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	/*
	* Copyright (c) 1996, 2021, 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.pkcs;

	import java.io.*;
	import java.security.Key;
	import java.security.KeyRep;
	import java.security.PrivateKey;
	import java.security.KeyFactory;
	import java.security.MessageDigest;
	import java.security.InvalidKeyException;
	import java.security.NoSuchAlgorithmException;
	import java.security.spec.InvalidKeySpecException;
	import java.security.spec.PKCS8EncodedKeySpec;
	import java.util.Arrays;

	import jdk.internal.access.SharedSecrets;
	import sun.security.x509.*;
	import sun.security.util.*;

	/**
	* Holds a PKCS#8 key, for example a private key
	*
	* According to https://tools.ietf.org/html/rfc5958:
	*
	* OneAsymmetricKey ::= SEQUENCE {
	* version Version,
	* privateKeyAlgorithm PrivateKeyAlgorithmIdentifier,
	* privateKey PrivateKey,
	* attributes [0] Attributes OPTIONAL,
	* ...,
	* [[2: publicKey [1] PublicKey OPTIONAL ]],
	* ...
	* }
	*
	* We support this format but do not parse attributes and publicKey now.
	*/
	public class PKCS8Key implements PrivateKey {

	/** use serialVersionUID from JDK 1.1. for interoperability */
	@java.io.Serial
	private static final long serialVersionUID = -3836890099307167124L;

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

	/* The key bytes, without the algorithm information */
	protected byte[] key;

	/* The encoded for the key. Created on demand by encode(). */
	protected byte[] encodedKey;

	/* The version for this key */
	private static final int V1 = 0;
	private static final int V2 = 1;

	/**
	* Default constructor. Constructors in sub-classes that create a new key
	* from its components require this. These constructors must initialize
	* {@link #algid} and {@link #key}.
	*/
	protected PKCS8Key() { }

	/**
	* Another constructor. Constructors in sub-classes that create a new key
	* from an encoded byte array require this. We do not assign this
	* encoding to {@link #encodedKey} directly.
	*
	* This method is also used by {@link #parseKey} to create a raw key.
	*/
	protected PKCS8Key(byte[] input) throws InvalidKeyException {
	decode(new ByteArrayInputStream(input));
	}

	private void decode(InputStream is) throws InvalidKeyException {
	DerValue val = null;
	try {
	val = new DerValue(is);
	if (val.tag != DerValue.tag_Sequence) {
	throw new InvalidKeyException("invalid key format");
	}

	int version = val.data.getInteger();
	if (version != V1 && version != V2) {
	throw new InvalidKeyException("unknown version: " + version);
	}
	algid = AlgorithmId.parse (val.data.getDerValue ());
	key = val.data.getOctetString();

	DerValue next;
	if (val.data.available() == 0) {
	return;
	}
	next = val.data.getDerValue();
	if (next.isContextSpecific((byte)0)) {
	if (val.data.available() == 0) {
	return;
	}
	next = val.data.getDerValue();
	}

	if (next.isContextSpecific((byte)1)) {
	if (version == V1) {
	throw new InvalidKeyException("publicKey seen in v1");
	}
	if (val.data.available() == 0) {
	return;
	}
	}
	throw new InvalidKeyException("Extra bytes");
	} catch (IOException e) {
	throw new InvalidKeyException("IOException : " + e.getMessage());
	} finally {
	if (val != null) {
	val.clear();
	}
	}
	}

	/**
	* Construct PKCS#8 subject public key from a DER encoding. If a
	* security provider supports the key algorithm with a specific class,
	* a PrivateKey from the provider is returned. Otherwise, a raw
	* PKCS8Key object is returned.
	*
	* <P>This mechanism guarantees 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 accommodated.
	*
	* @param encoded the DER-encoded SubjectPublicKeyInfo value
	* @exception IOException on data format errors
	*/
	public static PrivateKey parseKey(byte[] encoded) throws IOException {
	try {
	PKCS8Key rawKey = new PKCS8Key(encoded);
	byte[] internal = rawKey.getEncodedInternal();
	PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(internal);
	PrivateKey result = null;
	try {
	result = KeyFactory.getInstance(rawKey.algid.getName())
	.generatePrivate(pkcs8KeySpec);
	} catch (NoSuchAlgorithmException \| InvalidKeySpecException e) {
	// Ignore and return raw key
	result = rawKey;
	} finally {
	if (result != rawKey) {
	rawKey.clear();
	}
	SharedSecrets.getJavaSecuritySpecAccess()
	.clearEncodedKeySpec(pkcs8KeySpec);
	}
	return result;
	} catch (InvalidKeyException e) {
	throw new IOException("corrupt private key", e);
	}
	}

	/**
	* 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;
	}

	/**
	* Returns the DER-encoded form of the key as a byte array,
	* or {@code null} if an encoding error occurs.
	*/
	public byte[] getEncoded() {
	byte[] b = getEncodedInternal();
	return (b == null) ? null : b.clone();
	}

	/**
	* Returns the format for this key: "PKCS#8"
	*/
	public String getFormat() {
	return "PKCS#8";
	}

	/**
	* DER-encodes this key as a byte array stored inside this object
	* and return it.
	*
	* @return the encoding, or null if there is an I/O error.
	*/
	private synchronized byte[] getEncodedInternal() {
	if (encodedKey == null) {
	try {
	DerOutputStream tmp = new DerOutputStream();
	tmp.putInteger(V1);
	algid.encode(tmp);
	tmp.putOctetString(key);
	DerValue out = DerValue.wrap(DerValue.tag_Sequence, tmp);
	encodedKey = out.toByteArray();
	out.clear();
	} catch (IOException e) {
	// encodedKey is still null
	}
	}
	return encodedKey;
	}

	@java.io.Serial
	protected Object writeReplace() throws java.io.ObjectStreamException {
	return new KeyRep(KeyRep.Type.PRIVATE,
	getAlgorithm(),
	getFormat(),
	getEncodedInternal());
	}

	/**
	* We used to serialize a PKCS8Key as itself (instead of a KeyRep).
	*/
	@java.io.Serial
	private void readObject(ObjectInputStream stream) throws IOException {
	try {
	decode(stream);
	} catch (InvalidKeyException e) {
	throw new IOException("deserialized key is invalid: " +
	e.getMessage());
	}
	}

	/**
	* Compares two private keys. This returns false if the object with which
	* to compare is not of type <code>Key</code>.
	* Otherwise, the encoding of this key object is compared with the
	* encoding of the given key object.
	*
	* @param object the object with which to compare
	* @return {@code true} if this key has the same encoding as the
	* object argument; {@code false} otherwise.
	*/
	public boolean equals(Object object) {
	if (this == object) {
	return true;
	}
	if (object instanceof PKCS8Key) {
	// time-constant comparison
	return MessageDigest.isEqual(
	getEncodedInternal(),
	((PKCS8Key)object).getEncodedInternal());
	} else if (object instanceof Key) {
	// time-constant comparison
	byte[] otherEncoded = ((Key)object).getEncoded();
	try {
	return MessageDigest.isEqual(
	getEncodedInternal(),
	otherEncoded);
	} finally {
	if (otherEncoded != null) {
	Arrays.fill(otherEncoded, (byte) 0);
	}
	}
	}
	return false;
	}

	/**
	* Calculates a hash code value for this object. Objects
	* which are equal will also have the same hashcode.
	*/
	public int hashCode() {
	return Arrays.hashCode(getEncodedInternal());
	}

	public void clear() {
	if (encodedKey != null) {
	Arrays.fill(encodedKey, (byte)0);
	}
	Arrays.fill(key, (byte)0);
	}
	}

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