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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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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/**
 * 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.
/**
     * Construct an RSAPublicKey object.
     */
    RSAPublicKey(long hCryptProv, long hCryptKey, int keyLength)
    {
        super(new NativeHandles(hCryptProv, hCryptKey), keyLength);
    }

    
Construct an RSAPublicKey object.
/**
     * Construct an RSAPublicKey object.
     */
    RSAPublicKey(NativeHandles handles, int keyLength)
    {
        super(handles, 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 
Java Cryptography Architecture API Specification & Reference 
for information about standard algorithm names.
Returns:
the name of the algorithm associated with this key./**
     * 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.
/**
     * 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(handles.hCryptKey))
            .append(", container=").append(getContainerName(handles.hCryptProv))
            .append("]\n  modulus: ").append(getModulus())
            .append("\n  public exponent: ").append(getPublicExponent());

        return sb.toString();
    }

    
Returns the public exponent.
/**
     * Returns the public exponent.
     */
    public BigInteger getPublicExponent() {

        if (exponent == null) {

            try {
                publicKeyBlob = getPublicKeyBlob(handles.hCryptKey);
                exponent = new BigInteger(1, getExponent(publicKeyBlob));

            } catch (KeyException e) {
                throw new ProviderException(e);
            }
        }

        return exponent;
    }

    
Returns the modulus.
/**
     * Returns the modulus.
     */
    public BigInteger getModulus() {

        if (modulus == null) {

            try {
                publicKeyBlob = getPublicKeyBlob(handles.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 SubjectPublicKeyInfo, as
defined by the X.509 standard; in this case, the returned format is
"X.509". Similarly,
the name of the ASN.1 data format for private keys is
PrivateKeyInfo,
as defined by the PKCS #8 standard; in this case, the returned format is
"PKCS#8".
Returns:
the primary encoding format of the key./**
     * 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.
Returns:
the encoded key, or null if the key does not support
encoding./**
     * 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;
}