/*

 * Copyright (c) 2002, 2021, 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

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package com.sun.crypto.provider;

import java.io.*;

import java.util.Arrays;

import sun.security.util.*;

import sun.security.util.HexDumpEncoder;

import java.security.spec.AlgorithmParameterSpec;

import java.security.spec.InvalidParameterSpecException;

import javax.crypto.spec.IvParameterSpec;

/**

 * This class implements the parameter (IV) used with Block Ciphers

 * in feedback-mode. IV is defined in the standards as follows:

 *

 * <pre>

 * IV ::= OCTET STRING  -- length depends on the block size of the

 * block ciphers

 * </pre>

 *

 * @author Valerie Peng

 *

 */

final class BlockCipherParamsCore {

    private int block_size = 0;

    private byte[] iv = null;

    private int[] moreSizes = null;

    BlockCipherParamsCore(int blksize, int... moreSizes) {

        block_size = blksize;

        this.moreSizes = moreSizes;

    }

    void init(AlgorithmParameterSpec paramSpec)

        throws InvalidParameterSpecException {

        if (!(paramSpec instanceof IvParameterSpec)) {

            throw new InvalidParameterSpecException

                ("Inappropriate parameter specification");

        }

        byte[] tmpIv = ((IvParameterSpec)paramSpec).getIV();

        boolean check = (tmpIv.length == block_size);

        if (!check && moreSizes != null) {

            for (int s : moreSizes) {

                if (tmpIv.length == s) {

                    check = true;

                    break;

                }

            }

        }

        if (!check) {

            String expectedLen = block_size + (moreSizes == null? "" :

                Arrays.toString(moreSizes));

            throw new InvalidParameterSpecException("IV length not " +

                        expectedLen + " bytes long");

        }

        iv = tmpIv.clone();

    }

    void init(byte[] encoded) throws IOException {

        DerInputStream der = new DerInputStream(encoded);

        byte[] tmpIv = der.getOctetString();

        if (der.available() != 0) {

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

        }

        boolean check = (tmpIv.length == block_size);

        if (!check) {

            String expectedLen = block_size + (moreSizes == null? "" :

                Arrays.toString(moreSizes));

            throw new IOException("IV not " + expectedLen +

                " bytes long");

        }

        iv = tmpIv;

    }

    void init(byte[] encoded, String decodingMethod) throws IOException {

        if ((decodingMethod != null) &&

            (!decodingMethod.equalsIgnoreCase("ASN.1"))) {

            throw new IllegalArgumentException("Only support ASN.1 format");

        }

        init(encoded);

    }

    <T extends AlgorithmParameterSpec> T getParameterSpec(Class<T> paramSpec)

        throws InvalidParameterSpecException {

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

            return paramSpec.cast(new IvParameterSpec(this.iv));

        } else {

            throw new InvalidParameterSpecException

                ("Inappropriate parameter specification");

        }

    }

    byte[] getEncoded() throws IOException {

        DerOutputStream out = new DerOutputStream();

        out.putOctetString(this.iv);

        return out.toByteArray();

    }

    byte[] getEncoded(String encodingMethod)

        throws IOException {

        return getEncoded();

    }

    /*

     * Returns a formatted string describing the parameters.

     */

    public String toString() {

        String LINE_SEP = System.lineSeparator();

        String ivString = LINE_SEP + "    iv:" + LINE_SEP + "[";

        HexDumpEncoder encoder = new HexDumpEncoder();

        ivString += encoder.encodeBuffer(this.iv);

        ivString += "]" + LINE_SEP;

        return ivString;

    }

}