source4/libcli/ldap/ldap_bind.c

   1 /*
   2    Unix SMB/CIFS mplementation.
   3
   4    LDAP bind calls
   5
   6    Copyright (C) Andrew Tridgell  2005
   7    Copyright (C) Volker Lendecke  2004
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  21
  22 */
  23
  24 #include "includes.h"
  25 #include "libcli/ldap/ldap.h"
  26 #include "libcli/ldap/ldap_client.h"
  27 #include "lib/tls/tls.h"
  28 #include "auth/gensec/gensec.h"
  29 #include "auth/gensec/socket.h"
  30 #include "auth/credentials/credentials.h"
  31 #include "lib/stream/packet.h"
  32
  33 struct ldap_simple_creds {
  34         const char *dn;
  35         const char *pw;
  36 };
  37
  38 NTSTATUS ldap_rebind(struct ldap_connection *conn)
  39 {
  40         NTSTATUS status;
  41         struct ldap_simple_creds *creds;
  42
  43         switch (conn->bind.type) {
  44         case LDAP_BIND_SASL:
  45                 status = ldap_bind_sasl(conn, (struct cli_credentials *)conn->bind.creds);
  46                 break;
  47
  48         case LDAP_BIND_SIMPLE:
  49                 creds = (struct ldap_simple_creds *)conn->bind.creds;
  50
  51                 if (creds == NULL) {
  52                         return NT_STATUS_UNSUCCESSFUL;
  53                 }
  54
  55                 status = ldap_bind_simple(conn, creds->dn, creds->pw);
  56                 break;
  57
  58         default:
  59                 return NT_STATUS_UNSUCCESSFUL;
  60         }
  61
  62         return status;
  63 }
  64
  65
  66 static struct ldap_message *new_ldap_simple_bind_msg(struct ldap_connection *conn,
  67                                                      const char *dn, const char *pw)
  68 {
  69         struct ldap_message *res;
  70
  71         res = new_ldap_message(conn);
  72         if (!res) {
  73                 return NULL;
  74         }
  75
  76         res->type = LDAP_TAG_BindRequest;
  77         res->r.BindRequest.version = 3;
  78         res->r.BindRequest.dn = talloc_strdup(res, dn);
  79         res->r.BindRequest.mechanism = LDAP_AUTH_MECH_SIMPLE;
  80         res->r.BindRequest.creds.password = talloc_strdup(res, pw);
  81         res->controls = NULL;
  82
  83         return res;
  84 }
  85
  86
  87 /*
  88   perform a simple username/password bind
  89 */
  90 NTSTATUS ldap_bind_simple(struct ldap_connection *conn,
  91                           const char *userdn, const char *password)
  92 {
  93         struct ldap_request *req;
  94         struct ldap_message *msg;
  95         const char *dn, *pw;
  96         NTSTATUS status;
  97
  98         if (conn == NULL) {
  99                 return NT_STATUS_INVALID_CONNECTION;
 100         }
 101
 102         if (userdn) {
 103                 dn = userdn;
 104         } else {
 105                 if (conn->auth_dn) {
 106                         dn = conn->auth_dn;
 107                 } else {
 108                         dn = "";
 109                 }
 110         }
 111
 112         if (password) {
 113                 pw = password;
 114         } else {
 115                 if (conn->simple_pw) {
 116                         pw = conn->simple_pw;
 117                 } else {
 118                         pw = "";
 119                 }
 120         }
 121
 122         msg = new_ldap_simple_bind_msg(conn, dn, pw);
 123         NT_STATUS_HAVE_NO_MEMORY(msg);
 124
 125         /* send the request */
 126         req = ldap_request_send(conn, msg);
 127         talloc_free(msg);
 128         NT_STATUS_HAVE_NO_MEMORY(req);
 129
 130         /* wait for replies */
 131         status = ldap_request_wait(req);
 132         if (!NT_STATUS_IS_OK(status)) {
 133                 talloc_free(req);
 134                 return status;
 135         }
 136
 137         /* check its a valid reply */
 138         msg = req->replies[0];
 139         if (msg->type != LDAP_TAG_BindResponse) {
 140                 talloc_free(req);
 141                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 142         }
 143
 144         status = ldap_check_response(conn, &msg->r.BindResponse.response);
 145
 146         talloc_free(req);
 147
 148         if (NT_STATUS_IS_OK(status)) {
 149                 struct ldap_simple_creds *creds = talloc(conn, struct ldap_simple_creds);
 150                 if (creds == NULL) {
 151                         return NT_STATUS_NO_MEMORY;
 152                 }
 153                 creds->dn = talloc_strdup(creds, dn);
 154                 creds->pw = talloc_strdup(creds, pw);
 155                 if (creds->dn == NULL || creds->pw == NULL) {
 156                         return NT_STATUS_NO_MEMORY;
 157                 }
 158                 conn->bind.type = LDAP_BIND_SIMPLE;
 159                 conn->bind.creds = creds;
 160         }
 161
 162         return status;
 163 }
 164
 165
 166 static struct ldap_message *new_ldap_sasl_bind_msg(struct ldap_connection *conn,
 167                                                    const char *sasl_mechanism,
 168                                                    DATA_BLOB *secblob)
 169 {
 170         struct ldap_message *res;
 171
 172         res = new_ldap_message(conn);
 173         if (!res) {
 174                 return NULL;
 175         }
 176
 177         res->type = LDAP_TAG_BindRequest;
 178         res->r.BindRequest.version = 3;
 179         res->r.BindRequest.dn = "";
 180         res->r.BindRequest.mechanism = LDAP_AUTH_MECH_SASL;
 181         res->r.BindRequest.creds.SASL.mechanism = talloc_strdup(res, sasl_mechanism);
 182         if (secblob) {
 183                 res->r.BindRequest.creds.SASL.secblob = talloc(res, DATA_BLOB);
 184                 if (!res->r.BindRequest.creds.SASL.secblob) {
 185                         talloc_free(res);
 186                         return NULL;
 187                 }
 188                 *res->r.BindRequest.creds.SASL.secblob = *secblob;
 189         } else {
 190                 res->r.BindRequest.creds.SASL.secblob = NULL;
 191         }
 192         res->controls = NULL;
 193
 194         return res;
 195 }
 196
 197
 198 /*
 199   perform a sasl bind using the given credentials
 200 */
 201 NTSTATUS ldap_bind_sasl(struct ldap_connection *conn, struct cli_credentials *creds)
 202 {
 203         NTSTATUS status;
 204         TALLOC_CTX *tmp_ctx = NULL;
 205
 206         DATA_BLOB input = data_blob(NULL, 0);
 207         DATA_BLOB output = data_blob(NULL, 0);
 208
 209         struct ldap_message **sasl_mechs_msgs;
 210         struct ldap_SearchResEntry *search;
 211         int count, i;
 212
 213         const char **sasl_names;
 214         uint32_t old_gensec_features;
 215         static const char *supported_sasl_mech_attrs[] = {
 216                 "supportedSASLMechanisms",
 217                 NULL
 218         };
 219
 220         status = gensec_client_start(conn, &conn->gensec, NULL);
 221         if (!NT_STATUS_IS_OK(status)) {
 222                 DEBUG(0, ("Failed to start GENSEC engine (%s)\n", nt_errstr(status)));
 223                 goto failed;
 224         }
 225
 226         /* require Kerberos SIGN/SEAL only if we don't use SSL
 227          * Windows seem not to like double encryption */
 228         old_gensec_features = cli_credentials_get_gensec_features(creds);
 229         if (tls_enabled(conn->sock)) {
 230                 cli_credentials_set_gensec_features(creds, 0);
 231         }
 232
 233         /* this call also sets the gensec_want_features */
 234         status = gensec_set_credentials(conn->gensec, creds);
 235         if (!NT_STATUS_IS_OK(status)) {
 236                 DEBUG(1, ("Failed to set GENSEC creds: %s\n",
 237                           nt_errstr(status)));
 238                 goto failed;
 239         }
 240
 241         /* reset the original gensec_features */
 242         cli_credentials_set_gensec_features(creds, old_gensec_features);
 243
 244         if (conn->host) {
 245                 status = gensec_set_target_hostname(conn->gensec, conn->host);
 246                 if (!NT_STATUS_IS_OK(status)) {
 247                         DEBUG(1, ("Failed to set GENSEC target hostname: %s\n",
 248                                   nt_errstr(status)));
 249                         goto failed;
 250                 }
 251         }
 252
 253         status = gensec_set_target_service(conn->gensec, "ldap");
 254         if (!NT_STATUS_IS_OK(status)) {
 255                 DEBUG(1, ("Failed to set GENSEC target service: %s\n",
 256                           nt_errstr(status)));
 257                 goto failed;
 258         }
 259
 260         status = ildap_search(conn, "", LDAP_SEARCH_SCOPE_BASE, "", supported_sasl_mech_attrs,
 261                               false, NULL, NULL, &sasl_mechs_msgs);
 262         if (!NT_STATUS_IS_OK(status)) {
 263                 DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: %s\n",
 264                           nt_errstr(status)));
 265                 goto failed;
 266         }
 267
 268         count = ildap_count_entries(conn, sasl_mechs_msgs);
 269         if (count != 1) {
 270                 DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of replies: %d\n",
 271                           count));
 272                 goto failed;
 273         }
 274
 275         tmp_ctx = talloc_new(conn);
 276         if (tmp_ctx == NULL) goto failed;
 277
 278         search = &sasl_mechs_msgs[0]->r.SearchResultEntry;
 279         if (search->num_attributes != 1) {
 280                 DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of attributes: %d\n",
 281                           search->num_attributes));
 282                 goto failed;
 283         }
 284
 285         sasl_names = talloc_array(tmp_ctx, const char *, search->attributes[0].num_values + 1);
 286         if (!sasl_names) {
 287                 DEBUG(1, ("talloc_arry(char *, %d) failed\n",
 288                           count));
 289                 goto failed;
 290         }
 291
 292         for (i=0; i<search->attributes[0].num_values; i++) {
 293                 sasl_names[i] = (const char *)search->attributes[0].values[i].data;
 294         }
 295         sasl_names[i] = NULL;
 296
 297         status = gensec_start_mech_by_sasl_list(conn->gensec, sasl_names);
 298         if (!NT_STATUS_IS_OK(status)) {
 299                 DEBUG(1, ("None of the %d proposed SASL mechs were acceptable: %s\n",
 300                           count, nt_errstr(status)));
 301                 goto failed;
 302         }
 303
 304         while (1) {
 305                 NTSTATUS gensec_status;
 306                 struct ldap_message *response;
 307                 struct ldap_message *msg;
 308                 struct ldap_request *req;
 309                 int result = LDAP_OTHER;
 310
 311                 status = gensec_update(conn->gensec, tmp_ctx,
 312                                        input,
 313                                        &output);
 314                 /* The status value here, from GENSEC is vital to the security
 315                  * of the system.  Even if the other end accepts, if GENSEC
 316                  * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 317                  * feeding it blobs, or else the remote host/attacker might
 318                  * avoid mutal authentication requirements.
 319                  *
 320                  * Likewise, you must not feed GENSEC too much (after the OK),
 321                  * it doesn't like that either
 322                  */
 323
 324                 gensec_status = status;
 325
 326                 if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 327                     !NT_STATUS_IS_OK(status)) {
 328                         break;
 329                 }
 330                 if (NT_STATUS_IS_OK(status) && output.length == 0) {
 331                         break;
 332                 }
 333
 334                 /* Perhaps we should make gensec_start_mech_by_sasl_list() return the name we got? */
 335                 msg = new_ldap_sasl_bind_msg(tmp_ctx, conn->gensec->ops->sasl_name, (output.data?&output:NULL));
 336                 if (msg == NULL) {
 337                         status = NT_STATUS_NO_MEMORY;
 338                         goto failed;
 339                 }
 340
 341                 req = ldap_request_send(conn, msg);
 342                 if (req == NULL) {
 343                         status = NT_STATUS_NO_MEMORY;
 344                         goto failed;
 345                 }
 346                 talloc_steal(tmp_ctx, req);
 347
 348                 status = ldap_result_n(req, 0, &response);
 349                 if (!NT_STATUS_IS_OK(status)) {
 350                         goto failed;
 351                 }
 352
 353                 if (response->type != LDAP_TAG_BindResponse) {
 354                         status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 355                         goto failed;
 356                 }
 357
 358                 result = response->r.BindResponse.response.resultcode;
 359
 360                 if (result != LDAP_SUCCESS && result != LDAP_SASL_BIND_IN_PROGRESS) {
 361                         status = ldap_check_response(conn,
 362                                                      &response->r.BindResponse.response);
 363                         break;
 364                 }
 365
 366                 /* This is where we check if GENSEC wanted to be fed more data */
 367                 if (!NT_STATUS_EQUAL(gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 368                         break;
 369                 }
 370                 if (response->r.BindResponse.SASL.secblob) {
 371                         input = *response->r.BindResponse.SASL.secblob;
 372                 } else {
 373                         input = data_blob(NULL, 0);
 374                 }
 375         }
 376
 377         talloc_free(tmp_ctx);
 378
 379         if (NT_STATUS_IS_OK(status)) {
 380                 struct socket_context *sasl_socket;
 381                 status = gensec_socket_init(conn->gensec,
 382                                             conn->sock,
 383                                             conn->event.event_ctx,
 384                                             ldap_read_io_handler,
 385                                             conn,
 386                                             &sasl_socket);
 387                 if (!NT_STATUS_IS_OK(status)) goto failed;
 388
 389                 talloc_steal(conn->sock, sasl_socket);
 390                 talloc_unlink(conn, conn->sock);
 391                 conn->sock = sasl_socket;
 392                 packet_set_socket(conn->packet, conn->sock);
 393
 394                 conn->bind.type = LDAP_BIND_SASL;
 395                 conn->bind.creds = creds;
 396         }
 397
 398         return status;
 399
 400 failed:
 401         talloc_free(tmp_ctx);
 402         talloc_free(conn->gensec);
 403         conn->gensec = NULL;
 404         return status;
 405 }