/*

 * Copyright (c) 2000, 2012, 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.crypto;

import sun.security.krb5.Config;

import sun.security.krb5.Checksum;

import sun.security.krb5.EncryptedData;

import sun.security.krb5.KrbException;

import sun.security.krb5.KrbCryptoException;

import sun.security.krb5.internal.*;

public abstract class CksumType {

    private static boolean DEBUG = Krb5.DEBUG;

    public static CksumType getInstance(int cksumTypeConst)

        throws KdcErrException {

        CksumType cksumType = null;

        String cksumTypeName = null;

        switch (cksumTypeConst) {

        case Checksum.CKSUMTYPE_CRC32:

            cksumType = new Crc32CksumType();

            cksumTypeName = "sun.security.krb5.internal.crypto.Crc32CksumType";

            break;

        case Checksum.CKSUMTYPE_DES_MAC:

            cksumType = new DesMacCksumType();

            cksumTypeName = "sun.security.krb5.internal.crypto.DesMacCksumType";

            break;

        case Checksum.CKSUMTYPE_DES_MAC_K:

            cksumType = new DesMacKCksumType();

            cksumTypeName =

                "sun.security.krb5.internal.crypto.DesMacKCksumType";

            break;

        case Checksum.CKSUMTYPE_RSA_MD5:

            cksumType = new RsaMd5CksumType();

            cksumTypeName = "sun.security.krb5.internal.crypto.RsaMd5CksumType";

            break;

        case Checksum.CKSUMTYPE_RSA_MD5_DES:

            cksumType = new RsaMd5DesCksumType();

            cksumTypeName =

                "sun.security.krb5.internal.crypto.RsaMd5DesCksumType";

            break;

        case Checksum.CKSUMTYPE_HMAC_SHA1_DES3_KD:

            cksumType = new HmacSha1Des3KdCksumType();

            cksumTypeName =

                "sun.security.krb5.internal.crypto.HmacSha1Des3KdCksumType";

            break;

        case Checksum.CKSUMTYPE_HMAC_SHA1_96_AES128:

            cksumType = new HmacSha1Aes128CksumType();

            cksumTypeName =

                "sun.security.krb5.internal.crypto.HmacSha1Aes128CksumType";

            break;

        case Checksum.CKSUMTYPE_HMAC_SHA1_96_AES256:

            cksumType = new HmacSha1Aes256CksumType();

            cksumTypeName =

                "sun.security.krb5.internal.crypto.HmacSha1Aes256CksumType";

            break;

        case Checksum.CKSUMTYPE_HMAC_MD5_ARCFOUR:

            cksumType = new HmacMd5ArcFourCksumType();

            cksumTypeName =

                "sun.security.krb5.internal.crypto.HmacMd5ArcFourCksumType";

            break;

            // currently we don't support MD4.

        case Checksum.CKSUMTYPE_RSA_MD4_DES_K:

            // cksumType = new RsaMd4DesKCksumType();

            // cksumTypeName =

            //          "sun.security.krb5.internal.crypto.RsaMd4DesKCksumType";

        case Checksum.CKSUMTYPE_RSA_MD4:

            // cksumType = new RsaMd4CksumType();

            // linux box support rsamd4, how to solve conflict?

            // cksumTypeName =

            //          "sun.security.krb5.internal.crypto.RsaMd4CksumType";

        case Checksum.CKSUMTYPE_RSA_MD4_DES:

            // cksumType = new RsaMd4DesCksumType();

            // cksumTypeName =

            //          "sun.security.krb5.internal.crypto.RsaMd4DesCksumType";

        default:

            throw new KdcErrException(Krb5.KDC_ERR_SUMTYPE_NOSUPP);

        }

        if (DEBUG) {

            System.out.println(">>> CksumType: " + cksumTypeName);

        }

        return cksumType;

    }

    /**

     * Returns default checksum type.

     */

    public static CksumType getInstance() throws KdcErrException {

        // this method provided for Kerberos applications.

        int cksumType = Checksum.CKSUMTYPE_RSA_MD5; // default

        try {

            Config c = Config.getInstance();

            if ((cksumType = (Config.getType(c.get("libdefaults",

                    "ap_req_checksum_type")))) == - 1) {

                if ((cksumType = Config.getType(c.get("libdefaults",

                        "checksum_type"))) == -1) {

                    cksumType = Checksum.CKSUMTYPE_RSA_MD5; // default

                }

            }

        } catch (KrbException e) {

        }

        return getInstance(cksumType);

    }

    public abstract int confounderSize();

    public abstract int cksumType();

    public abstract boolean isSafe();

    public abstract int cksumSize();

    public abstract int keyType();

    public abstract int keySize();

    public abstract byte[] calculateChecksum(byte[] data, int size)

        throws KrbCryptoException;

    public abstract byte[] calculateKeyedChecksum(byte[] data, int size,

        byte[] key, int usage) throws KrbCryptoException;

    public abstract boolean verifyKeyedChecksum(byte[] data, int size,

        byte[] key, byte[] checksum, int usage) throws KrbCryptoException;

    public static boolean isChecksumEqual(byte[] cksum1, byte[] cksum2) {

        if (cksum1 == cksum2)

            return true;

        if ((cksum1 == null && cksum2 != null) ||

            (cksum1 != null && cksum2 == null))

            return false;

        if (cksum1.length != cksum2.length)

            return false;

        for (int i = 0; i < cksum1.length; i++)

            if (cksum1[i] != cksum2[i])

                return false;

        return true;

    }

}