/*

 * Copyright 1997-2008 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package sun.security.x509;

import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.Serializable;

import java.math.BigInteger;

import java.security.*;

import java.util.Date;

import java.util.Enumeration;

import sun.security.util.*;     // DER

/**

 * @author David Brownell

 *

 * @see CertAndKeyGen

 * @deprecated  Use the new X509Certificate class.

 *              This class is only restored for backwards compatibility.

 */

@Deprecated

public class X509Cert implements Certificate, Serializable {

    static final long serialVersionUID = -52595524744692374L;

    /*

     * NOTE: All fields are marked transient, because we do not want them to

     * be included in the class description when we serialize an object of

     * this class. We override "writeObject" and "readObject" to use the

     * ASN.1 encoding of a certificate as the serialized form, instead of

     * calling the default routines which would operate on the field values.

     *

     * MAKE SURE TO MARK ANY FIELDS THAT ARE ADDED IN THE FUTURE AS TRANSIENT.

     */

    /* The algorithm id */

    transient protected AlgorithmId algid;

    /*

     * Certificate data, and its envelope

     */

    transient private byte rawCert [];

    transient private byte signature [];

    transient private byte signedCert [];

    /*

     * X509.v1 data (parsed)

     */

    transient private X500Name subject; // from subject

    transient private PublicKey pubkey;

    transient private Date notafter;    // from CA (constructor)

    transient private Date notbefore;

    transient private int version;      // from CA (signAndEncode)

    transient private BigInteger serialnum;

    transient private X500Name issuer;

    transient private AlgorithmId issuerSigAlg;

    /*

     * flag to indicate whether or not this certificate has already been parsed

     * (through a call to one of the constructors or the "decode" or

     * "readObject" methods). This is to ensure that certificates are

     * immutable.

     */

    transient private boolean parsed=false;

    /*

     * X509.v2 extensions

     */

    /*

     * X509.v3 extensions

     */

    /*

     * Other extensions ... Netscape, Verisign, SET, etc

     */

    /**

     * Construct a uninitialized X509 Cert on which <a href="#decode">

     * decode</a> must later be called (or which may be deserialized).

     */

    // XXX deprecated, delete this

    public X509Cert() { }

    /**

     * Unmarshals a certificate from its encoded form, parsing the

     * encoded bytes.  This form of constructor is used by agents which

     * need to examine and use certificate contents.  That is, this is

     * one of the more commonly used constructors.  Note that the buffer

     * must include only a certificate, and no "garbage" may be left at

     * the end.  If you need to ignore data at the end of a certificate,

     * use another constructor.

     *

     * @param cert the encoded bytes, with no terminatu (CONSUMED)

     * @exception IOException when the certificate is improperly encoded.

     */

    public X509Cert(byte cert []) throws IOException

    {

        DerValue in = new DerValue (cert);

        parse (in);

        if (in.data.available () != 0)

            throw new CertParseError ("garbage at end");

        signedCert = cert;

    }

    /**

     * Unmarshals a certificate from its encoded form, parsing the

     * encoded bytes.  This form of constructor is used by agents which

     * need to examine and use certificate contents.  That is, this is

     * one of the most commonly used constructors.

     *

     * @param buf the buffer holding the encoded bytes

     * @param offset the offset in the buffer where the bytes begin

     * @param len how many bytes of certificate exist

     *

     * @exception IOException when the certificate is improperly encoded.

     */

    public X509Cert(byte buf [], int offset, int len) throws IOException

    {

        DerValue in = new DerValue (buf, offset, len);

        parse (in);

        if (in.data.available () != 0)

            throw new CertParseError ("garbage at end");

        signedCert = new byte [len];

        System.arraycopy (buf, offset, signedCert, 0, len);

    }

    /**

     * Unmarshal a certificate from its encoded form, parsing a DER value.

     * This form of constructor is used by agents which need to examine

     * and use certificate contents.

     *

     * @param derVal the der value containing the encoded cert.

     * @exception IOException when the certificate is improperly encoded.

     */

    public X509Cert(DerValue derVal) throws IOException

    {

        parse (derVal);

        if (derVal.data.available () != 0)

            throw new CertParseError ("garbage at end");

        signedCert = derVal.toByteArray ();

    }

    /**

     * Partially constructs a certificate from descriptive parameters.

     * This constructor may be used by Certificate Authority (CA) code,

     * which later <a href="#signAndEncode">signs and encodes</a> the

     * certificate.  Also, self-signed certificates serve as CA certificates,

     * and are sometimes used as certificate requests.

     *

     * <P>Until the certificate has been signed and encoded, some of

     * the mandatory fields in the certificate will not be available

     * via accessor functions:  the serial number, issuer name and signing

     * algorithm, and of course the signed certificate.  The fields passed

     * to this constructor are available, and must be non-null.

     *

     * <P>Note that the public key being signed is generally independent of

     * the signature algorithm being used.  So for example Diffie-Hellman

     * keys (which do not support signatures) can be placed in X.509

     * certificates when some other signature algorithm (e.g. DSS/DSA,

     * or one of the RSA based algorithms) is used.

     *

     * @see CertAndKeyGen

     *

     * @param subjectName the X.500 distinguished name being certified

     * @param subjectPublicKey the public key being certified.  This

     *  must be an "X509Key" implementing the "PublicKey" interface.

     * @param notBefore the first time the certificate is valid

     * @param notAfter the last time the certificate is valid

     *

     * @exception CertException if the public key is inappropriate

     */

    public X509Cert(X500Name subjectName, X509Key subjectPublicKey,

                    Date notBefore, Date notAfter) throws CertException

    {

        subject = subjectName;

        if (!(subjectPublicKey instanceof PublicKey))

            throw new CertException (CertException.err_INVALID_PUBLIC_KEY,

                "Doesn't implement PublicKey interface");

        // The X509 cert API requires X509 keys, else things break.

        pubkey = subjectPublicKey;

        notbefore = notBefore;

        notafter = notAfter;

        version = 0;

    }

    /**

     * Decode an X.509 certificate from an input stream.

     *

     * @param in an input stream holding at least one certificate

     * @exception IOException when the certificate is improperly encoded, or

     * if it has already been parsed.

     */

    public void decode(InputStream in) throws IOException

    {

        DerValue val = new DerValue(in);

        parse(val);

        signedCert = val.toByteArray();

    }

    /**

     * Appends the certificate to an output stream.

     *

     * @param out an input stream to which the certificate is appended.

     * @exception IOException when appending fails.

     */

    public void encode (OutputStream out) throws IOException

        { out.write (getSignedCert ()); }

    /**

     * Compares two certificates.  This is false if the

     * certificates are not both X.509 certs, otherwise it

     * compares them as binary data.

     *

     * @param other the object being compared with this one

     * @return true iff the certificates are equivalent

     */

    public boolean      equals (Object other)

    {

        if (other instanceof X509Cert)

            return equals ((X509Cert) other);

        else

            return false;

    }

    /**

     * Compares two certificates, returning false if any data

     * differs between the two.

     *

     * @param other the object being compared with this one

     * @return true iff the certificates are equivalent

     */

    public boolean      equals (X509Cert src)

    {

        if (this == src)

            return true;

        if (signedCert == null || src.signedCert == null)

            return false;

        if (signedCert.length != src.signedCert.length)

            return false;

        for (int i = 0; i < signedCert.length; i++)

            if (signedCert [i] != src.signedCert [i])

                return false;

        return true;

    }

    /** Returns the "X.509" format identifier. */

    public String getFormat () // for Certificate

        { return "X.509"; }

    /** Returns <a href="#getIssuerName">getIssuerName</a> */

    public Principal getGuarantor () // for Certificate

        { return getIssuerName (); }

    /** Returns <a href="#getSubjectName">getSubjectName</a> */

    public Principal getPrincipal ()

        { return getSubjectName (); }

    /**

     * Throws an exception if the certificate is invalid because it is

     * now outside of the certificate's validity period, or because it

     * was not signed using the verification key provided.  Successfully

     * verifying a certificate does <em>not</em> indicate that one should

     * trust the entity which it represents.

     *

     * <P><em>Note that since this class represents only a single X.509

     * certificate, it cannot know anything about the certificate chain

     * which is used to provide the verification key and to establish trust.

     * Other code must manage and use those cert chains.

     *

     * <P>For now, you must walk the cert chain being used to verify any

     * given cert.  Start at the root, which is a self-signed certificate;

     * verify it using the key inside the certificate.  Then use that to

     * verify the next certificate in the chain, issued by that CA.  In

     * this manner, verify each certificate until you reach the particular

     * certificate you wish to verify.  You should not use a certificate

     * if any of the verification operations for its certificate chain

     * were unsuccessful.

     * </em>

     *

     * @param issuerPublicKey the public key of the issuing CA

     * @exception CertException when the certificate is not valid.

     */

    public void verify (PublicKey issuerPublicKey)

    throws CertException

    {

        Date    now = new Date ();

        if (now.before (notbefore))

            throw new CertException (CertException.verf_INVALID_NOTBEFORE);

        if (now.after (notafter))

            throw new CertException (CertException.verf_INVALID_EXPIRED);

        if (signedCert == null)

            throw new CertException (CertException.verf_INVALID_SIG,

                "?? certificate is not signed yet ??");

        //

        // Verify the signature ...

        //

        String          algName = null;

        try {

            Signature   sigVerf = null;

            algName = issuerSigAlg.getName();

            sigVerf = Signature.getInstance(algName);

            sigVerf.initVerify (issuerPublicKey);

            sigVerf.update (rawCert, 0, rawCert.length);

            if (!sigVerf.verify (signature)) {

                throw new CertException (CertException.verf_INVALID_SIG,

                    "Signature ... by <" + issuer + "> for <" + subject + ">");

            }

        // Gag -- too many catch clauses, let most through.

        } catch (NoSuchAlgorithmException e) {

            throw new CertException (CertException.verf_INVALID_SIG,

                "Unsupported signature algorithm (" + algName + ")");

        } catch (InvalidKeyException e) {

            // e.printStackTrace();

            throw new CertException (CertException.err_INVALID_PUBLIC_KEY,

                "Algorithm (" + algName + ") rejected public key");

        } catch (SignatureException e) {

            throw new CertException (CertException.verf_INVALID_SIG,

                "Signature by <" + issuer + "> for <" + subject + ">");

        }

    }

    /**

     * Creates an X.509 certificate, and signs it using the issuer

     * passed (associating a signature algorithm and an X.500 name).

     * This operation is used to implement the certificate generation

     * functionality of a certificate authority.

     *

     * @see #getSignedCert

     * @see #getSigner

     * @see CertAndKeyGen

     *

     * @param serial the serial number of the certificate (non-null)

     * @param issuer the certificate issuer (CA) (non-null)

     * @return the signed certificate, as returned by getSignedCert

     *

     * @exception IOException if any of the data could not be encoded,

     *  or when any mandatory data was omitted

     * @exception SignatureException on signing failures

     */

    public byte []

    encodeAndSign (

        BigInteger      serial,

        X500Signer      issuer

    ) throws IOException, SignatureException

    {

        rawCert = null;

        /*

         * Get the remaining cert parameters, and make sure we have enough.

         *

         * We deduce version based on what attribute data are available

         * For now, we have no attributes, so we always deduce X.509v1 !

         */

        version = 0;

        serialnum = serial;

        this.issuer = issuer.getSigner ();

        issuerSigAlg = issuer.getAlgorithmId ();

        if (subject == null || pubkey == null

                || notbefore == null || notafter == null)

            throw new IOException ("not enough cert parameters");

        /*

         * Encode the raw cert, create its signature and put it

         * into the envelope.

         */

        rawCert = DERencode ();

        signedCert = sign (issuer, rawCert);

        return signedCert;

    }

    /**

     * Returns an X500Signer that may be used to create signatures.  Those

     * signature may in turn be verified using this certificate (or a

     * copy of it).

     *

     * <P><em><b>NOTE:</b>  If the private key is by itself capable of

     * creating signatures, this fact may not be recognized at this time.

     * Specifically, the case of DSS/DSA keys which get their algorithm

     * parameters from higher in the certificate chain is not supportable

     * without using an X509CertChain API, and there is no current support

     * for other sources of algorithm parameters.</em>

     *

     * @param algorithm the signature algorithm to be used.  Note that a

     *  given public/private key pair may support several such algorithms.

     * @param privateKey the private key used to create the signature,

     *  which must correspond to the public key in this certificate

     * @return the Signer object

     *

     * @exception NoSuchAlgorithmException if the signature

     *  algorithm is not supported

     * @exception InvalidKeyException if either the key in the certificate,

     *  or the private key parameter, does not support the requested

     *  signature algorithm

     */

    public X500Signer   getSigner (AlgorithmId algorithmId,

                                   PrivateKey privateKey)

    throws NoSuchAlgorithmException, InvalidKeyException

    {

        String algorithm;

        Signature       sig;

        if (privateKey instanceof Key) {

            Key key = (Key)privateKey;

            algorithm = key.getAlgorithm();

        } else {

            throw new InvalidKeyException("private key not a key!");

        }

        sig = Signature.getInstance(algorithmId.getName());

        if (!pubkey.getAlgorithm ().equals (algorithm)) {

          throw new InvalidKeyException( "Private key algorithm " +

                                         algorithm +

                                         " incompatible with certificate " +

                                         pubkey.getAlgorithm());

        }

        sig.initSign (privateKey);

        return new X500Signer (sig, subject);

    }

    /**

     * Returns a signature object that may be used to verify signatures

     * created using a specified signature algorithm and the public key

     * contained in this certificate.

     *

     * <P><em><b>NOTE:</b>  If the public key in this certificate is not by

     * itself capable of verifying signatures, this may not be recognized

     * at this time.  Specifically, the case of DSS/DSA keys which get

     * their algorithm parameters from higher in the certificate chain

     * is not supportable without using an X509CertChain API, and there

     * is no current support for other sources of algorithm parameters.</em>

     *

     * @param algorithm the algorithm of the signature to be verified

     * @return the Signature object

     * @exception NoSuchAlgorithmException if the signature

     *  algorithm is not supported

     * @exception InvalidKeyException if the key in the certificate

     *  does not support the requested signature algorithm

     */

    public Signature getVerifier(String algorithm)

    throws NoSuchAlgorithmException, InvalidKeyException

    {

        String          algName;

        Signature       sig;

        sig = Signature.getInstance(algorithm);

        sig.initVerify (pubkey);

        return sig;

    }

    /**

     * Return the signed X.509 certificate as a byte array.

     * The bytes are in standard DER marshaled form.

     * Null is returned in the case of a partially constructed cert.

     */

    public byte []      getSignedCert ()

        { return signedCert.clone(); }

    /**

     * Returns the certificate's serial number.

     * Null is returned in the case of a partially constructed cert.

     */

    public BigInteger   getSerialNumber ()

        { return serialnum; }