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         SMB_ASSERT(cred->machine_account_pending == false);
 307         cred->machine_account_pending = false;
 308
 309         /* We have to do this, as the fallback in
 310          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 311         domain = cli_credentials_get_domain(cred);
 312
 313         if (db_ctx) {
 314                 TDB_DATA dbuf;
 315                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 316                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 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) && dbuf.dsize == 4) {
 322                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 323                 }
 324
 325                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 326                                          SECRETS_MACHINE_PASSWORD,
 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_password = (char *)dbuf.dptr;
 333                 }
 334
 335                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 336                                          SECRETS_MACHINE_PASSWORD_PREV,
 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)) {
 342                         secrets_tdb_old_password = (char *)dbuf.dptr;
 343                 }
 344
 345                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 346                                          SECRETS_MACHINE_SEC_CHANNEL_TYPE,
 347                                          domain);
 348                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 349                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 350                                       &dbuf);
 351                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 352                         secrets_tdb_secure_channel_type = IVAL(dbuf.dptr,0);
 353                 }
 354         }
 355
 356         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 357                                  domain);
 358         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 359                                                  SECRETS_PRIMARY_DOMAIN_DN,
 360                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 361         if (secrets_tdb_password == NULL) {
 362                 secrets_tdb_password_more_recent = false;
 363         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 364             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 365                 secrets_tdb_password_more_recent = true;
 366         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 367                 secrets_tdb_password_more_recent = true;
 368         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 369                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 370         } else {
 371                 secrets_tdb_password_more_recent = false;
 372         }
 373
 374         if (secrets_tdb_password_more_recent) {
 375                 enum credentials_use_kerberos use_kerberos = CRED_DONT_USE_KERBEROS;
 376                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 377                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 378                 cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
 379                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 380                 if (strequal(domain, lpcfg_workgroup(lp_ctx))) {
 381                         cli_credentials_set_realm(cred, lpcfg_realm(lp_ctx), CRED_SPECIFIED);
 382
 383                         switch (server_role) {
 384                         case ROLE_DOMAIN_MEMBER:
 385                                 if (security != SEC_ADS) {
 386                                         break;
 387                                 }
 388
 389                                 FALL_THROUGH;
 390                         case ROLE_ACTIVE_DIRECTORY_DC:
 391                                 use_kerberos = CRED_AUTO_USE_KERBEROS;
 392                                 break;
 393                         }
 394                 }
 395                 cli_credentials_set_kerberos_state(cred, use_kerberos);
 396                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 397                 cli_credentials_set_password_last_changed_time(cred, secrets_tdb_lct);
 398                 cli_credentials_set_secure_channel_type(cred, secrets_tdb_secure_channel_type);
 399                 status = NT_STATUS_OK;
 400         } else if (!NT_STATUS_IS_OK(status)) {
 401                 if (db_ctx) {
 402                         error_string
 403                                 = talloc_asprintf(cred,
 404                                                   "Failed to fetch machine account password for %s from both "
 405                                                   "secrets.ldb (%s) and from %s",
 406                                                   domain,
 407                                                   error_string == NULL ? "error" : error_string,
 408                                                   dbwrap_name(db_ctx));
 409                 } else {
 410                         char *secrets_tdb_path;
 411
 412                         secrets_tdb_path = lpcfg_private_db_path(tmp_ctx,
 413                                                                  lp_ctx,
 414                                                                  "secrets");
 415                         if (secrets_tdb_path == NULL) {
 416                                 return NT_STATUS_NO_MEMORY;
 417                         }
 418
 419                         error_string = talloc_asprintf(cred,
 420                                                        "Failed to fetch machine account password from "
 421                                                        "secrets.ldb: %s and failed to open %s",
 422                                                        error_string == NULL ? "error" : error_string,
 423                                                        secrets_tdb_path);
 424                 }
 425                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 426                           error_string == NULL ? "error" : error_string,
 427                           nt_errstr(status)));
 428                 /* set anonymous as the fallback, if the machine account won't work */
 429                 cli_credentials_set_anonymous(cred);
 430         }
 431
 432         TALLOC_FREE(tmp_ctx);
 433         return status;
 434 }
 435
 436 /**
 437  * Fill in credentials for a particular principal, from the secrets database.
 438  *
 439  * @param cred Credentials structure to fill in
 440  * @retval NTSTATUS error detailing any failure
 441  */
 442 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 443                                               struct loadparm_context *lp_ctx,
 444                                               const char *serviceprincipal)
 445 {
 446         NTSTATUS status;
 447         char *filter;
 448         char *error_string = NULL;
 449         /* Bleh, nasty recursion issues: We are setting a machine
 450          * account here, so we don't want the 'pending' flag around
 451          * any more */
 452         cred->machine_account_pending = false;
 453         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 454                                  cli_credentials_get_realm(cred),
 455                                  cli_credentials_get_domain(cred),
 456                                  serviceprincipal);
 457         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 458                                              SECRETS_PRINCIPALS_DN, filter,
 459                                              0, NULL, &error_string);
 460         if (!NT_STATUS_IS_OK(status)) {
 461                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n",
 462                           serviceprincipal, nt_errstr(status),
 463                           error_string ? error_string : "<no error>"));
 464         }
 465         return status;
 466 }
 467
 468 /**
 469  * Ask that when required, the credentials system will be filled with
 470  * machine trust account, from the secrets database.
 471  *
 472  * @param cred Credentials structure to fill in
 473  * @note This function is used to call the above function after, rather
 474  *       than during, popt processing.
 475  *
 476  */
 477 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 478                                                  struct loadparm_context *lp_ctx)
 479 {
 480         cred->machine_account_pending = true;
 481         cred->machine_account_pending_lp_ctx = lp_ctx;
 482 }
 483
 484