/*

 * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

 * 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.internal;

import java.io.ObjectOutputStream;

import sun.security.krb5.PrincipalName;

import sun.security.krb5.Checksum;

import sun.security.krb5.Asn1Exception;

import sun.security.krb5.Realm;

import sun.security.krb5.RealmException;

import sun.security.util.*;

import java.io.IOException;

import java.io.ObjectInputStream;

import java.math.BigInteger;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.List;

import sun.security.krb5.internal.util.KerberosString;

/**

 * Implements the ASN.1 KRBError type.

 *

 * <pre>{@code

 * KRB-ERROR       ::= [APPLICATION 30] SEQUENCE {

 *         pvno            [0] INTEGER (5),

 *         msg-type        [1] INTEGER (30),

 *         ctime           [2] KerberosTime OPTIONAL,

 *         cusec           [3] Microseconds OPTIONAL,

 *         stime           [4] KerberosTime,

 *         susec           [5] Microseconds,

 *         error-code      [6] Int32,

 *         crealm          [7] Realm OPTIONAL,

 *         cname           [8] PrincipalName OPTIONAL,

 *         realm           [9] Realm -- service realm --,

 *         sname           [10] PrincipalName -- service name --,

 *         e-text          [11] KerberosString OPTIONAL,

 *         e-data          [12] OCTET STRING OPTIONAL

 * }

 *

 * METHOD-DATA     ::= SEQUENCE OF PA-DATA

 *

 * TYPED-DATA      ::= SEQUENCE SIZE (1..MAX) OF SEQUENCE {

 *         data-type       [0] Int32,

 *         data-value      [1] OCTET STRING OPTIONAL

 * }

 * }</pre>

 *

 * <p>

 * This definition reflects the Network Working Group RFC 4120

 * specification available at

 * <a href="http://www.ietf.org/rfc/rfc4120.txt">

 * http://www.ietf.org/rfc/rfc4120.txt</a>.

 */

public class KRBError implements java.io.Serializable {

    static final long serialVersionUID = 3643809337475284503L;

    private int pvno;

    private int msgType;

    private KerberosTime cTime; //optional

    private Integer cuSec; //optional

    private KerberosTime sTime;

    private Integer suSec;

    private int errorCode;

    private Realm crealm; //optional

    private PrincipalName cname; //optional

    private PrincipalName sname;

    private String eText; //optional

    private byte[] eData; //optional

    private Checksum eCksum; //optional

    private PAData[] pa;    // PA-DATA in eData

    private static boolean DEBUG = Krb5.DEBUG;

    private void readObject(ObjectInputStream is)

            throws IOException, ClassNotFoundException {

        try {

            init(new DerValue((byte[])is.readObject()));

            parseEData(eData);

        } catch (Exception e) {

            throw new IOException(e);

        }

    }

    private void writeObject(ObjectOutputStream os)

            throws IOException {

        try {

            os.writeObject(asn1Encode());

        } catch (Exception e) {

            throw new IOException(e);

        }

    }

    public KRBError(

                    APOptions new_apOptions,

                    KerberosTime new_cTime,

                    Integer new_cuSec,

                    KerberosTime new_sTime,

                    Integer new_suSec,

                    int new_errorCode,

                    PrincipalName new_cname,

                    PrincipalName new_sname,

                    String new_eText,

                    byte[] new_eData

                        ) throws IOException, Asn1Exception {

        pvno = Krb5.PVNO;

        msgType = Krb5.KRB_ERROR;

        cTime = new_cTime;

        cuSec = new_cuSec;

        sTime = new_sTime;

        suSec = new_suSec;

        errorCode = new_errorCode;

        cname = new_cname;

        sname = new_sname;

        eText = new_eText;

        eData = new_eData;

        parseEData(eData);

    }

    public KRBError(

                    APOptions new_apOptions,

                    KerberosTime new_cTime,

                    Integer new_cuSec,

                    KerberosTime new_sTime,

                    Integer new_suSec,

                    int new_errorCode,

                    PrincipalName new_cname,

                    PrincipalName new_sname,

                    String new_eText,

                    byte[] new_eData,

                    Checksum new_eCksum

                        ) throws IOException, Asn1Exception {

        pvno = Krb5.PVNO;

        msgType = Krb5.KRB_ERROR;

        cTime = new_cTime;

        cuSec = new_cuSec;

        sTime = new_sTime;

        suSec = new_suSec;

        errorCode = new_errorCode;

        cname = new_cname;

        sname = new_sname;

        eText = new_eText;

        eData = new_eData;

        eCksum = new_eCksum;

        parseEData(eData);

    }

    public KRBError(byte[] data) throws Asn1Exception,

            RealmException, KrbApErrException, IOException {

        init(new DerValue(data));

        parseEData(eData);

    }

    public KRBError(DerValue encoding) throws Asn1Exception,

            RealmException, KrbApErrException, IOException {

        init(encoding);

        showDebug();

        parseEData(eData);

    }

    /*

     * Attention:

     *

     * According to RFC 4120, e-data field in a KRB-ERROR message is

     * a METHOD-DATA when errorCode is KDC_ERR_PREAUTH_REQUIRED,

     * and application-specific otherwise (The RFC suggests using

     * TYPED-DATA).

     *

     * Hence, the ideal procedure to parse e-data should look like:

     *

     * if (errorCode is KDC_ERR_PREAUTH_REQUIRED) {

     *    parse as METHOD-DATA

     * } else {

     *    try parsing as TYPED-DATA

     * }

     *

     * Unfortunately, we know that some implementations also use the

     * METHOD-DATA format for errorcode KDC_ERR_PREAUTH_FAILED, and

     * do not use the TYPED-DATA for other errorcodes (say,

     * KDC_ERR_CLIENT_REVOKED).

     */

    // parse the edata field

    private void parseEData(byte[] data) throws IOException {

        if (data == null) {

            return;

        }

        // We need to parse eData as METHOD-DATA for both errorcodes.

        if (errorCode == Krb5.KDC_ERR_PREAUTH_REQUIRED

                || errorCode == Krb5.KDC_ERR_PREAUTH_FAILED) {

            try {

                // RFC 4120 does not guarantee that eData is METHOD-DATA when

                // errorCode is KDC_ERR_PREAUTH_FAILED. Therefore, the parse

                // may fail.

                parsePAData(data);

            } catch (Exception e) {

                if (DEBUG) {

                    System.out.println("Unable to parse eData field of KRB-ERROR:\n" +

                            new sun.security.util.HexDumpEncoder().encodeBuffer(data));

                }

                IOException ioe = new IOException(

                        "Unable to parse eData field of KRB-ERROR");

                ioe.initCause(e);

                throw ioe;

            }

        } else {

            if (DEBUG) {

                System.out.println("Unknown eData field of KRB-ERROR:\n" +

                        new sun.security.util.HexDumpEncoder().encodeBuffer(data));

            }

        }

    }

    /**

     * Try parsing the data as a sequence of PA-DATA.

     * @param data the data block

     */

    private void parsePAData(byte[] data)

            throws IOException, Asn1Exception {

        DerValue derPA = new DerValue(data);

        List<PAData> paList = new ArrayList<>();

        while (derPA.data.available() > 0) {

            // read the PA-DATA

            DerValue tmp = derPA.data.getDerValue();

            PAData pa_data = new PAData(tmp);

            paList.add(pa_data);

            if (DEBUG) {

                System.out.println(pa_data);

            }

        }

        pa = paList.toArray(new PAData[paList.size()]);

    }

    public final Realm getClientRealm() {

        return crealm;

    }

    public final KerberosTime getServerTime() {

        return sTime;

    }

    public final KerberosTime getClientTime() {

        return cTime;

    }

    public final Integer getServerMicroSeconds() {

        return suSec;

    }

    public final Integer getClientMicroSeconds() {

        return cuSec;

    }

    public final int getErrorCode() {

        return errorCode;

    }

    // access pre-auth info

    public final PAData[] getPA() {

        return pa;

    }

    public final String getErrorString() {

        return eText;

    }

    /**

     * Initializes a KRBError object.

     * @param encoding a DER-encoded data.

     * @exception Asn1Exception if an error occurs while decoding an ASN1 encoded data.

     * @exception IOException if an I/O error occurs while reading encoded data.

     * @exception KrbApErrException if the value read from the DER-encoded data

     *  stream does not match the pre-defined value.

     * @exception RealmException if an error occurs while parsing a Realm object.

     */

    private void init(DerValue encoding) throws Asn1Exception,

            RealmException, KrbApErrException, IOException {

        DerValue der, subDer;

        if (((encoding.getTag() & (byte)0x1F) != (byte)0x1E)

                || (encoding.isApplication() != true)

                || (encoding.isConstructed() != true)) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        der = encoding.getData().getDerValue();

        if (der.getTag() != DerValue.tag_Sequence) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        subDer = der.getData().getDerValue();

        if ((subDer.getTag() & (byte)0x1F) == (byte)0x00) {

            pvno = subDer.getData().getBigInteger().intValue();

            if (pvno != Krb5.PVNO)

                throw new KrbApErrException(Krb5.KRB_AP_ERR_BADVERSION);

        } else {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        subDer = der.getData().getDerValue();

        if ((subDer.getTag() & (byte)0x1F) == (byte)0x01) {

            msgType = subDer.getData().getBigInteger().intValue();

            if (msgType != Krb5.KRB_ERROR) {

                throw new KrbApErrException(Krb5.KRB_AP_ERR_MSG_TYPE);

            }

        } else {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        cTime = KerberosTime.parse(der.getData(), (byte)0x02, true);

        if ((der.getData().peekByte() & 0x1F) == 0x03) {

            subDer = der.getData().getDerValue();

            cuSec = subDer.getData().getBigInteger().intValue();

        }

        else cuSec = null;

        sTime = KerberosTime.parse(der.getData(), (byte)0x04, false);

        subDer = der.getData().getDerValue();

        if ((subDer.getTag() & (byte)0x1F) == (byte)0x05) {

            suSec = subDer.getData().getBigInteger().intValue();

        }

        else  throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        subDer = der.getData().getDerValue();

        if ((subDer.getTag() & (byte)0x1F) == (byte)0x06) {

            errorCode = subDer.getData().getBigInteger().intValue();

        }

        else  throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        crealm = Realm.parse(der.getData(), (byte)0x07, true);

        cname = PrincipalName.parse(der.getData(), (byte)0x08, true, crealm);

        Realm realm = Realm.parse(der.getData(), (byte)0x09, false);

        sname = PrincipalName.parse(der.getData(), (byte)0x0A, false, realm);

        eText = null;

        eData = null;

        eCksum = null;

        if (der.getData().available() >0) {

            if ((der.getData().peekByte() & 0x1F) == 0x0B) {

                subDer = der.getData().getDerValue();

                eText = new KerberosString(subDer.getData().getDerValue())

                        .toString();

            }

        }

        if (der.getData().available() >0) {

            if ((der.getData().peekByte() & 0x1F) == 0x0C) {

                subDer = der.getData().getDerValue();

                eData = subDer.getData().getOctetString();

            }

        }

        if (der.getData().available() >0) {

            eCksum = Checksum.parse(der.getData(), (byte)0x0D, true);

        }

        if (der.getData().available() >0)

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

    }

    /**

     * For debug use only

     */

    private void showDebug() {

        if (DEBUG) {

            System.out.println(">>>KRBError:");

            if (cTime != null)

                System.out.println("\t cTime is " + cTime.toDate().toString() + " " + cTime.toDate().getTime());

            if (cuSec != null) {

                System.out.println("\t cuSec is " + cuSec.intValue());

            }

            System.out.println("\t sTime is " + sTime.toDate().toString

                               () + " " + sTime.toDate().getTime());

            System.out.println("\t suSec is " + suSec);

            System.out.println("\t error code is " + errorCode);

            System.out.println("\t error Message is " + Krb5.getErrorMessage(errorCode));

            if (crealm != null) {

                System.out.println("\t crealm is " + crealm.toString());

            }

            if (cname != null) {

                System.out.println("\t cname is " + cname.toString());

            }

            if (sname != null) {

                System.out.println("\t sname is " + sname.toString());

            }

            if (eData != null) {

                System.out.println("\t eData provided.");

            }

            if (eCksum != null) {

                System.out.println("\t checksum provided.");

            }

            System.out.println("\t msgType is " + msgType);

        }

    }

    /**

     * Encodes an KRBError object.

     * @return the byte array of encoded KRBError object.

     * @exception Asn1Exception if an error occurs while decoding an ASN1 encoded data.

     * @exception IOException if an I/O error occurs while reading encoded data.

     */

    public byte[] asn1Encode() throws Asn1Exception, IOException {

        DerOutputStream temp = new DerOutputStream();

        DerOutputStream bytes = new DerOutputStream();

        temp.putInteger(BigInteger.valueOf(pvno));

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x00), temp);

        temp = new DerOutputStream();

        temp.putInteger(BigInteger.valueOf(msgType));

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x01), temp);

        if (cTime != null) {

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x02), cTime.asn1Encode());

        }

        if (cuSec != null) {

            temp = new DerOutputStream();

            temp.putInteger(BigInteger.valueOf(cuSec.intValue()));

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x03), temp);

        }

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x04), sTime.asn1Encode());

        temp = new DerOutputStream();

        temp.putInteger(BigInteger.valueOf(suSec.intValue()));

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x05), temp);

        temp = new DerOutputStream();

        temp.putInteger(BigInteger.valueOf(errorCode));

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x06), temp);

        if (crealm != null) {

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x07), crealm.asn1Encode());

        }

        if (cname != null) {

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x08), cname.asn1Encode());

        }

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x09), sname.getRealm().asn1Encode());

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x0A), sname.asn1Encode());

        if (eText != null) {

            temp = new DerOutputStream();

            temp.putDerValue(new KerberosString(eText).toDerValue());

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x0B), temp);

        }

        if (eData != null) {

            temp = new DerOutputStream();

            temp.putOctetString(eData);

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x0C), temp);

        }

        if (eCksum != null) {

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte)0x0D), eCksum.asn1Encode());

        }

        temp = new DerOutputStream();

        temp.write(DerValue.tag_Sequence, bytes);

        bytes = new DerOutputStream();

        bytes.write(DerValue.createTag(DerValue.TAG_APPLICATION, true, (byte)0x1E), temp);

        return bytes.toByteArray();

    }

    @Override public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        }

        if (!(obj instanceof KRBError)) {

            return false;

        }

        KRBError other = (KRBError)obj;

        return  pvno == other.pvno &&

                msgType == other.msgType &&

                isEqual(cTime, other.cTime) &&

                isEqual(cuSec, other.cuSec) &&

                isEqual(sTime, other.sTime) &&

                isEqual(suSec, other.suSec) &&

                errorCode == other.errorCode &&

                isEqual(crealm, other.crealm) &&

                isEqual(cname, other.cname) &&

                isEqual(sname, other.sname) &&

                isEqual(eText, other.eText) &&

                java.util.Arrays.equals(eData, other.eData) &&

                isEqual(eCksum, other.eCksum);

    }

    private static boolean isEqual(Object a, Object b) {

        return (a == null)?(b == null):(a.equals(b));

    }

    @Override public int hashCode() {

        int result = 17;

        result = 37 * result + pvno;

        result = 37 * result + msgType;

        if (cTime != null) result = 37 * result + cTime.hashCode();

        if (cuSec != null) result = 37 * result + cuSec.hashCode();

        if (sTime != null) result = 37 * result + sTime.hashCode();

        if (suSec != null) result = 37 * result + suSec.hashCode();