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	/*
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code 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
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/*
	*
	* (C) Copyright IBM Corp. 1999 All Rights Reserved.
	* Copyright 1997 The Open Group Research Institute. All rights reserved.
	*/

	package sun.security.krb5;

	import sun.security.krb5.internal.*;
	import sun.security.krb5.internal.crypto.KeyUsage;
	import sun.security.util.DerInputStream;

	abstract class KrbKdcRep {

	static void check(
	boolean isAsReq,
	KDCReq req,
	KDCRep rep,
	EncryptionKey replyKey
	) throws KrbApErrException {

	// cname change in AS-REP is allowed only if the client
	// sent CANONICALIZE or an NT-ENTERPRISE cname in the request, and the
	// server supports RFC 6806 - Section 11 FAST scheme (ENC-PA-REP flag).
	if (isAsReq && !req.reqBody.cname.equals(rep.cname) &&
	((!req.reqBody.kdcOptions.get(KDCOptions.CANONICALIZE) &&
	req.reqBody.cname.getNameType() !=
	PrincipalName.KRB_NT_ENTERPRISE) \|\|
	!rep.encKDCRepPart.flags.get(Krb5.TKT_OPTS_ENC_PA_REP))) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}

	// sname change in TGS-REP is allowed only if client
	// sent CANONICALIZE and new sname is a referral of
	// the form krbtgt/TO-REALM.COM@FROM-REALM.COM.
	if (!req.reqBody.sname.equals(rep.encKDCRepPart.sname)) {
	String[] snameStrings = rep.encKDCRepPart.sname.getNameStrings();
	if (isAsReq \|\| !req.reqBody.kdcOptions.get(KDCOptions.CANONICALIZE) \|\|
	snameStrings == null \|\| snameStrings.length != 2 \|\|
	!snameStrings[0].equals(PrincipalName.TGS_DEFAULT_SRV_NAME) \|\|
	!rep.encKDCRepPart.sname.getRealmString().equals(
	req.reqBody.sname.getRealmString())) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}
	}

	if (req.reqBody.getNonce() != rep.encKDCRepPart.nonce) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}

	if (
	((req.reqBody.addresses != null && rep.encKDCRepPart.caddr != null) &&
	!req.reqBody.addresses.equals(rep.encKDCRepPart.caddr))) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}

	// We allow KDC to return a non-forwardable ticket if request has -f
	for (int i = 2; i < 6; i++) {
	if (req.reqBody.kdcOptions.get(i) !=
	rep.encKDCRepPart.flags.get(i)) {
	if (Krb5.DEBUG) {
	System.out.println("> KrbKdcRep.check: at #" + i
	+ ". request for " + req.reqBody.kdcOptions.get(i)
	+ ", received " + rep.encKDCRepPart.flags.get(i));
	}
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}
	}

	// Reply to a renewable request should be renewable, but if request does
	// not contain renewable, KDC is free to issue a renewable ticket (for
	// example, if ticket_lifetime is too big).
	if (req.reqBody.kdcOptions.get(KDCOptions.RENEWABLE) &&
	!rep.encKDCRepPart.flags.get(KDCOptions.RENEWABLE)) {
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}

	if ((req.reqBody.from == null) \|\| req.reqBody.from.isZero()) {
	// verify this is allowed
	if ((rep.encKDCRepPart.starttime != null) &&
	!rep.encKDCRepPart.starttime.inClockSkew()) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_SKEW);
	}
	}

	if ((req.reqBody.from != null) && !req.reqBody.from.isZero()) {
	// verify this is allowed
	if ((rep.encKDCRepPart.starttime != null) &&
	!req.reqBody.from.equals(rep.encKDCRepPart.starttime)) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}
	}

	if (!req.reqBody.till.isZero() &&
	rep.encKDCRepPart.endtime.greaterThan(req.reqBody.till)) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}

	// RFC 6806 - Section 11 mechanism check
	// The availability of the ENC-PA-REP flag in the KDC response is
	// mandatory on some cases (see Krb5.TKT_OPTS_ENC_PA_REP check above).
	if (rep.encKDCRepPart.flags.get(Krb5.TKT_OPTS_ENC_PA_REP)) {
	boolean reqPaReqEncPaRep = false;
	boolean repPaReqEncPaRepValid = false;

	if (req.pAData != null) {
	for (PAData pa : req.pAData) {
	if (pa.getType() == Krb5.PA_REQ_ENC_PA_REP) {
	// The KDC supports RFC 6806 and ENC-PA-REP was sent in
	// the request (AS-REQ). A valid checksum is now required.
	reqPaReqEncPaRep = true;
	break;
	}
	}
	}

	if (rep.encKDCRepPart.pAData != null) {
	for (PAData pa : rep.encKDCRepPart.pAData) {
	if (pa.getType() == Krb5.PA_REQ_ENC_PA_REP) {
	try {
	Checksum repCksum = new Checksum(
	new DerInputStream(
	pa.getValue()).getDerValue());
	// The checksum is inside encKDCRepPart so we don't
	// care if it's keyed or not.
	repPaReqEncPaRepValid =
	repCksum.verifyAnyChecksum(
	req.asn1Encode(), replyKey,
	KeyUsage.KU_AS_REQ);
	} catch (Exception e) {
	if (Krb5.DEBUG) {
	e.printStackTrace();
	}
	}
	break;
	}
	}
	}

	if (reqPaReqEncPaRep && !repPaReqEncPaRepValid) {
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}
	}

	if (req.reqBody.kdcOptions.get(KDCOptions.RENEWABLE)) {
	if (req.reqBody.rtime != null && !req.reqBody.rtime.isZero()) {
	// verify this is required
	if ((rep.encKDCRepPart.renewTill == null) \|\|
	rep.encKDCRepPart.renewTill.greaterThan(req.reqBody.rtime)
	) {
	rep.encKDCRepPart.key.destroy();
	throw new KrbApErrException(Krb5.KRB_AP_ERR_MODIFIED);
	}

	}
	}
	}
	}

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