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         const struct samr_Password *previous_nt_hash = NULL;
 119         enum netr_SchannelType sec_channel_type = SEC_CHAN_NULL;
 120         time_t pass_last_set_time;
 121         uint32_t old_version = 0;
 122         struct pdb_trusted_domain *td = NULL;
 123         struct timeval g_timeout = { 0, };
 124         int timeout = 0;
 125         struct timeval tv = { 0, };
 126         char *new_trust_passwd = NULL;
 127         uint32_t new_version = 0;
 128         uint32_t *new_trust_version = NULL;
 129         NTSTATUS status;
 130         bool ok;
 131
 132         state = talloc_zero(frame, struct trust_pw_change_state);
 133         if (state == NULL) {
 134                 TALLOC_FREE(frame);
 135                 return NT_STATUS_NO_MEMORY;
 136         }
 137
 138         state->g_ctx = g_lock_ctx_init(state, msg_ctx);
 139         if (state->g_ctx == NULL) {
 140                 TALLOC_FREE(frame);
 141                 return NT_STATUS_NO_MEMORY;
 142         }
 143
 144         state->g_lock_key = talloc_asprintf(state,
 145                                 "trust_password_change_%s",
 146                                 domain);
 147         if (state->g_lock_key == NULL) {
 148                 TALLOC_FREE(frame);
 149                 return NT_STATUS_NO_MEMORY;
 150         }
 151
 152         g_timeout = timeval_current_ofs(10, 0);
 153         status = g_lock_lock(state->g_ctx,
 154                              state->g_lock_key,
 155                              G_LOCK_WRITE, g_timeout);
 156         if (!NT_STATUS_IS_OK(status)) {
 157                 DEBUG(1, ("could not get g_lock on [%s]!\n",
 158                           state->g_lock_key));
 159                 TALLOC_FREE(frame);
 160                 return status;
 161         }
 162
 163         talloc_set_destructor(state, trust_pw_change_state_destructor);
 164
 165         status = pdb_get_trust_credentials(domain, NULL, frame, &creds);
 166         if (!NT_STATUS_IS_OK(status)) {
 167                 DEBUG(0, ("could not fetch domain creds for domain %s - %s!\n",
 168                           domain, nt_errstr(status)));
 169                 TALLOC_FREE(frame);
 170                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 171         }
 172
 173         current_nt_hash = cli_credentials_get_nt_hash(creds, frame);
 174         if (current_nt_hash == NULL) {
 175                 DEBUG(0, ("cli_credentials_get_nt_hash failed for domain %s!\n",
 176                           domain));
 177                 TALLOC_FREE(frame);
 178                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 179         }
 180
 181         old_version = cli_credentials_get_kvno(creds);
 182         pass_last_set_time = cli_credentials_get_password_last_changed_time(creds);
 183         sec_channel_type = cli_credentials_get_secure_channel_type(creds);
 184
 185         new_version = old_version + 1;
 186
 187         switch (sec_channel_type) {
 188         case SEC_CHAN_WKSTA:
 189         case SEC_CHAN_BDC:
 190                 break;
 191         case SEC_CHAN_DNS_DOMAIN:
 192         case SEC_CHAN_DOMAIN:
 193                 status = pdb_get_trusted_domain(frame, domain, &td);
 194                 if (!NT_STATUS_IS_OK(status)) {
 195                         DEBUG(0, ("pdb_get_trusted_domain() failed for domain %s - %s!\n",
 196                                   domain, nt_errstr(status)));
 197                         TALLOC_FREE(frame);
 198                         return status;
 199                 }
 200
 201                 new_trust_version = &new_version;
 202                 break;
 203         default:
 204                 TALLOC_FREE(frame);
 205                 return NT_STATUS_NOT_SUPPORTED;
 206         }
 207
 208         timeout = lp_machine_password_timeout();
 209         if (timeout == 0) {
 210                 if (!force) {
 211                         DEBUG(10,("machine password never expires\n"));
 212                         TALLOC_FREE(frame);
 213                         return NT_STATUS_OK;
 214                 }
 215         }
 216
 217         tv.tv_sec = pass_last_set_time;
 218         DEBUG(10, ("password last changed %s\n",
 219                    timeval_string(talloc_tos(), &tv, false)));
 220         tv.tv_sec += timeout;
 221         DEBUGADD(10, ("password valid until %s\n",
 222                       timeval_string(talloc_tos(), &tv, false)));
 223
 224         if (!force && !timeval_expired(&tv)) {
 225                 TALLOC_FREE(frame);
 226                 return NT_STATUS_OK;
 227         }
 228
 229         context_name = netlogon_creds_cli_debug_string(context, talloc_tos());
 230         if (context_name == NULL) {
 231                 TALLOC_FREE(frame);
 232                 return NT_STATUS_NO_MEMORY;
 233         }
 234
 235         /*
 236          * Create a random machine account password
 237          * We create a random buffer and convert that to utf8.
 238          * This is similar to what windows is doing.
 239          */
 240         new_trust_passwd = trust_pw_new_value(frame, sec_channel_type,
 241                                               lp_security());
 242         if (new_trust_passwd == NULL) {
 243                 DEBUG(0, ("trust_pw_new_value() failed\n"));
 244                 TALLOC_FREE(frame);
 245                 return NT_STATUS_NO_MEMORY;
 246         }
 247
 248         /*
 249          * We could use cli_credentials_get_old_nt_hash(creds, frame) to
 250          * set previous_nt_hash.
 251          *
 252          * But we want to check if the dc has our current password and only do
 253          * a change if that's the case. So we keep previous_nt_hash = NULL.
 254          *
 255          * TODO:
 256          * If the previous password is the only password in common with the dc,
 257          * we better skip the password change, or use something like
 258          * ServerTrustPasswordsGet() or netr_ServerGetTrustInfo() to fix our
 259          * local secrets before doing the change.
 260          */
 261         status = netlogon_creds_cli_auth(context, b,
 262                                          *current_nt_hash,
 263                                          previous_nt_hash);
 264         if (!NT_STATUS_IS_OK(status)) {
 265                 DEBUG(0, ("netlogon_creds_cli_auth(%s) failed for old password - %s!\n",
 266                           context_name, nt_errstr(status)));
 267                 TALLOC_FREE(frame);
 268                 return status;
 269         }
 270
 271         DEBUG(0,("%s : %s(%s): Verified old password remotely using %s\n",
 272                  current_timestring(talloc_tos(), false),
 273                  __func__, domain, context_name));
 274
 275         /*
 276          * Return the result of trying to write the new password
 277          * back into the trust account file.
 278          */
 279
 280         switch (sec_channel_type) {
 281
 282         case SEC_CHAN_WKSTA:
 283         case SEC_CHAN_BDC:
 284                 ok = secrets_store_machine_password(new_trust_passwd, domain, sec_channel_type);
 285                 if (!ok) {
 286                         DEBUG(0, ("secrets_store_machine_password failed for domain %s!\n",
 287                                   domain));
 288                         TALLOC_FREE(frame);
 289                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 290                 }
 291                 break;
 292
 293         case SEC_CHAN_DNS_DOMAIN:
 294         case SEC_CHAN_DOMAIN:
 295                 /*
 296                  * we need to get the sid first for the
 297                  * pdb_set_trusteddom_pw call
 298                  */
 299                 ok = pdb_set_trusteddom_pw(domain, new_trust_passwd,
 300                                            &td->security_identifier);
 301                 if (!ok) {
 302                         DEBUG(0, ("pdb_set_trusteddom_pw() failed for domain %s!\n",
 303                                   domain));
 304                         TALLOC_FREE(frame);
 305                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 306                 }
 307                 break;
 308
 309         default:
 310                 smb_panic("Unsupported secure channel type");
 311                 break;
 312         }
 313
 314         DEBUG(0,("%s : %s(%s): Changed password locally\n",
 315                  current_timestring(talloc_tos(), false), __func__, domain));
 316
 317         status = netlogon_creds_cli_ServerPasswordSet(context, b,
 318                                                       new_trust_passwd,
 319                                                       new_trust_version);
 320         if (!NT_STATUS_IS_OK(status)) {
 321                 DEBUG(0,("%s : %s(%s) remote password change set with %s failed - %s\n",
 322                          current_timestring(talloc_tos(), false),
 323                          __func__, domain, context_name,
 324                          nt_errstr(status)));
 325                 TALLOC_FREE(frame);
 326                 return status;
 327         }
 328
 329         DEBUG(0,("%s : %s(%s): Changed password remotely using %s\n",
 330                  current_timestring(talloc_tos(), false),
 331                  __func__, domain, context_name));
 332
 333         ok = cli_credentials_set_password(creds, new_trust_passwd, CRED_SPECIFIED);
 334         if (!ok) {
 335                 DEBUG(0, ("cli_credentials_set_password failed for domain %s!\n",
 336                           domain));
 337                 TALLOC_FREE(frame);
 338                 return NT_STATUS_NO_MEMORY;
 339         }
 340
 341         current_nt_hash = cli_credentials_get_nt_hash(creds, frame);
 342         if (current_nt_hash == NULL) {
 343                 DEBUG(0, ("cli_credentials_get_nt_hash failed for domain %s!\n",
 344                           domain));
 345                 TALLOC_FREE(frame);
 346                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 347         }
 348
 349         /*
 350          * Now we verify the new password.
 351          */
 352         status = netlogon_creds_cli_auth(context, b,
 353                                          *current_nt_hash,
 354                                          NULL); /* previous_nt_hash */
 355         if (!NT_STATUS_IS_OK(status)) {
 356                 DEBUG(0, ("netlogon_creds_cli_auth(%s) failed for new password - %s!\n",
 357                           context_name, nt_errstr(status)));
 358                 TALLOC_FREE(frame);
 359                 return status;
 360         }
 361
 362         DEBUG(0,("%s : %s(%s): Verified new password remotely using %s\n",
 363                  current_timestring(talloc_tos(), false),
 364                  __func__, domain, context_name));
 365
 366         TALLOC_FREE(frame);
 367         return NT_STATUS_OK;
 368 }