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_proto.h"
  32 #include "auth/credentials/credentials_krb5.h"
  33 #include "auth/kerberos/kerberos_util.h"
  34 #include "param/param.h"
  35 #include "lib/events/events.h"
  36 #include "dsdb/samdb/samdb.h"
  37 #include "source3/include/secrets.h"
  38 #include "dbwrap/dbwrap.h"
  39 #include "dbwrap/dbwrap_open.h"
  40 #include "lib/util/util_tdb.h"
  41
  42
  43 /**
  44  * Fill in credentials for the machine trust account, from the secrets database.
  45  *
  46  * @param cred Credentials structure to fill in
  47  * @retval NTSTATUS error detailing any failure
  48  */
  49 _PUBLIC_ NTSTATUS cli_credentials_set_secrets(struct cli_credentials *cred,
  50                                               struct loadparm_context *lp_ctx,
  51                                               struct ldb_context *ldb,
  52                                               const char *base,
  53                                               const char *filter,
  54                                               char **error_string)
  55 {
  56         TALLOC_CTX *mem_ctx;
  57
  58         int ldb_ret;
  59         struct ldb_message *msg;
  60
  61         const char *machine_account;
  62         const char *password;
  63         const char *domain;
  64         const char *realm;
  65         enum netr_SchannelType sct;
  66         const char *salt_principal;
  67         char *keytab;
  68         const struct ldb_val *whenChanged;
  69
  70         /* ok, we are going to get it now, don't recurse back here */
  71         cred->machine_account_pending = false;
  72
  73         /* some other parts of the system will key off this */
  74         cred->machine_account = true;
  75
  76         mem_ctx = talloc_named(cred, 0, "cli_credentials fetch machine password");
  77
  78         if (!ldb) {
  79                 /* Local secrets are stored in secrets.ldb */
  80                 ldb = secrets_db_connect(mem_ctx, lp_ctx);
  81                 if (!ldb) {
  82                         /* set anonymous as the fallback, if the machine account won't work */
  83                         cli_credentials_set_anonymous(cred);
  84                         *error_string = talloc_strdup(cred, "Could not open secrets.ldb");
  85                         talloc_free(mem_ctx);
  86                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
  87                 }
  88         }
  89
  90         ldb_ret = dsdb_search_one(ldb, mem_ctx, &msg,
  91                                   ldb_dn_new(mem_ctx, ldb, base),
  92                                   LDB_SCOPE_SUBTREE,
  93                                   NULL, 0, "%s", filter);
  94
  95         if (ldb_ret != LDB_SUCCESS) {
  96                 *error_string = talloc_asprintf(cred, "Could not find entry to match filter: '%s' base: '%s': %s: %s",
  97                                                 filter, base ? base : "",
  98                                                 ldb_strerror(ldb_ret), ldb_errstring(ldb));
  99                 /* set anonymous as the fallback, if the machine account won't work */
 100                 cli_credentials_set_anonymous(cred);
 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         machine_account = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);
 108
 109         if (!machine_account) {
 110                 machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);
 111
 112                 if (!machine_account) {
 113                         const char *ldap_bind_dn = ldb_msg_find_attr_as_string(msg, "ldapBindDn", NULL);
 114                         if (!ldap_bind_dn) {
 115                                 *error_string = talloc_asprintf(cred,
 116                                                                 "Could not find 'samAccountName', "
 117                                                                 "'servicePrincipalName' or "
 118                                                                 "'ldapBindDn' in secrets record: %s",
 119                                                                 ldb_dn_get_linearized(msg->dn));
 120                                 /* set anonymous as the fallback, if the machine account won't work */
 121                                 cli_credentials_set_anonymous(cred);
 122                                 talloc_free(mem_ctx);
 123                                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 124                         } else {
 125                                 /* store bind dn in credentials */
 126                                 cli_credentials_set_bind_dn(cred, ldap_bind_dn);
 127                         }
 128                 }
 129         }
 130
 131         salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
 132         cli_credentials_set_salt_principal(cred, salt_principal);
 133
 134         sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
 135         if (sct) {
 136                 cli_credentials_set_secure_channel_type(cred, sct);
 137         }
 138
 139         if (!password) {
 140                 const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
 141                 struct samr_Password hash;
 142                 ZERO_STRUCT(hash);
 143                 if (nt_password_hash) {
 144                         memcpy(hash.hash, nt_password_hash->data,
 145                                MIN(nt_password_hash->length, sizeof(hash.hash)));
 146
 147                         cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
 148                 } else {
 149                         cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
 150                 }
 151         } else {
 152                 cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 153         }
 154
 155
 156         domain = ldb_msg_find_attr_as_string(msg, "flatname", NULL);
 157         if (domain) {
 158                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 159         }
 160
 161         realm = ldb_msg_find_attr_as_string(msg, "realm", NULL);
 162         if (realm) {
 163                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 164         }
 165
 166         if (machine_account) {
 167                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 168         }
 169
 170         cli_credentials_set_kvno(cred, ldb_msg_find_attr_as_int(msg, "msDS-KeyVersionNumber", 0));
 171
 172         whenChanged = ldb_msg_find_ldb_val(msg, "whenChanged");
 173         if (whenChanged) {
 174                 time_t lct;
 175                 if (ldb_val_to_time(whenChanged, &lct) == LDB_SUCCESS) {
 176                         cli_credentials_set_password_last_changed_time(cred, lct);
 177                 }
 178         }
 179
 180         /* If there was an external keytab specified by reference in
 181          * the LDB, then use this.  Otherwise we will make one up
 182          * (chewing CPU time) from the password */
 183         keytab = keytab_name_from_msg(cred, ldb, msg);
 184         if (keytab) {
 185                 cli_credentials_set_keytab_name(cred, lp_ctx, keytab, CRED_SPECIFIED);
 186                 talloc_free(keytab);
 187         }
 188         talloc_free(mem_ctx);
 189
 190         return NT_STATUS_OK;
 191 }
 192
 193 /**
 194  * Fill in credentials for the machine trust account, from the secrets database.
 195  *
 196  * @param cred Credentials structure to fill in
 197  * @retval NTSTATUS error detailing any failure
 198  */
 199 _PUBLIC_ NTSTATUS cli_credentials_set_machine_account(struct cli_credentials *cred,
 200                                                       struct loadparm_context *lp_ctx)
 201 {
 202         NTSTATUS status;
 203         char *filter;
 204         char *error_string;
 205         const char *domain;
 206         const char *realm;
 207         bool secrets_tdb_password_more_recent;
 208         time_t secrets_tdb_lct = 0;
 209         char *secrets_tdb_password = NULL;
 210         char *keystr;
 211         char *keystr_upper = NULL;
 212         char *secrets_tdb = lpcfg_private_path(cred, lp_ctx, "secrets.tdb");
 213         struct db_context *db_ctx = dbwrap_local_open(cred, lp_ctx, secrets_tdb, 0,
 214                                                       TDB_DEFAULT, O_RDWR, 0600,
 215                                                       DBWRAP_LOCK_ORDER_1);
 216         /* Bleh, nasty recursion issues: We are setting a machine
 217          * account here, so we don't want the 'pending' flag around
 218          * any more */
 219         cred->machine_account_pending = false;
 220
 221         /* We have to do this, as the fallback in
 222          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 223         domain = cli_credentials_get_domain(cred);
 224         realm = cli_credentials_get_realm(cred);
 225
 226         if (db_ctx) {
 227                 TDB_DATA dbuf;
 228                 keystr = talloc_asprintf(cred, "%s/%s",
 229                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 230                                          domain);
 231                 keystr_upper = strupper_talloc(cred, keystr);
 232                 TALLOC_FREE(keystr);
 233                 status = dbwrap_fetch(db_ctx, cred, string_tdb_data(keystr_upper),
 234                                       &dbuf);
 235                 TALLOC_FREE(keystr_upper);
 236                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 237                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 238                         TALLOC_FREE(dbuf.dptr);
 239                 }
 240
 241                 keystr = talloc_asprintf(cred, "%s/%s",
 242                                          SECRETS_MACHINE_PASSWORD,
 243                                          domain);
 244                 keystr_upper = strupper_talloc(cred, keystr);
 245                 TALLOC_FREE(keystr);
 246                 status = dbwrap_fetch(db_ctx, cred, string_tdb_data(keystr_upper),
 247                                       &dbuf);
 248                 if (NT_STATUS_IS_OK(status)) {
 249                         secrets_tdb_password = (char *)dbuf.dptr;
 250                 }
 251         }
 252
 253         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 254                                  domain);
 255         status = cli_credentials_set_secrets(cred, lp_ctx, NULL,
 256                                              SECRETS_PRIMARY_DOMAIN_DN,
 257                                              filter, &error_string);
 258         if (secrets_tdb_password == NULL) {
 259                 secrets_tdb_password_more_recent = false;
 260         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 261             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 262                 secrets_tdb_password_more_recent = true;
 263         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 264                 secrets_tdb_password_more_recent = true;
 265         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 266                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 267         } else {
 268                 secrets_tdb_password_more_recent = false;
 269         }
 270
 271         if (secrets_tdb_password_more_recent) {
 272                 char *machine_account = talloc_asprintf(cred, "%s$", lpcfg_netbios_name(lp_ctx));
 273                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 274                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 275                 cli_credentials_set_realm(cred, realm, CRED_SPECIFIED);
 276                 cli_credentials_set_workstation(cred, lpcfg_netbios_name(lp_ctx), CRED_SPECIFIED);
 277                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 278                 TALLOC_FREE(machine_account);
 279         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 280                    || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 281                 if (db_ctx) {
 282                         error_string = talloc_asprintf(cred,
 283                                                        "Failed to fetch machine account password from "
 284                                                        "secrets.ldb: %s and failed to fetch %s from %s",
 285                                                        error_string, keystr_upper, secrets_tdb);
 286                 } else {
 287                         error_string = talloc_asprintf(cred,
 288                                                        "Failed to fetch machine account password from "
 289                                                        "secrets.ldb: %s and failed to open %s",
 290                                                        error_string, secrets_tdb);
 291                 }
 292         }
 293
 294         TALLOC_FREE(secrets_tdb_password);
 295         TALLOC_FREE(secrets_tdb);
 296         TALLOC_FREE(db_ctx);
 297         if (!NT_STATUS_IS_OK(status)) {
 298                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 299                           error_string, nt_errstr(status)));
 300                 talloc_free(error_string);
 301         }
 302         return status;
 303 }
 304
 305 /**
 306  * Fill in credentials for the machine trust account, from the secrets database.
 307  *
 308  * @param cred Credentials structure to fill in
 309  * @retval NTSTATUS error detailing any failure
 310  */
 311 NTSTATUS cli_credentials_set_krbtgt(struct cli_credentials *cred,
 312                                     struct loadparm_context *lp_ctx)
 313 {
 314         NTSTATUS status;
 315         char *filter;
 316         char *error_string;
 317         /* Bleh, nasty recursion issues: We are setting a machine
 318          * account here, so we don't want the 'pending' flag around
 319          * any more */
 320         cred->machine_account_pending = false;
 321         filter = talloc_asprintf(cred, SECRETS_KRBTGT_SEARCH,
 322                                        cli_credentials_get_realm(cred),
 323                                        cli_credentials_get_domain(cred));
 324         status = cli_credentials_set_secrets(cred, lp_ctx, NULL,
 325                                              SECRETS_PRINCIPALS_DN,
 326                                              filter, &error_string);
 327         if (!NT_STATUS_IS_OK(status)) {
 328                 DEBUG(1, ("Could not find krbtgt (master Kerberos) account in secrets database: %s: %s\n", nt_errstr(status), error_string));
 329                 talloc_free(error_string);
 330         }
 331         return status;
 332 }
 333
 334 /**
 335  * Fill in credentials for a particular prinicpal, from the secrets database.
 336  *
 337  * @param cred Credentials structure to fill in
 338  * @retval NTSTATUS error detailing any failure
 339  */
 340 _PUBLIC_ NTSTATUS cli_credentials_set_stored_principal(struct cli_credentials *cred,
 341                                               struct loadparm_context *lp_ctx,
 342                                               const char *serviceprincipal)
 343 {
 344         NTSTATUS status;
 345         char *filter;
 346         char *error_string;
 347         /* Bleh, nasty recursion issues: We are setting a machine
 348          * account here, so we don't want the 'pending' flag around
 349          * any more */
 350         cred->machine_account_pending = false;
 351         filter = talloc_asprintf(cred, SECRETS_PRINCIPAL_SEARCH,
 352                                  cli_credentials_get_realm(cred),
 353                                  cli_credentials_get_domain(cred),
 354                                  serviceprincipal);
 355         status = cli_credentials_set_secrets(cred, lp_ctx, NULL,
 356                                              SECRETS_PRINCIPALS_DN, filter,
 357                                              &error_string);
 358         if (!NT_STATUS_IS_OK(status)) {
 359                 DEBUG(1, ("Could not find %s principal in secrets database: %s: %s\n", serviceprincipal, nt_errstr(status), error_string));
 360         }
 361         return status;
 362 }
 363
 364 /**
 365  * Ask that when required, the credentials system will be filled with
 366  * machine trust account, from the secrets database.
 367  *
 368  * @param cred Credentials structure to fill in
 369  * @note This function is used to call the above function after, rather
 370  *       than during, popt processing.
 371  *
 372  */
 373 _PUBLIC_ void cli_credentials_set_machine_account_pending(struct cli_credentials *cred,
 374                                                  struct loadparm_context *lp_ctx)
 375 {
 376         cred->machine_account_pending = true;
 377         cred->machine_account_pending_lp_ctx = lp_ctx;
 378 }
 379
 380