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                          bool force)
 111 {
 112         TALLOC_CTX *frame = talloc_stackframe();
 113         const char *context_name = NULL;
 114         struct trust_pw_change_state *state;
 115         struct cli_credentials *creds = NULL;
 116         const struct samr_Password *current_nt_hash = NULL;
 117         const struct samr_Password *previous_nt_hash = NULL;
 118         enum netr_SchannelType sec_channel_type = SEC_CHAN_NULL;
 119         time_t pass_last_set_time;
 120         uint32_t old_version = 0;
 121         struct pdb_trusted_domain *td = NULL;
 122         struct timeval g_timeout = { 0, };
 123         int timeout = 0;
 124         struct timeval tv = { 0, };
 125         size_t new_len = DEFAULT_TRUST_ACCOUNT_PASSWORD_LENGTH;
 126         uint8_t new_password_buffer[256 * 2] = { 0, };
 127         char *new_trust_passwd = NULL;
 128         size_t len = 0;
 129         uint32_t new_version = 0;
 130         uint32_t *new_trust_version = NULL;
 131         NTSTATUS status;
 132         bool ok;
 133
 134         state = talloc_zero(frame, struct trust_pw_change_state);
 135         if (state == NULL) {
 136                 TALLOC_FREE(frame);
 137                 return NT_STATUS_NO_MEMORY;
 138         }
 139
 140         state->g_ctx = g_lock_ctx_init(state, msg_ctx);
 141         if (state->g_ctx == NULL) {
 142                 TALLOC_FREE(frame);
 143                 return NT_STATUS_NO_MEMORY;
 144         }
 145
 146         state->g_lock_key = talloc_asprintf(state,
 147                                 "trust_password_change_%s",
 148                                 domain);
 149         if (state->g_lock_key == NULL) {
 150                 TALLOC_FREE(frame);
 151                 return NT_STATUS_NO_MEMORY;
 152         }
 153
 154         g_timeout = timeval_current_ofs(10, 0);
 155         status = g_lock_lock(state->g_ctx,
 156                              state->g_lock_key,
 157                              G_LOCK_WRITE, g_timeout);
 158         if (!NT_STATUS_IS_OK(status)) {
 159                 DEBUG(1, ("could not get g_lock on [%s]!\n",
 160                           state->g_lock_key));
 161                 TALLOC_FREE(frame);
 162                 return status;
 163         }
 164
 165         talloc_set_destructor(state, trust_pw_change_state_destructor);
 166
 167         status = pdb_get_trust_credentials(domain, NULL, frame, &creds);
 168         if (!NT_STATUS_IS_OK(status)) {
 169                 DEBUG(0, ("could not fetch domain creds for domain %s - %s!\n",
 170                           domain, nt_errstr(status)));
 171                 TALLOC_FREE(frame);
 172                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 173         }
 174
 175         current_nt_hash = cli_credentials_get_nt_hash(creds, frame);
 176         if (current_nt_hash == NULL) {
 177                 DEBUG(0, ("cli_credentials_get_nt_hash failed for domain %s!\n",
 178                           domain));
 179                 TALLOC_FREE(frame);
 180                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 181         }
 182
 183         old_version = cli_credentials_get_kvno(creds);
 184         pass_last_set_time = cli_credentials_get_password_last_changed_time(creds);
 185         sec_channel_type = cli_credentials_get_secure_channel_type(creds);
 186
 187         new_version = old_version + 1;
 188
 189         switch (sec_channel_type) {
 190         case SEC_CHAN_WKSTA:
 191         case SEC_CHAN_BDC:
 192                 break;
 193         case SEC_CHAN_DNS_DOMAIN:
 194                 /*
 195                  * new_len * 2 = 498 bytes is the largest possible length
 196                  * NL_PASSWORD_VERSION consumes the rest of the possible 512 bytes
 197                  * and a confounder with at least 2 bytes is required.
 198                  *
 199                  * Windows uses new_len = 120 => 240 bytes.
 200                  */
 201                 new_len = 120;
 202
 203                 /* fall through */
 204         case SEC_CHAN_DOMAIN:
 205                 status = pdb_get_trusted_domain(frame, domain, &td);
 206                 if (!NT_STATUS_IS_OK(status)) {
 207                         DEBUG(0, ("pdb_get_trusted_domain() failed for domain %s - %s!\n",
 208                                   domain, nt_errstr(status)));
 209                         TALLOC_FREE(frame);
 210                         return status;
 211                 }
 212
 213                 new_trust_version = &new_version;
 214                 break;
 215         default:
 216                 TALLOC_FREE(frame);
 217                 return NT_STATUS_NOT_SUPPORTED;
 218         }
 219
 220         timeout = lp_machine_password_timeout();
 221         if (timeout == 0) {
 222                 if (!force) {
 223                         DEBUG(10,("machine password never expires\n"));
 224                         TALLOC_FREE(frame);
 225                         return NT_STATUS_OK;
 226                 }
 227         }
 228
 229         tv.tv_sec = pass_last_set_time;
 230         DEBUG(10, ("password last changed %s\n",
 231                    timeval_string(talloc_tos(), &tv, false)));
 232         tv.tv_sec += timeout;
 233         DEBUGADD(10, ("password valid until %s\n",
 234                       timeval_string(talloc_tos(), &tv, false)));
 235
 236         if (!force && !timeval_expired(&tv)) {
 237                 TALLOC_FREE(frame);
 238                 return NT_STATUS_OK;
 239         }
 240
 241         context_name = netlogon_creds_cli_debug_string(context, talloc_tos());
 242         if (context_name == NULL) {
 243                 TALLOC_FREE(frame);
 244                 return NT_STATUS_NO_MEMORY;
 245         }
 246
 247         /*
 248          * Create a random machine account password
 249          * We create a random buffer and convert that to utf8.
 250          * This is similar to what windows is doing.
 251          */
 252         generate_secret_buffer(new_password_buffer, new_len * 2);
 253         ok = convert_string_talloc(frame,
 254                                    CH_UTF16MUNGED, CH_UTF8,
 255                                    new_password_buffer, new_len * 2,
 256                                    (void *)&new_trust_passwd, &len);
 257         ZERO_STRUCT(new_password_buffer);
 258         if (!ok) {
 259                 DEBUG(0, ("convert_string_talloc failed\n"));
 260                 TALLOC_FREE(frame);
 261                 return NT_STATUS_NO_MEMORY;
 262         }
 263
 264         /*
 265          * We could use cli_credentials_get_old_nt_hash(creds, frame) to
 266          * set previous_nt_hash.
 267          *
 268          * But we want to check if the dc has our current password and only do
 269          * a change if that's the case. So we keep previous_nt_hash = NULL.
 270          *
 271          * TODO:
 272          * If the previous password is the only password in common with the dc,
 273          * we better skip the password change, or use something like
 274          * ServerTrustPasswordsGet() or netr_ServerGetTrustInfo() to fix our
 275          * local secrets before doing the change.
 276          */
 277         status = netlogon_creds_cli_auth(context, b,
 278                                          *current_nt_hash,
 279                                          previous_nt_hash);
 280         if (!NT_STATUS_IS_OK(status)) {
 281                 DEBUG(0, ("netlogon_creds_cli_auth(%s) failed for old password - %s!\n",
 282                           context_name, nt_errstr(status)));
 283                 TALLOC_FREE(frame);
 284                 return status;
 285         }
 286
 287         DEBUG(0,("%s : %s(%s): Verified old password remotely using %s\n",
 288                  current_timestring(talloc_tos(), false),
 289                  __func__, domain, context_name));
 290
 291         /*
 292          * Return the result of trying to write the new password
 293          * back into the trust account file.
 294          */
 295
 296         switch (sec_channel_type) {
 297
 298         case SEC_CHAN_WKSTA:
 299         case SEC_CHAN_BDC:
 300                 ok = secrets_store_machine_password(new_trust_passwd, domain, sec_channel_type);
 301                 if (!ok) {
 302                         DEBUG(0, ("secrets_store_machine_password failed for domain %s!\n",
 303                                   domain));
 304                         TALLOC_FREE(frame);
 305                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 306                 }
 307                 break;
 308
 309         case SEC_CHAN_DNS_DOMAIN:
 310         case SEC_CHAN_DOMAIN:
 311                 /*
 312                  * we need to get the sid first for the
 313                  * pdb_set_trusteddom_pw call
 314                  */
 315                 ok = pdb_set_trusteddom_pw(domain, new_trust_passwd,
 316                                            &td->security_identifier);
 317                 if (!ok) {
 318                         DEBUG(0, ("pdb_set_trusteddom_pw() failed for domain %s!\n",
 319                                   domain));
 320                         TALLOC_FREE(frame);
 321                         return NT_STATUS_INTERNAL_DB_CORRUPTION;
 322                 }
 323                 break;
 324
 325         default:
 326                 smb_panic("Unsupported secure channel type");
 327                 break;
 328         }
 329
 330         DEBUG(0,("%s : %s(%s): Changed password locally\n",
 331                  current_timestring(talloc_tos(), false), __func__, domain));
 332
 333         status = netlogon_creds_cli_ServerPasswordSet(context, b,
 334                                                       new_trust_passwd,
 335                                                       new_trust_version);
 336         if (!NT_STATUS_IS_OK(status)) {
 337                 DEBUG(0,("%s : %s(%s) remote password change set with %s failed - %s\n",
 338                          current_timestring(talloc_tos(), false),
 339                          __func__, domain, context_name,
 340                          nt_errstr(status)));
 341                 TALLOC_FREE(frame);
 342                 return status;
 343         }
 344
 345         DEBUG(0,("%s : %s(%s): Changed password remotely using %s\n",
 346                  current_timestring(talloc_tos(), false),
 347                  __func__, domain, context_name));
 348
 349         ok = cli_credentials_set_password(creds, new_trust_passwd, CRED_SPECIFIED);
 350         if (!ok) {
 351                 DEBUG(0, ("cli_credentials_set_password failed for domain %s!\n",
 352                           domain));
 353                 TALLOC_FREE(frame);
 354                 return NT_STATUS_NO_MEMORY;
 355         }
 356
 357         current_nt_hash = cli_credentials_get_nt_hash(creds, frame);
 358         if (current_nt_hash == NULL) {
 359                 DEBUG(0, ("cli_credentials_get_nt_hash failed for domain %s!\n",
 360                           domain));
 361                 TALLOC_FREE(frame);
 362                 return NT_STATUS_TRUSTED_RELATIONSHIP_FAILURE;
 363         }
 364
 365         /*
 366          * Now we verify the new password.
 367          */
 368         status = netlogon_creds_cli_auth(context, b,
 369                                          *current_nt_hash,
 370                                          NULL); /* previous_nt_hash */
 371         if (!NT_STATUS_IS_OK(status)) {
 372                 DEBUG(0, ("netlogon_creds_cli_auth(%s) failed for new password - %s!\n",
 373                           context_name, nt_errstr(status)));
 374                 TALLOC_FREE(frame);
 375                 return status;
 376         }
 377
 378         DEBUG(0,("%s : %s(%s): Verified new password remotely using %s\n",
 379                  current_timestring(talloc_tos(), false),
 380                  __func__, domain, context_name));
 381
 382         TALLOC_FREE(frame);
 383         return NT_STATUS_OK;
 384 }