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	/*
	* Copyright (c) 1996, 2013, 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 sun.security.x509;

	import java.io.*;
	import java.util.Arrays;
	import java.util.Properties;
	import java.security.Key;
	import java.security.PublicKey;
	import java.security.KeyFactory;
	import java.security.Security;
	import java.security.Provider;
	import java.security.InvalidKeyException;
	import java.security.NoSuchAlgorithmException;
	import java.security.spec.InvalidKeySpecException;
	import java.security.spec.X509EncodedKeySpec;

	import sun.security.util.HexDumpEncoder;
	import sun.security.util.*;

	/**
	* Holds an X.509 key, for example a public key found in an X.509
	* certificate. Includes a description of the algorithm to be used
	* with the key; these keys normally are used as
	* "SubjectPublicKeyInfo".
	*
	* <P>While this class can represent any kind of X.509 key, it may be
	* desirable to provide subclasses which understand how to parse keying
	* data. For example, RSA public keys have two members, one for the
	* public modulus and one for the prime exponent. If such a class is
	* provided, it is used when parsing X.509 keys. If one is not provided,
	* the key still parses correctly.
	*
	* @author David Brownell
	*/
	public class X509Key implements PublicKey {

	/** use serialVersionUID from JDK 1.1. for interoperability */
	private static final long serialVersionUID = -5359250853002055002L;

	/* The algorithm information (name, parameters, etc). */
	protected AlgorithmId algid;

	/**
	* The key bytes, without the algorithm information.
	* @deprecated Use the BitArray form which does not require keys to
	* be byte aligned.
	* @see sun.security.x509.X509Key#setKey(BitArray)
	* @see sun.security.x509.X509Key#getKey()
	*/
	@Deprecated
	protected byte[] key = null;

	/*
	* The number of bits unused in the last byte of the key.
	* Added to keep the byte[] key form consistent with the BitArray
	* form. Can de deleted when byte[] key is deleted.
	*/
	@Deprecated
	private int unusedBits = 0;

	/* BitArray form of key */
	private BitArray bitStringKey = null;

	/* The encoding for the key. */
	protected byte[] encodedKey;

	/**
	* Default constructor. The key constructed must have its key
	* and algorithm initialized before it may be used, for example
	* by using <code>decode</code>.
	*/
	public X509Key() { }

	/*
	* Build and initialize as a "default" key. All X.509 key
	* data is stored and transmitted losslessly, but no knowledge
	* about this particular algorithm is available.
	*/
	private X509Key(AlgorithmId algid, BitArray key)
	throws InvalidKeyException {
	this.algid = algid;
	setKey(key);
	encode();
	}

	/**
	* Sets the key in the BitArray form.
	*/
	protected void setKey(BitArray key) {
	this.bitStringKey = (BitArray)key.clone();

	/*
	* Do this to keep the byte array form consistent with
	* this. Can delete when byte[] key is deleted.
	*/
	this.key = key.toByteArray();
	int remaining = key.length() % 8;
	this.unusedBits =
	((remaining == 0) ? 0 : 8 - remaining);
	}

	/**
	* Gets the key. The key may or may not be byte aligned.
	* @return a BitArray containing the key.
	*/
	protected BitArray getKey() {
	/*
	* Do this for consistency in case a subclass
	* modifies byte[] key directly. Remove when
	* byte[] key is deleted.
	* Note: the consistency checks fail when the subclass
	* modifies a non byte-aligned key (into a byte-aligned key)
	* using the deprecated byte[] key field.
	*/
	this.bitStringKey = new BitArray(
	this.key.length * 8 - this.unusedBits,
	this.key);

	return (BitArray)bitStringKey.clone();
	}

	/**
	* Construct X.509 subject public key from a DER value. If
	* the runtime environment is configured with a specific class for
	* this kind of key, a subclass is returned. Otherwise, a generic
	* X509Key object is returned.
	*
	* <P>This mechanism gurantees that keys (and algorithms) may be
	* freely manipulated and transferred, without risk of losing
	* information. Also, when a key (or algorithm) needs some special
	* handling, that specific need can be accomodated.
	*
	* @param in the DER-encoded SubjectPublicKeyInfo value
	* @exception IOException on data format errors
	*/
	public static PublicKey parse(DerValue in) throws IOException
	{
	AlgorithmId algorithm;
	PublicKey subjectKey;

	if (in.tag != DerValue.tag_Sequence)
	throw new IOException("corrupt subject key");

	algorithm = AlgorithmId.parse(in.data.getDerValue());
	try {
	subjectKey = buildX509Key(algorithm,
	in.data.getUnalignedBitString());

	} catch (InvalidKeyException e) {
	throw new IOException("subject key, " + e.getMessage(), e);
	}

	if (in.data.available() != 0)
	throw new IOException("excess subject key");
	return subjectKey;
	}

	/**
	* Parse the key bits. This may be redefined by subclasses to take
	* advantage of structure within the key. For example, RSA public
	* keys encapsulate two unsigned integers (modulus and exponent) as
	* DER values within the <code>key</code> bits; Diffie-Hellman and
	* DSS/DSA keys encapsulate a single unsigned integer.
	*
	* <P>This function is called when creating X.509 SubjectPublicKeyInfo
	* values using the X509Key member functions, such as <code>parse</code>
	* and <code>decode</code>.
	*
	* @exception IOException on parsing errors.
	* @exception InvalidKeyException on invalid key encodings.
	*/
	protected void parseKeyBits() throws IOException, InvalidKeyException {
	encode();
	}

	/*
	* Factory interface, building the kind of key associated with this
	* specific algorithm ID or else returning this generic base class.
	* See the description above.
	*/
	static PublicKey buildX509Key(AlgorithmId algid, BitArray key)
	throws IOException, InvalidKeyException
	{
	/*
	* Use the algid and key parameters to produce the ASN.1 encoding
	* of the key, which will then be used as the input to the
	* key factory.
	*/
	DerOutputStream x509EncodedKeyStream = new DerOutputStream();
	encode(x509EncodedKeyStream, algid, key);
	X509EncodedKeySpec x509KeySpec
	= new X509EncodedKeySpec(x509EncodedKeyStream.toByteArray());

	try {
	// Instantiate the key factory of the appropriate algorithm
	KeyFactory keyFac = KeyFactory.getInstance(algid.getName());

	// Generate the public key
	return keyFac.generatePublic(x509KeySpec);
	} catch (NoSuchAlgorithmException e) {
	// Return generic X509Key with opaque key data (see below)
	} catch (InvalidKeySpecException e) {
	throw new InvalidKeyException(e.getMessage(), e);
	}

	/*
	* Try again using JDK1.1-style for backwards compatibility.
	*/
	String classname = "";
	try {
	Properties props;
	String keytype;
	Provider sunProvider;

	sunProvider = Security.getProvider("SUN");
	if (sunProvider == null)
	throw new InstantiationException();
	classname = sunProvider.getProperty("PublicKey.X.509." +
	algid.getName());
	if (classname == null) {
	throw new InstantiationException();
	}

	Class<?> keyClass = null;
	try {
	keyClass = Class.forName(classname);
	} catch (ClassNotFoundException e) {
	ClassLoader cl = ClassLoader.getSystemClassLoader();
	if (cl != null) {
	keyClass = cl.loadClass(classname);
	}
	}

	@SuppressWarnings("deprecation")
	Object inst = (keyClass != null) ? keyClass.newInstance() : null;
	X509Key result;

	if (inst instanceof X509Key) {
	result = (X509Key) inst;
	result.algid = algid;
	result.setKey(key);
	result.parseKeyBits();
	return result;
	}
	} catch (ClassNotFoundException e) {
	} catch (InstantiationException e) {
	} catch (IllegalAccessException e) {
	// this should not happen.
	throw new IOException (classname + " [internal error]");
	}

	X509Key result = new X509Key(algid, key);
	return result;
	}

	/**
	* Returns the algorithm to be used with this key.
	*/
	public String getAlgorithm() {
	return algid.getName();
	}

	/**
	* Returns the algorithm ID to be used with this key.
	*/
	public AlgorithmId getAlgorithmId() { return algid; }

	/**
	* Encode SubjectPublicKeyInfo sequence on the DER output stream.
	*
	* @exception IOException on encoding errors.
	*/
	public final void encode(DerOutputStream out) throws IOException
	{
	encode(out, this.algid, getKey());
	}

	/**
	* Returns the DER-encoded form of the key as a byte array.
	*/
	public byte[] getEncoded() {
	try {
	return getEncodedInternal().clone();
	} catch (InvalidKeyException e) {
	// XXX
	}
	return null;
	}

	public byte[] getEncodedInternal() throws InvalidKeyException {
	byte[] encoded = encodedKey;
	if (encoded == null) {
	try {
	DerOutputStream out = new DerOutputStream();
	encode(out);
	encoded = out.toByteArray();
	} catch (IOException e) {
	throw new InvalidKeyException("IOException : " +
	e.getMessage());
	}
	encodedKey = encoded;
	}
	return encoded;
	}

	/**
	* Returns the format for this key: "X.509"
	*/
	public String getFormat() {
	return "X.509";
	}

	/**
	* Returns the DER-encoded form of the key as a byte array.
	*
	* @exception InvalidKeyException on encoding errors.
	*/
	public byte[] encode() throws InvalidKeyException {
	return getEncodedInternal().clone();
	}

	/*
	* Returns a printable representation of the key
	*/
	public String toString()
	{
	HexDumpEncoder encoder = new HexDumpEncoder();

	return "algorithm = " + algid.toString()
	+ ", unparsed keybits = \n" + encoder.encodeBuffer(key);
	}

	/**
	* Initialize an X509Key object from an input stream. The data on that
	* input stream must be encoded using DER, obeying the X.509
	* <code>SubjectPublicKeyInfo</code> format. That is, the data is a
	* sequence consisting of an algorithm ID and a bit string which holds
	* the key. (That bit string is often used to encapsulate another DER
	* encoded sequence.)
	*
	* <P>Subclasses should not normally redefine this method; they should
	* instead provide a <code>parseKeyBits</code> method to parse any
	* fields inside the <code>key</code> member.
	*
	* <P>The exception to this rule is that since private keys need not
	* be encoded using the X.509 <code>SubjectPublicKeyInfo</code> format,
	* private keys may override this method, <code>encode</code>, and
	* of course <code>getFormat</code>.
	*
	* @param in an input stream with a DER-encoded X.509
	* SubjectPublicKeyInfo value
	* @exception InvalidKeyException on parsing errors.
	*/
	public void decode(InputStream in)
	throws InvalidKeyException
	{
	DerValue val;

	try {
	val = new DerValue(in);
	if (val.tag != DerValue.tag_Sequence)
	throw new InvalidKeyException("invalid key format");

	algid = AlgorithmId.parse(val.data.getDerValue());
	setKey(val.data.getUnalignedBitString());
	parseKeyBits();
	if (val.data.available() != 0)
	throw new InvalidKeyException ("excess key data");

	} catch (IOException e) {
	throw new InvalidKeyException("IOException: " +
	e.getMessage());
	}
	}

	public void decode(byte[] encodedKey) throws InvalidKeyException {
	decode(new ByteArrayInputStream(encodedKey));
	}

	/**
	* Serialization write ... X.509 keys serialize as
	* themselves, and they're parsed when they get read back.
	*/
	private void writeObject(ObjectOutputStream stream) throws IOException {
	stream.write(getEncoded());
	}

	/**
	* Serialization read ... X.509 keys serialize as
	* themselves, and they're parsed when they get read back.
	*/
	private void readObject(ObjectInputStream stream) throws IOException {
	try {
	decode(stream);
	} catch (InvalidKeyException e) {
	e.printStackTrace();
	throw new IOException("deserialized key is invalid: " +
	e.getMessage());
	}
	}

	public boolean equals(Object obj) {
	if (this == obj) {
	return true;
	}
	if (obj instanceof Key == false) {
	return false;
	}
	try {
	byte[] thisEncoded = this.getEncodedInternal();
	byte[] otherEncoded;
	if (obj instanceof X509Key) {
	otherEncoded = ((X509Key)obj).getEncodedInternal();
	} else {
	otherEncoded = ((Key)obj).getEncoded();
	}
	return Arrays.equals(thisEncoded, otherEncoded);
	} catch (InvalidKeyException e) {
	return false;
	}
	}

	/**
	* Calculates a hash code value for the object. Objects
	* which are equal will also have the same hashcode.
	*/
	public int hashCode() {
	try {
	byte[] b1 = getEncodedInternal();
	int r = b1.length;
	for (int i = 0; i < b1.length; i++) {
	r += (b1[i] & 0xff) * 37;
	}
	return r;
	} catch (InvalidKeyException e) {
	// should not happen
	return 0;
	}
	}

	/*
	* Produce SubjectPublicKey encoding from algorithm id and key material.
	*/
	static void encode(DerOutputStream out, AlgorithmId algid, BitArray key)
	throws IOException {
	DerOutputStream tmp = new DerOutputStream();
	algid.encode(tmp);
	tmp.putUnalignedBitString(key);
	out.write(DerValue.tag_Sequence, tmp);
	}
	}

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