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
 242         secrets_tdb_path = lpcfg_private_db_path(cred, lp_ctx, "secrets");
 243         if (secrets_tdb_path == NULL) {
 244                 return NT_STATUS_NO_MEMORY;
 245         }
 246
 247         db_ctx = dbwrap_local_open(cred, lp_ctx, secrets_tdb_path, 0,
 248                                    TDB_DEFAULT, O_RDWR, 0600,
 249                                    DBWRAP_LOCK_ORDER_1,
 250                                    DBWRAP_FLAG_NONE);
 251         TALLOC_FREE(secrets_tdb_path);
 252
 253         /*
 254          * We do not check for errors here, we might not have a
 255          * secrets.tdb at all, and so we just need to check the
 256          * secrets.ldb
 257          */
 258         return cli_credentials_set_machine_account_db_ctx(cred, lp_ctx, db_ctx);
 259 }
 260
 261 /**
 262  * Fill in credentials for the machine trust account, from the
 263  * secrets.ldb or passed in handle to secrets.tdb (perhaps in CTDB).
 264  *
 265  * This version is used in parts of the code that can link in the
 266  * CTDB dbwrap backend, by passing down the already open handle.
 267  *
 268  * @param cred Credentials structure to fill in
 269  * @param db_ctx dbwrap context for secrets.tdb
 270  * @retval NTSTATUS error detailing any failure
 271  */
 272 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account_db_ctx(struct cli_credentials *cred,
 273                                                              struct loadparm_context *lp_ctx,
 274                                                              struct db_context *db_ctx)
 275 {
 276         NTSTATUS status;
 277         char *filter;
 278         char *error_string = NULL;
 279         const char *domain;
 280         bool secrets_tdb_password_more_recent;
 281         time_t secrets_tdb_lct = 0;
 282         char *secrets_tdb_password = NULL;
 283         char *secrets_tdb_old_password = NULL;
 284         uint32_t secrets_tdb_secure_channel_type = SEC_CHAN_NULL;
 285         int server_role = lpcfg_server_role(lp_ctx);
 286         int security = lpcfg_security(lp_ctx);
 287         char *keystr;
 288         char *keystr_upper = NULL;
 289         TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
 290         if (!tmp_ctx) {
 291                 return NT_STATUS_NO_MEMORY;
 292         }
 293
 294         /* Bleh, nasty recursion issues: We are setting a machine
 295          * account here, so we don't want the 'pending' flag around
 296          * any more */
 297         cred->machine_account_pending = false;
 298
 299         /* We have to do this, as the fallback in
 300          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 301         domain = cli_credentials_get_domain(cred);
 302
 303         if (db_ctx) {
 304                 TDB_DATA dbuf;
 305                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 306                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 307                                          domain);
 308                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 309                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 310                                       &dbuf);
 311                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 312                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 313                 }
 314
 315                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 316                                          SECRETS_MACHINE_PASSWORD,
 317                                          domain);
 318                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 319                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 320                                       &dbuf);
 321                 if (NT_STATUS_IS_OK(status)) {
 322                         secrets_tdb_password = (char *)dbuf.dptr;
 323                 }
 324
 325                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 326                                          SECRETS_MACHINE_PASSWORD_PREV,
 327                                          domain);
 328                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 329                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 330                                       &dbuf);
 331                 if (NT_STATUS_IS_OK(status)) {
 332                         secrets_tdb_old_password = (char *)dbuf.dptr;
 333                 }
 334
 335                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 336                                          SECRETS_MACHINE_SEC_CHANNEL_TYPE,
 337                                          domain);
 338                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 339                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 340                                       &dbuf);
 341                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 342                         secrets_tdb_secure_channel_type = IVAL(dbuf.dptr,0);
 343                 }
 344         }
 345
 346         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 347                                  domain);
 348         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 349                                                  SECRETS_PRIMARY_DOMAIN_DN,
 350                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 351         if (secrets_tdb_password == NULL) {
 352                 secrets_tdb_password_more_recent = false;
 353         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 354             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 355                 secrets_tdb_password_more_recent = true;
 356         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 357                 secrets_tdb_password_more_recent = true;
 358         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 359                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 360         } else {
 361                 secrets_tdb_password_more_recent = false;
 362         }
 363
 364         if (secrets_tdb_password_more_recent) {
 365                 enum credentials_use_kerberos use_kerberos = CRED_DONT_USE_KERBEROS;
 366                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 367                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 368                 cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
 369                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 370                 if (strequal(domain, lpcfg_workgroup(lp_ctx))) {
 371                         cli_credentials_set_realm(cred, lpcfg_realm(lp_ctx), CRED_SPECIFIED);
 372
 373                         switch (server_role) {
 374                         case ROLE_DOMAIN_MEMBER:
 375                                 if (security != SEC_ADS) {
 376                                         break;
 377                                 }
 378
 379                                 FALL_THROUGH;
 380                         case ROLE_ACTIVE_DIRECTORY_DC:
 381                                 use_kerberos = CRED_AUTO_USE_KERBEROS;
 382                                 break;
 383                         }
 384                 }
 385                 cli_credentials_set_kerberos_state(cred, use_kerberos);
 386                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 387                 cli_credentials_set_password_last_changed_time(cred, secrets_tdb_lct);
 388                 cli_credentials_set_secure_channel_type(cred, secrets_tdb_secure_channel_type);
 389                 status = NT_STATUS_OK;
 390         } else if (!NT_STATUS_IS_OK(status)) {
 391                 if (db_ctx) {
 392                         error_string
 393                                 = talloc_asprintf(cred,
 394                                                   "Failed to fetch machine account password for %s from both "
 395                                                   "secrets.ldb (%s) and from %s",
 396                                                   domain,
 397                                                   error_string == NULL ? "error" : error_string,
 398                                                   dbwrap_name(db_ctx));
 399                 } else {
 400                         char *secrets_tdb_path;
 401
 402                         secrets_tdb_path = lpcfg_private_db_path(tmp_ctx,
 403                                                                  lp_ctx,
 404                                                                  "secrets");
 405                         if (secrets_tdb_path == NULL) {
 406                                 return NT_STATUS_NO_MEMORY;
 407                         }
 408
 409                         error_string = talloc_asprintf(cred,
 410                                                        "Failed to fetch machine account password from "
 411                                                        "secrets.ldb: %s and failed to open %s",
 412                                                        error_string == NULL ? "error" : error_string,
 413                                                        secrets_tdb_path);
 414                 }
 415                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 416                           error_string == NULL ? "error" : error_string,
 417                           nt_errstr(status)));
 418                 /* set anonymous as the fallback, if the machine account won't work */
 419                 cli_credentials_set_anonymous(cred);
 420         }
 421
 422         TALLOC_FREE(tmp_ctx);
 423         return status;
 424 }
 425
 426 /**
 427  * Fill in credentials for a particular principal, from the secrets database.
 428  *
 429  * @param cred Credentials structure to fill in
 430  * @retval NTSTATUS error detailing any failure
 431  */
 432 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 433                                               struct loadparm_context *lp_ctx,
 434                                               const char *serviceprincipal)
 435 {
 436         NTSTATUS status;
 437         char *filter;
 438         char *error_string = NULL;
 439         /* Bleh, nasty recursion issues: We are setting a machine
 440          * account here, so we don't want the 'pending' flag around
 441          * any more */
 442         cred->machine_account_pending = false;
 443         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 444                                  cli_credentials_get_realm(cred),
 445                                  cli_credentials_get_domain(cred),
 446                                  serviceprincipal);
 447         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 448                                              SECRETS_PRINCIPALS_DN, filter,
 449                                              0, NULL, &error_string);
 450         if (!NT_STATUS_IS_OK(status)) {
 451                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n",
 452                           serviceprincipal, nt_errstr(status),
 453                           error_string ? error_string : "<no error>"));
 454         }
 455         return status;
 456 }
 457
 458 /**
 459  * Ask that when required, the credentials system will be filled with
 460  * machine trust account, from the secrets database.
 461  *
 462  * @param cred Credentials structure to fill in
 463  * @note This function is used to call the above function after, rather
 464  *       than during, popt processing.
 465  *
 466  */
 467 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 468                                                  struct loadparm_context *lp_ctx)
 469 {
 470         cred->machine_account_pending = true;
 471         cred->machine_account_pending_lp_ctx = lp_ctx;
 472 }
 473
 474