/*

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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

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package com.sun.crypto.provider;

import java.math.*;

import java.io.*;

import sun.security.x509.AlgorithmId;

import sun.security.util.*;

/**

 * This class implements the <code>PrivateKeyInfo</code> type,

 * which is defined in PKCS #8 as follows:

 *

 * <pre>

 * PrivateKeyInfo ::=  SEQUENCE {

 *     version   INTEGER,

 *     privateKeyAlgorithm   AlgorithmIdentifier,

 *     privateKey   OCTET STRING,

 *     attributes   [0] IMPLICIT Attributes OPTIONAL }

 * </pre>

 *

 * @author Jan Luehe

 */

final class PrivateKeyInfo {

    // the version number defined by the PKCS #8 standard

    private static final BigInteger VERSION = BigInteger.ZERO;

    // the private-key algorithm

    private AlgorithmId algid;

    // the private-key value

    private byte[] privkey;

    /**

     * Constructs a PKCS#8 PrivateKeyInfo from its ASN.1 encoding.

     */

    PrivateKeyInfo(byte[] encoded) throws IOException {

        DerValue val = new DerValue(encoded);

        if (val.tag != DerValue.tag_Sequence)

            throw new IOException("private key parse error: not a sequence");

        // version

        BigInteger parsedVersion = val.data.getBigInteger();

        if (!parsedVersion.equals(VERSION)) {

            throw new IOException("version mismatch: (supported: " +

                                  VERSION + ", parsed: " + parsedVersion);

        }

        // privateKeyAlgorithm

        this.algid = AlgorithmId.parse(val.data.getDerValue());

        // privateKey

        this.privkey = val.data.getOctetString();

        // OPTIONAL attributes not supported yet

    }

    /**

     * Returns the private-key algorithm.

     */

    AlgorithmId getAlgorithm() {

        return this.algid;

    }

}