auth/credentials/credentials_secrets.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    User credentials handling (as regards on-disk files)
   5
   6    Copyright (C) Jelmer Vernooij 2005
   7    Copyright (C) Tim Potter 2001
   8    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "lib/events/events.h"
  26 #include <ldb.h>
  27 #include "librpc/gen_ndr/samr.h" /* for struct samrPassword */
  28 #include "param/secrets.h"
  29 #include "system/filesys.h"
  30 #include "auth/credentials/credentials.h"
  31 #include "auth/credentials/credentials_internal.h"
  32 #include "auth/credentials/credentials_proto.h"
  33 #include "auth/credentials/credentials_krb5.h"
  34 #include "auth/kerberos/kerberos_util.h"
  35 #include "param/param.h"
  36 #include "lib/events/events.h"
  37 #include "dsdb/samdb/samdb.h"
  38 #include "source3/include/secrets.h"
  39 #include "dbwrap/dbwrap.h"
  40 #include "dbwrap/dbwrap_open.h"
  41 #include "lib/util/util_tdb.h"
  42 #include "libds/common/roles.h"
  43
  44 #undef DBGC_CLASS
  45 #define DBGC_CLASS DBGC_AUTH
  46
  47 /**
  48  * Fill in credentials for the machine trust account, from the secrets database.
  49  *
  50  * @param cred Credentials structure to fill in
  51  * @retval NTSTATUS error detailing any failure
  52  */
  53 static NTSTATUS cli_credentials_set_secrets_lct(struct cli_credentials *cred,
  54                                                 struct loadparm_context *lp_ctx,
  55                                                 struct ldb_context *ldb,
  56                                                 const char *base,
  57                                                 const char *filter,
  58                                                 time_t secrets_tdb_last_change_time,
  59                                                 const char *secrets_tdb_password,
  60                                                 char **error_string)
  61 {
  62         TALLOC_CTX *mem_ctx;
  63
  64         int ldb_ret;
  65         struct ldb_message *msg;
  66
  67         const char *machine_account;
  68         const char *password;
  69         const char *domain;
  70         const char *realm;
  71         enum netr_SchannelType sct;
  72         const char *salt_principal;
  73         char *keytab;
  74         const struct ldb_val *whenChanged;
  75         time_t lct;
  76
  77         /* ok, we are going to get it now, don't recurse back here */
  78         cred->machine_account_pending = false;
  79
  80         /* some other parts of the system will key off this */
  81         cred->machine_account = true;
  82
  83         mem_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
  84
  85         if (!ldb) {
  86                 /* Local secrets are stored in secrets.ldb */
  87                 ldb = secrets_db_connect(mem_ctx, lp_ctx);
  88                 if (!ldb) {
  89                         *error_string = talloc_strdup(cred, "Could not open secrets.ldb");
  90                         talloc_free(mem_ctx);
  91                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
  92                 }
  93         }
  94
  95         ldb_ret = dsdb_search_one(ldb, mem_ctx, &msg,
  96                                   ldb_dn_new(mem_ctx, ldb, base),
  97                                   LDB_SCOPE_SUBTREE,
  98                                   NULL, 0, "%s", filter);
  99
 100         if (ldb_ret != LDB_SUCCESS) {
 101                 *error_string = talloc_asprintf(cred, "Could not find entry to match filter: '%s' base: '%s': %s: %s",
 102                                                 filter, base ? base : "",
 103                                                 ldb_strerror(ldb_ret), ldb_errstring(ldb));
 104                 talloc_free(mem_ctx);
 105                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 106         }
 107
 108         password = ldb_msg_find_attr_as_string(msg, "secret", NULL);
 109
 110         whenChanged = ldb_msg_find_ldb_val(msg, "whenChanged");
 111         if (!whenChanged || ldb_val_to_time(whenChanged, &lct) != LDB_SUCCESS) {
 112                 /* This attribute is mandatory */
 113                 talloc_free(mem_ctx);
 114                 return NT_STATUS_NOT_FOUND;
 115         }
 116
 117         /* Don't set secrets.ldb info if the secrets.tdb entry was more recent */
 118         if (lct < secrets_tdb_last_change_time) {
 119                 talloc_free(mem_ctx);
 120                 return NT_STATUS_NOT_FOUND;
 121         }
 122
 123         if ((lct == secrets_tdb_last_change_time) &&
 124             (secrets_tdb_password != NULL) &&
 125             (password != NULL) &&
 126             (strcmp(password, secrets_tdb_password) != 0)) {
 127                 talloc_free(mem_ctx);
 128                 return NT_STATUS_NOT_FOUND;
 129         }
 130
 131         cli_credentials_set_password_last_changed_time(cred, lct);
 132
 133         machine_account = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);
 134
 135         if (!machine_account) {
 136                 machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);
 137
 138                 if (!machine_account) {
 139                         const char *ldap_bind_dn = ldb_msg_find_attr_as_string(msg, "ldapBindDn", NULL);
 140                         if (!ldap_bind_dn) {
 141                                 *error_string = talloc_asprintf(cred,
 142                                                                 "Could not find 'samAccountName', "
 143                                                                 "'servicePrincipalName' or "
 144                                                                 "'ldapBindDn' in secrets record: %s",
 145                                                                 ldb_dn_get_linearized(msg->dn));
 146                                 talloc_free(mem_ctx);
 147                                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 148                         } else {
 149                                 /* store bind dn in credentials */
 150                                 cli_credentials_set_bind_dn(cred, ldap_bind_dn);
 151                         }
 152                 }
 153         }
 154
 155         salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
 156         cli_credentials_set_salt_principal(cred, salt_principal);
 157
 158         sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
 159         if (sct) {
 160                 cli_credentials_set_secure_channel_type(cred, sct);
 161         }
 162
 163         if (!password) {
 164                 const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
 165                 struct samr_Password hash;
 166                 ZERO_STRUCT(hash);
 167                 if (nt_password_hash) {
 168                         memcpy(hash.hash, nt_password_hash->data,
 169                                MIN(nt_password_hash->length, sizeof(hash.hash)));
 170
 171                         cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
 172                 } else {
 173                         cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
 174                 }
 175         } else {
 176                 cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 177         }
 178
 179         domain = ldb_msg_find_attr_as_string(msg, "flatname", NULL);
 180         if (domain) {
 181                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 182         }
 183
 184         realm = ldb_msg_find_attr_as_string(msg, "realm", NULL);
 185         if (realm) {
 186                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 187         }
 188
 189         if (machine_account) {
 190                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 191         }
 192
 193         cli_credentials_set_kvno(cred, ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0));
 194
 195         /* If there was an external keytab specified by reference in
 196          * the LDB, then use this.  Otherwise we will make one up
 197          * (chewing CPU time) from the password */
 198         keytab = keytab_name_from_msg(cred, ldb, msg);
 199         if (keytab) {
 200                 cli_credentials_set_keytab_name(cred, lp_ctx, keytab, CRED_SPECIFIED);
 201                 talloc_free(keytab);
 202         }
 203         talloc_free(mem_ctx);
 204
 205         return NT_STATUS_OK;
 206 }
 207
 208
 209 /**
 210  * Fill in credentials for the machine trust account, from the secrets database.
 211  *
 212  * @param cred Credentials structure to fill in
 213  * @retval NTSTATUS error detailing any failure
 214  */
 215 _PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
 216                                               struct loadparm_context *lp_ctx,
 217                                               struct ldb_context *ldb,
 218                                               const char *base,
 219                                               const char *filter,
 220                                               char **error_string)
 221 {
 222         NTSTATUS status = cli_credentials_set_secrets_lct(cred, lp_ctx, ldb, base, filter, 0, NULL, error_string);
 223         if (!NT_STATUS_IS_OK(status)) {
 224                 /* set anonymous as the fallback, if the machine account won't work */
 225                 cli_credentials_set_anonymous(cred);
 226         }
 227         return status;
 228 }
 229
 230 /**
 231  * Fill in credentials for the machine trust account, from the secrets database.
 232  *
 233  * @param cred Credentials structure to fill in
 234  * @retval NTSTATUS error detailing any failure
 235  */
 236 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
 237                                                       struct loadparm_context *lp_ctx)
 238 {
 239         struct db_context *db_ctx;
 240         char *secrets_tdb_path;
 241         int hash_size, tdb_flags;
 242
 243         secrets_tdb_path = lpcfg_private_db_path(cred, lp_ctx, "secrets");
 244         if (secrets_tdb_path == NULL) {
 245                 return NT_STATUS_NO_MEMORY;
 246         }
 247
 248         hash_size = lpcfg_tdb_hash_size(lp_ctx, secrets_tdb_path);
 249         tdb_flags = lpcfg_tdb_flags(lp_ctx, TDB_DEFAULT);
 250
 251         db_ctx = dbwrap_local_open(
 252                 cred,
 253                 secrets_tdb_path,
 254                 hash_size,
 255                 tdb_flags,
 256                 O_RDWR,
 257                 0600,
 258                 DBWRAP_LOCK_ORDER_1,
 259                 DBWRAP_FLAG_NONE);
 260         TALLOC_FREE(secrets_tdb_path);
 261
 262         /*
 263          * We do not check for errors here, we might not have a
 264          * secrets.tdb at all, and so we just need to check the
 265          * secrets.ldb
 266          */
 267         return cli_credentials_set_machine_account_db_ctx(cred, lp_ctx, db_ctx);
 268 }
 269
 270 /**
 271  * Fill in credentials for the machine trust account, from the
 272  * secrets.ldb or passed in handle to secrets.tdb (perhaps in CTDB).
 273  *
 274  * This version is used in parts of the code that can link in the
 275  * CTDB dbwrap backend, by passing down the already open handle.
 276  *
 277  * @param cred Credentials structure to fill in
 278  * @param db_ctx dbwrap context for secrets.tdb
 279  * @retval NTSTATUS error detailing any failure
 280  */
 281 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account_db_ctx(struct cli_credentials *cred,
 282                                                              struct loadparm_context *lp_ctx,
 283                                                              struct db_context *db_ctx)
 284 {
 285         NTSTATUS status;
 286         char *filter;
 287         char *error_string = NULL;
 288         const char *domain;
 289         bool secrets_tdb_password_more_recent;
 290         time_t secrets_tdb_lct = 0;
 291         char *secrets_tdb_password = NULL;
 292         char *secrets_tdb_old_password = NULL;
 293         uint32_t secrets_tdb_secure_channel_type = SEC_CHAN_NULL;
 294         int server_role = lpcfg_server_role(lp_ctx);
 295         int security = lpcfg_security(lp_ctx);
 296         char *keystr;
 297         char *keystr_upper = NULL;
 298         TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
 299         if (!tmp_ctx) {
 300                 return NT_STATUS_NO_MEMORY;
 301         }
 302
 303         /* Bleh, nasty recursion issues: We are setting a machine
 304          * account here, so we don't want the 'pending' flag around
 305          * any more */
 306         cred->machine_account_pending = false;
 307
 308         /* We have to do this, as the fallback in
 309          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 310         domain = cli_credentials_get_domain(cred);
 311
 312         if (db_ctx) {
 313                 TDB_DATA dbuf;
 314                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 315                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 316                                          domain);
 317                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 318                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 319                                       &dbuf);
 320                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 321                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 322                 }
 323
 324                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 325                                          SECRETS_MACHINE_PASSWORD,
 326                                          domain);
 327                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 328                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 329                                       &dbuf);
 330                 if (NT_STATUS_IS_OK(status)) {
 331                         secrets_tdb_password = (char *)dbuf.dptr;
 332                 }
 333
 334                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 335                                          SECRETS_MACHINE_PASSWORD_PREV,
 336                                          domain);
 337                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 338                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 339                                       &dbuf);
 340                 if (NT_STATUS_IS_OK(status)) {
 341                         secrets_tdb_old_password = (char *)dbuf.dptr;
 342                 }
 343
 344                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 345                                          SECRETS_MACHINE_SEC_CHANNEL_TYPE,
 346                                          domain);
 347                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 348                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 349                                       &dbuf);
 350                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 351                         secrets_tdb_secure_channel_type = IVAL(dbuf.dptr,0);
 352                 }
 353         }
 354
 355         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 356                                  domain);
 357         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 358                                                  SECRETS_PRIMARY_DOMAIN_DN,
 359                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 360         if (secrets_tdb_password == NULL) {
 361                 secrets_tdb_password_more_recent = false;
 362         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 363             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 364                 secrets_tdb_password_more_recent = true;
 365         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 366                 secrets_tdb_password_more_recent = true;
 367         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 368                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 369         } else {
 370                 secrets_tdb_password_more_recent = false;
 371         }
 372
 373         if (secrets_tdb_password_more_recent) {
 374                 enum credentials_use_kerberos use_kerberos = CRED_DONT_USE_KERBEROS;
 375                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 376                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 377                 cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
 378                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 379                 if (strequal(domain, lpcfg_workgroup(lp_ctx))) {
 380                         cli_credentials_set_realm(cred, lpcfg_realm(lp_ctx), CRED_SPECIFIED);
 381
 382                         switch (server_role) {
 383                         case ROLE_DOMAIN_MEMBER:
 384                                 if (security != SEC_ADS) {
 385                                         break;
 386                                 }
 387
 388                                 FALL_THROUGH;
 389                         case ROLE_ACTIVE_DIRECTORY_DC:
 390                                 use_kerberos = CRED_AUTO_USE_KERBEROS;
 391                                 break;
 392                         }
 393                 }
 394                 cli_credentials_set_kerberos_state(cred, use_kerberos);
 395                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 396                 cli_credentials_set_password_last_changed_time(cred, secrets_tdb_lct);
 397                 cli_credentials_set_secure_channel_type(cred, secrets_tdb_secure_channel_type);
 398                 status = NT_STATUS_OK;
 399         } else if (!NT_STATUS_IS_OK(status)) {
 400                 if (db_ctx) {
 401                         error_string
 402                                 = talloc_asprintf(cred,
 403                                                   "Failed to fetch machine account password for %s from both "
 404                                                   "secrets.ldb (%s) and from %s",
 405                                                   domain,
 406                                                   error_string == NULL ? "error" : error_string,
 407                                                   dbwrap_name(db_ctx));
 408                 } else {
 409                         char *secrets_tdb_path;
 410
 411                         secrets_tdb_path = lpcfg_private_db_path(tmp_ctx,
 412                                                                  lp_ctx,
 413                                                                  "secrets");
 414                         if (secrets_tdb_path == NULL) {
 415                                 return NT_STATUS_NO_MEMORY;
 416                         }
 417
 418                         error_string = talloc_asprintf(cred,
 419                                                        "Failed to fetch machine account password from "
 420                                                        "secrets.ldb: %s and failed to open %s",
 421                                                        error_string == NULL ? "error" : error_string,
 422                                                        secrets_tdb_path);
 423                 }
 424                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 425                           error_string == NULL ? "error" : error_string,
 426                           nt_errstr(status)));
 427                 /* set anonymous as the fallback, if the machine account won't work */
 428                 cli_credentials_set_anonymous(cred);
 429         }
 430
 431         TALLOC_FREE(tmp_ctx);
 432         return status;
 433 }
 434
 435 /**
 436  * Fill in credentials for a particular principal, from the secrets database.
 437  *
 438  * @param cred Credentials structure to fill in
 439  * @retval NTSTATUS error detailing any failure
 440  */
 441 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 442                                               struct loadparm_context *lp_ctx,
 443                                               const char *serviceprincipal)
 444 {
 445         NTSTATUS status;
 446         char *filter;
 447         char *error_string = NULL;
 448         /* Bleh, nasty recursion issues: We are setting a machine
 449          * account here, so we don't want the 'pending' flag around
 450          * any more */
 451         cred->machine_account_pending = false;
 452         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 453                                  cli_credentials_get_realm(cred),
 454                                  cli_credentials_get_domain(cred),
 455                                  serviceprincipal);
 456         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 457                                              SECRETS_PRINCIPALS_DN, filter,
 458                                              0, NULL, &error_string);
 459         if (!NT_STATUS_IS_OK(status)) {
 460                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n",
 461                           serviceprincipal, nt_errstr(status),
 462                           error_string ? error_string : "<no error>"));
 463         }
 464         return status;
 465 }
 466
 467 /**
 468  * Ask that when required, the credentials system will be filled with
 469  * machine trust account, from the secrets database.
 470  *
 471  * @param cred Credentials structure to fill in
 472  * @note This function is used to call the above function after, rather
 473  *       than during, popt processing.
 474  *
 475  */
 476 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 477                                                  struct loadparm_context *lp_ctx)
 478 {
 479         cred->machine_account_pending = true;
 480         cred->machine_account_pending_lp_ctx = lp_ctx;
 481 }
 482
 483