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 static NTSTATUS cli_credentials_set_secrets_lct(struct cli_credentials *cred,
  50                                                 struct loadparm_context *lp_ctx,
  51                                                 struct ldb_context *ldb,
  52                                                 const char *base,
  53                                                 const char *filter,
  54                                                 time_t secrets_tdb_last_change_time,
  55                                                 const char *secrets_tdb_password,
  56                                                 char **error_string)
  57 {
  58         TALLOC_CTX *mem_ctx;
  59
  60         int ldb_ret;
  61         struct ldb_message *msg;
  62
  63         const char *machine_account;
  64         const char *password;
  65         const char *domain;
  66         const char *realm;
  67         enum netr_SchannelType sct;
  68         const char *salt_principal;
  69         char *keytab;
  70         const struct ldb_val *whenChanged;
  71         time_t lct;
  72
  73         /* ok, we are going to get it now, don't recurse back here */
  74         cred->machine_account_pending = false;
  75
  76         /* some other parts of the system will key off this */
  77         cred->machine_account = true;
  78
  79         mem_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
  80
  81         if (!ldb) {
  82                 /* Local secrets are stored in secrets.ldb */
  83                 ldb = secrets_db_connect(mem_ctx, lp_ctx);
  84                 if (!ldb) {
  85                         *error_string = talloc_strdup(cred, "Could not open secrets.ldb");
  86                         talloc_free(mem_ctx);
  87                         return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
  88                 }
  89         }
  90
  91         ldb_ret = dsdb_search_one(ldb, mem_ctx, &msg,
  92                                   ldb_dn_new(mem_ctx, ldb, base),
  93                                   LDB_SCOPE_SUBTREE,
  94                                   NULL, 0, "%s", filter);
  95
  96         if (ldb_ret != LDB_SUCCESS) {
  97                 *error_string = talloc_asprintf(cred, "Could not find entry to match filter: '%s' base: '%s': %s: %s",
  98                                                 filter, base ? base : "",
  99                                                 ldb_strerror(ldb_ret), ldb_errstring(ldb));
 100                 talloc_free(mem_ctx);
 101                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 102         }
 103
 104         password = ldb_msg_find_attr_as_string(msg, "secret", NULL);
 105
 106         whenChanged = ldb_msg_find_ldb_val(msg, "whenChanged");
 107         if (!whenChanged || ldb_val_to_time(whenChanged, &lct) != LDB_SUCCESS) {
 108                 /* This attribute is mandetory */
 109                 talloc_free(mem_ctx);
 110                 return NT_STATUS_NOT_FOUND;
 111         }
 112
 113         /* Don't set secrets.ldb info if the secrets.tdb entry was more recent */
 114         if (lct < secrets_tdb_last_change_time) {
 115                 talloc_free(mem_ctx);
 116                 return NT_STATUS_NOT_FOUND;
 117         }
 118
 119         if (lct == secrets_tdb_last_change_time && secrets_tdb_password && strcmp(password, secrets_tdb_password) != 0) {
 120                 talloc_free(mem_ctx);
 121                 return NT_STATUS_NOT_FOUND;
 122         }
 123
 124         cli_credentials_set_password_last_changed_time(cred, lct);
 125
 126         machine_account = ldb_msg_find_attr_as_string(msg, "samAccountName", NULL);
 127
 128         if (!machine_account) {
 129                 machine_account = ldb_msg_find_attr_as_string(msg, "servicePrincipalName", NULL);
 130
 131                 if (!machine_account) {
 132                         const char *ldap_bind_dn = ldb_msg_find_attr_as_string(msg, "ldapBindDn", NULL);
 133                         if (!ldap_bind_dn) {
 134                                 *error_string = talloc_asprintf(cred,
 135                                                                 "Could not find 'samAccountName', "
 136                                                                 "'servicePrincipalName' or "
 137                                                                 "'ldapBindDn' in secrets record: %s",
 138                                                                 ldb_dn_get_linearized(msg->dn));
 139                                 talloc_free(mem_ctx);
 140                                 return NT_STATUS_CANT_ACCESS_DOMAIN_INFO;
 141                         } else {
 142                                 /* store bind dn in credentials */
 143                                 cli_credentials_set_bind_dn(cred, ldap_bind_dn);
 144                         }
 145                 }
 146         }
 147
 148         salt_principal = ldb_msg_find_attr_as_string(msg, "saltPrincipal", NULL);
 149         cli_credentials_set_salt_principal(cred, salt_principal);
 150
 151         sct = ldb_msg_find_attr_as_int(msg, "secureChannelType", 0);
 152         if (sct) {
 153                 cli_credentials_set_secure_channel_type(cred, sct);
 154         }
 155
 156         if (!password) {
 157                 const struct ldb_val *nt_password_hash = ldb_msg_find_ldb_val(msg, "unicodePwd");
 158                 struct samr_Password hash;
 159                 ZERO_STRUCT(hash);
 160                 if (nt_password_hash) {
 161                         memcpy(hash.hash, nt_password_hash->data,
 162                                MIN(nt_password_hash->length, sizeof(hash.hash)));
 163
 164                         cli_credentials_set_nt_hash(cred, &hash, CRED_SPECIFIED);
 165                 } else {
 166                         cli_credentials_set_password(cred, NULL, CRED_SPECIFIED);
 167                 }
 168         } else {
 169                 cli_credentials_set_password(cred, password, CRED_SPECIFIED);
 170         }
 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         NTSTATUS status;
 234         char *filter;
 235         char *error_string;
 236         const char *domain;
 237         bool secrets_tdb_password_more_recent;
 238         time_t secrets_tdb_lct = 0;
 239         char *secrets_tdb_password = NULL;
 240         char *keystr;
 241         char *keystr_upper = NULL;
 242         char *secrets_tdb;
 243         struct db_context *db_ctx;
 244         TALLOC_CTX *tmp_ctx = talloc_named(cred, 0, "cli_credentials_set_secrets from ldb");
 245         if (!tmp_ctx) {
 246                 return NT_STATUS_NO_MEMORY;
 247         }
 248         secrets_tdb = lpcfg_private_db_path(cred, lp_ctx, "secrets");
 249         if (!secrets_tdb) {
 250                 TALLOC_FREE(tmp_ctx);
 251                 return NT_STATUS_NO_MEMORY;
 252         }
 253
 254         db_ctx = dbwrap_local_open(cred, lp_ctx, secrets_tdb, 0,
 255                                    TDB_DEFAULT, O_RDWR, 0600,
 256                                    DBWRAP_LOCK_ORDER_1);
 257         /* Bleh, nasty recursion issues: We are setting a machine
 258          * account here, so we don't want the 'pending' flag around
 259          * any more */
 260         cred->machine_account_pending = false;
 261
 262         /* We have to do this, as the fallback in
 263          * cli_credentials_set_secrets is to run as anonymous, so the domain is wiped */
 264         domain = cli_credentials_get_domain(cred);
 265
 266         if (db_ctx) {
 267                 TDB_DATA dbuf;
 268                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 269                                          SECRETS_MACHINE_LAST_CHANGE_TIME,
 270                                          domain);
 271                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 272                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 273                                       &dbuf);
 274                 if (NT_STATUS_IS_OK(status) && dbuf.dsize == 4) {
 275                         secrets_tdb_lct = IVAL(dbuf.dptr,0);
 276                 }
 277
 278                 keystr = talloc_asprintf(tmp_ctx, "%s/%s",
 279                                          SECRETS_MACHINE_PASSWORD,
 280                                          domain);
 281                 keystr_upper = strupper_talloc(tmp_ctx, keystr);
 282                 status = dbwrap_fetch(db_ctx, tmp_ctx, string_tdb_data(keystr_upper),
 283                                       &dbuf);
 284                 if (NT_STATUS_IS_OK(status)) {
 285                         secrets_tdb_password = (char *)dbuf.dptr;
 286                 }
 287         }
 288
 289         filter = talloc_asprintf(cred, SECRETS_PRIMARY_DOMAIN_FILTER,
 290                                  domain);
 291         status = cli_credentials_set_secrets_lct(cred, lp_ctx, NULL,
 292                                                  SECRETS_PRIMARY_DOMAIN_DN,
 293                                                  filter, secrets_tdb_lct, secrets_tdb_password, &error_string);
 294         if (secrets_tdb_password == NULL) {
 295                 secrets_tdb_password_more_recent = false;
 296         } else if (NT_STATUS_EQUAL(NT_STATUS_CANT_ACCESS_DOMAIN_INFO, status)
 297             || NT_STATUS_EQUAL(NT_STATUS_NOT_FOUND, status)) {
 298                 secrets_tdb_password_more_recent = true;
 299         } else if (secrets_tdb_lct > cli_credentials_get_password_last_changed_time(cred)) {
 300                 secrets_tdb_password_more_recent = true;
 301         } else if (secrets_tdb_lct == cli_credentials_get_password_last_changed_time(cred)) {
 302                 secrets_tdb_password_more_recent = strcmp(secrets_tdb_password, cli_credentials_get_password(cred)) != 0;
 303         } else {
 304                 secrets_tdb_password_more_recent = false;
 305         }
 306
 307         if (secrets_tdb_password_more_recent) {
 308                 char *machine_account = talloc_asprintf(tmp_ctx, "%s$", lpcfg_netbios_name(lp_ctx));
 309                 cli_credentials_set_password(cred, secrets_tdb_password, CRED_SPECIFIED);
 310                 cli_credentials_set_domain(cred, domain, CRED_SPECIFIED);
 311                 cli_credentials_set_username(cred, machine_account, CRED_SPECIFIED);
 312         } else if (!NT_STATUS_IS_OK(status)) {
 313                 if (db_ctx) {
 314                         error_string = talloc_asprintf(cred,
 315                                                        "Failed to fetch machine account password from "
 316                                                        "secrets.ldb: %s and failed to fetch %s from %s",
 317                                                        error_string, keystr_upper, secrets_tdb);
 318                 } else {
 319                         error_string = talloc_asprintf(cred,
 320                                                        "Failed to fetch machine account password from "
 321                                                        "secrets.ldb: %s and failed to open %s",
 322                                                        error_string, secrets_tdb);
 323                 }
 324                 DEBUG(1, ("Could not find machine account in secrets database: %s: %s\n",
 325                           error_string, nt_errstr(status)));
 326                 /* set anonymous as the fallback, if the machine account won't work */
 327                 cli_credentials_set_anonymous(cred);
 328         }
 329
 330         TALLOC_FREE(tmp_ctx);
 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_lct(cred, lp_ctx, NULL,
 356                                              SECRETS_PRINCIPALS_DN, filter,
 357                                              0, NULL, &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