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 #include "param/param.h"
  33
  34 struct ldap_simple_creds {
  35         const char *dn;
  36         const char *pw;
  37 };
  38
  39 NTSTATUS ldap_rebind(struct ldap_connection *conn)
  40 {
  41         NTSTATUS status;
  42         struct ldap_simple_creds *creds;
  43
  44         switch (conn->bind.type) {
  45         case LDAP_BIND_SASL:
  46                 status = ldap_bind_sasl(conn, (struct cli_credentials *)conn->bind.creds);
  47                 break;
  48
  49         case LDAP_BIND_SIMPLE:
  50                 creds = (struct ldap_simple_creds *)conn->bind.creds;
  51
  52                 if (creds == NULL) {
  53                         return NT_STATUS_UNSUCCESSFUL;
  54                 }
  55
  56                 status = ldap_bind_simple(conn, creds->dn, creds->pw);
  57                 break;
  58
  59         default:
  60                 return NT_STATUS_UNSUCCESSFUL;
  61         }
  62
  63         return status;
  64 }
  65
  66
  67 static struct ldap_message *new_ldap_simple_bind_msg(struct ldap_connection *conn,
  68                                                      const char *dn, const char *pw)
  69 {
  70         struct ldap_message *res;
  71
  72         res = new_ldap_message(conn);
  73         if (!res) {
  74                 return NULL;
  75         }
  76
  77         res->type = LDAP_TAG_BindRequest;
  78         res->r.BindRequest.version = 3;
  79         res->r.BindRequest.dn = talloc_strdup(res, dn);
  80         res->r.BindRequest.mechanism = LDAP_AUTH_MECH_SIMPLE;
  81         res->r.BindRequest.creds.password = talloc_strdup(res, pw);
  82         res->controls = NULL;
  83
  84         return res;
  85 }
  86
  87
  88 /*
  89   perform a simple username/password bind
  90 */
  91 NTSTATUS ldap_bind_simple(struct ldap_connection *conn,
  92                           const char *userdn, const char *password)
  93 {
  94         struct ldap_request *req;
  95         struct ldap_message *msg;
  96         const char *dn, *pw;
  97         NTSTATUS status;
  98
  99         if (conn == NULL) {
 100                 return NT_STATUS_INVALID_CONNECTION;
 101         }
 102
 103         if (userdn) {
 104                 dn = userdn;
 105         } else {
 106                 if (conn->auth_dn) {
 107                         dn = conn->auth_dn;
 108                 } else {
 109                         dn = "";
 110                 }
 111         }
 112
 113         if (password) {
 114                 pw = password;
 115         } else {
 116                 if (conn->simple_pw) {
 117                         pw = conn->simple_pw;
 118                 } else {
 119                         pw = "";
 120                 }
 121         }
 122
 123         msg = new_ldap_simple_bind_msg(conn, dn, pw);
 124         NT_STATUS_HAVE_NO_MEMORY(msg);
 125
 126         /* send the request */
 127         req = ldap_request_send(conn, msg);
 128         talloc_free(msg);
 129         NT_STATUS_HAVE_NO_MEMORY(req);
 130
 131         /* wait for replies */
 132         status = ldap_request_wait(req);
 133         if (!NT_STATUS_IS_OK(status)) {
 134                 talloc_free(req);
 135                 return status;
 136         }
 137
 138         /* check its a valid reply */
 139         msg = req->replies[0];
 140         if (msg->type != LDAP_TAG_BindResponse) {
 141                 talloc_free(req);
 142                 return NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 143         }
 144
 145         status = ldap_check_response(conn, &msg->r.BindResponse.response);
 146
 147         talloc_free(req);
 148
 149         if (NT_STATUS_IS_OK(status)) {
 150                 struct ldap_simple_creds *creds = talloc(conn, struct ldap_simple_creds);
 151                 if (creds == NULL) {
 152                         return NT_STATUS_NO_MEMORY;
 153                 }
 154                 creds->dn = talloc_strdup(creds, dn);
 155                 creds->pw = talloc_strdup(creds, pw);
 156                 if (creds->dn == NULL || creds->pw == NULL) {
 157                         return NT_STATUS_NO_MEMORY;
 158                 }
 159                 conn->bind.type = LDAP_BIND_SIMPLE;
 160                 conn->bind.creds = creds;
 161         }
 162
 163         return status;
 164 }
 165
 166
 167 static struct ldap_message *new_ldap_sasl_bind_msg(struct ldap_connection *conn,
 168                                                    const char *sasl_mechanism,
 169                                                    DATA_BLOB *secblob)
 170 {
 171         struct ldap_message *res;
 172
 173         res = new_ldap_message(conn);
 174         if (!res) {
 175                 return NULL;
 176         }
 177
 178         res->type = LDAP_TAG_BindRequest;
 179         res->r.BindRequest.version = 3;
 180         res->r.BindRequest.dn = "";
 181         res->r.BindRequest.mechanism = LDAP_AUTH_MECH_SASL;
 182         res->r.BindRequest.creds.SASL.mechanism = talloc_strdup(res, sasl_mechanism);
 183         if (secblob) {
 184                 res->r.BindRequest.creds.SASL.secblob = talloc(res, DATA_BLOB);
 185                 if (!res->r.BindRequest.creds.SASL.secblob) {
 186                         talloc_free(res);
 187                         return NULL;
 188                 }
 189                 *res->r.BindRequest.creds.SASL.secblob = *secblob;
 190         } else {
 191                 res->r.BindRequest.creds.SASL.secblob = NULL;
 192         }
 193         res->controls = NULL;
 194
 195         return res;
 196 }
 197
 198
 199 /*
 200   perform a sasl bind using the given credentials
 201 */
 202 NTSTATUS ldap_bind_sasl(struct ldap_connection *conn, struct cli_credentials *creds)
 203 {
 204         NTSTATUS status;
 205         TALLOC_CTX *tmp_ctx = NULL;
 206
 207         DATA_BLOB input = data_blob(NULL, 0);
 208         DATA_BLOB output = data_blob(NULL, 0);
 209
 210         struct ldap_message **sasl_mechs_msgs;
 211         struct ldap_SearchResEntry *search;
 212         int count, i;
 213
 214         const char **sasl_names;
 215         uint32_t old_gensec_features;
 216         static const char *supported_sasl_mech_attrs[] = {
 217                 "supportedSASLMechanisms",
 218                 NULL
 219         };
 220
 221         status = gensec_client_start(conn, &conn->gensec, NULL, global_loadparm);
 222         if (!NT_STATUS_IS_OK(status)) {
 223                 DEBUG(0, ("Failed to start GENSEC engine (%s)\n", nt_errstr(status)));
 224                 goto failed;
 225         }
 226
 227         /* require Kerberos SIGN/SEAL only if we don't use SSL
 228          * Windows seem not to like double encryption */
 229         old_gensec_features = cli_credentials_get_gensec_features(creds);
 230         if (tls_enabled(conn->sock)) {
 231                 cli_credentials_set_gensec_features(creds, 0);
 232         }
 233
 234         /* this call also sets the gensec_want_features */
 235         status = gensec_set_credentials(conn->gensec, creds);
 236         if (!NT_STATUS_IS_OK(status)) {
 237                 DEBUG(1, ("Failed to set GENSEC creds: %s\n",
 238                           nt_errstr(status)));
 239                 goto failed;
 240         }
 241
 242         /* reset the original gensec_features */
 243         cli_credentials_set_gensec_features(creds, old_gensec_features);
 244
 245         if (conn->host) {
 246                 status = gensec_set_target_hostname(conn->gensec, conn->host);
 247                 if (!NT_STATUS_IS_OK(status)) {
 248                         DEBUG(1, ("Failed to set GENSEC target hostname: %s\n",
 249                                   nt_errstr(status)));
 250                         goto failed;
 251                 }
 252         }
 253
 254         status = gensec_set_target_service(conn->gensec, "ldap");
 255         if (!NT_STATUS_IS_OK(status)) {
 256                 DEBUG(1, ("Failed to set GENSEC target service: %s\n",
 257                           nt_errstr(status)));
 258                 goto failed;
 259         }
 260
 261         status = ildap_search(conn, "", LDAP_SEARCH_SCOPE_BASE, "", supported_sasl_mech_attrs,
 262                               false, NULL, NULL, &sasl_mechs_msgs);
 263         if (!NT_STATUS_IS_OK(status)) {
 264                 DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: %s\n",
 265                           nt_errstr(status)));
 266                 goto failed;
 267         }
 268
 269         count = ildap_count_entries(conn, sasl_mechs_msgs);
 270         if (count != 1) {
 271                 DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of replies: %d\n",
 272                           count));
 273                 goto failed;
 274         }
 275
 276         tmp_ctx = talloc_new(conn);
 277         if (tmp_ctx == NULL) goto failed;
 278
 279         search = &sasl_mechs_msgs[0]->r.SearchResultEntry;
 280         if (search->num_attributes != 1) {
 281                 DEBUG(1, ("Failed to inquire of target's available sasl mechs in rootdse search: wrong number of attributes: %d\n",
 282                           search->num_attributes));
 283                 goto failed;
 284         }
 285
 286         sasl_names = talloc_array(tmp_ctx, const char *, search->attributes[0].num_values + 1);
 287         if (!sasl_names) {
 288                 DEBUG(1, ("talloc_arry(char *, %d) failed\n",
 289                           count));
 290                 goto failed;
 291         }
 292
 293         for (i=0; i<search->attributes[0].num_values; i++) {
 294                 sasl_names[i] = (const char *)search->attributes[0].values[i].data;
 295         }
 296         sasl_names[i] = NULL;
 297
 298         status = gensec_start_mech_by_sasl_list(conn->gensec, sasl_names);
 299         if (!NT_STATUS_IS_OK(status)) {
 300                 DEBUG(1, ("None of the %d proposed SASL mechs were acceptable: %s\n",
 301                           count, nt_errstr(status)));
 302                 goto failed;
 303         }
 304
 305         while (1) {
 306                 NTSTATUS gensec_status;
 307                 struct ldap_message *response;
 308                 struct ldap_message *msg;
 309                 struct ldap_request *req;
 310                 int result = LDAP_OTHER;
 311
 312                 status = gensec_update(conn->gensec, tmp_ctx,
 313                                        input,
 314                                        &output);
 315                 /* The status value here, from GENSEC is vital to the security
 316                  * of the system.  Even if the other end accepts, if GENSEC
 317                  * claims 'MORE_PROCESSING_REQUIRED' then you must keep
 318                  * feeding it blobs, or else the remote host/attacker might
 319                  * avoid mutal authentication requirements.
 320                  *
 321                  * Likewise, you must not feed GENSEC too much (after the OK),
 322                  * it doesn't like that either
 323                  */
 324
 325                 gensec_status = status;
 326
 327                 if (!NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED) &&
 328                     !NT_STATUS_IS_OK(status)) {
 329                         break;
 330                 }
 331                 if (NT_STATUS_IS_OK(status) && output.length == 0) {
 332                         break;
 333                 }
 334
 335                 /* Perhaps we should make gensec_start_mech_by_sasl_list() return the name we got? */
 336                 msg = new_ldap_sasl_bind_msg(tmp_ctx, conn->gensec->ops->sasl_name, (output.data?&output:NULL));
 337                 if (msg == NULL) {
 338                         status = NT_STATUS_NO_MEMORY;
 339                         goto failed;
 340                 }
 341
 342                 req = ldap_request_send(conn, msg);
 343                 if (req == NULL) {
 344                         status = NT_STATUS_NO_MEMORY;
 345                         goto failed;
 346                 }
 347                 talloc_steal(tmp_ctx, req);
 348
 349                 status = ldap_result_n(req, 0, &response);
 350                 if (!NT_STATUS_IS_OK(status)) {
 351                         goto failed;
 352                 }
 353
 354                 if (response->type != LDAP_TAG_BindResponse) {
 355                         status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 356                         goto failed;
 357                 }
 358
 359                 result = response->r.BindResponse.response.resultcode;
 360
 361                 if (result != LDAP_SUCCESS && result != LDAP_SASL_BIND_IN_PROGRESS) {
 362                         status = ldap_check_response(conn,
 363                                                      &response->r.BindResponse.response);
 364                         break;
 365                 }
 366
 367                 /* This is where we check if GENSEC wanted to be fed more data */
 368                 if (!NT_STATUS_EQUAL(gensec_status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
 369                         break;
 370                 }
 371                 if (response->r.BindResponse.SASL.secblob) {
 372                         input = *response->r.BindResponse.SASL.secblob;
 373                 } else {
 374                         input = data_blob(NULL, 0);
 375                 }
 376         }
 377
 378         talloc_free(tmp_ctx);
 379
 380         if (NT_STATUS_IS_OK(status)) {
 381                 struct socket_context *sasl_socket;
 382                 status = gensec_socket_init(conn->gensec,
 383                                             conn->sock,
 384                                             conn->event.event_ctx,
 385                                             ldap_read_io_handler,
 386                                             conn,
 387                                             &sasl_socket);
 388                 if (!NT_STATUS_IS_OK(status)) goto failed;
 389
 390                 talloc_steal(conn->sock, sasl_socket);
 391                 talloc_unlink(conn, conn->sock);
 392                 conn->sock = sasl_socket;
 393                 packet_set_socket(conn->packet, conn->sock);
 394
 395                 conn->bind.type = LDAP_BIND_SASL;
 396                 conn->bind.creds = creds;
 397         }
 398
 399         return status;
 400
 401 failed:
 402         talloc_free(tmp_ctx);
 403         talloc_free(conn->gensec);
 404         conn->gensec = NULL;
 405         return status;
 406 }