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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 * 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,

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 *

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package com.sun.crypto.provider;

import java.io.IOException;

import java.security.AlgorithmParametersSpi;

import java.security.spec.AlgorithmParameterSpec;

import java.security.spec.InvalidParameterSpecException;

import javax.crypto.spec.RC2ParameterSpec;

import sun.misc.HexDumpEncoder;

import sun.security.util.*;

/**

 * This class implements the parameter set used with RC2

 * encryption, which is defined in RFC2268 as follows:

 *

 * <pre>

 * RC2-CBCParameter ::= CHOICE {

 *   iv IV,

 *   params SEQUENCE {

 *     version RC2Version,

 *     iv IV

 *   }

 * }

 *

 * where

 *

 * IV ::= OCTET STRING -- 8 octets

 * RC2Version ::= INTEGER -- 1-1024

 * </pre>

 *

 * @author Sean Mullan

 * @since 1.5

 */

public final class RC2Parameters extends AlgorithmParametersSpi {

    // TABLE[EKB] from section 6 of RFC 2268, used to convert effective key

    // size to/from encoded version number

    private final static int[] EKB_TABLE = new int[] {

        0xbd, 0x56, 0xea, 0xf2, 0xa2, 0xf1, 0xac, 0x2a,

        0xb0, 0x93, 0xd1, 0x9c, 0x1b, 0x33, 0xfd, 0xd0,

        0x30, 0x04, 0xb6, 0xdc, 0x7d, 0xdf, 0x32, 0x4b,

        0xf7, 0xcb, 0x45, 0x9b, 0x31, 0xbb, 0x21, 0x5a,

        0x41, 0x9f, 0xe1, 0xd9, 0x4a, 0x4d, 0x9e, 0xda,

        0xa0, 0x68, 0x2c, 0xc3, 0x27, 0x5f, 0x80, 0x36,

        0x3e, 0xee, 0xfb, 0x95, 0x1a, 0xfe, 0xce, 0xa8,

        0x34, 0xa9, 0x13, 0xf0, 0xa6, 0x3f, 0xd8, 0x0c,

        0x78, 0x24, 0xaf, 0x23, 0x52, 0xc1, 0x67, 0x17,

        0xf5, 0x66, 0x90, 0xe7, 0xe8, 0x07, 0xb8, 0x60,

        0x48, 0xe6, 0x1e, 0x53, 0xf3, 0x92, 0xa4, 0x72,

        0x8c, 0x08, 0x15, 0x6e, 0x86, 0x00, 0x84, 0xfa,

        0xf4, 0x7f, 0x8a, 0x42, 0x19, 0xf6, 0xdb, 0xcd,

        0x14, 0x8d, 0x50, 0x12, 0xba, 0x3c, 0x06, 0x4e,

        0xec, 0xb3, 0x35, 0x11, 0xa1, 0x88, 0x8e, 0x2b,

        0x94, 0x99, 0xb7, 0x71, 0x74, 0xd3, 0xe4, 0xbf,

        0x3a, 0xde, 0x96, 0x0e, 0xbc, 0x0a, 0xed, 0x77,

        0xfc, 0x37, 0x6b, 0x03, 0x79, 0x89, 0x62, 0xc6,

        0xd7, 0xc0, 0xd2, 0x7c, 0x6a, 0x8b, 0x22, 0xa3,

        0x5b, 0x05, 0x5d, 0x02, 0x75, 0xd5, 0x61, 0xe3,

        0x18, 0x8f, 0x55, 0x51, 0xad, 0x1f, 0x0b, 0x5e,

        0x85, 0xe5, 0xc2, 0x57, 0x63, 0xca, 0x3d, 0x6c,

        0xb4, 0xc5, 0xcc, 0x70, 0xb2, 0x91, 0x59, 0x0d,

        0x47, 0x20, 0xc8, 0x4f, 0x58, 0xe0, 0x01, 0xe2,

        0x16, 0x38, 0xc4, 0x6f, 0x3b, 0x0f, 0x65, 0x46,

        0xbe, 0x7e, 0x2d, 0x7b, 0x82, 0xf9, 0x40, 0xb5,

        0x1d, 0x73, 0xf8, 0xeb, 0x26, 0xc7, 0x87, 0x97,

        0x25, 0x54, 0xb1, 0x28, 0xaa, 0x98, 0x9d, 0xa5,

        0x64, 0x6d, 0x7a, 0xd4, 0x10, 0x81, 0x44, 0xef,

        0x49, 0xd6, 0xae, 0x2e, 0xdd, 0x76, 0x5c, 0x2f,

        0xa7, 0x1c, 0xc9, 0x09, 0x69, 0x9a, 0x83, 0xcf,

        0x29, 0x39, 0xb9, 0xe9, 0x4c, 0xff, 0x43, 0xab

    };

    // the iv

    private byte[] iv;

    // the version number

    private int version = 0;

    // the effective key size

    private int effectiveKeySize = 0;

    public RC2Parameters() {}

    protected void engineInit(AlgorithmParameterSpec paramSpec)

        throws InvalidParameterSpecException {

        if (!(paramSpec instanceof RC2ParameterSpec)) {

            throw new InvalidParameterSpecException

                ("Inappropriate parameter specification");

        }

        RC2ParameterSpec rps = (RC2ParameterSpec) paramSpec;

        // check effective key size (a value of 0 means it is unspecified)

        effectiveKeySize = rps.getEffectiveKeyBits();

        if (effectiveKeySize != 0) {

            if (effectiveKeySize < 1 || effectiveKeySize > 1024) {

                throw new InvalidParameterSpecException("RC2 effective key " +

                    "size must be between 1 and 1024 bits");

            }

            if (effectiveKeySize < 256) {

                version = EKB_TABLE[effectiveKeySize];

            } else {

                version = effectiveKeySize;

            }

        }

        this.iv = rps.getIV();

    }

    protected void engineInit(byte[] encoded) throws IOException {

        DerValue val = new DerValue(encoded);

        // check if IV or params

        if (val.tag == DerValue.tag_Sequence) {

            val.data.reset();

            version = val.data.getInteger();

            if (version < 0 || version > 1024) {

                throw new IOException("RC2 parameter parsing error: " +

                    "version number out of legal range (0-1024): " + version);

            }

            if (version > 255) {

                effectiveKeySize = version;

            } else {

                // search table for index containing version

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

                    if (version == EKB_TABLE[i]) {

                        effectiveKeySize = i;

                        break;

                    }

                }

            }

            iv = val.data.getOctetString();

        } else {

            val.data.reset();

            iv = val.getOctetString();

            version = 0;

            effectiveKeySize = 0;

        }

        if (iv.length != 8) {

            throw new IOException("RC2 parameter parsing error: iv length " +

                "must be 8 bits, actual: " + iv.length);

        }

        if (val.data.available() != 0) {

            throw new IOException("RC2 parameter parsing error: extra data");

        }

    }

    protected void engineInit(byte[] encoded, String decodingMethod)

        throws IOException {

        engineInit(encoded);

    }

    protected <T extends AlgorithmParameterSpec>

            T engineGetParameterSpec(Class<T> paramSpec)

        throws InvalidParameterSpecException {

        if (RC2ParameterSpec.class.isAssignableFrom(paramSpec)) {

            return paramSpec.cast((iv == null ?

                                   new RC2ParameterSpec(effectiveKeySize) :

                                   new RC2ParameterSpec(effectiveKeySize, iv)));

        } else {

            throw new InvalidParameterSpecException

                ("Inappropriate parameter specification");

        }

    }

    protected byte[] engineGetEncoded() throws IOException {

        DerOutputStream out = new DerOutputStream();

        DerOutputStream bytes = new DerOutputStream();

        if (this.effectiveKeySize != 0) {

            bytes.putInteger(version);

            bytes.putOctetString(iv);

            out.write(DerValue.tag_Sequence, bytes);

        } else {

            out.putOctetString(iv);

        }

        return out.toByteArray();

    }

    protected byte[] engineGetEncoded(String encodingMethod)

        throws IOException {

        return engineGetEncoded();

    }

    /*

     * Returns a formatted string describing the parameters.

     */

    protected String engineToString() {

        String LINE_SEP = System.getProperty("line.separator");

        HexDumpEncoder encoder = new HexDumpEncoder();

        StringBuilder sb

            = new StringBuilder(LINE_SEP + "    iv:" + LINE_SEP + "["

                + encoder.encodeBuffer(iv) + "]");

        if (version != 0) {

            sb.append(LINE_SEP + "version:" + LINE_SEP

                + version + LINE_SEP);

        }

        return sb.toString();

    }

}