source/libads/sasl.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    ads sasl code
   4    Copyright (C) Andrew Tridgell 2001
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22
  23 #ifdef HAVE_LDAP
  24
  25 /*
  26    perform a LDAP/SASL/SPNEGO/NTLMSSP bind (just how many layers can
  27    we fit on one socket??)
  28 */
  29 static ADS_STATUS ads_sasl_spnego_ntlmssp_bind(ADS_STRUCT *ads)
  30 {
  31         DATA_BLOB msg1 = data_blob(NULL, 0);
  32         DATA_BLOB blob = data_blob(NULL, 0);
  33         DATA_BLOB blob_in = data_blob(NULL, 0);
  34         DATA_BLOB blob_out = data_blob(NULL, 0);
  35         struct berval cred, *scred = NULL;
  36         int rc;
  37         NTSTATUS nt_status;
  38         int turn = 1;
  39
  40         struct ntlmssp_state *ntlmssp_state;
  41
  42         if (!NT_STATUS_IS_OK(nt_status = ntlmssp_client_start(&ntlmssp_state))) {
  43                 return ADS_ERROR_NT(nt_status);
  44         }
  45         ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_SIGN;
  46
  47         if (!NT_STATUS_IS_OK(nt_status = ntlmssp_set_username(ntlmssp_state, ads->auth.user_name))) {
  48                 return ADS_ERROR_NT(nt_status);
  49         }
  50         if (!NT_STATUS_IS_OK(nt_status = ntlmssp_set_domain(ntlmssp_state, ads->auth.realm))) {
  51                 return ADS_ERROR_NT(nt_status);
  52         }
  53         if (!NT_STATUS_IS_OK(nt_status = ntlmssp_set_password(ntlmssp_state, ads->auth.password))) {
  54                 return ADS_ERROR_NT(nt_status);
  55         }
  56
  57         blob_in = data_blob(NULL, 0);
  58
  59         do {
  60                 nt_status = ntlmssp_update(ntlmssp_state,
  61                                            blob_in, &blob_out);
  62                 data_blob_free(&blob_in);
  63                 if ((NT_STATUS_EQUAL(nt_status, NT_STATUS_MORE_PROCESSING_REQUIRED)
  64                      || NT_STATUS_IS_OK(nt_status))
  65                     && blob_out.length) {
  66                         if (turn == 1) {
  67                                 /* and wrap it in a SPNEGO wrapper */
  68                                 msg1 = gen_negTokenInit(OID_NTLMSSP, blob_out);
  69                         } else {
  70                                 /* wrap it in SPNEGO */
  71                                 msg1 = spnego_gen_auth(blob_out);
  72                         }
  73
  74                         data_blob_free(&blob_out);
  75
  76                         cred.bv_val = (char *)msg1.data;
  77                         cred.bv_len = msg1.length;
  78                         scred = NULL;
  79                         rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", &cred, NULL, NULL, &scred);
  80                         data_blob_free(&msg1);
  81                         if ((rc != LDAP_SASL_BIND_IN_PROGRESS) && (rc != 0)) {
  82                                 if (scred) {
  83                                         ber_bvfree(scred);
  84                                 }
  85
  86                                 ntlmssp_end(&ntlmssp_state);
  87                                 return ADS_ERROR(rc);
  88                         }
  89                         if (scred) {
  90                                 blob = data_blob(scred->bv_val, scred->bv_len);
  91                                 ber_bvfree(scred);
  92                         } else {
  93                                 blob = data_blob(NULL, 0);
  94                         }
  95
  96                 } else {
  97
  98                         ntlmssp_end(&ntlmssp_state);
  99                         data_blob_free(&blob_out);
 100                         return ADS_ERROR_NT(nt_status);
 101                 }
 102
 103                 if ((turn == 1) &&
 104                     (rc == LDAP_SASL_BIND_IN_PROGRESS)) {
 105                         DATA_BLOB tmp_blob = data_blob(NULL, 0);
 106                         /* the server might give us back two challenges */
 107                         if (!spnego_parse_challenge(blob, &blob_in,
 108                                                     &tmp_blob)) {
 109
 110                                 ntlmssp_end(&ntlmssp_state);
 111                                 data_blob_free(&blob);
 112                                 DEBUG(3,("Failed to parse challenges\n"));
 113                                 return ADS_ERROR_NT(NT_STATUS_INVALID_PARAMETER);
 114                         }
 115                         data_blob_free(&tmp_blob);
 116                 } else if (rc == LDAP_SASL_BIND_IN_PROGRESS) {
 117                         if (!spnego_parse_auth_response(blob, nt_status,
 118                                                         &blob_in)) {
 119
 120                                 ntlmssp_end(&ntlmssp_state);
 121                                 data_blob_free(&blob);
 122                                 DEBUG(3,("Failed to parse auth response\n"));
 123                                 return ADS_ERROR_NT(NT_STATUS_INVALID_PARAMETER);
 124                         }
 125                 }
 126                 data_blob_free(&blob);
 127                 data_blob_free(&blob_out);
 128                 turn++;
 129         } while (rc == LDAP_SASL_BIND_IN_PROGRESS && !NT_STATUS_IS_OK(nt_status));
 130
 131         /* we have a reference conter on ntlmssp_state, if we are signing
 132            then the state will be kept by the signing engine */
 133
 134         ntlmssp_end(&ntlmssp_state);
 135
 136         return ADS_ERROR(rc);
 137 }
 138
 139 #ifdef HAVE_KRB5
 140 /*
 141    perform a LDAP/SASL/SPNEGO/KRB5 bind
 142 */
 143 static ADS_STATUS ads_sasl_spnego_krb5_bind(ADS_STRUCT *ads, const char *principal)
 144 {
 145         DATA_BLOB blob = data_blob(NULL, 0);
 146         struct berval cred, *scred = NULL;
 147         DATA_BLOB session_key = data_blob(NULL, 0);
 148         int rc;
 149
 150         rc = spnego_gen_negTokenTarg(principal, ads->auth.time_offset, &blob, &session_key, 0,
 151                                      &ads->auth.tgs_expire);
 152
 153         if (rc) {
 154                 return ADS_ERROR_KRB5(rc);
 155         }
 156
 157         /* now send the auth packet and we should be done */
 158         cred.bv_val = (char *)blob.data;
 159         cred.bv_len = blob.length;
 160
 161         rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", &cred, NULL, NULL, &scred);
 162
 163         data_blob_free(&blob);
 164         data_blob_free(&session_key);
 165         if(scred)
 166                 ber_bvfree(scred);
 167
 168         return ADS_ERROR(rc);
 169 }
 170 #endif
 171
 172 /*
 173    this performs a SASL/SPNEGO bind
 174 */
 175 static ADS_STATUS ads_sasl_spnego_bind(ADS_STRUCT *ads)
 176 {
 177         struct berval *scred=NULL;
 178         int rc, i;
 179         ADS_STATUS status;
 180         DATA_BLOB blob;
 181         char *principal = NULL;
 182         char *OIDs[ASN1_MAX_OIDS];
 183 #ifdef HAVE_KRB5
 184         BOOL got_kerberos_mechanism = False;
 185 #endif
 186
 187         rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", NULL, NULL, NULL, &scred);
 188
 189         if (rc != LDAP_SASL_BIND_IN_PROGRESS) {
 190                 status = ADS_ERROR(rc);
 191                 goto failed;
 192         }
 193
 194         blob = data_blob(scred->bv_val, scred->bv_len);
 195
 196         ber_bvfree(scred);
 197
 198 #if 0
 199         file_save("sasl_spnego.dat", blob.data, blob.length);
 200 #endif
 201
 202         /* the server sent us the first part of the SPNEGO exchange in the negprot
 203            reply */
 204         if (!spnego_parse_negTokenInit(blob, OIDs, &principal)) {
 205                 data_blob_free(&blob);
 206                 status = ADS_ERROR(LDAP_OPERATIONS_ERROR);
 207                 goto failed;
 208         }
 209         data_blob_free(&blob);
 210
 211         /* make sure the server understands kerberos */
 212         for (i=0;OIDs[i];i++) {
 213                 DEBUG(3,("ads_sasl_spnego_bind: got OID=%s\n", OIDs[i]));
 214 #ifdef HAVE_KRB5
 215                 if (strcmp(OIDs[i], OID_KERBEROS5_OLD) == 0 ||
 216                     strcmp(OIDs[i], OID_KERBEROS5) == 0) {
 217                         got_kerberos_mechanism = True;
 218                 }
 219 #endif
 220                 free(OIDs[i]);
 221         }
 222         DEBUG(3,("ads_sasl_spnego_bind: got server principal name = %s\n", principal));
 223
 224 #ifdef HAVE_KRB5
 225         if (!(ads->auth.flags & ADS_AUTH_DISABLE_KERBEROS) &&
 226             got_kerberos_mechanism)
 227         {
 228                 /* I've seen a child Windows 2000 domain not send
 229                    the principal name back in the first round of
 230                    the SASL bind reply.  So we guess based on server
 231                    name and realm.  --jerry  */
 232                 if ( !principal ) {
 233                         if ( ads->server.realm && ads->server.ldap_server ) {
 234                                 char *server, *server_realm;
 235
 236                                 server = SMB_STRDUP( ads->server.ldap_server );
 237                                 server_realm = SMB_STRDUP( ads->server.realm );
 238
 239                                 if ( !server || !server_realm )
 240                                         return ADS_ERROR(LDAP_NO_MEMORY);
 241
 242                                 strlower_m( server );
 243                                 strupper_m( server_realm );
 244                                 asprintf( &principal, "ldap/%s@%s", server, server_realm );
 245
 246                                 SAFE_FREE( server );
 247                                 SAFE_FREE( server_realm );
 248
 249                                 if ( !principal )
 250                                         return ADS_ERROR(LDAP_NO_MEMORY);
 251                         }
 252
 253                 }
 254
 255                 status = ads_sasl_spnego_krb5_bind(ads, principal);
 256                 if (ADS_ERR_OK(status)) {
 257                         SAFE_FREE(principal);
 258                         return status;
 259                 }
 260
 261                 DEBUG(10,("ads_sasl_spnego_krb5_bind failed with: %s, "
 262                           "calling kinit\n", ads_errstr(status)));
 263
 264                 status = ADS_ERROR_KRB5(ads_kinit_password(ads));
 265
 266                 if (ADS_ERR_OK(status)) {
 267                         status = ads_sasl_spnego_krb5_bind(ads, principal);
 268                 }
 269
 270                 /* only fallback to NTLMSSP if allowed */
 271                 if (ADS_ERR_OK(status) ||
 272                     !(ads->auth.flags & ADS_AUTH_ALLOW_NTLMSSP)) {
 273                         SAFE_FREE(principal);
 274                         return status;
 275                 }
 276         }
 277 #endif
 278
 279         SAFE_FREE(principal);
 280
 281         /* lets do NTLMSSP ... this has the big advantage that we don't need
 282            to sync clocks, and we don't rely on special versions of the krb5
 283            library for HMAC_MD4 encryption */
 284         return ads_sasl_spnego_ntlmssp_bind(ads);
 285
 286 failed:
 287         return status;
 288 }
 289
 290 #ifdef HAVE_GSSAPI
 291 #define MAX_GSS_PASSES 3
 292
 293 /* this performs a SASL/gssapi bind
 294    we avoid using cyrus-sasl to make Samba more robust. cyrus-sasl
 295    is very dependent on correctly configured DNS whereas
 296    this routine is much less fragile
 297    see RFC2078 and RFC2222 for details
 298 */
 299 static ADS_STATUS ads_sasl_gssapi_bind(ADS_STRUCT *ads)
 300 {
 301         uint32 minor_status;
 302         gss_name_t serv_name;
 303         gss_buffer_desc input_name;
 304         gss_ctx_id_t context_handle;
 305         gss_OID mech_type = GSS_C_NULL_OID;
 306         gss_buffer_desc output_token, input_token;
 307         uint32 ret_flags, conf_state;
 308         struct berval cred;
 309         struct berval *scred = NULL;
 310         int i=0;
 311         int gss_rc, rc;
 312         uint8 *p;
 313         uint32 max_msg_size = 0;
 314         char *sname;
 315         ADS_STATUS status;
 316         krb5_principal principal;
 317         krb5_context ctx = NULL;
 318         krb5_enctype enc_types[] = {
 319 #ifdef ENCTYPE_ARCFOUR_HMAC
 320                         ENCTYPE_ARCFOUR_HMAC,
 321 #endif
 322                         ENCTYPE_DES_CBC_MD5,
 323                         ENCTYPE_NULL};
 324         gss_OID_desc nt_principal =
 325         {10, CONST_DISCARD(char *, "\052\206\110\206\367\022\001\002\002\002")};
 326
 327         /* we need to fetch a service ticket as the ldap user in the
 328            servers realm, regardless of our realm */
 329         asprintf(&sname, "ldap/%s@%s", ads->config.ldap_server_name, ads->config.realm);
 330
 331         initialize_krb5_error_table();
 332         status = ADS_ERROR_KRB5(krb5_init_context(&ctx));
 333         if (!ADS_ERR_OK(status)) {
 334                 return status;
 335         }
 336         status = ADS_ERROR_KRB5(krb5_set_default_tgs_ktypes(ctx, enc_types));
 337         if (!ADS_ERR_OK(status)) {
 338                 return status;
 339         }
 340         status = ADS_ERROR_KRB5(smb_krb5_parse_name(ctx, sname, &principal));
 341         if (!ADS_ERR_OK(status)) {
 342                 return status;
 343         }
 344
 345         free(sname);
 346         krb5_free_context(ctx);
 347
 348         input_name.value = &principal;
 349         input_name.length = sizeof(principal);
 350
 351         gss_rc = gss_import_name(&minor_status, &input_name, &nt_principal, &serv_name);
 352         if (gss_rc) {
 353                 return ADS_ERROR_GSS(gss_rc, minor_status);
 354         }
 355
 356         context_handle = GSS_C_NO_CONTEXT;
 357
 358         input_token.value = NULL;
 359         input_token.length = 0;
 360
 361         for (i=0; i < MAX_GSS_PASSES; i++) {
 362                 gss_rc = gss_init_sec_context(&minor_status,
 363                                           GSS_C_NO_CREDENTIAL,
 364                                           &context_handle,
 365                                           serv_name,
 366                                           mech_type,
 367                                           GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG,
 368                                           0,
 369                                           NULL,
 370                                           &input_token,
 371                                           NULL,
 372                                           &output_token,
 373                                           &ret_flags,
 374                                           NULL);
 375
 376                 if (input_token.value) {
 377                         gss_release_buffer(&minor_status, &input_token);
 378                 }
 379
 380                 if (gss_rc && gss_rc != GSS_S_CONTINUE_NEEDED) {
 381                         status = ADS_ERROR_GSS(gss_rc, minor_status);
 382                         goto failed;
 383                 }
 384
 385                 cred.bv_val = (char *)output_token.value;
 386                 cred.bv_len = output_token.length;
 387
 388                 rc = ldap_sasl_bind_s(ads->ld, NULL, "GSSAPI", &cred, NULL, NULL,
 389                                       &scred);
 390                 if (rc != LDAP_SASL_BIND_IN_PROGRESS) {
 391                         status = ADS_ERROR(rc);
 392                         goto failed;
 393                 }
 394
 395                 if (output_token.value) {
 396                         gss_release_buffer(&minor_status, &output_token);
 397                 }
 398
 399                 if (scred) {
 400                         input_token.value = scred->bv_val;
 401                         input_token.length = scred->bv_len;
 402                 } else {
 403                         input_token.value = NULL;
 404                         input_token.length = 0;
 405                 }
 406
 407                 if (gss_rc == 0) break;
 408         }
 409
 410         gss_release_name(&minor_status, &serv_name);
 411
 412         gss_rc = gss_unwrap(&minor_status,context_handle,&input_token,&output_token,
 413                             (int *)&conf_state,NULL);
 414         if (gss_rc) {
 415                 status = ADS_ERROR_GSS(gss_rc, minor_status);
 416                 goto failed;
 417         }
 418
 419         gss_release_buffer(&minor_status, &input_token);
 420
 421         p = (uint8 *)output_token.value;
 422
 423 #if 0
 424         file_save("sasl_gssapi.dat", output_token.value, output_token.length);
 425 #endif
 426
 427         if (p) {
 428                 max_msg_size = (p[1]<<16) | (p[2]<<8) | p[3];
 429         }
 430
 431         gss_release_buffer(&minor_status, &output_token);
 432
 433         output_token.value = SMB_MALLOC(strlen(ads->config.bind_path) + 8);
 434         p = (uint8 *)output_token.value;
 435
 436         *p++ = 1; /* no sign & seal selection */
 437         /* choose the same size as the server gave us */
 438         *p++ = max_msg_size>>16;
 439         *p++ = max_msg_size>>8;
 440         *p++ = max_msg_size;
 441         snprintf((char *)p, strlen(ads->config.bind_path)+4, "dn:%s", ads->config.bind_path);
 442         p += strlen((const char *)p);
 443
 444         output_token.length = PTR_DIFF(p, output_token.value);
 445
 446         gss_rc = gss_wrap(&minor_status, context_handle,0,GSS_C_QOP_DEFAULT,
 447                           &output_token, (int *)&conf_state,
 448                           &input_token);
 449         if (gss_rc) {
 450                 status = ADS_ERROR_GSS(gss_rc, minor_status);
 451                 goto failed;
 452         }
 453
 454         free(output_token.value);
 455
 456         cred.bv_val = (char *)input_token.value;
 457         cred.bv_len = input_token.length;
 458
 459         rc = ldap_sasl_bind_s(ads->ld, NULL, "GSSAPI", &cred, NULL, NULL,
 460                               &scred);
 461         status = ADS_ERROR(rc);
 462
 463         gss_release_buffer(&minor_status, &input_token);
 464
 465 failed:
 466         if(scred)
 467                 ber_bvfree(scred);
 468         return status;
 469 }
 470 #endif /* HAVE_GGSAPI */
 471
 472 /* mapping between SASL mechanisms and functions */
 473 static struct {
 474         const char *name;
 475         ADS_STATUS (*fn)(ADS_STRUCT *);
 476 } sasl_mechanisms[] = {
 477         {"GSS-SPNEGO", ads_sasl_spnego_bind},
 478 #ifdef HAVE_GSSAPI
 479         {"GSSAPI", ads_sasl_gssapi_bind}, /* doesn't work with .NET RC1. No idea why */
 480 #endif
 481         {NULL, NULL}
 482 };
 483
 484 ADS_STATUS ads_sasl_bind(ADS_STRUCT *ads)
 485 {
 486         const char *attrs[] = {"supportedSASLMechanisms", NULL};
 487         char **values;
 488         ADS_STATUS status;
 489         int i, j;
 490         LDAPMessage *res;
 491
 492         /* get a list of supported SASL mechanisms */
 493         status = ads_do_search(ads, "", LDAP_SCOPE_BASE, "(objectclass=*)", attrs, &res);
 494         if (!ADS_ERR_OK(status)) return status;
 495
 496         values = ldap_get_values(ads->ld, res, "supportedSASLMechanisms");
 497
 498         /* try our supported mechanisms in order */
 499         for (i=0;sasl_mechanisms[i].name;i++) {
 500                 /* see if the server supports it */
 501                 for (j=0;values && values[j];j++) {
 502                         if (strcmp(values[j], sasl_mechanisms[i].name) == 0) {
 503                                 DEBUG(4,("Found SASL mechanism %s\n", values[j]));
 504                                 status = sasl_mechanisms[i].fn(ads);
 505                                 ldap_value_free(values);
 506                                 ldap_msgfree(res);
 507                                 return status;
 508                         }
 509                 }
 510         }
 511
 512         ldap_value_free(values);
 513         ldap_msgfree(res);
 514         return ADS_ERROR(LDAP_AUTH_METHOD_NOT_SUPPORTED);
 515 }
 516
 517 #endif /* HAVE_LDAP */
 518