/*

 * Copyright (c) 2005, 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

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 */

package sun.security.mscapi;

import java.math.BigInteger;

import java.security.KeyException;

import java.security.KeyRep;

import java.security.ProviderException;

import sun.security.rsa.RSAPublicKeyImpl;

/**

 * The handle for an RSA public key using the Microsoft Crypto API.

 *

 * @since 1.6

 */

class RSAPublicKey extends Key implements java.security.interfaces.RSAPublicKey

{

    private static final long serialVersionUID = -2289561342425825391L;

    private byte[] publicKeyBlob = null;

    private byte[] encoding = null;

    private BigInteger modulus = null;

    private BigInteger exponent = null;

    /**

     * Construct an RSAPublicKey object.

     */

    RSAPublicKey(long hCryptProv, long hCryptKey, int keyLength)

    {

        super(hCryptProv, hCryptKey, keyLength);

    }

    /**

     * Returns the standard algorithm name for this key. For

     * example, "RSA" would indicate that this key is a RSA key.

     * See Appendix A in the <a href=

     * "../../../guide/security/CryptoSpec.html#AppA">

     * Java Cryptography Architecture API Specification &amp; Reference </a>

     * for information about standard algorithm names.

     *

     * @return the name of the algorithm associated with this key.

     */

    public String getAlgorithm()

    {

        return "RSA";

    }

    /**

     * Returns a printable description of the key.

     */

    public String toString()

    {

        StringBuffer sb = new StringBuffer();

        sb.append("RSAPublicKey [size=").append(keyLength)

            .append(" bits, type=").append(getKeyType(hCryptKey))

            .append(", container=").append(getContainerName(hCryptProv))

            .append("]\n  modulus: ").append(getModulus())

            .append("\n  public exponent: ").append(getPublicExponent());

        return sb.toString();

    }

    /**

     * Returns the public exponent.

     */

    public BigInteger getPublicExponent() {

        if (exponent == null) {

            try {

                publicKeyBlob = getPublicKeyBlob(hCryptKey);

                exponent = new BigInteger(1, getExponent(publicKeyBlob));

            } catch (KeyException e) {

                throw new ProviderException(e);

            }

        }

        return exponent;

    }

    /**

     * Returns the modulus.

     */

    public BigInteger getModulus() {

        if (modulus == null) {

            try {

                publicKeyBlob = getPublicKeyBlob(hCryptKey);

                modulus = new BigInteger(1, getModulus(publicKeyBlob));

            } catch (KeyException e) {

                throw new ProviderException(e);

            }

        }

        return modulus;

    }

    /**

     * Returns the name of the primary encoding format of this key,

     * or null if this key does not support encoding.

     * The primary encoding format is

     * named in terms of the appropriate ASN.1 data format, if an

     * ASN.1 specification for this key exists.

     * For example, the name of the ASN.1 data format for public

     * keys is <I>SubjectPublicKeyInfo</I>, as

     * defined by the X.509 standard; in this case, the returned format is

     * <code>"X.509"</code>. Similarly,

     * the name of the ASN.1 data format for private keys is

     * <I>PrivateKeyInfo</I>,

     * as defined by the PKCS #8 standard; in this case, the returned format is

     * <code>"PKCS#8"</code>.

     *

     * @return the primary encoding format of the key.

     */

    public String getFormat()

    {

        return "X.509";

    }

    /**

     * Returns the key in its primary encoding format, or null

     * if this key does not support encoding.

     *

     * @return the encoded key, or null if the key does not support

     * encoding.

     */

    public byte[] getEncoded()

    {

        if (encoding == null) {

            try {

                encoding = new RSAPublicKeyImpl(getModulus(),

                    getPublicExponent()).getEncoded();

            } catch (KeyException e) {

                // ignore

            }

        }

        return encoding;

    }

    protected Object writeReplace() throws java.io.ObjectStreamException {

        return new KeyRep(KeyRep.Type.PUBLIC,

                        getAlgorithm(),

                        getFormat(),

                        getEncoded());

    }

    /*

     * Returns the Microsoft CryptoAPI representation of the key.

     */

    private native byte[] getPublicKeyBlob(long hCryptKey) throws KeyException;

    /*

     * Returns the key's public exponent (in big-endian 2's complement format).

     */

    private native byte[] getExponent(byte[] keyBlob) throws KeyException;

    /*

     * Returns the key's modulus (in big-endian 2's complement format).

     */

    private native byte[] getModulus(byte[] keyBlob) throws KeyException;

}