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/*
* Unix SMB/CIFS implementation.
*
* Copyright (c) 2015 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 "includes.h"
#include "system/kerberos.h"
#include "source4/auth/kerberos/kerberos.h"
#include "auth/kerberos/pac_utils.h"
#include "librpc/gen_ndr/irpc.h"
#include "lib/messaging/irpc.h"
#include "source4/librpc/gen_ndr/ndr_irpc.h"
#include "source4/librpc/gen_ndr/irpc.h"
#include "librpc/gen_ndr/ndr_krb5pac.h"
#include "source4/smbd/process_model.h"
#include "lib/param/param.h"
#include "samba_kdc.h"
#include "db-glue.h"
#include "sdb.h"
#include "mit_kdc_irpc.h"
struct mit_kdc_irpc_context {
struct task_server *task;
krb5_context krb5_context;
struct samba_kdc_db_context *db_ctx;
};
static NTSTATUS netr_samlogon_generic_logon(struct irpc_message *msg,
struct kdc_check_generic_kerberos *r)
{
struct PAC_Validate pac_validate;
DATA_BLOB pac_chksum;
struct PAC_SIGNATURE_DATA pac_kdc_sig;
struct mit_kdc_irpc_context *mki_ctx =
talloc_get_type(msg->private_data,
struct mit_kdc_irpc_context);
enum ndr_err_code ndr_err;
int code;
krb5_principal principal;
struct sdb_entry_ex sentry = {};
struct sdb_keys skeys;
unsigned int i;
const uint8_t *d = NULL;
/* There is no reply to this request */
r->out.generic_reply = data_blob(NULL, 0);
ndr_err =
ndr_pull_struct_blob(&r->in.generic_request,
msg,
&pac_validate,
(ndr_pull_flags_fn_t)ndr_pull_PAC_Validate);
if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
return NT_STATUS_INVALID_PARAMETER;
}
if (pac_validate.MessageType != NETLOGON_GENERIC_KRB5_PAC_VALIDATE) {
/*
* We don't implement any other message types - such as
* certificate validation - yet
*/
return NT_STATUS_INVALID_PARAMETER;
}
if ((pac_validate.ChecksumAndSignature.length !=
(pac_validate.ChecksumLength + pac_validate.SignatureLength)) ||
(pac_validate.ChecksumAndSignature.length <
pac_validate.ChecksumLength) ||
(pac_validate.ChecksumAndSignature.length <
pac_validate.SignatureLength)) {
return NT_STATUS_INVALID_PARAMETER;
}
/* PAC Checksum */
pac_chksum = data_blob_const(pac_validate.ChecksumAndSignature.data,
pac_validate.ChecksumLength);
/* Create the krbtgt principal */
code = smb_krb5_make_principal(mki_ctx->krb5_context,
&principal,
lpcfg_realm(mki_ctx->task->lp_ctx),
"krbtgt",
lpcfg_realm(mki_ctx->task->lp_ctx),
NULL);
if (code != 0) {
DEBUG(0, ("Failed to create krbtgt@%s principal!\n",
lpcfg_realm(mki_ctx->task->lp_ctx)));
return NT_STATUS_NO_MEMORY;
}
/* Get the krbtgt from the DB */
code = samba_kdc_fetch(mki_ctx->krb5_context,
mki_ctx->db_ctx,
principal,
SDB_F_GET_KRBTGT | SDB_F_DECRYPT,
0,
&sentry);
krb5_free_principal(mki_ctx->krb5_context, principal);
if (code != 0) {
DEBUG(0, ("Failed to fetch krbtgt@%s principal entry!\n",
lpcfg_realm(mki_ctx->task->lp_ctx)));
return NT_STATUS_LOGON_FAILURE;
}
/* PAC Signature */
pac_kdc_sig.type = pac_validate.SignatureType;
d = &pac_validate.ChecksumAndSignature.data[pac_validate.ChecksumLength];
pac_kdc_sig.signature =
data_blob_const(d, pac_validate.SignatureLength);
/*
* Brute force variant because MIT KRB5 doesn't provide a function like
* krb5_checksum_to_enctype().
*/
skeys = sentry.entry.keys;
for (i = 0; i < skeys.len; i++) {
krb5_keyblock krbtgt_keyblock = skeys.val[i].key;
code = check_pac_checksum(pac_chksum,
&pac_kdc_sig,
mki_ctx->krb5_context,
&krbtgt_keyblock);
if (code == 0) {
break;
}
}
sdb_free_entry(&sentry);
if (code != 0) {
return NT_STATUS_LOGON_FAILURE;
}
return NT_STATUS_OK;
}
NTSTATUS samba_setup_mit_kdc_irpc(struct task_server *task)
{
struct samba_kdc_base_context base_ctx;
struct mit_kdc_irpc_context *mki_ctx;
NTSTATUS status;
int code;
mki_ctx = talloc_zero(task, struct mit_kdc_irpc_context);
if (mki_ctx == NULL) {
return NT_STATUS_NO_MEMORY;
}
mki_ctx->task = task;
base_ctx.ev_ctx = task->event_ctx;
base_ctx.lp_ctx = task->lp_ctx;
/* db-glue.h */
status = samba_kdc_setup_db_ctx(mki_ctx,
&base_ctx,
&mki_ctx->db_ctx);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
code = smb_krb5_init_context_basic(mki_ctx,
task->lp_ctx,
&mki_ctx->krb5_context);
if (code != 0) {
return NT_STATUS_INTERNAL_ERROR;
}
status = IRPC_REGISTER(task->msg_ctx,
irpc,
KDC_CHECK_GENERIC_KERBEROS,
netr_samlogon_generic_logon,
mki_ctx);
if (!NT_STATUS_IS_OK(status)) {
return status;
}
irpc_add_name(task->msg_ctx, "kdc_server");
return status;
}
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