diff options
Diffstat (limited to '')
-rw-r--r-- | source4/kdc/mit-kdb/kdb_samba_policies.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/source4/kdc/mit-kdb/kdb_samba_policies.c b/source4/kdc/mit-kdb/kdb_samba_policies.c new file mode 100644 index 0000000..56bd0dd --- /dev/null +++ b/source4/kdc/mit-kdb/kdb_samba_policies.c @@ -0,0 +1,397 @@ +/* + Unix SMB/CIFS implementation. + + Samba KDB plugin for MIT Kerberos + + Copyright (c) 2010 Simo Sorce <idra@samba.org>. + Copyright (c) 2014-2021 Andreas Schneider <asn@samba.org> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +#include "lib/replace/replace.h" +#include "lib/replace/system/kerberos.h" +#include "lib/util/data_blob.h" +#include "lib/util/debug.h" +#include "lib/util/fault.h" +#include "lib/util/memory.h" +#include "libcli/util/ntstatus.h" +#include "lib/krb5_wrap/krb5_samba.h" + +#include <profile.h> +#include <kdb.h> + +#include "kdc/mit_samba.h" +#include "kdb_samba.h" + +#undef DBGC_CLASS +#define DBGC_CLASS DBGC_KERBEROS + +/* FIXME: This is a krb5 function which is exported, but in no header */ +extern krb5_error_code decode_krb5_padata_sequence(const krb5_data *output, + krb5_pa_data ***rep); + +static krb5_error_code ks_get_netbios_name(krb5_address **addrs, char **name) +{ + char *nb_name = NULL; + int len, i; + + for (i = 0; addrs[i]; i++) { + if (addrs[i]->addrtype != ADDRTYPE_NETBIOS) { + continue; + } + len = MIN(addrs[i]->length, 15); + nb_name = strndup((const char *)addrs[i]->contents, len); + if (!nb_name) { + return ENOMEM; + } + break; + } + + if (nb_name) { + /* Strip space padding */ + i = strlen(nb_name) - 1; + for (i = strlen(nb_name) - 1; + i > 0 && nb_name[i] == ' '; + i--) { + nb_name[i] = '\0'; + } + } + + *name = nb_name; + + return 0; +} + +krb5_error_code kdb_samba_db_check_policy_as(krb5_context context, + krb5_kdc_req *kdcreq, + krb5_db_entry *client, + krb5_db_entry *server, + krb5_timestamp kdc_time, + const char **status, + krb5_pa_data ***e_data_out) +{ + struct mit_samba_context *mit_ctx; + krb5_error_code code; + char *client_name = NULL; + char *server_name = NULL; + char *netbios_name = NULL; + char *realm = NULL; + bool password_change = false; + krb5_const_principal client_princ; + DATA_BLOB int_data = { NULL, 0 }; + krb5_data d; + krb5_pa_data **e_data; + + mit_ctx = ks_get_context(context); + if (mit_ctx == NULL) { + return KRB5_KDB_DBNOTINITED; + } + + /* Prefer canonicalised name from client entry */ + client_princ = client ? client->princ : kdcreq->client; + + if (client_princ == NULL || ks_is_kadmin(context, client_princ)) { + return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN; + } + + if (krb5_princ_size(context, kdcreq->server) == 2 && + ks_is_kadmin_changepw(context, kdcreq->server)) { + code = krb5_get_default_realm(context, &realm); + if (code) { + goto done; + } + + if (ks_data_eq_string(kdcreq->server->realm, realm)) { + password_change = true; + } + } + + code = krb5_unparse_name(context, kdcreq->server, &server_name); + if (code) { + goto done; + } + + code = krb5_unparse_name(context, client_princ, &client_name); + if (code) { + goto done; + } + + if (kdcreq->addresses) { + code = ks_get_netbios_name(kdcreq->addresses, &netbios_name); + if (code) { + goto done; + } + } + + code = mit_samba_check_client_access(mit_ctx, + client, + client_name, + server, + server_name, + netbios_name, + password_change, + &int_data); + + if (int_data.length && int_data.data) { + + /* make sure the mapped return code is returned - gd */ + int code_tmp; + + d = smb_krb5_data_from_blob(int_data); + + code_tmp = decode_krb5_padata_sequence(&d, &e_data); + if (code_tmp == 0) { + *e_data_out = e_data; + } + } +done: + free(realm); + free(server_name); + free(client_name); + free(netbios_name); + + return code; +} + +static krb5_error_code ks_get_pac(krb5_context context, + uint32_t flags, + krb5_db_entry *client, + krb5_db_entry *server, + krb5_keyblock *client_key, + krb5_pac *pac) +{ + struct mit_samba_context *mit_ctx; + krb5_error_code code; + + mit_ctx = ks_get_context(context); + if (mit_ctx == NULL) { + return KRB5_KDB_DBNOTINITED; + } + + code = mit_samba_get_pac(mit_ctx, + context, + flags, + client, + server, + client_key, + pac); + if (code != 0) { + return code; + } + + return code; +} + +static krb5_error_code ks_update_pac(krb5_context context, + int flags, + krb5_db_entry *client, + krb5_db_entry *server, + krb5_db_entry *signing_krbtgt, + krb5_pac old_pac, + krb5_pac new_pac) +{ + struct mit_samba_context *mit_ctx = NULL; + krb5_error_code code; + + mit_ctx = ks_get_context(context); + if (mit_ctx == NULL) { + return KRB5_KDB_DBNOTINITED; + } + + code = mit_samba_update_pac(mit_ctx, + context, + flags, + client, + server, + signing_krbtgt, + old_pac, + new_pac); + if (code != 0) { + return code; + } + + return code; +} + +krb5_error_code kdb_samba_db_issue_pac(krb5_context context, + unsigned int flags, + krb5_db_entry *client, + krb5_keyblock *replaced_reply_key, + krb5_db_entry *server, + krb5_db_entry *signing_krbtgt, + krb5_timestamp authtime, + krb5_pac old_pac, + krb5_pac new_pac, + krb5_data ***auth_indicators) +{ + char *client_name = NULL; + char *server_name = NULL; + krb5_error_code code = EINVAL; + + /* The KDC handles both signing and verification for us. */ + + if (client != NULL) { + code = krb5_unparse_name(context, + client->princ, + &client_name); + if (code != 0) { + return code; + } + } + + if (server != NULL) { + code = krb5_unparse_name(context, + server->princ, + &server_name); + if (code != 0) { + SAFE_FREE(client_name); + return code; + } + } + + /* + * Get a new PAC for AS-REQ or S4U2Self for our realm. + * + * For a simple cross-realm S4U2Proxy there will be the following TGS + * requests after the client realm is identified: + * + * 1. server@SREALM to SREALM for krbtgt/CREALM@SREALM -- a regular TGS + * request with server's normal TGT and no S4U2Self padata. + * 2. server@SREALM to CREALM for server@SREALM (expressed as an + * enterprise principal), with the TGT from #1 as header ticket and + * S4U2Self padata identifying the client. + * 3. server@SREALM to SREALM for server@SREALM with S4U2Self padata, + * with the referral TGT from #2 as header ticket + * + * In request 2 the PROTOCOL_TRANSITION and CROSS_REALM flags are set, + * and the request is for a local client (so client != NULL) and we + * want to make a new PAC. + * + * In request 3 the PROTOCOL_TRANSITION and CROSS_REALM flags are also + * set, but the request is for a non-local client (so client == NULL) + * and we want to copy the subject PAC contained in the referral TGT. + */ + if (old_pac == NULL || + (client != NULL && (flags & KRB5_KDB_FLAG_PROTOCOL_TRANSITION))) { + DBG_NOTICE("Generate PAC for AS-REQ [client=%s, flags=%#08x]\n", + client_name != NULL ? client_name : "<unknown>", + flags); + + code = ks_get_pac(context, + flags, + client, + server, + replaced_reply_key, + &new_pac); + } else { + DBG_NOTICE("Update PAC for TGS-REQ [client=%s, server=%s, " + "flags=%#08x]\n", + client_name != NULL ? client_name : "<unknown>", + server_name != NULL ? server_name : "<unknown>", + flags); + + code = ks_update_pac(context, + flags, + client, + server, + signing_krbtgt, + old_pac, + new_pac); + } + SAFE_FREE(client_name); + SAFE_FREE(server_name); + + return code; +} + +krb5_error_code kdb_samba_db_check_allowed_to_delegate(krb5_context context, + krb5_const_principal client, + const krb5_db_entry *server, + krb5_const_principal proxy) +{ + struct mit_samba_context *mit_ctx = NULL; + + mit_ctx = ks_get_context(context); + if (mit_ctx == NULL) { + return KRB5_KDB_DBNOTINITED; + } + + return mit_samba_check_s4u2proxy(mit_ctx, + server, + proxy); + +} + + +krb5_error_code kdb_samba_db_allowed_to_delegate_from( + krb5_context context, + krb5_const_principal client_principal, + krb5_const_principal server_principal, + krb5_pac header_pac, + const krb5_db_entry *proxy) +{ + struct mit_samba_context *mit_ctx = NULL; + krb5_error_code code; + + mit_ctx = ks_get_context(context); + if (mit_ctx == NULL) { + return KRB5_KDB_DBNOTINITED; + } + + code = mit_samba_check_allowed_to_delegate_from(mit_ctx, + client_principal, + server_principal, + header_pac, + proxy); + + return code; +} + + +static void samba_bad_password_count(krb5_db_entry *client, + krb5_error_code error_code) +{ + switch (error_code) { + case 0: + mit_samba_zero_bad_password_count(client); + break; + case KRB5KDC_ERR_PREAUTH_FAILED: + case KRB5KRB_AP_ERR_BAD_INTEGRITY: + mit_samba_update_bad_password_count(client); + break; + } +} + +void kdb_samba_db_audit_as_req(krb5_context context, + krb5_kdc_req *request, + const krb5_address *local_addr, + const krb5_address *remote_addr, + krb5_db_entry *client, + krb5_db_entry *server, + krb5_timestamp authtime, + krb5_error_code error_code) +{ + /* + * FIXME: This segfaulted with a FAST test + * FIND_FAST: <unknown client> for <unknown server>, Unknown FAST armor type 0 + */ + if (client == NULL) { + return; + } + + samba_bad_password_count(client, error_code); + + /* TODO: perform proper audit logging for addresses */ +} |