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         if (password == NULL) {
 110                 /* This attribute is mandatory */
 111                 talloc_free(mem_ctx);
 112                 return NT_STATUS_NOT_FOUND;
 113         }
 114
 115         whenChanged = ldb_msg_find_ldb_val(msg, "whenChanged");
 116         if (!whenChanged || ldb_val_to_time(whenChanged, &lct) != LDB_SUCCESS) {
 117                 /* This attribute is mandetory */
 118                 talloc_free(mem_ctx);
 119                 return NT_STATUS_NOT_FOUND;
 120         }
 121
 122         /* Don't set secrets.ldb info if the secrets.tdb entry was more recent */
 123         if (lct < secrets_tdb_last_change_time) {
 124                 talloc_free(mem_ctx);
 125                 return NT_STATUS_NOT_FOUND;
 126         }
 127
 128         if (lct == secrets_tdb_last_change_time && secrets_tdb_password && strcmp(password, secrets_tdb_password) != 0) {
 129                 talloc_free(mem_ctx);
 130                 return NT_STATUS_NOT_FOUND;
 131         }
 132
 133         cli_credentials_set_password_last_changed_time(cred, lct);
 134
 135         machine_account = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);
 136
 137         if (!machine_account) {
 138                 machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);
 139
 140                 if (!machine_account) {
 141                         const char *ldap_bind_dn = ldb_msg_find_attr_as_string(msg, "ldapBindDn", NULL);
 142                         if (!ldap_bind_dn) {
 143                                 *error_string = talloc_asprintf(cred,
 144                                                                 "Could not find 'samAccountName', "
 145                                                                 "'servicePrincipalName' or "
 146                                                                 "'ldapBindDn' in secrets record: %s",
 147                                                                 ldb_dn_get_linearized(msg->dn));
 148                                 talloc_free(mem_ctx);
 149                                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 150                         } else {
 151                                 /* store bind dn in credentials */
 152                                 cli_credentials_set_bind_dn(cred, ldap_bind_dn);
 153                         }
 154                 }
 155         }
 156
 157         salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
 158         cli_credentials_set_salt_principal(cred, salt_principal);
 159
 160         sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
 161         if (sct) {
 162                 cli_credentials_set_secure_channel_type(cred, sct);
 163         }
 164
 165         if (!password) {
 166                 const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
 167                 struct samr_Password hash;
 168                 ZERO_STRUCT(hash);
 169                 if (nt_password_hash) {
 170                         memcpy(hash.hash, nt_password_hash->data,
 171                                MIN(nt_password_hash->length, sizeof(hash.hash)));
 172
 173                         cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
 174                 } else {
 175                         cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
 176                 }
 177         } else {
 178                 cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 179         }
 180
 181         domain = ldb_msg_find_attr_as_string(msg, "flatname", NULL);
 182         if (domain) {
 183                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 184         }
 185
 186         realm = ldb_msg_find_attr_as_string(msg, "realm", NULL);
 187         if (realm) {
 188                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 189         }
 190
 191         if (machine_account) {
 192                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 193         }
 194
 195         cli_credentials_set_kvno(cred, ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0));
 196
 197         /* If there was an external keytab specified by reference in
 198          * the LDB, then use this.  Otherwise we will make one up
 199          * (chewing CPU time) from the password */
 200         keytab = keytab_name_from_msg(cred, ldb, msg);
 201         if (keytab) {
 202                 cli_credentials_set_keytab_name(cred, lp_ctx, keytab, CRED_SPECIFIED);
 203                 talloc_free(keytab);
 204         }
 205         talloc_free(mem_ctx);
 206
 207         return NT_STATUS_OK;
 208 }
 209
 210
 211 /**
 212  * Fill in credentials for the machine trust account, from the secrets database.
 213  *
 214  * @param cred Credentials structure to fill in
 215  * @retval NTSTATUS error detailing any failure
 216  */
 217 _PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
 218                                               struct loadparm_context *lp_ctx,
 219                                               struct ldb_context *ldb,
 220                                               const char *base,
 221                                               const char *filter,
 222                                               char **error_string)
 223 {
 224         NTSTATUS status = cli_credentials_set_secrets_lct(cred, lp_ctx, ldb, base, filter, 0, NULL, error_string);
 225         if (!NT_STATUS_IS_OK(status)) {
 226                 /* set anonymous as the fallback, if the machine account won't work */
 227                 cli_credentials_set_anonymous(cred);
 228         }
 229         return status;
 230 }
 231
 232 /**
 233  * Fill in credentials for the machine trust account, from the secrets database.
 234  *
 235  * @param cred Credentials structure to fill in
 236  * @retval NTSTATUS error detailing any failure
 237  */
 238 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
 239                                                       struct loadparm_context *lp_ctx)
 240 {
 241         struct db_context *db_ctx;
 242         char *secrets_tdb_path;
 243
 244         secrets_tdb_path = lpcfg_private_db_path(cred, lp_ctx, "secrets");
 245         if (secrets_tdb_path == NULL) {
 246                 return NT_STATUS_NO_MEMORY;
 247         }
 248
 249         db_ctx = dbwrap_local_open(cred, lp_ctx, secrets_tdb_path, 0,
 250                                    TDB_DEFAULT, O_RDWR, 0600,
 251                                    DBWRAP_LOCK_ORDER_1,
 252                                    DBWRAP_FLAG_NONE);
 253         TALLOC_FREE(secrets_tdb_path);
 254
 255         /*
 256          * We do not check for errors here, we might not have a
 257          * secrets.tdb at all, and so we just need to check the
 258          * secrets.ldb
 259          */
 260         return cli_credentials_set_machine_account_db_ctx(cred, lp_ctx, db_ctx);
 261 }
 262
 263 /**
 264  * Fill in credentials for the machine trust account, from the
 265  * secrets.ldb or passed in handle to secrets.tdb (perhaps in CTDB).
 266  *
 267  * This version is used in parts of the code that can link in the
 268  * CTDB dbwrap backend, by passing down the already open handle.
 269  *
 270  * @param cred Credentials structure to fill in
 271  * @param db_ctx dbwrap context for secrets.tdb
 272  * @retval NTSTATUS error detailing any failure
 273  */
 274 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account_db_ctx(struct cli_credentials *cred,
 275                                                              struct loadparm_context *lp_ctx,
 276                                                              struct db_context *db_ctx)
 277 {
 278         NTSTATUS status;
 279         char *filter;
 280         char *error_string = NULL;
 281         const char *domain;
 282         bool secrets_tdb_password_more_recent;
 283         time_t secrets_tdb_lct = 0;
 284         char *secrets_tdb_password = NULL;
 285         char *secrets_tdb_old_password = NULL;
 286         uint32_t secrets_tdb_secure_channel_type = SEC_CHAN_NULL;
 287         int server_role = lpcfg_server_role(lp_ctx);
 288         int security = lpcfg_security(lp_ctx);
 289         char *keystr;
 290         char *keystr_upper = NULL;
 291         TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
 292         if (!tmp_ctx) {
 293                 return NT_STATUS_NO_MEMORY;
 294         }
 295
 296         /* Bleh, nasty recursion issues: We are setting a machine
 297          * account here, so we don't want the 'pending' flag around
 298          * any more */
 299         cred->machine_account_pending = false;
 300
 301         /* We have to do this, as the fallback in
 302          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 303         domain = cli_credentials_get_domain(cred);
 304
 305         if (db_ctx) {
 306                 TDB_DATA dbuf;
 307                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 308                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 309                                          domain);
 310                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 311                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 312                                       &dbuf);
 313                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 314                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 315                 }
 316
 317                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 318                                          SECRETS_MACHINE_PASSWORD,
 319                                          domain);
 320                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 321                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 322                                       &dbuf);
 323                 if (NT_STATUS_IS_OK(status)) {
 324                         secrets_tdb_password = (char *)dbuf.dptr;
 325                 }
 326
 327                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 328                                          SECRETS_MACHINE_PASSWORD_PREV,
 329                                          domain);
 330                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 331                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 332                                       &dbuf);
 333                 if (NT_STATUS_IS_OK(status)) {
 334                         secrets_tdb_old_password = (char *)dbuf.dptr;
 335                 }
 336
 337                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 338                                          SECRETS_MACHINE_SEC_CHANNEL_TYPE,
 339                                          domain);
 340                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 341                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 342                                       &dbuf);
 343                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 344                         secrets_tdb_secure_channel_type = IVAL(dbuf.dptr,0);
 345                 }
 346         }
 347
 348         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 349                                  domain);
 350         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 351                                                  SECRETS_PRIMARY_DOMAIN_DN,
 352                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 353         if (secrets_tdb_password == NULL) {
 354                 secrets_tdb_password_more_recent = false;
 355         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 356             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 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 = true;
 360         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 361                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 362         } else {
 363                 secrets_tdb_password_more_recent = false;
 364         }
 365
 366         if (secrets_tdb_password_more_recent) {
 367                 enum credentials_use_kerberos use_kerberos = CRED_DONT_USE_KERBEROS;
 368                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 369                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 370                 cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
 371                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 372                 if (strequal(domain, lpcfg_workgroup(lp_ctx))) {
 373                         cli_credentials_set_realm(cred, lpcfg_realm(lp_ctx), CRED_SPECIFIED);
 374
 375                         switch (server_role) {
 376                         case ROLE_DOMAIN_MEMBER:
 377                                 if (security != SEC_ADS) {
 378                                         break;
 379                                 }
 380
 381                                 FALL_THROUGH;
 382                         case ROLE_ACTIVE_DIRECTORY_DC:
 383                                 use_kerberos = CRED_AUTO_USE_KERBEROS;
 384                                 break;
 385                         }
 386                 }
 387                 cli_credentials_set_kerberos_state(cred, use_kerberos);
 388                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 389                 cli_credentials_set_password_last_changed_time(cred, secrets_tdb_lct);
 390                 cli_credentials_set_secure_channel_type(cred, secrets_tdb_secure_channel_type);
 391                 status = NT_STATUS_OK;
 392         } else if (!NT_STATUS_IS_OK(status)) {
 393                 if (db_ctx) {
 394                         error_string
 395                                 = talloc_asprintf(cred,
 396                                                   "Failed to fetch machine account password for %s from both "
 397                                                   "secrets.ldb (%s) and from %s",
 398                                                   domain,
 399                                                   error_string == NULL ? "error" : error_string,
 400                                                   dbwrap_name(db_ctx));
 401                 } else {
 402                         char *secrets_tdb_path;
 403
 404                         secrets_tdb_path = lpcfg_private_db_path(tmp_ctx,
 405                                                                  lp_ctx,
 406                                                                  "secrets");
 407                         if (secrets_tdb_path == NULL) {
 408                                 return NT_STATUS_NO_MEMORY;
 409                         }
 410
 411                         error_string = talloc_asprintf(cred,
 412                                                        "Failed to fetch machine account password from "
 413                                                        "secrets.ldb: %s and failed to open %s",
 414                                                        error_string == NULL ? "error" : error_string,
 415                                                        secrets_tdb_path);
 416                 }
 417                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 418                           error_string == NULL ? "error" : error_string,
 419                           nt_errstr(status)));
 420                 /* set anonymous as the fallback, if the machine account won't work */
 421                 cli_credentials_set_anonymous(cred);
 422         }
 423
 424         TALLOC_FREE(tmp_ctx);
 425         return status;
 426 }
 427
 428 /**
 429  * Fill in credentials for a particular principal, from the secrets database.
 430  *
 431  * @param cred Credentials structure to fill in
 432  * @retval NTSTATUS error detailing any failure
 433  */
 434 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 435                                               struct loadparm_context *lp_ctx,
 436                                               const char *serviceprincipal)
 437 {
 438         NTSTATUS status;
 439         char *filter;
 440         char *error_string = NULL;
 441         /* Bleh, nasty recursion issues: We are setting a machine
 442          * account here, so we don't want the 'pending' flag around
 443          * any more */
 444         cred->machine_account_pending = false;
 445         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 446                                  cli_credentials_get_realm(cred),
 447                                  cli_credentials_get_domain(cred),
 448                                  serviceprincipal);
 449         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 450                                              SECRETS_PRINCIPALS_DN, filter,
 451                                              0, NULL, &error_string);
 452         if (!NT_STATUS_IS_OK(status)) {
 453                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n",
 454                           serviceprincipal, nt_errstr(status),
 455                           error_string ? error_string : "<no error>"));
 456         }
 457         return status;
 458 }
 459
 460 /**
 461  * Ask that when required, the credentials system will be filled with
 462  * machine trust account, from the secrets database.
 463  *
 464  * @param cred Credentials structure to fill in
 465  * @note This function is used to call the above function after, rather
 466  *       than during, popt processing.
 467  *
 468  */
 469 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 470                                                  struct loadparm_context *lp_ctx)
 471 {
 472         cred->machine_account_pending = true;
 473         cred->machine_account_pending_lp_ctx = lp_ctx;
 474 }
 475
 476