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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.AlgorithmId;
import sun.security.x509.CertificateAlgorithmId;
import sun.security.x509.CertificateExtensions;
import sun.security.x509.CertificateIssuerName;
import sun.security.x509.CertificateSerialNumber;
import sun.security.x509.CertificateSubjectName;
import sun.security.x509.CertificateValidity;
import sun.security.x509.CertificateVersion;
import sun.security.x509.CertificateX509Key;
import sun.security.x509.X500Name;
import sun.security.x509.X509CertImpl;
import sun.security.x509.X509CertInfo;
import sun.security.x509.X509Key;


Generate a pair of keys, and provide access to them.  This class is
provided primarily for ease of use.
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.
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.  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.
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, Hemma Prafullchandra
See Also:
PKCS10
X509CertImpl/**
 * 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.
Params:
keyType – type of key, e.g. "RSA", "DSA"
sigAlg – name of the signature algorithm, e.g. "MD5WithRSA",
         "MD2WithRSA", "SHAwithDSA".
Throws:
NoSuchAlgorithmException – on unrecognized algorithms./**
     * 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".
     * @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.
Params:
keyType – type of key, e.g. "RSA", "DSA"
sigAlg – name of the signature algorithm, e.g. "MD5WithRSA",
         "MD2WithRSA", "SHAwithDSA".
providerName – name of the provider
Throws:
NoSuchAlgorithmException – on unrecognized algorithms.
NoSuchProviderException – on unrecognized providers./**
     * 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".
     * @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.
/**
     * 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.
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.
Params:
keyBits – the number of bits in the keys.
Throws:
InvalidKeyException – if the environment does not
 provide X.509 public keys for this signature algorithm./**
     * 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.
        // Allow "X509" in 7u for backwards compatibility.
        if (!"X.509".equalsIgnoreCase(publicKey.getFormat()) &&
            !"X509".equalsIgnoreCase(publicKey.getFormat())) {
            throw new IllegalArgumentException("Public key format is " +
                publicKey.getFormat() + ", must be X.509");
        }
    }


    
Returns the public key of the generated key pair if it is of type
X509Key, 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
X509Key. Accordingly, the return type of this method
should be PublicKey.
/**
     * 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.
/**
     * 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.
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!
/**
     * 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.
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.
Params:
myname – X.500 name of the subject (who is also the issuer)
firstDate – the issue time of the certificate
validity – how long the certificate should be valid, in seconds
Throws:
CertificateException – on certificate handling errors.
InvalidKeyException – on key handling errors.
SignatureException – on signature handling errors.
NoSuchAlgorithmException – on unrecognized algorithms.
NoSuchProviderException – on unrecognized providers./**
     * 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, new CertificateSubjectName(myname));
            info.set(X509CertInfo.KEY, new CertificateX509Key(publicKey));
            info.set(X509CertInfo.VALIDITY, interval);
            info.set(X509CertInfo.ISSUER, new CertificateIssuerName(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
PKCS10.print or PKCS10.toByteArray
operations on the result, to get the request in an appropriate
transmission format.
PKCS #10 certificate requests are sent, along with some proof
of identity, to Certificate Authorities (CAs) which then issue
X.509 public key certificates.
Params:
myname – X.500 name of the subject
Throws:
InvalidKeyException – on key handling errors.
SignatureException – on signature handling errors./**
     * 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;
}