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 mandetory */
 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 && secrets_tdb_password && strcmp(password, secrets_tdb_password) != 0) {
 124                 talloc_free(mem_ctx);
 125                 return NT_STATUS_NOT_FOUND;
 126         }
 127
 128         cli_credentials_set_password_last_changed_time(cred, lct);
 129
 130         machine_account = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);
 131
 132         if (!machine_account) {
 133                 machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);
 134
 135                 if (!machine_account) {
 136                         const char *ldap_bind_dn = ldb_msg_find_attr_as_string(msg, "ldapBindDn", NULL);
 137                         if (!ldap_bind_dn) {
 138                                 *error_string = talloc_asprintf(cred,
 139                                                                 "Could not find 'samAccountName', "
 140                                                                 "'servicePrincipalName' or "
 141                                                                 "'ldapBindDn' in secrets record: %s",
 142                                                                 ldb_dn_get_linearized(msg->dn));
 143                                 talloc_free(mem_ctx);
 144                                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 145                         } else {
 146                                 /* store bind dn in credentials */
 147                                 cli_credentials_set_bind_dn(cred, ldap_bind_dn);
 148                         }
 149                 }
 150         }
 151
 152         salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
 153         cli_credentials_set_salt_principal(cred, salt_principal);
 154
 155         sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
 156         if (sct) {
 157                 cli_credentials_set_secure_channel_type(cred, sct);
 158         }
 159
 160         if (!password) {
 161                 const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
 162                 struct samr_Password hash;
 163                 ZERO_STRUCT(hash);
 164                 if (nt_password_hash) {
 165                         memcpy(hash.hash, nt_password_hash->data,
 166                                MIN(nt_password_hash->length, sizeof(hash.hash)));
 167
 168                         cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
 169                 } else {
 170                         cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
 171                 }
 172         } else {
 173                 cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 174         }
 175
 176         domain = ldb_msg_find_attr_as_string(msg, "flatname", NULL);
 177         if (domain) {
 178                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 179         }
 180
 181         realm = ldb_msg_find_attr_as_string(msg, "realm", NULL);
 182         if (realm) {
 183                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 184         }
 185
 186         if (machine_account) {
 187                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 188         }
 189
 190         cli_credentials_set_kvno(cred, ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0));
 191
 192         /* If there was an external keytab specified by reference in
 193          * the LDB, then use this.  Otherwise we will make one up
 194          * (chewing CPU time) from the password */
 195         keytab = keytab_name_from_msg(cred, ldb, msg);
 196         if (keytab) {
 197                 cli_credentials_set_keytab_name(cred, lp_ctx, keytab, CRED_SPECIFIED);
 198                 talloc_free(keytab);
 199         }
 200         talloc_free(mem_ctx);
 201
 202         return NT_STATUS_OK;
 203 }
 204
 205
 206 /**
 207  * Fill in credentials for the machine trust account, from the secrets database.
 208  *
 209  * @param cred Credentials structure to fill in
 210  * @retval NTSTATUS error detailing any failure
 211  */
 212 _PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
 213                                               struct loadparm_context *lp_ctx,
 214                                               struct ldb_context *ldb,
 215                                               const char *base,
 216                                               const char *filter,
 217                                               char **error_string)
 218 {
 219         NTSTATUS status = cli_credentials_set_secrets_lct(cred, lp_ctx, ldb, base, filter, 0, NULL, error_string);
 220         if (!NT_STATUS_IS_OK(status)) {
 221                 /* set anonymous as the fallback, if the machine account won't work */
 222                 cli_credentials_set_anonymous(cred);
 223         }
 224         return status;
 225 }
 226
 227 /**
 228  * Fill in credentials for the machine trust account, from the secrets database.
 229  *
 230  * @param cred Credentials structure to fill in
 231  * @retval NTSTATUS error detailing any failure
 232  */
 233 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
 234                                                       struct loadparm_context *lp_ctx)
 235 {
 236         struct db_context *db_ctx;
 237         char *secrets_tdb_path;
 238
 239         secrets_tdb_path = lpcfg_private_db_path(cred, lp_ctx, "secrets");
 240         if (secrets_tdb_path == NULL) {
 241                 return NT_STATUS_NO_MEMORY;
 242         }
 243
 244         db_ctx = dbwrap_local_open(cred, lp_ctx, secrets_tdb_path, 0,
 245                                    TDB_DEFAULT, O_RDWR, 0600,
 246                                    DBWRAP_LOCK_ORDER_1,
 247                                    DBWRAP_FLAG_NONE);
 248         TALLOC_FREE(secrets_tdb_path);
 249
 250         /*
 251          * We do not check for errors here, we might not have a
 252          * secrets.tdb at all, and so we just need to check the
 253          * secrets.ldb
 254          */
 255         return cli_credentials_set_machine_account_db_ctx(cred, lp_ctx, db_ctx);
 256 }
 257
 258 /**
 259  * Fill in credentials for the machine trust account, from the
 260  * secrets.ldb or passed in handle to secrets.tdb (perhaps in CTDB).
 261  *
 262  * This version is used in parts of the code that can link in the
 263  * CTDB dbwrap backend, by passing down the already open handle.
 264  *
 265  * @param cred Credentials structure to fill in
 266  * @param db_ctx dbwrap context for secrets.tdb
 267  * @retval NTSTATUS error detailing any failure
 268  */
 269 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account_db_ctx(struct cli_credentials *cred,
 270                                                              struct loadparm_context *lp_ctx,
 271                                                              struct db_context *db_ctx)
 272 {
 273         NTSTATUS status;
 274         char *filter;
 275         char *error_string = NULL;
 276         const char *domain;
 277         bool secrets_tdb_password_more_recent;
 278         time_t secrets_tdb_lct = 0;
 279         char *secrets_tdb_password = NULL;
 280         char *secrets_tdb_old_password = NULL;
 281         uint32_t secrets_tdb_secure_channel_type = SEC_CHAN_NULL;
 282         int server_role = lpcfg_server_role(lp_ctx);
 283         int security = lpcfg_security(lp_ctx);
 284         char *keystr;
 285         char *keystr_upper = NULL;
 286         TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
 287         if (!tmp_ctx) {
 288                 return NT_STATUS_NO_MEMORY;
 289         }
 290
 291         /* Bleh, nasty recursion issues: We are setting a machine
 292          * account here, so we don't want the 'pending' flag around
 293          * any more */
 294         cred->machine_account_pending = false;
 295
 296         /* We have to do this, as the fallback in
 297          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 298         domain = cli_credentials_get_domain(cred);
 299
 300         if (db_ctx) {
 301                 TDB_DATA dbuf;
 302                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 303                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 304                                          domain);
 305                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 306                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 307                                       &dbuf);
 308                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 309                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 310                 }
 311
 312                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 313                                          SECRETS_MACHINE_PASSWORD,
 314                                          domain);
 315                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 316                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 317                                       &dbuf);
 318                 if (NT_STATUS_IS_OK(status)) {
 319                         secrets_tdb_password = (char *)dbuf.dptr;
 320                 }
 321
 322                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 323                                          SECRETS_MACHINE_PASSWORD_PREV,
 324                                          domain);
 325                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 326                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 327                                       &dbuf);
 328                 if (NT_STATUS_IS_OK(status)) {
 329                         secrets_tdb_old_password = (char *)dbuf.dptr;
 330                 }
 331
 332                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 333                                          SECRETS_MACHINE_SEC_CHANNEL_TYPE,
 334                                          domain);
 335                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 336                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 337                                       &dbuf);
 338                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 339                         secrets_tdb_secure_channel_type = IVAL(dbuf.dptr,0);
 340                 }
 341         }
 342
 343         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 344                                  domain);
 345         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 346                                                  SECRETS_PRIMARY_DOMAIN_DN,
 347                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 348         if (secrets_tdb_password == NULL) {
 349                 secrets_tdb_password_more_recent = false;
 350         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 351             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 352                 secrets_tdb_password_more_recent = true;
 353         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 354                 secrets_tdb_password_more_recent = true;
 355         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 356                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 357         } else {
 358                 secrets_tdb_password_more_recent = false;
 359         }
 360
 361         if (secrets_tdb_password_more_recent) {
 362                 enum credentials_use_kerberos use_kerberos = CRED_DONT_USE_KERBEROS;
 363                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 364                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 365                 cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
 366                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 367                 if (strequal(domain, lpcfg_workgroup(lp_ctx))) {
 368                         cli_credentials_set_realm(cred, lpcfg_realm(lp_ctx), CRED_SPECIFIED);
 369
 370                         switch (server_role) {
 371                         case ROLE_DOMAIN_MEMBER:
 372                                 if (security != SEC_ADS) {
 373                                         break;
 374                                 }
 375                                 /* fall through */
 376                         case ROLE_ACTIVE_DIRECTORY_DC:
 377                                 use_kerberos = CRED_AUTO_USE_KERBEROS;
 378                                 break;
 379                         }
 380                 }
 381                 cli_credentials_set_kerberos_state(cred, use_kerberos);
 382                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 383                 cli_credentials_set_password_last_changed_time(cred, secrets_tdb_lct);
 384                 cli_credentials_set_secure_channel_type(cred, secrets_tdb_secure_channel_type);
 385                 status = NT_STATUS_OK;
 386         } else if (!NT_STATUS_IS_OK(status)) {
 387                 if (db_ctx) {
 388                         error_string
 389                                 = talloc_asprintf(cred,
 390                                                   "Failed to fetch machine account password for %s from both "
 391                                                   "secrets.ldb (%s) and from %s",
 392                                                   domain,
 393                                                   error_string == NULL ? "error" : error_string,
 394                                                   dbwrap_name(db_ctx));
 395                 } else {
 396                         char *secrets_tdb_path;
 397
 398                         secrets_tdb_path = lpcfg_private_db_path(tmp_ctx,
 399                                                                  lp_ctx,
 400                                                                  "secrets");
 401                         if (secrets_tdb_path == NULL) {
 402                                 return NT_STATUS_NO_MEMORY;
 403                         }
 404
 405                         error_string = talloc_asprintf(cred,
 406                                                        "Failed to fetch machine account password from "
 407                                                        "secrets.ldb: %s and failed to open %s",
 408                                                        error_string == NULL ? "error" : error_string,
 409                                                        secrets_tdb_path);
 410                 }
 411                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 412                           error_string == NULL ? "error" : error_string,
 413                           nt_errstr(status)));
 414                 /* set anonymous as the fallback, if the machine account won't work */
 415                 cli_credentials_set_anonymous(cred);
 416         }
 417
 418         TALLOC_FREE(tmp_ctx);
 419         return status;
 420 }
 421
 422 /**
 423  * Fill in credentials for a particular principal, from the secrets database.
 424  *
 425  * @param cred Credentials structure to fill in
 426  * @retval NTSTATUS error detailing any failure
 427  */
 428 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 429                                               struct loadparm_context *lp_ctx,
 430                                               const char *serviceprincipal)
 431 {
 432         NTSTATUS status;
 433         char *filter;
 434         char *error_string = NULL;
 435         /* Bleh, nasty recursion issues: We are setting a machine
 436          * account here, so we don't want the 'pending' flag around
 437          * any more */
 438         cred->machine_account_pending = false;
 439         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 440                                  cli_credentials_get_realm(cred),
 441                                  cli_credentials_get_domain(cred),
 442                                  serviceprincipal);
 443         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 444                                              SECRETS_PRINCIPALS_DN, filter,
 445                                              0, NULL, &error_string);
 446         if (!NT_STATUS_IS_OK(status)) {
 447                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n",
 448                           serviceprincipal, nt_errstr(status),
 449                           error_string ? error_string : "<no error>"));
 450         }
 451         return status;
 452 }
 453
 454 /**
 455  * Ask that when required, the credentials system will be filled with
 456  * machine trust account, from the secrets database.
 457  *
 458  * @param cred Credentials structure to fill in
 459  * @note This function is used to call the above function after, rather
 460  *       than during, popt processing.
 461  *
 462  */
 463 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 464                                                  struct loadparm_context *lp_ctx)
 465 {
 466         cred->machine_account_pending = true;
 467         cred->machine_account_pending_lp_ctx = lp_ctx;
 468 }
 469
 470