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 /*
 140    perform a LDAP/SASL/SPNEGO/KRB5 bind
 141 */
 142 static ADS_STATUS ads_sasl_spnego_krb5_bind(ADS_STRUCT *ads, const char *principal)
 143 {
 144         DATA_BLOB blob = data_blob(NULL, 0);
 145         struct berval cred, *scred = NULL;
 146         DATA_BLOB session_key = data_blob(NULL, 0);
 147         int rc;
 148
 149         rc = spnego_gen_negTokenTarg(principal, ads->auth.time_offset, &blob, &session_key, 0);
 150
 151         if (rc) {
 152                 return ADS_ERROR_KRB5(rc);
 153         }
 154
 155         /* now send the auth packet and we should be done */
 156         cred.bv_val = (char *)blob.data;
 157         cred.bv_len = blob.length;
 158
 159         rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", &cred, NULL, NULL, &scred);
 160
 161         data_blob_free(&blob);
 162         data_blob_free(&session_key);
 163         if(scred)
 164                 ber_bvfree(scred);
 165
 166         return ADS_ERROR(rc);
 167 }
 168
 169 /*
 170    this performs a SASL/SPNEGO bind
 171 */
 172 static ADS_STATUS ads_sasl_spnego_bind(ADS_STRUCT *ads)
 173 {
 174         struct berval *scred=NULL;
 175         int rc, i;
 176         ADS_STATUS status;
 177         DATA_BLOB blob;
 178         char *principal = NULL;
 179         char *OIDs[ASN1_MAX_OIDS];
 180 #ifdef HAVE_KRB5
 181         BOOL got_kerberos_mechanism = False;
 182 #endif
 183
 184         rc = ldap_sasl_bind_s(ads->ld, NULL, "GSS-SPNEGO", NULL, NULL, NULL, &scred);
 185
 186         if (rc != LDAP_SASL_BIND_IN_PROGRESS) {
 187                 status = ADS_ERROR(rc);
 188                 goto failed;
 189         }
 190
 191         blob = data_blob(scred->bv_val, scred->bv_len);
 192
 193         ber_bvfree(scred);
 194
 195 #if 0
 196         file_save("sasl_spnego.dat", blob.data, blob.length);
 197 #endif
 198
 199         /* the server sent us the first part of the SPNEGO exchange in the negprot
 200            reply */
 201         if (!spnego_parse_negTokenInit(blob, OIDs, &principal)) {
 202                 data_blob_free(&blob);
 203                 status = ADS_ERROR(LDAP_OPERATIONS_ERROR);
 204                 goto failed;
 205         }
 206         data_blob_free(&blob);
 207
 208         /* make sure the server understands kerberos */
 209         for (i=0;OIDs[i];i++) {
 210                 DEBUG(3,("ads_sasl_spnego_bind: got OID=%s\n", OIDs[i]));
 211 #ifdef HAVE_KRB5
 212                 if (strcmp(OIDs[i], OID_KERBEROS5_OLD) == 0 ||
 213                     strcmp(OIDs[i], OID_KERBEROS5) == 0) {
 214                         got_kerberos_mechanism = True;
 215                 }
 216 #endif
 217                 free(OIDs[i]);
 218         }
 219         DEBUG(3,("ads_sasl_spnego_bind: got server principal name =%s\n", principal));
 220
 221 #ifdef HAVE_KRB5
 222         if (!(ads->auth.flags & ADS_AUTH_DISABLE_KERBEROS) &&
 223             got_kerberos_mechanism) {
 224                 status = ads_sasl_spnego_krb5_bind(ads, principal);
 225                 if (ADS_ERR_OK(status)) {
 226                         SAFE_FREE(principal);
 227                         return status;
 228                 }
 229
 230                 status = ADS_ERROR_KRB5(ads_kinit_password(ads));
 231
 232                 if (ADS_ERR_OK(status)) {
 233                         status = ads_sasl_spnego_krb5_bind(ads, principal);
 234                 }
 235
 236                 /* only fallback to NTLMSSP if allowed */
 237                 if (ADS_ERR_OK(status) ||
 238                     !(ads->auth.flags & ADS_AUTH_ALLOW_NTLMSSP)) {
 239                         SAFE_FREE(principal);
 240                         return status;
 241                 }
 242         }
 243 #endif
 244
 245         SAFE_FREE(principal);
 246
 247         /* lets do NTLMSSP ... this has the big advantage that we don't need
 248            to sync clocks, and we don't rely on special versions of the krb5
 249            library for HMAC_MD4 encryption */
 250         return ads_sasl_spnego_ntlmssp_bind(ads);
 251
 252 failed:
 253         return status;
 254 }
 255
 256 #ifdef HAVE_GSSAPI
 257 #define MAX_GSS_PASSES 3
 258
 259 /* this performs a SASL/gssapi bind
 260    we avoid using cyrus-sasl to make Samba more robust. cyrus-sasl
 261    is very dependent on correctly configured DNS whereas
 262    this routine is much less fragile
 263    see RFC2078 and RFC2222 for details
 264 */
 265 static ADS_STATUS ads_sasl_gssapi_bind(ADS_STRUCT *ads)
 266 {
 267         uint32 minor_status;
 268         gss_name_t serv_name;
 269         gss_buffer_desc input_name;
 270         gss_ctx_id_t context_handle;
 271         gss_OID mech_type = GSS_C_NULL_OID;
 272         gss_buffer_desc output_token, input_token;
 273         uint32 ret_flags, conf_state;
 274         struct berval cred;
 275         struct berval *scred = NULL;
 276         int i=0;
 277         int gss_rc, rc;
 278         uint8 *p;
 279         uint32 max_msg_size = 0;
 280         char *sname;
 281         ADS_STATUS status;
 282         krb5_principal principal;
 283         krb5_context ctx = NULL;
 284         krb5_enctype enc_types[] = {
 285 #ifdef ENCTYPE_ARCFOUR_HMAC
 286                         ENCTYPE_ARCFOUR_HMAC,
 287 #endif
 288                         ENCTYPE_DES_CBC_MD5,
 289                         ENCTYPE_NULL};
 290         gss_OID_desc nt_principal =
 291         {10, CONST_DISCARD(char *, "\052\206\110\206\367\022\001\002\002\002")};
 292
 293         /* we need to fetch a service ticket as the ldap user in the
 294            servers realm, regardless of our realm */
 295         asprintf(&sname, "ldap/%s@%s", ads->config.ldap_server_name, ads->config.realm);
 296
 297         initialize_krb5_error_table();
 298         status = ADS_ERROR_KRB5(krb5_init_context(&ctx));
 299         if (!ADS_ERR_OK(status)) {
 300                 return status;
 301         }
 302         status = ADS_ERROR_KRB5(krb5_set_default_tgs_ktypes(ctx, enc_types));
 303         if (!ADS_ERR_OK(status)) {
 304                 return status;
 305         }
 306         status = ADS_ERROR_KRB5(smb_krb5_parse_name(ctx, sname, &principal));
 307         if (!ADS_ERR_OK(status)) {
 308                 return status;
 309         }
 310
 311         free(sname);
 312         krb5_free_context(ctx);
 313
 314         input_name.value = &principal;
 315         input_name.length = sizeof(principal);
 316
 317         gss_rc = gss_import_name(&minor_status, &input_name, &nt_principal, &serv_name);
 318         if (gss_rc) {
 319                 return ADS_ERROR_GSS(gss_rc, minor_status);
 320         }
 321
 322         context_handle = GSS_C_NO_CONTEXT;
 323
 324         input_token.value = NULL;
 325         input_token.length = 0;
 326
 327         for (i=0; i < MAX_GSS_PASSES; i++) {
 328                 gss_rc = gss_init_sec_context(&minor_status,
 329                                           GSS_C_NO_CREDENTIAL,
 330                                           &context_handle,
 331                                           serv_name,
 332                                           mech_type,
 333                                           GSS_C_MUTUAL_FLAG | GSS_C_REPLAY_FLAG,
 334                                           0,
 335                                           NULL,
 336                                           &input_token,
 337                                           NULL,
 338                                           &output_token,
 339                                           &ret_flags,
 340                                           NULL);
 341
 342                 if (input_token.value) {
 343                         gss_release_buffer(&minor_status, &input_token);
 344                 }
 345
 346                 if (gss_rc && gss_rc != GSS_S_CONTINUE_NEEDED) {
 347                         status = ADS_ERROR_GSS(gss_rc, minor_status);
 348                         goto failed;
 349                 }
 350
 351                 cred.bv_val = output_token.value;
 352                 cred.bv_len = output_token.length;
 353
 354                 rc = ldap_sasl_bind_s(ads->ld, NULL, "GSSAPI", &cred, NULL, NULL,
 355                                       &scred);
 356                 if (rc != LDAP_SASL_BIND_IN_PROGRESS) {
 357                         status = ADS_ERROR(rc);
 358                         goto failed;
 359                 }
 360
 361                 if (output_token.value) {
 362                         gss_release_buffer(&minor_status, &output_token);
 363                 }
 364
 365                 if (scred) {
 366                         input_token.value = scred->bv_val;
 367                         input_token.length = scred->bv_len;
 368                 } else {
 369                         input_token.value = NULL;
 370                         input_token.length = 0;
 371                 }
 372
 373                 if (gss_rc == 0) break;
 374         }
 375
 376         gss_release_name(&minor_status, &serv_name);
 377
 378         gss_rc = gss_unwrap(&minor_status,context_handle,&input_token,&output_token,
 379                             (int *)&conf_state,NULL);
 380         if (gss_rc) {
 381                 status = ADS_ERROR_GSS(gss_rc, minor_status);
 382                 goto failed;
 383         }
 384
 385         gss_release_buffer(&minor_status, &input_token);
 386
 387         p = (uint8 *)output_token.value;
 388
 389 #if 0
 390         file_save("sasl_gssapi.dat", output_token.value, output_token.length);
 391 #endif
 392         if (p) {
 393                 max_msg_size = (p[1]<<16) | (p[2]<<8) | p[3];
 394         }
 395
 396         gss_release_buffer(&minor_status, &output_token);
 397
 398         output_token.value = SMB_MALLOC(strlen(ads->config.bind_path) + 8);
 399         p = output_token.value;
 400
 401         *p++ = 1; /* no sign & seal selection */
 402         /* choose the same size as the server gave us */
 403         *p++ = max_msg_size>>16;
 404         *p++ = max_msg_size>>8;
 405         *p++ = max_msg_size;
 406         snprintf((char *)p, strlen(ads->config.bind_path)+4, "dn:%s", ads->config.bind_path);
 407         p += strlen((const char *)p);
 408
 409         output_token.length = PTR_DIFF(p, output_token.value);
 410
 411         gss_rc = gss_wrap(&minor_status, context_handle,0,GSS_C_QOP_DEFAULT,
 412                           &output_token, (int *)&conf_state,
 413                           &input_token);
 414         if (gss_rc) {
 415                 status = ADS_ERROR_GSS(gss_rc, minor_status);
 416                 goto failed;
 417         }
 418
 419         free(output_token.value);
 420
 421         cred.bv_val = input_token.value;
 422         cred.bv_len = input_token.length;
 423
 424         rc = ldap_sasl_bind_s(ads->ld, NULL, "GSSAPI", &cred, NULL, NULL,
 425                               &scred);
 426         status = ADS_ERROR(rc);
 427
 428         gss_release_buffer(&minor_status, &input_token);
 429
 430 failed:
 431         if(scred)
 432                 ber_bvfree(scred);
 433         return status;
 434 }
 435 #endif /* HAVE_GGSAPI */
 436
 437 /* mapping between SASL mechanisms and functions */
 438 static struct {
 439         const char *name;
 440         ADS_STATUS (*fn)(ADS_STRUCT *);
 441 } sasl_mechanisms[] = {
 442         {"GSS-SPNEGO", ads_sasl_spnego_bind},
 443 #ifdef HAVE_GSSAPI
 444         {"GSSAPI", ads_sasl_gssapi_bind}, /* doesn't work with .NET RC1. No idea why */
 445 #endif
 446         {NULL, NULL}
 447 };
 448
 449 ADS_STATUS ads_sasl_bind(ADS_STRUCT *ads)
 450 {
 451         const char *attrs[] = {"supportedSASLMechanisms", NULL};
 452         char **values;
 453         ADS_STATUS status;
 454         int i, j;
 455         void *res;
 456
 457         /* get a list of supported SASL mechanisms */
 458         status = ads_do_search(ads, "", LDAP_SCOPE_BASE, "(objectclass=*)", attrs, &res);
 459         if (!ADS_ERR_OK(status)) return status;
 460
 461         values = ldap_get_values(ads->ld, res, "supportedSASLMechanisms");
 462
 463         /* try our supported mechanisms in order */
 464         for (i=0;sasl_mechanisms[i].name;i++) {
 465                 /* see if the server supports it */
 466                 for (j=0;values && values[j];j++) {
 467                         if (strcmp(values[j], sasl_mechanisms[i].name) == 0) {
 468                                 DEBUG(4,("Found SASL mechanism %s\n", values[j]));
 469                                 status = sasl_mechanisms[i].fn(ads);
 470                                 ldap_value_free(values);
 471                                 ldap_msgfree(res);
 472                                 return status;
 473                         }
 474                 }
 475         }
 476
 477         ldap_value_free(values);
 478         ldap_msgfree(res);
 479         return ADS_ERROR(LDAP_AUTH_METHOD_NOT_SUPPORTED);
 480 }
 481
 482 #endif /* HAVE_LDAP */
 483