source3/libsmb/trusts_util.c

   1 /*
   2  *  Unix SMB/CIFS implementation.
   3  *  Routines to operate on various trust relationships
   4  *  Copyright (C) Andrew Bartlett                   2001
   5  *  Copyright (C) Rafal Szczesniak                  2003
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 3 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "includes.h"
  22 #include "../libcli/auth/libcli_auth.h"
  23 #include "../libcli/auth/netlogon_creds_cli.h"
  24 #include "rpc_client/cli_netlogon.h"
  25 #include "rpc_client/cli_pipe.h"
  26 #include "../librpc/gen_ndr/ndr_netlogon.h"
  27 #include "secrets.h"
  28 #include "passdb.h"
  29 #include "libsmb/libsmb.h"
  30 #include "source3/include/messages.h"
  31 #include "source3/include/g_lock.h"
  32
  33 /*********************************************************
  34  Change the domain password on the PDC.
  35  Do most of the legwork ourselfs.  Caller must have
  36  already setup the connection to the NETLOGON pipe
  37 **********************************************************/
  38
  39 struct trust_pw_change_state {
  40         struct g_lock_ctx *g_ctx;
  41         char *g_lock_key;
  42 };
  43
  44 static int trust_pw_change_state_destructor(struct trust_pw_change_state *state)
  45 {
  46         g_lock_unlock(state->g_ctx, state->g_lock_key);
  47         return 0;
  48 }
  49
  50 char *trust_pw_new_value(TALLOC_CTX *mem_ctx,
  51                          enum netr_SchannelType sec_channel_type,
  52                          int security)
  53 {
  54         /*
  55          * use secure defaults.
  56          */
  57         size_t min = 128;
  58         size_t max = 255;
  59
  60         switch (sec_channel_type) {
  61         case SEC_CHAN_WKSTA:
  62         case SEC_CHAN_BDC:
  63                 if (security == SEC_DOMAIN) {
  64                         /*
  65                          * The maximum length of a trust account password.
  66                          * Used when we randomly create it, 15 char passwords
  67                          * exceed NT4's max password length.
  68                          */
  69                         min = 14;
  70                         max = 14;
  71                 }
  72                 break;
  73         case SEC_CHAN_DNS_DOMAIN:
  74                 /*
  75                  * new_len * 2 = 498 bytes is the largest possible length
  76                  * NL_PASSWORD_VERSION consumes the rest of the possible 512 bytes
  77                  * and a confounder with at least 2 bytes is required.
  78                  *
  79                  * Windows uses new_len = 120 => 240 bytes (utf16)
  80                  */
  81                 min = 120;
  82                 max = 120;
  83                 break;
  84                 /* fall through */
  85         case SEC_CHAN_DOMAIN:
  86                 /*
  87                  * The maximum length of a trust account password.
  88                  * Used when we randomly create it, 15 char passwords
  89                  * exceed NT4's max password length.
  90                  */
  91                 min = 14;
  92                 max = 14;
  93                 break;
  94         default:
  95                 break;
  96         }
  97
  98         /*
  99          * Create a random machine account password
 100          * We create a random buffer and convert that to utf8.
 101          * This is similar to what windows is doing.
 102          */
 103         return generate_random_machine_password(mem_ctx, min, max);
 104 }
 105
 106 NTSTATUS trust_pw_change(struct netlogon_creds_cli_context *context,
 107                          struct messaging_context *msg_ctx,
 108                          struct dcerpc_binding_handle *b,
 109                          const char *domain,
 110                          const char *dcname,
 111                          bool force)
 112 {
 113         TALLOC_CTX *frame = talloc_stackframe();
 114         const char *context_name = NULL;
 115         struct trust_pw_change_state *state;
 116         struct cli_credentials *creds = NULL;
 117         const struct samr_Password *current_nt_hash = NULL;
 118         uint8_t num_nt_hashes = 0;
 119         const struct samr_Password *nt_hashes[1] = { NULL, };
 120         uint8_t idx_nt_hashes = 0;
 121         enum netr_SchannelType sec_channel_type = SEC_CHAN_NULL;
 122         time_t pass_last_set_time;
 123         uint32_t old_version = 0;
 124         struct pdb_trusted_domain *td = NULL;
 125         struct timeval g_timeout = { 0, };
 126         int timeout = 0;
 127         struct timeval tv = { 0, };
 128         char *new_trust_pw_str = NULL;
 129         size_t len = 0;
 130         DATA_BLOB new_trust_pw_blob = data_blob_null;
 131         uint32_t new_version = 0;
 132         uint32_t *new_trust_version = NULL;
 133         NTSTATUS status;
 134         bool ok;
 135
 136         state = talloc_zero(frame, struct trust_pw_change_state);
 137         if (state == NULL) {
 138                 TALLOC_FREE(frame);
 139                 return NT_STATUS_NO_MEMORY;
 140         }
 141
 142         state->g_ctx = g_lock_ctx_init(state, msg_ctx);
 143         if (state->g_ctx == NULL) {
 144                 TALLOC_FREE(frame);
 145                 return NT_STATUS_NO_MEMORY;
 146         }
 147
 148         state->g_lock_key = talloc_asprintf(state,
 149                                 "trust_password_change_%s",
 150                                 domain);
 151         if (state->g_lock_key == NULL) {
 152                 TALLOC_FREE(frame);
 153                 return NT_STATUS_NO_MEMORY;
 154         }
 155
 156         g_timeout = timeval_current_ofs(10, 0);
 157         status = g_lock_lock(state->g_ctx,
 158                              state->g_lock_key,
 159                              G_LOCK_WRITE, g_timeout);
 160         if (!NT_STATUS_IS_OK(status)) {
 161                 DEBUG(1, ("could not get g_lock on [%s]!\n",
 162                           state->g_lock_key));
 163                 TALLOC_FREE(frame);
 164                 return status;
 165         }
 166
 167         talloc_set_destructor(state, trust_pw_change_state_destructor);
 168
 169         status = pdb_get_trust_credentials(domain, NULL, frame, &creds);
 170         if (!NT_STATUS_IS_OK(status)) {
 171                 DEBUG(0, ("could not fetch domain creds for domain %s - %s!\n",
 172                           domain, nt_errstr(status)));
 173                 TALLOC_FREE(frame);
 174                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 175         }
 176
 177         current_nt_hash = cli_credentials_get_nt_hash(creds, frame);
 178         if (current_nt_hash == NULL) {
 179                 DEBUG(0, ("cli_credentials_get_nt_hash failed for domain %s!\n",
 180                           domain));
 181                 TALLOC_FREE(frame);
 182                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 183         }
 184
 185         old_version = cli_credentials_get_kvno(creds);
 186         pass_last_set_time = cli_credentials_get_password_last_changed_time(creds);
 187         sec_channel_type = cli_credentials_get_secure_channel_type(creds);
 188
 189         new_version = old_version + 1;
 190
 191         switch (sec_channel_type) {
 192         case SEC_CHAN_WKSTA:
 193         case SEC_CHAN_BDC:
 194                 break;
 195         case SEC_CHAN_DNS_DOMAIN:
 196         case SEC_CHAN_DOMAIN:
 197                 status = pdb_get_trusted_domain(frame, domain, &td);
 198                 if (!NT_STATUS_IS_OK(status)) {
 199                         DEBUG(0, ("pdb_get_trusted_domain() failed for domain %s - %s!\n",
 200                                   domain, nt_errstr(status)));
 201                         TALLOC_FREE(frame);
 202                         return status;
 203                 }
 204
 205                 new_trust_version = &new_version;
 206                 break;
 207         default:
 208                 TALLOC_FREE(frame);
 209                 return NT_STATUS_NOT_SUPPORTED;
 210         }
 211
 212         timeout = lp_machine_password_timeout();
 213         if (timeout == 0) {
 214                 if (!force) {
 215                         DEBUG(10,("machine password never expires\n"));
 216                         TALLOC_FREE(frame);
 217                         return NT_STATUS_OK;
 218                 }
 219         }
 220
 221         tv.tv_sec = pass_last_set_time;
 222         DEBUG(10, ("password last changed %s\n",
 223                    timeval_string(talloc_tos(), &tv, false)));
 224         tv.tv_sec += timeout;
 225         DEBUGADD(10, ("password valid until %s\n",
 226                       timeval_string(talloc_tos(), &tv, false)));
 227
 228         if (!force && !timeval_expired(&tv)) {
 229                 TALLOC_FREE(frame);
 230                 return NT_STATUS_OK;
 231         }
 232
 233         context_name = netlogon_creds_cli_debug_string(context, talloc_tos());
 234         if (context_name == NULL) {
 235                 TALLOC_FREE(frame);
 236                 return NT_STATUS_NO_MEMORY;
 237         }
 238
 239         /*
 240          * Create a random machine account password
 241          * We create a random buffer and convert that to utf8.
 242          * This is similar to what windows is doing.
 243          */
 244         new_trust_pw_str = trust_pw_new_value(frame, sec_channel_type,
 245                                               lp_security());
 246         if (new_trust_pw_str == NULL) {
 247                 DEBUG(0, ("trust_pw_new_value() failed\n"));
 248                 TALLOC_FREE(frame);
 249                 return NT_STATUS_NO_MEMORY;
 250         }
 251
 252         len = strlen(new_trust_pw_str);
 253         ok = convert_string_talloc(frame, CH_UNIX, CH_UTF16,
 254                                    new_trust_pw_str, len,
 255                                    (void **)&new_trust_pw_blob.data,
 256                                    &new_trust_pw_blob.length);
 257         if (!ok) {
 258                 status = NT_STATUS_UNMAPPABLE_CHARACTER;
 259                 if (errno == ENOMEM) {
 260                         status = NT_STATUS_NO_MEMORY;
 261                 }
 262                 DBG_ERR("convert_string_talloc(CH_UTF16MUNGED, CH_UNIX) "
 263                         "failed for of %s - %s\n",
 264                         domain, nt_errstr(status));
 265                 TALLOC_FREE(frame);
 266                 return status;
 267         }
 268
 269         nt_hashes[0] = current_nt_hash;
 270         num_nt_hashes = 1;
 271
 272         /*
 273          * We could use cli_credentials_get_old_nt_hash(creds, frame) to
 274          * set previous_nt_hash.
 275          *
 276          * But we want to check if the dc has our current password and only do
 277          * a change if that's the case. So we keep previous_nt_hash = NULL.
 278          *
 279          * TODO:
 280          * If the previous password is the only password in common with the dc,
 281          * we better skip the password change, or use something like
 282          * ServerTrustPasswordsGet() or netr_ServerGetTrustInfo() to fix our
 283          * local secrets before doing the change.
 284          */
 285         status = netlogon_creds_cli_auth(context, b,
 286                                          num_nt_hashes,
 287                                          nt_hashes,
 288                                          &idx_nt_hashes);
 289         if (!NT_STATUS_IS_OK(status)) {
 290                 DEBUG(0, ("netlogon_creds_cli_auth(%s) failed for old password - %s!\n",
 291                           context_name, nt_errstr(status)));
 292                 TALLOC_FREE(frame);
 293                 return status;
 294         }
 295
 296         DEBUG(0,("%s : %s(%s): Verified old password remotely using %s\n",
 297                  current_timestring(talloc_tos(), false),
 298                  __func__, domain, context_name));
 299
 300         /*
 301          * Return the result of trying to write the new password
 302          * back into the trust account file.
 303          */
 304
 305         switch (sec_channel_type) {
 306
 307         case SEC_CHAN_WKSTA:
 308         case SEC_CHAN_BDC:
 309                 ok = secrets_store_machine_password(new_trust_pw_str,
 310                                                     domain,
 311                                                     sec_channel_type);
 312                 if (!ok) {
 313                         DEBUG(0, ("secrets_store_machine_password failed for domain %s!\n",
 314                                   domain));
 315                         TALLOC_FREE(frame);
 316                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 317                 }
 318                 TALLOC_FREE(new_trust_pw_str);
 319                 break;
 320
 321         case SEC_CHAN_DNS_DOMAIN:
 322         case SEC_CHAN_DOMAIN:
 323                 /*
 324                  * we need to get the sid first for the
 325                  * pdb_set_trusteddom_pw call
 326                  */
 327                 ok = pdb_set_trusteddom_pw(domain, new_trust_pw_str,
 328                                            &td->security_identifier);
 329                 if (!ok) {
 330                         DEBUG(0, ("pdb_set_trusteddom_pw() failed for domain %s!\n",
 331                                   domain));
 332                         TALLOC_FREE(frame);
 333                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 334                 }
 335                 TALLOC_FREE(new_trust_pw_str);
 336                 break;
 337
 338         default:
 339                 smb_panic("Unsupported secure channel type");
 340                 break;
 341         }
 342
 343         DEBUG(0,("%s : %s(%s): Changed password locally\n",
 344                  current_timestring(talloc_tos(), false), __func__, domain));
 345
 346         status = netlogon_creds_cli_ServerPasswordSet(context, b,
 347                                                       &new_trust_pw_blob,
 348                                                       new_trust_version);
 349         if (!NT_STATUS_IS_OK(status)) {
 350                 DEBUG(0,("%s : %s(%s) remote password change set with %s failed - %s\n",
 351                          current_timestring(talloc_tos(), false),
 352                          __func__, domain, context_name,
 353                          nt_errstr(status)));
 354                 TALLOC_FREE(frame);
 355                 return status;
 356         }
 357
 358         DEBUG(0,("%s : %s(%s): Changed password remotely using %s\n",
 359                  current_timestring(talloc_tos(), false),
 360                  __func__, domain, context_name));
 361
 362         ok = cli_credentials_set_utf16_password(creds,
 363                                                 &new_trust_pw_blob,
 364                                                 CRED_SPECIFIED);
 365         if (!ok) {
 366                 DEBUG(0, ("cli_credentials_set_password failed for domain %s!\n",
 367                           domain));
 368                 TALLOC_FREE(frame);
 369                 return NT_STATUS_NO_MEMORY;
 370         }
 371
 372         current_nt_hash = cli_credentials_get_nt_hash(creds, frame);
 373         if (current_nt_hash == NULL) {
 374                 DEBUG(0, ("cli_credentials_get_nt_hash failed for domain %s!\n",
 375                           domain));
 376                 TALLOC_FREE(frame);
 377                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 378         }
 379
 380         /*
 381          * Now we verify the new password.
 382          */
 383         nt_hashes[0] = current_nt_hash;
 384         num_nt_hashes = 1;
 385         status = netlogon_creds_cli_auth(context, b,
 386                                          num_nt_hashes,
 387                                          nt_hashes,
 388                                          &idx_nt_hashes);
 389         if (!NT_STATUS_IS_OK(status)) {
 390                 DEBUG(0, ("netlogon_creds_cli_auth(%s) failed for new password - %s!\n",
 391                           context_name, nt_errstr(status)));
 392                 TALLOC_FREE(frame);
 393                 return status;
 394         }
 395
 396         DEBUG(0,("%s : %s(%s): Verified new password remotely using %s\n",
 397                  current_timestring(talloc_tos(), false),
 398                  __func__, domain, context_name));
 399
 400         TALLOC_FREE(frame);
 401         return NT_STATUS_OK;
 402 }