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
  43
  44 /**
  45  * Fill in credentials for the machine trust account, from the secrets database.
  46  *
  47  * @param cred Credentials structure to fill in
  48  * @retval NTSTATUS error detailing any failure
  49  */
  50 static NTSTATUS cli_credentials_set_secrets_lct(struct cli_credentials *cred,
  51                                                 struct loadparm_context *lp_ctx,
  52                                                 struct ldb_context *ldb,
  53                                                 const char *base,
  54                                                 const char *filter,
  55                                                 time_t secrets_tdb_last_change_time,
  56                                                 const char *secrets_tdb_password,
  57                                                 char **error_string)
  58 {
  59         TALLOC_CTX *mem_ctx;
  60
  61         int ldb_ret;
  62         struct ldb_message *msg;
  63
  64         const char *machine_account;
  65         const char *password;
  66         const char *domain;
  67         const char *realm;
  68         enum netr_SchannelType sct;
  69         const char *salt_principal;
  70         char *keytab;
  71         const struct ldb_val *whenChanged;
  72         time_t lct;
  73
  74         /* ok, we are going to get it now, don't recurse back here */
  75         cred->machine_account_pending = false;
  76
  77         /* some other parts of the system will key off this */
  78         cred->machine_account = true;
  79
  80         mem_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
  81
  82         if (!ldb) {
  83                 /* Local secrets are stored in secrets.ldb */
  84                 ldb = secrets_db_connect(mem_ctx, lp_ctx);
  85                 if (!ldb) {
  86                         *error_string = talloc_strdup(cred, "Could not open secrets.ldb");
  87                         talloc_free(mem_ctx);
  88                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
  89                 }
  90         }
  91
  92         ldb_ret = dsdb_search_one(ldb, mem_ctx, &msg,
  93                                   ldb_dn_new(mem_ctx, ldb, base),
  94                                   LDB_SCOPE_SUBTREE,
  95                                   NULL, 0, "%s", filter);
  96
  97         if (ldb_ret != LDB_SUCCESS) {
  98                 *error_string = talloc_asprintf(cred, "Could not find entry to match filter: '%s' base: '%s': %s: %s",
  99                                                 filter, base ? base : "",
 100                                                 ldb_strerror(ldb_ret), ldb_errstring(ldb));
 101                 talloc_free(mem_ctx);
 102                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 103         }
 104
 105         password = ldb_msg_find_attr_as_string(msg, "secret", NULL);
 106
 107         whenChanged = ldb_msg_find_ldb_val(msg, "whenChanged");
 108         if (!whenChanged || ldb_val_to_time(whenChanged, &lct) != LDB_SUCCESS) {
 109                 /* This attribute is mandetory */
 110                 talloc_free(mem_ctx);
 111                 return NT_STATUS_NOT_FOUND;
 112         }
 113
 114         /* Don't set secrets.ldb info if the secrets.tdb entry was more recent */
 115         if (lct < secrets_tdb_last_change_time) {
 116                 talloc_free(mem_ctx);
 117                 return NT_STATUS_NOT_FOUND;
 118         }
 119
 120         if (lct == secrets_tdb_last_change_time && secrets_tdb_password && strcmp(password, secrets_tdb_password) != 0) {
 121                 talloc_free(mem_ctx);
 122                 return NT_STATUS_NOT_FOUND;
 123         }
 124
 125         cli_credentials_set_password_last_changed_time(cred, lct);
 126
 127         machine_account = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);
 128
 129         if (!machine_account) {
 130                 machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);
 131
 132                 if (!machine_account) {
 133                         const char *ldap_bind_dn = ldb_msg_find_attr_as_string(msg, "ldapBindDn", NULL);
 134                         if (!ldap_bind_dn) {
 135                                 *error_string = talloc_asprintf(cred,
 136                                                                 "Could not find 'samAccountName', "
 137                                                                 "'servicePrincipalName' or "
 138                                                                 "'ldapBindDn' in secrets record: %s",
 139                                                                 ldb_dn_get_linearized(msg->dn));
 140                                 talloc_free(mem_ctx);
 141                                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 142                         } else {
 143                                 /* store bind dn in credentials */
 144                                 cli_credentials_set_bind_dn(cred, ldap_bind_dn);
 145                         }
 146                 }
 147         }
 148
 149         salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
 150         cli_credentials_set_salt_principal(cred, salt_principal);
 151
 152         sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
 153         if (sct) {
 154                 cli_credentials_set_secure_channel_type(cred, sct);
 155         }
 156
 157         if (!password) {
 158                 const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
 159                 struct samr_Password hash;
 160                 ZERO_STRUCT(hash);
 161                 if (nt_password_hash) {
 162                         memcpy(hash.hash, nt_password_hash->data,
 163                                MIN(nt_password_hash->length, sizeof(hash.hash)));
 164
 165                         cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
 166                 } else {
 167                         cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
 168                 }
 169         } else {
 170                 cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 171         }
 172
 173         domain = ldb_msg_find_attr_as_string(msg, "flatname", NULL);
 174         if (domain) {
 175                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 176         }
 177
 178         realm = ldb_msg_find_attr_as_string(msg, "realm", NULL);
 179         if (realm) {
 180                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 181         }
 182
 183         if (machine_account) {
 184                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 185         }
 186
 187         cli_credentials_set_kvno(cred, ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0));
 188
 189         /* If there was an external keytab specified by reference in
 190          * the LDB, then use this.  Otherwise we will make one up
 191          * (chewing CPU time) from the password */
 192         keytab = keytab_name_from_msg(cred, ldb, msg);
 193         if (keytab) {
 194                 cli_credentials_set_keytab_name(cred, lp_ctx, keytab, CRED_SPECIFIED);
 195                 talloc_free(keytab);
 196         }
 197         talloc_free(mem_ctx);
 198
 199         return NT_STATUS_OK;
 200 }
 201
 202
 203 /**
 204  * Fill in credentials for the machine trust account, from the secrets database.
 205  *
 206  * @param cred Credentials structure to fill in
 207  * @retval NTSTATUS error detailing any failure
 208  */
 209 _PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
 210                                               struct loadparm_context *lp_ctx,
 211                                               struct ldb_context *ldb,
 212                                               const char *base,
 213                                               const char *filter,
 214                                               char **error_string)
 215 {
 216         NTSTATUS status = cli_credentials_set_secrets_lct(cred, lp_ctx, ldb, base, filter, 0, NULL, error_string);
 217         if (!NT_STATUS_IS_OK(status)) {
 218                 /* set anonymous as the fallback, if the machine account won't work */
 219                 cli_credentials_set_anonymous(cred);
 220         }
 221         return status;
 222 }
 223
 224 /**
 225  * Fill in credentials for the machine trust account, from the secrets database.
 226  *
 227  * @param cred Credentials structure to fill in
 228  * @retval NTSTATUS error detailing any failure
 229  */
 230 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
 231                                                       struct loadparm_context *lp_ctx)
 232 {
 233         struct db_context *db_ctx;
 234         char *secrets_tdb_path;
 235
 236         secrets_tdb_path = lpcfg_private_db_path(cred, lp_ctx, "secrets");
 237         if (secrets_tdb_path == NULL) {
 238                 return NT_STATUS_NO_MEMORY;
 239         }
 240
 241         db_ctx = dbwrap_local_open(cred, lp_ctx, secrets_tdb_path, 0,
 242                                    TDB_DEFAULT, O_RDWR, 0600,
 243                                    DBWRAP_LOCK_ORDER_1,
 244                                    DBWRAP_FLAG_NONE);
 245         TALLOC_FREE(secrets_tdb_path);
 246
 247         /*
 248          * We do not check for errors here, we might not have a
 249          * secrets.tdb at all, and so we just need to check the
 250          * secrets.ldb
 251          */
 252         return cli_credentials_set_machine_account_db_ctx(cred, lp_ctx, db_ctx);
 253 }
 254
 255 /**
 256  * Fill in credentials for the machine trust account, from the
 257  * secrets.ldb or passed in handle to secrets.tdb (perhaps in CTDB).
 258  *
 259  * This version is used in parts of the code that can link in the
 260  * CTDB dbwrap backend, by passing down the already open handle.
 261  *
 262  * @param cred Credentials structure to fill in
 263  * @param db_ctx dbwrap context for secrets.tdb
 264  * @retval NTSTATUS error detailing any failure
 265  */
 266 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account_db_ctx(struct cli_credentials *cred,
 267                                                              struct loadparm_context *lp_ctx,
 268                                                              struct db_context *db_ctx)
 269 {
 270         NTSTATUS status;
 271         char *filter;
 272         char *error_string = NULL;
 273         const char *domain;
 274         bool secrets_tdb_password_more_recent;
 275         time_t secrets_tdb_lct = 0;
 276         char *secrets_tdb_password = NULL;
 277         char *secrets_tdb_old_password = NULL;
 278         uint32_t secrets_tdb_secure_channel_type = SEC_CHAN_NULL;
 279         char *keystr;
 280         char *keystr_upper = NULL;
 281         TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
 282         if (!tmp_ctx) {
 283                 return NT_STATUS_NO_MEMORY;
 284         }
 285
 286         /* Bleh, nasty recursion issues: We are setting a machine
 287          * account here, so we don't want the 'pending' flag around
 288          * any more */
 289         cred->machine_account_pending = false;
 290
 291         /* We have to do this, as the fallback in
 292          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 293         domain = cli_credentials_get_domain(cred);
 294
 295         if (db_ctx) {
 296                 TDB_DATA dbuf;
 297                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 298                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 299                                          domain);
 300                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 301                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 302                                       &dbuf);
 303                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 304                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 305                 }
 306
 307                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 308                                          SECRETS_MACHINE_PASSWORD,
 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)) {
 314                         secrets_tdb_password = (char *)dbuf.dptr;
 315                 }
 316
 317                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 318                                          SECRETS_MACHINE_PASSWORD_PREV,
 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_old_password = (char *)dbuf.dptr;
 325                 }
 326
 327                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 328                                          SECRETS_MACHINE_SEC_CHANNEL_TYPE,
 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) && dbuf.dsize == 4) {
 334                         secrets_tdb_secure_channel_type = IVAL(dbuf.dptr,0);
 335                 }
 336         }
 337
 338         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 339                                  domain);
 340         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 341                                                  SECRETS_PRIMARY_DOMAIN_DN,
 342                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 343         if (secrets_tdb_password == NULL) {
 344                 secrets_tdb_password_more_recent = false;
 345         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 346             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 347                 secrets_tdb_password_more_recent = true;
 348         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 349                 secrets_tdb_password_more_recent = true;
 350         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 351                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 352         } else {
 353                 secrets_tdb_password_more_recent = false;
 354         }
 355
 356         if (secrets_tdb_password_more_recent) {
 357                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 358                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 359                 cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
 360                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 361                 if (strequal(domain, lpcfg_workgroup(lp_ctx))) {
 362                         cli_credentials_set_realm(cred, lpcfg_realm(lp_ctx), CRED_SPECIFIED);
 363                 }
 364                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 365                 cli_credentials_set_password_last_changed_time(cred, secrets_tdb_lct);
 366                 cli_credentials_set_secure_channel_type(cred, secrets_tdb_secure_channel_type);
 367                 status = NT_STATUS_OK;
 368         } else if (!NT_STATUS_IS_OK(status)) {
 369                 if (db_ctx) {
 370                         error_string
 371                                 = talloc_asprintf(cred,
 372                                                   "Failed to fetch machine account password for %s from both "
 373                                                   "secrets.ldb (%s) and from %s",
 374                                                   domain,
 375                                                   error_string == NULL ? "error" : error_string,
 376                                                   dbwrap_name(db_ctx));
 377                 } else {
 378                         char *secrets_tdb_path;
 379
 380                         secrets_tdb_path = lpcfg_private_db_path(tmp_ctx,
 381                                                                  lp_ctx,
 382                                                                  "secrets");
 383                         if (secrets_tdb_path == NULL) {
 384                                 return NT_STATUS_NO_MEMORY;
 385                         }
 386
 387                         error_string = talloc_asprintf(cred,
 388                                                        "Failed to fetch machine account password from "
 389                                                        "secrets.ldb: %s and failed to open %s",
 390                                                        error_string == NULL ? "error" : error_string,
 391                                                        secrets_tdb_path);
 392                 }
 393                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 394                           error_string == NULL ? "error" : error_string,
 395                           nt_errstr(status)));
 396                 /* set anonymous as the fallback, if the machine account won't work */
 397                 cli_credentials_set_anonymous(cred);
 398         }
 399
 400         TALLOC_FREE(tmp_ctx);
 401         return status;
 402 }
 403
 404 /**
 405  * Fill in credentials for a particular principal, from the secrets database.
 406  *
 407  * @param cred Credentials structure to fill in
 408  * @retval NTSTATUS error detailing any failure
 409  */
 410 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 411                                               struct loadparm_context *lp_ctx,
 412                                               const char *serviceprincipal)
 413 {
 414         NTSTATUS status;
 415         char *filter;
 416         char *error_string = NULL;
 417         /* Bleh, nasty recursion issues: We are setting a machine
 418          * account here, so we don't want the 'pending' flag around
 419          * any more */
 420         cred->machine_account_pending = false;
 421         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 422                                  cli_credentials_get_realm(cred),
 423                                  cli_credentials_get_domain(cred),
 424                                  serviceprincipal);
 425         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 426                                              SECRETS_PRINCIPALS_DN, filter,
 427                                              0, NULL, &error_string);
 428         if (!NT_STATUS_IS_OK(status)) {
 429                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n",
 430                           serviceprincipal, nt_errstr(status),
 431                           error_string ? error_string : "<no error>"));
 432         }
 433         return status;
 434 }
 435
 436 /**
 437  * Ask that when required, the credentials system will be filled with
 438  * machine trust account, from the secrets database.
 439  *
 440  * @param cred Credentials structure to fill in
 441  * @note This function is used to call the above function after, rather
 442  *       than during, popt processing.
 443  *
 444  */
 445 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 446                                                  struct loadparm_context *lp_ctx)
 447 {
 448         cred->machine_account_pending = true;
 449         cred->machine_account_pending_lp_ctx = lp_ctx;
 450 }
 451
 452