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	/*
	* Copyright (c) 1996, 2014, 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
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	*/

	package sun.security.tools.keytool;

	import java.io.IOException;
	import java.security.cert.X509Certificate;
	import java.security.cert.CertificateException;
	import java.security.cert.CertificateEncodingException;
	import java.security.*;
	import java.util.Date;

	import sun.security.pkcs10.PKCS10;
	import sun.security.x509.*;


	/**
	* Generate a pair of keys, and provide access to them. This class is
	* provided primarily for ease of use.
	*
	* <P>This provides some simple certificate management functionality.
	* Specifically, it allows you to create self-signed X.509 certificates
	* as well as PKCS 10 based certificate signing requests.
	*
	* <P>Keys for some public key signature algorithms have algorithm
	* parameters, such as DSS/DSA. Some sites' Certificate Authorities
	* adopt fixed algorithm parameters, which speeds up some operations
	* including key generation and signing. <em>At this time, this interface
	* does not provide a way to provide such algorithm parameters, e.g.
	* by providing the CA certificate which includes those parameters.</em>
	*
	* <P>Also, note that at this time only signature-capable keys may be
	* acquired through this interface. Diffie-Hellman keys, used for secure
	* key exchange, may be supported later.
	*
	* @author David Brownell
	* @author Hemma Prafullchandra
	* @see PKCS10
	* @see X509CertImpl
	*/
	public final class CertAndKeyGen {
	/**
	* Creates a CertAndKeyGen object for a particular key type
	* and signature algorithm.
	*
	* @param keyType type of key, e.g. "RSA", "DSA"
	* @param sigAlg name of the signature algorithm, e.g. "MD5WithRSA",
	* "MD2WithRSA", "SHAwithDSA". If set to null, a default
	* algorithm matching the private key will be chosen after
	* the first keypair is generated.
	* @exception NoSuchAlgorithmException on unrecognized algorithms.
	*/
	public CertAndKeyGen (String keyType, String sigAlg)
	throws NoSuchAlgorithmException
	{
	keyGen = KeyPairGenerator.getInstance(keyType);
	this.sigAlg = sigAlg;
	}

	/**
	* Creates a CertAndKeyGen object for a particular key type,
	* signature algorithm, and provider.
	*
	* @param keyType type of key, e.g. "RSA", "DSA"
	* @param sigAlg name of the signature algorithm, e.g. "MD5WithRSA",
	* "MD2WithRSA", "SHAwithDSA". If set to null, a default
	* algorithm matching the private key will be chosen after
	* the first keypair is generated.
	* @param providerName name of the provider
	* @exception NoSuchAlgorithmException on unrecognized algorithms.
	* @exception NoSuchProviderException on unrecognized providers.
	*/
	public CertAndKeyGen (String keyType, String sigAlg, String providerName)
	throws NoSuchAlgorithmException, NoSuchProviderException
	{
	if (providerName == null) {
	keyGen = KeyPairGenerator.getInstance(keyType);
	} else {
	try {
	keyGen = KeyPairGenerator.getInstance(keyType, providerName);
	} catch (Exception e) {
	// try first available provider instead
	keyGen = KeyPairGenerator.getInstance(keyType);
	}
	}
	this.sigAlg = sigAlg;
	}

	/**
	* Sets the source of random numbers used when generating keys.
	* If you do not provide one, a system default facility is used.
	* You may wish to provide your own source of random numbers
	* to get a reproducible sequence of keys and signatures, or
	* because you may be able to take advantage of strong sources
	* of randomness/entropy in your environment.
	*/
	public void setRandom (SecureRandom generator)
	{
	prng = generator;
	}

	// want "public void generate (X509Certificate)" ... inherit DSA/D-H param

	/**
	* Generates a random public/private key pair, with a given key
	* size. Different algorithms provide different degrees of security
	* for the same key size, because of the "work factor" involved in
	* brute force attacks. As computers become faster, it becomes
	* easier to perform such attacks. Small keys are to be avoided.
	*
	* <P>Note that not all values of "keyBits" are valid for all
	* algorithms, and not all public key algorithms are currently
	* supported for use in X.509 certificates. If the algorithm
	* you specified does not produce X.509 compatible keys, an
	* invalid key exception is thrown.
	*
	* @param keyBits the number of bits in the keys.
	* @exception InvalidKeyException if the environment does not
	* provide X.509 public keys for this signature algorithm.
	*/
	public void generate (int keyBits)
	throws InvalidKeyException
	{
	KeyPair pair;

	try {
	if (prng == null) {
	prng = new SecureRandom();
	}
	keyGen.initialize(keyBits, prng);
	pair = keyGen.generateKeyPair();

	} catch (Exception e) {
	throw new IllegalArgumentException(e.getMessage());
	}

	publicKey = pair.getPublic();
	privateKey = pair.getPrivate();

	// publicKey's format must be X.509 otherwise
	// the whole CertGen part of this class is broken.
	if (!"X.509".equalsIgnoreCase(publicKey.getFormat())) {
	throw new IllegalArgumentException("Public key format is "
	+ publicKey.getFormat() + ", must be X.509");
	}

	if (sigAlg == null) {
	sigAlg = AlgorithmId.getDefaultSigAlgForKey(privateKey);
	if (sigAlg == null) {
	throw new IllegalArgumentException(
	"Cannot derive signature algorithm from "
	+ privateKey.getAlgorithm());
	}
	}
	}

	/**
	* Returns the public key of the generated key pair if it is of type
	* <code>X509Key</code>, or null if the public key is of a different type.
	*
	* XXX Note: This behaviour is needed for backwards compatibility.
	* What this method really should return is the public key of the
	* generated key pair, regardless of whether or not it is an instance of
	* <code>X509Key</code>. Accordingly, the return type of this method
	* should be <code>PublicKey</code>.
	*/
	public X509Key getPublicKey()
	{
	if (!(publicKey instanceof X509Key)) {
	return null;
	}
	return (X509Key)publicKey;
	}

	/**
	* Always returns the public key of the generated key pair. Used
	* by KeyTool only.
	*
	* The publicKey is not necessarily to be an instance of
	* X509Key in some JCA/JCE providers, for example SunPKCS11.
	*/
	public PublicKey getPublicKeyAnyway() {
	return publicKey;
	}

	/**
	* Returns the private key of the generated key pair.
	*
	* <P><STRONG><em>Be extremely careful when handling private keys.
	* When private keys are not kept secret, they lose their ability
	* to securely authenticate specific entities ... that is a huge
	* security risk!</em></STRONG>
	*/
	public PrivateKey getPrivateKey ()
	{
	return privateKey;
	}

	/**
	* Returns a self-signed X.509v3 certificate for the public key.
	* The certificate is immediately valid. No extensions.
	*
	* <P>Such certificates normally are used to identify a "Certificate
	* Authority" (CA). Accordingly, they will not always be accepted by
	* other parties. However, such certificates are also useful when
	* you are bootstrapping your security infrastructure, or deploying
	* system prototypes.
	*
	* @param myname X.500 name of the subject (who is also the issuer)
	* @param firstDate the issue time of the certificate
	* @param validity how long the certificate should be valid, in seconds
	* @exception CertificateException on certificate handling errors.
	* @exception InvalidKeyException on key handling errors.
	* @exception SignatureException on signature handling errors.
	* @exception NoSuchAlgorithmException on unrecognized algorithms.
	* @exception NoSuchProviderException on unrecognized providers.
	*/
	public X509Certificate getSelfCertificate (
	X500Name myname, Date firstDate, long validity)
	throws CertificateException, InvalidKeyException, SignatureException,
	NoSuchAlgorithmException, NoSuchProviderException
	{
	return getSelfCertificate(myname, firstDate, validity, null);
	}

	// Like above, plus a CertificateExtensions argument, which can be null.
	public X509Certificate getSelfCertificate (X500Name myname, Date firstDate,
	long validity, CertificateExtensions ext)
	throws CertificateException, InvalidKeyException, SignatureException,
	NoSuchAlgorithmException, NoSuchProviderException
	{
	X509CertImpl cert;
	Date lastDate;

	try {
	lastDate = new Date ();
	lastDate.setTime (firstDate.getTime () + validity * 1000);

	CertificateValidity interval =
	new CertificateValidity(firstDate,lastDate);

	X509CertInfo info = new X509CertInfo();
	// Add all mandatory attributes
	info.set(X509CertInfo.VERSION,
	new CertificateVersion(CertificateVersion.V3));
	info.set(X509CertInfo.SERIAL_NUMBER, new CertificateSerialNumber(
	new java.util.Random().nextInt() & 0x7fffffff));
	AlgorithmId algID = AlgorithmId.get(sigAlg);
	info.set(X509CertInfo.ALGORITHM_ID,
	new CertificateAlgorithmId(algID));
	info.set(X509CertInfo.SUBJECT, myname);
	info.set(X509CertInfo.KEY, new CertificateX509Key(publicKey));
	info.set(X509CertInfo.VALIDITY, interval);
	info.set(X509CertInfo.ISSUER, myname);
	if (ext != null) info.set(X509CertInfo.EXTENSIONS, ext);

	cert = new X509CertImpl(info);
	cert.sign(privateKey, this.sigAlg);

	return (X509Certificate)cert;

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

	// Keep the old method
	public X509Certificate getSelfCertificate (X500Name myname, long validity)
	throws CertificateException, InvalidKeyException, SignatureException,
	NoSuchAlgorithmException, NoSuchProviderException
	{
	return getSelfCertificate(myname, new Date(), validity);
	}

	/**
	* Returns a PKCS #10 certificate request. The caller uses either
	* <code>PKCS10.print</code> or <code>PKCS10.toByteArray</code>
	* operations on the result, to get the request in an appropriate
	* transmission format.
	*
	* <P>PKCS #10 certificate requests are sent, along with some proof
	* of identity, to Certificate Authorities (CAs) which then issue
	* X.509 public key certificates.
	*
	* @param myname X.500 name of the subject
	* @exception InvalidKeyException on key handling errors.
	* @exception SignatureException on signature handling errors.
	*/
	public PKCS10 getCertRequest (X500Name myname)
	throws InvalidKeyException, SignatureException
	{
	PKCS10 req = new PKCS10 (publicKey);

	try {
	Signature signature = Signature.getInstance(sigAlg);
	signature.initSign (privateKey);
	req.encodeAndSign(myname, signature);

	} catch (CertificateException e) {
	throw new SignatureException (sigAlg + " CertificateException");

	} catch (IOException e) {
	throw new SignatureException (sigAlg + " IOException");

	} catch (NoSuchAlgorithmException e) {
	// "can't happen"
	throw new SignatureException (sigAlg + " unavailable?");
	}
	return req;
	}

	private SecureRandom prng;
	private String sigAlg;
	private KeyPairGenerator keyGen;
	private PublicKey publicKey;
	private PrivateKey privateKey;
	}

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