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
 174         domain = ldb_msg_find_attr_as_string(msg, "flatname", NULL);
 175         if (domain) {
 176                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 177         }
 178
 179         realm = ldb_msg_find_attr_as_string(msg, "realm", NULL);
 180         if (realm) {
 181                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 182         }
 183
 184         if (machine_account) {
 185                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 186         }
 187
 188         cli_credentials_set_kvno(cred, ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0));
 189
 190         /* If there was an external keytab specified by reference in
 191          * the LDB, then use this.  Otherwise we will make one up
 192          * (chewing CPU time) from the password */
 193         keytab = keytab_name_from_msg(cred, ldb, msg);
 194         if (keytab) {
 195                 cli_credentials_set_keytab_name(cred, lp_ctx, keytab, CRED_SPECIFIED);
 196                 talloc_free(keytab);
 197         }
 198         talloc_free(mem_ctx);
 199
 200         return NT_STATUS_OK;
 201 }
 202
 203
 204 /**
 205  * Fill in credentials for the machine trust account, from the secrets database.
 206  *
 207  * @param cred Credentials structure to fill in
 208  * @retval NTSTATUS error detailing any failure
 209  */
 210 _PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
 211                                               struct loadparm_context *lp_ctx,
 212                                               struct ldb_context *ldb,
 213                                               const char *base,
 214                                               const char *filter,
 215                                               char **error_string)
 216 {
 217         NTSTATUS status = cli_credentials_set_secrets_lct(cred, lp_ctx, ldb, base, filter, 0, NULL, error_string);
 218         if (!NT_STATUS_IS_OK(status)) {
 219                 /* set anonymous as the fallback, if the machine account won't work */
 220                 cli_credentials_set_anonymous(cred);
 221         }
 222         return status;
 223 }
 224
 225 /**
 226  * Fill in credentials for the machine trust account, from the secrets database.
 227  *
 228  * @param cred Credentials structure to fill in
 229  * @retval NTSTATUS error detailing any failure
 230  */
 231 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
 232                                                       struct loadparm_context *lp_ctx)
 233 {
 234         NTSTATUS status;
 235         char *filter;
 236         char *error_string;
 237         const char *domain;
 238         bool secrets_tdb_password_more_recent;
 239         time_t secrets_tdb_lct = 0;
 240         char *secrets_tdb_password = NULL;
 241         char *secrets_tdb_old_password = NULL;
 242         char *keystr;
 243         char *keystr_upper = NULL;
 244         char *secrets_tdb;
 245         struct db_context *db_ctx;
 246         TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
 247         if (!tmp_ctx) {
 248                 return NT_STATUS_NO_MEMORY;
 249         }
 250         secrets_tdb = lpcfg_private_db_path(cred, lp_ctx, "secrets");
 251         if (!secrets_tdb) {
 252                 TALLOC_FREE(tmp_ctx);
 253                 return NT_STATUS_NO_MEMORY;
 254         }
 255
 256         db_ctx = dbwrap_local_open(cred, lp_ctx, secrets_tdb, 0,
 257                                    TDB_DEFAULT, O_RDWR, 0600,
 258                                    DBWRAP_LOCK_ORDER_1,
 259                                    DBWRAP_FLAG_NONE);
 260         /* Bleh, nasty recursion issues: We are setting a machine
 261          * account here, so we don't want the 'pending' flag around
 262          * any more */
 263         cred->machine_account_pending = false;
 264
 265         /* We have to do this, as the fallback in
 266          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 267         domain = cli_credentials_get_domain(cred);
 268
 269         if (db_ctx) {
 270                 TDB_DATA dbuf;
 271                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 272                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 273                                          domain);
 274                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 275                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 276                                       &dbuf);
 277                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 278                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 279                 }
 280
 281                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 282                                          SECRETS_MACHINE_PASSWORD,
 283                                          domain);
 284                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 285                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 286                                       &dbuf);
 287                 if (NT_STATUS_IS_OK(status)) {
 288                         secrets_tdb_password = (char *)dbuf.dptr;
 289                 }
 290                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 291                                          SECRETS_MACHINE_PASSWORD_PREV,
 292                                          domain);
 293                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 294                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 295                                       &dbuf);
 296                 if (NT_STATUS_IS_OK(status)) {
 297                         secrets_tdb_old_password = (char *)dbuf.dptr;
 298                 }
 299         }
 300
 301         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 302                                  domain);
 303         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 304                                                  SECRETS_PRIMARY_DOMAIN_DN,
 305                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 306         if (secrets_tdb_password == NULL) {
 307                 secrets_tdb_password_more_recent = false;
 308         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 309             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 310                 secrets_tdb_password_more_recent = true;
 311         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 312                 secrets_tdb_password_more_recent = true;
 313         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 314                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 315         } else {
 316                 secrets_tdb_password_more_recent = false;
 317         }
 318
 319         if (secrets_tdb_password_more_recent) {
 320                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 321                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 322                 cli_credentials_set_old_password(cred, secrets_tdb_old_password, CRED_SPECIFIED);
 323                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 324                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 325         } else if (!NT_STATUS_IS_OK(status)) {
 326                 if (db_ctx) {
 327                         error_string = talloc_asprintf(cred,
 328                                                        "Failed to fetch machine account password from "
 329                                                        "secrets.ldb: %s and failed to fetch %s from %s",
 330                                                        error_string, keystr_upper, secrets_tdb);
 331                 } else {
 332                         error_string = talloc_asprintf(cred,
 333                                                        "Failed to fetch machine account password from "
 334                                                        "secrets.ldb: %s and failed to open %s",
 335                                                        error_string, secrets_tdb);
 336                 }
 337                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 338                           error_string, nt_errstr(status)));
 339                 /* set anonymous as the fallback, if the machine account won't work */
 340                 cli_credentials_set_anonymous(cred);
 341         }
 342
 343         TALLOC_FREE(tmp_ctx);
 344         return status;
 345 }
 346
 347 /**
 348  * Fill in credentials for a particular prinicpal, from the secrets database.
 349  *
 350  * @param cred Credentials structure to fill in
 351  * @retval NTSTATUS error detailing any failure
 352  */
 353 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 354                                               struct loadparm_context *lp_ctx,
 355                                               const char *serviceprincipal)
 356 {
 357         NTSTATUS status;
 358         char *filter;
 359         char *error_string;
 360         /* Bleh, nasty recursion issues: We are setting a machine
 361          * account here, so we don't want the 'pending' flag around
 362          * any more */
 363         cred->machine_account_pending = false;
 364         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 365                                  cli_credentials_get_realm(cred),
 366                                  cli_credentials_get_domain(cred),
 367                                  serviceprincipal);
 368         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 369                                              SECRETS_PRINCIPALS_DN, filter,
 370                                              0, NULL, &error_string);
 371         if (!NT_STATUS_IS_OK(status)) {
 372                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n", serviceprincipal, nt_errstr(status), error_string));
 373         }
 374         return status;
 375 }
 376
 377 /**
 378  * Ask that when required, the credentials system will be filled with
 379  * machine trust account, from the secrets database.
 380  *
 381  * @param cred Credentials structure to fill in
 382  * @note This function is used to call the above function after, rather
 383  *       than during, popt processing.
 384  *
 385  */
 386 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 387                                                  struct loadparm_context *lp_ctx)
 388 {
 389         cred->machine_account_pending = true;
 390         cred->machine_account_pending_lp_ctx = lp_ctx;
 391 }
 392
 393