/*

 * Copyright (c) 1998, 2011, 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.

 */

package com.sun.crypto.provider;

import java.io.*;

import sun.security.x509.AlgorithmId;

import sun.security.util.*;

/**

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

 * which is defined in PKCS #8 as follows:

 *

 * <pre>

 * EncryptedPrivateKeyInfo ::=  SEQUENCE {

 *     encryptionAlgorithm   AlgorithmIdentifier,

 *     encryptedData   OCTET STRING }

 * </pre>

 *

 * @author Jan Luehe

 */

final class EncryptedPrivateKeyInfo {

    // the "encryptionAlgorithm" field

    private AlgorithmId algid;

    // the "encryptedData" field

    private byte[] encryptedData;

    // the ASN.1 encoded contents of this class

    private byte[] encoded;

    /**

     * Constructs (i.e., parses) an <code>EncryptedPrivateKeyInfo</code> from

     * its encoding.

     */

    EncryptedPrivateKeyInfo(byte[] encoded) throws IOException {

        DerValue val = new DerValue(encoded);

        DerValue[] seq = new DerValue[2];

        seq[0] = val.data.getDerValue();

        seq[1] = val.data.getDerValue();

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

            throw new IOException("overrun, bytes = " + val.data.available());

        }

        this.algid = AlgorithmId.parse(seq[0]);

        if (seq[0].data.available() != 0) {

            throw new IOException("encryptionAlgorithm field overrun");

        }

        this.encryptedData = seq[1].getOctetString();

        if (seq[1].data.available() != 0)

            throw new IOException("encryptedData field overrun");

        this.encoded = encoded.clone();

    }

    /**

     * Constructs an <code>EncryptedPrivateKeyInfo</code> from the

     * encryption algorithm and the encrypted data.

     */

    EncryptedPrivateKeyInfo(AlgorithmId algid, byte[] encryptedData) {

        this.algid = algid;

        this.encryptedData = encryptedData.clone();

        this.encoded = null; // lazy generation of encoding

    }

    /**

     * Returns the encryption algorithm.

     */

    AlgorithmId getAlgorithm() {

        return this.algid;

    }

    /**

     * Returns the encrypted data.

     */

    byte[] getEncryptedData() {

        return this.encryptedData.clone();

    }

    /**

     * Returns the ASN.1 encoding of this class.

     */

    byte[] getEncoded()

        throws IOException

    {

        if (this.encoded != null) return this.encoded.clone();

        DerOutputStream out = new DerOutputStream();

        DerOutputStream tmp = new DerOutputStream();

        // encode encryption algorithm

        algid.encode(tmp);

        // encode encrypted data

        tmp.putOctetString(encryptedData);

        // wrap everything into a SEQUENCE

        out.write(DerValue.tag_Sequence, tmp);

        this.encoded = out.toByteArray();

        return this.encoded.clone();

    }

}