session;
 972                 return 1;
 973
 974         } else if ( opt == LBER_SB_OPT_DATA_READY ) {
 975                 if( gnutls_record_check_pending( p->session->session ) > 0 ) {
 976                         return 1;
 977                 }
 978         }
 979
 980         return LBER_SBIOD_CTRL_NEXT( sbiod, opt, arg );
 981 }
 982
 983 static ber_slen_t
 984 tlsg_sb_read( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
 985 {
 986         struct tls_data         *p;
 987         ber_slen_t              ret;
 988
 989         assert( sbiod != NULL );
 990         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
 991
 992         p = (struct tls_data *)sbiod->sbiod_pvt;
 993
 994         ret = gnutls_record_recv ( p->session->session, buf, len );
 995         switch (ret) {
 996         case GNUTLS_E_INTERRUPTED:
 997         case GNUTLS_E_AGAIN:
 998                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
 999                 sock_errset(EWOULDBLOCK);
1000                 ret = 0;
1001                 break;
1002         case GNUTLS_E_REHANDSHAKE:
1003                 for ( ret = gnutls_handshake ( p->session->session );
1004                       ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN;
1005                       ret = gnutls_handshake ( p->session->session ) );
1006                 sbiod->sbiod_sb->sb_trans_needs_read = 1;
1007                 ret = 0;
1008                 break;
1009         default:
1010                 sbiod->sbiod_sb->sb_trans_needs_read = 0;
1011         }
1012         return ret;
1013 }
1014
1015 static ber_slen_t
1016 tlsg_sb_write( Sockbuf_IO_Desc *sbiod, void *buf, ber_len_t len)
1017 {
1018         struct tls_data         *p;
1019         ber_slen_t              ret;
1020
1021         assert( sbiod != NULL );
1022         assert( SOCKBUF_VALID( sbiod->sbiod_sb ) );
1023
1024         p = (struct tls_data *)sbiod->sbiod_pvt;
1025
1026         ret = gnutls_record_send ( p->session->session, (char *)buf, len );
1027
1028         if ( ret == GNUTLS_E_INTERRUPTED || ret == GNUTLS_E_AGAIN ) {
1029                 sbiod->sbiod_sb->sb_trans_needs_write = 1;
1030                 sock_errset(EWOULDBLOCK);
1031                 ret = 0;
1032         } else {
1033                 sbiod->sbiod_sb->sb_trans_needs_write = 0;
1034         }
1035         return ret;
1036 }
1037
1038 static Sockbuf_IO tlsg_sbio =
1039 {
1040         tlsg_sb_setup,          /* sbi_setup */
1041         tlsg_sb_remove,         /* sbi_remove */
1042         tlsg_sb_ctrl,           /* sbi_ctrl */
1043         tlsg_sb_read,           /* sbi_read */
1044         tlsg_sb_write,          /* sbi_write */
1045         tlsg_sb_close           /* sbi_close */
1046 };
1047
1048 /* Certs are not automatically varified during the handshake */
1049 static int
1050 tlsg_cert_verify( tlsg_session *ssl )
1051 {
1052         unsigned int status = 0;
1053         int err;
1054         time_t now = time(0);
1055         time_t peertime;
1056
1057         err = gnutls_certificate_verify_peers2( ssl->session, &status );
1058         if ( err < 0 ) {
1059                 Debug( LDAP_DEBUG_ANY,"TLS: gnutls_certificate_verify_peers2 failed %d\n",
1060                         err,0,0 );
1061                 return -1;
1062         }
1063         if ( status ) {
1064                 Debug( LDAP_DEBUG_TRACE,"TLS: peer cert untrusted or revoked (0x%x)\n",
1065                         status, 0,0 );
1066                 return -1;
1067         }
1068         peertime = gnutls_certificate_expiration_time_peers( ssl->session );
1069         if ( peertime == (time_t) -1 ) {
1070                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_expiration_time_peers failed\n",
1071                         0, 0, 0 );
1072                 return -1;
1073         }
1074         if ( peertime < now ) {
1075                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate is expired\n",
1076                         0, 0, 0 );
1077                 return -1;
1078         }
1079         peertime = gnutls_certificate_activation_time_peers( ssl->session );
1080         if ( peertime == (time_t) -1 ) {
1081                 Debug( LDAP_DEBUG_ANY, "TLS: gnutls_certificate_activation_time_peers failed\n",
1082                         0, 0, 0 );
1083                 return -1;
1084         }
1085         if ( peertime > now ) {
1086                 Debug( LDAP_DEBUG_ANY, "TLS: peer certificate not yet active\n",
1087                         0, 0, 0 );
1088                 return -1;
1089         }
1090         return 0;
1091 }
1092
1093 tls_impl ldap_int_tls_impl = {
1094         "GnuTLS",
1095
1096         tlsg_init,
1097         tlsg_destroy,
1098
1099         tlsg_ctx_new,
1100         tlsg_ctx_ref,
1101         tlsg_ctx_free,
1102         tlsg_ctx_init,
1103
1104         tlsg_session_new,
1105         tlsg_session_connect,
1106         tlsg_session_accept,
1107         tlsg_session_upflags,
1108         tlsg_session_errmsg,
1109         tlsg_session_my_dn,
1110         tlsg_session_peer_dn,
1111         tlsg_session_chkhost,
1112         tlsg_session_strength,
1113
1114         &tlsg_sbio,
1115
1116 #ifdef LDAP_R_COMPILE
1117         tlsg_thr_init,
1118 #else
1119         NULL,
1120 #endif
1121
1122         0
1123 };
1124
1125 #endif /* HAVE_GNUTLS */