https://openjdk.java.net/ 
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 * 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
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 *
 * 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).
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 * 2 along with this work; if not, write to the Free Software Foundation,
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package com.sun.crypto.provider;

import java.io.*;
import java.util.*;
import java.security.AccessController;
import java.security.DigestInputStream;
import java.security.DigestOutputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.Key;
import java.security.PrivateKey;
import java.security.PrivilegedAction;
import java.security.KeyStoreSpi;
import java.security.KeyStoreException;
import java.security.UnrecoverableKeyException;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.CertificateException;
import javax.crypto.SealedObject;

import sun.misc.ObjectInputFilter;


This class provides the keystore implementation referred to as "jceks".
This implementation strongly protects the keystore private keys using
triple-DES, where the triple-DES encryption/decryption key is derived from
the user's password.
The encrypted private keys are stored in the keystore in a standard format,
namely the EncryptedPrivateKeyInfo format defined in PKCS #8.

Author:Jan Luehe
See Also:
/**
 * This class provides the keystore implementation referred to as "jceks".
 * This implementation strongly protects the keystore private keys using
 * triple-DES, where the triple-DES encryption/decryption key is derived from
 * the user's password.
 * The encrypted private keys are stored in the keystore in a standard format,
 * namely the <code>EncryptedPrivateKeyInfo</code> format defined in PKCS #8.
 *
 * @author Jan Luehe
 *
 *
 * @see java.security.KeyStoreSpi
 */

public final class JceKeyStore extends KeyStoreSpi {

    private static final int JCEKS_MAGIC = 0xcececece;
    private static final int JKS_MAGIC = 0xfeedfeed;
    private static final int VERSION_1 = 0x01;
    private static final int VERSION_2 = 0x02;

    // Private key and supporting certificate chain
    private static final class PrivateKeyEntry {
        Date date; // the creation date of this entry
        byte[] protectedKey;
        Certificate chain[];
    };

    // Secret key
    private static final class SecretKeyEntry {
        Date date; // the creation date of this entry
        SealedObject sealedKey;
    }

    // Trusted certificate
    private static final class TrustedCertEntry {
        Date date; // the creation date of this entry
        Certificate cert;
    };

    
Private keys and certificates are stored in a hashtable.
Hash entries are keyed by alias names.

/**
     * Private keys and certificates are stored in a hashtable.
     * Hash entries are keyed by alias names.
     */
    private Hashtable<String, Object> entries = new Hashtable<String, Object>();

    
Returns the key associated with the given alias, using the given
password to recover it.

Params:
  • alias – the alias name
  • password – the password for recovering the key
Throws:
Returns:the requested key, or null if the given alias does not exist
or does not identify a key entry.
/**
     * Returns the key associated with the given alias, using the given
     * password to recover it.
     *
     * @param alias the alias name
     * @param password the password for recovering the key
     *
     * @return the requested key, or null if the given alias does not exist
     * or does not identify a <i>key entry</i>.
     *
     * @exception NoSuchAlgorithmException if the algorithm for recovering the
     * key cannot be found
     * @exception UnrecoverableKeyException if the key cannot be recovered
     * (e.g., the given password is wrong).
     */
    public Key engineGetKey(String alias, char[] password)
        throws NoSuchAlgorithmException, UnrecoverableKeyException
    {
        Key key = null;

        Object entry = entries.get(alias.toLowerCase());

        if (!((entry instanceof PrivateKeyEntry) ||
              (entry instanceof SecretKeyEntry))) {
            return null;
        }

        KeyProtector keyProtector = new KeyProtector(password);

        if (entry instanceof PrivateKeyEntry) {
            byte[] encrBytes = ((PrivateKeyEntry)entry).protectedKey;
            EncryptedPrivateKeyInfo encrInfo;
            try {
                encrInfo = new EncryptedPrivateKeyInfo(encrBytes);
            } catch (IOException ioe) {
                throw new UnrecoverableKeyException("Private key not stored "
                                                    + "as PKCS #8 " +
                                                    "EncryptedPrivateKeyInfo");
            }
            key = keyProtector.recover(encrInfo);
        } else {
            key =
                keyProtector.unseal(((SecretKeyEntry)entry).sealedKey);
        }

        return key;
    }

    
Returns the certificate chain associated with the given alias.

Params:
  • alias – the alias name
Returns:the certificate chain (ordered with the user's certificate first
and the root certificate authority last), or null if the given alias
does not exist or does not contain a certificate chain (i.e., the given
alias identifies either a trusted certificate entry or a
key entry without a certificate chain).
/**
     * Returns the certificate chain associated with the given alias.
     *
     * @param alias the alias name
     *
     * @return the certificate chain (ordered with the user's certificate first
     * and the root certificate authority last), or null if the given alias
     * does not exist or does not contain a certificate chain (i.e., the given
     * alias identifies either a <i>trusted certificate entry</i> or a
     * <i>key entry</i> without a certificate chain).
     */
    public Certificate[] engineGetCertificateChain(String alias)
    {
        Certificate[] chain = null;

        Object entry = entries.get(alias.toLowerCase());

        if ((entry instanceof PrivateKeyEntry)
            && (((PrivateKeyEntry)entry).chain != null)) {
            chain = ((PrivateKeyEntry)entry).chain.clone();
        }

        return chain;
    }

    
Returns the certificate associated with the given alias.

If the given alias name identifies a
trusted certificate entry, the certificate associated with that
entry is returned. If the given alias name identifies a
key entry, the first element of the certificate chain of that
entry is returned, or null if that entry does not have a certificate
chain.

Params:
  • alias – the alias name
Returns:the certificate, or null if the given alias does not exist or
does not contain a certificate.
/**
     * Returns the certificate associated with the given alias.
     *
     * <p>If the given alias name identifies a
     * <i>trusted certificate entry</i>, the certificate associated with that
     * entry is returned. If the given alias name identifies a
     * <i>key entry</i>, the first element of the certificate chain of that
     * entry is returned, or null if that entry does not have a certificate
     * chain.
     *
     * @param alias the alias name
     *
     * @return the certificate, or null if the given alias does not exist or
     * does not contain a certificate.
     */
    public Certificate engineGetCertificate(String alias) {
        Certificate cert = null;

        Object entry = entries.get(alias.toLowerCase());

        if (entry != null) {
            if (entry instanceof TrustedCertEntry) {
                cert = ((TrustedCertEntry)entry).cert;
            } else if ((entry instanceof PrivateKeyEntry) &&
                       (((PrivateKeyEntry)entry).chain != null)) {
                cert = ((PrivateKeyEntry)entry).chain[0];
            }
        }

        return cert;
    }

    
Returns the creation date of the entry identified by the given alias.

Params:
  • alias – the alias name
Returns:the creation date of this entry, or null if the given alias does
not exist
/**
     * Returns the creation date of the entry identified by the given alias.
     *
     * @param alias the alias name
     *
     * @return the creation date of this entry, or null if the given alias does
     * not exist
     */
    public Date engineGetCreationDate(String alias) {
        Date date = null;

        Object entry = entries.get(alias.toLowerCase());

        if (entry != null) {
            // We have to create a new instance of java.util.Date because
            // dates are not immutable
            if (entry instanceof TrustedCertEntry) {
                date = new Date(((TrustedCertEntry)entry).date.getTime());
            } else if (entry instanceof PrivateKeyEntry) {
                date = new Date(((PrivateKeyEntry)entry).date.getTime());
            } else {
                date = new Date(((SecretKeyEntry)entry).date.getTime());
            }
        }

        return date;
    }

    
Assigns the given key to the given alias, protecting it with the given
password.

If the given key is of type java.security.PrivateKey,
it must be accompanied by a certificate chain certifying the
corresponding public key.

If the given alias already exists, the keystore information
associated with it is overridden by the given key (and possibly
certificate chain).

Params:
  • alias – the alias name
  • key – the key to be associated with the alias
  • password – the password to protect the key
  • chain – the certificate chain for the corresponding public
key (only required if the given key is of type
java.security.PrivateKey).
Throws:
  • KeyStoreException – if the given key cannot be protected, or
this operation fails for some other reason
/**
     * Assigns the given key to the given alias, protecting it with the given
     * password.
     *
     * <p>If the given key is of type <code>java.security.PrivateKey</code>,
     * it must be accompanied by a certificate chain certifying the
     * corresponding public key.
     *
     * <p>If the given alias already exists, the keystore information
     * associated with it is overridden by the given key (and possibly
     * certificate chain).
     *
     * @param alias the alias name
     * @param key the key to be associated with the alias
     * @param password the password to protect the key
     * @param chain the certificate chain for the corresponding public
     * key (only required if the given key is of type
     * <code>java.security.PrivateKey</code>).
     *
     * @exception KeyStoreException if the given key cannot be protected, or
     * this operation fails for some other reason
     */
    public void engineSetKeyEntry(String alias, Key key, char[] password,
                                  Certificate[] chain)
        throws KeyStoreException
    {
        synchronized(entries) {
            try {
                KeyProtector keyProtector = new KeyProtector(password);

                if (key instanceof PrivateKey) {
                    PrivateKeyEntry entry = new PrivateKeyEntry();
                    entry.date = new Date();

                    // protect the private key
                    entry.protectedKey = keyProtector.protect((PrivateKey)key);

                    // clone the chain
                    if ((chain != null) &&
                        (chain.length !=0)) {
                        entry.chain = chain.clone();
                    } else {
                        entry.chain = null;
                    }

                    // store the entry
                    entries.put(alias.toLowerCase(), entry);

                } else {
                    SecretKeyEntry entry = new SecretKeyEntry();
                    entry.date = new Date();

                    // seal and store the key
                    entry.sealedKey = keyProtector.seal(key);
                    entries.put(alias.toLowerCase(), entry);
                }

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

    
Assigns the given key (that has already been protected) to the given
alias.

If the protected key is of type
java.security.PrivateKey,
it must be accompanied by a certificate chain certifying the
corresponding public key.

If the given alias already exists, the keystore information
associated with it is overridden by the given key (and possibly
certificate chain).

Params:
  • alias – the alias name
  • key – the key (in protected format) to be associated with the alias
  • chain – the certificate chain for the corresponding public
key (only useful if the protected key is of type
java.security.PrivateKey).
Throws:
/**
     * Assigns the given key (that has already been protected) to the given
     * alias.
     *
     * <p>If the protected key is of type
     * <code>java.security.PrivateKey</code>,
     * it must be accompanied by a certificate chain certifying the
     * corresponding public key.
     *
     * <p>If the given alias already exists, the keystore information
     * associated with it is overridden by the given key (and possibly
     * certificate chain).
     *
     * @param alias the alias name
     * @param key the key (in protected format) to be associated with the alias
     * @param chain the certificate chain for the corresponding public
     * key (only useful if the protected key is of type
     * <code>java.security.PrivateKey</code>).
     *
     * @exception KeyStoreException if this operation fails.
     */
    public void engineSetKeyEntry(String alias, byte[] key,
                                  Certificate[] chain)
        throws KeyStoreException
    {
        synchronized(entries) {
            // We assume it's a private key, because there is no standard
            // (ASN.1) encoding format for wrapped secret keys
            PrivateKeyEntry entry = new PrivateKeyEntry();
            entry.date = new Date();

            entry.protectedKey = key.clone();
            if ((chain != null) &&
                (chain.length != 0)) {
                entry.chain = chain.clone();
            } else {
                entry.chain = null;
            }

            entries.put(alias.toLowerCase(), entry);
        }
    }

    
Assigns the given certificate to the given alias.

If the given alias already exists in this keystore and identifies a
trusted certificate entry, the certificate associated with it is
overridden by the given certificate.

Params:
  • alias – the alias name
  • cert – the certificate
Throws:
  • KeyStoreException – if the given alias already exists and does
not identify a trusted certificate entry, or this operation
fails for some other reason.
/**
     * Assigns the given certificate to the given alias.
     *
     * <p>If the given alias already exists in this keystore and identifies a
     * <i>trusted certificate entry</i>, the certificate associated with it is
     * overridden by the given certificate.
     *
     * @param alias the alias name
     * @param cert the certificate
     *
     * @exception KeyStoreException if the given alias already exists and does
     * not identify a <i>trusted certificate entry</i>, or this operation
     * fails for some other reason.
     */
    public void engineSetCertificateEntry(String alias, Certificate cert)
        throws KeyStoreException
    {
        synchronized(entries) {

            Object entry = entries.get(alias.toLowerCase());
            if (entry != null) {
                if (entry instanceof PrivateKeyEntry) {
                    throw new KeyStoreException("Cannot overwrite own "
                                                + "certificate");
                } else if (entry instanceof SecretKeyEntry) {
                    throw new KeyStoreException("Cannot overwrite secret key");
                }
            }

            TrustedCertEntry trustedCertEntry = new TrustedCertEntry();
            trustedCertEntry.cert = cert;
            trustedCertEntry.date = new Date();
            entries.put(alias.toLowerCase(), trustedCertEntry);
        }
    }

    
Deletes the entry identified by the given alias from this keystore.

Params:
  • alias – the alias name
Throws:
/**
     * Deletes the entry identified by the given alias from this keystore.
     *
     * @param alias the alias name
     *
     * @exception KeyStoreException if the entry cannot be removed.
     */
    public void engineDeleteEntry(String alias)
        throws KeyStoreException
    {
        synchronized(entries) {
            entries.remove(alias.toLowerCase());
        }
    }

    
Lists all the alias names of this keystore.

Returns:enumeration of the alias names
/**
     * Lists all the alias names of this keystore.
     *
     * @return enumeration of the alias names
     */
    public Enumeration<String> engineAliases() {
        return entries.keys();
    }

    
Checks if the given alias exists in this keystore.

Params:
  • alias – the alias name
Returns:true if the alias exists, false otherwise
/**
     * Checks if the given alias exists in this keystore.
     *
     * @param alias the alias name
     *
     * @return true if the alias exists, false otherwise
     */
    public boolean engineContainsAlias(String alias) {
        return entries.containsKey(alias.toLowerCase());
    }

    
Retrieves the number of entries in this keystore.

Returns:the number of entries in this keystore
/**
     * Retrieves the number of entries in this keystore.
     *
     * @return the number of entries in this keystore
     */
    public int engineSize() {
        return entries.size();
    }

    
Returns true if the entry identified by the given alias is a
key entry, and false otherwise.

Returns:true if the entry identified by the given alias is a
key entry, false otherwise.
/**
     * Returns true if the entry identified by the given alias is a
     * <i>key entry</i>, and false otherwise.
     *
     * @return true if the entry identified by the given alias is a
     * <i>key entry</i>, false otherwise.
     */
    public boolean engineIsKeyEntry(String alias) {
        boolean isKey = false;

        Object entry = entries.get(alias.toLowerCase());
        if ((entry instanceof PrivateKeyEntry)
            || (entry instanceof SecretKeyEntry)) {
            isKey = true;
        }

        return isKey;
    }

    
Returns true if the entry identified by the given alias is a
trusted certificate entry, and false otherwise.

Returns:true if the entry identified by the given alias is a
trusted certificate entry, false otherwise.
/**
     * Returns true if the entry identified by the given alias is a
     * <i>trusted certificate entry</i>, and false otherwise.
     *
     * @return true if the entry identified by the given alias is a
     * <i>trusted certificate entry</i>, false otherwise.
     */
    public boolean engineIsCertificateEntry(String alias) {
        boolean isCert = false;
        Object entry = entries.get(alias.toLowerCase());
        if (entry instanceof TrustedCertEntry) {
            isCert = true;
        }
        return isCert;
    }

    
Returns the (alias) name of the first keystore entry whose certificate
matches the given certificate.

This method attempts to match the given certificate with each
keystore entry. If the entry being considered
is a trusted certificate entry, the given certificate is
compared to that entry's certificate. If the entry being considered is
a key entry, the given certificate is compared to the first
element of that entry's certificate chain (if a chain exists).

Params:
  • cert – the certificate to match with.
Returns:the (alias) name of the first entry with matching certificate,
or null if no such entry exists in this keystore.
/**
     * Returns the (alias) name of the first keystore entry whose certificate
     * matches the given certificate.
     *
     * <p>This method attempts to match the given certificate with each
     * keystore entry. If the entry being considered
     * is a <i>trusted certificate entry</i>, the given certificate is
     * compared to that entry's certificate. If the entry being considered is
     * a <i>key entry</i>, the given certificate is compared to the first
     * element of that entry's certificate chain (if a chain exists).
     *
     * @param cert the certificate to match with.
     *
     * @return the (alias) name of the first entry with matching certificate,
     * or null if no such entry exists in this keystore.
     */
    public String engineGetCertificateAlias(Certificate cert) {
        Certificate certElem;

        Enumeration<String> e = entries.keys();
        while (e.hasMoreElements()) {
            String alias = e.nextElement();
            Object entry = entries.get(alias);
            if (entry instanceof TrustedCertEntry) {
                certElem = ((TrustedCertEntry)entry).cert;
            } else if ((entry instanceof PrivateKeyEntry) &&
                       (((PrivateKeyEntry)entry).chain != null)) {
                certElem = ((PrivateKeyEntry)entry).chain[0];
            } else {
                continue;
            }
            if (certElem.equals(cert)) {
                return alias;
            }
        }
        return null;
    }

    
Stores this keystore to the given output stream, and protects its
integrity with the given password.

Params:
  • stream – the output stream to which this keystore is written.
  • password – the password to generate the keystore integrity check
Throws:
/**
     * Stores this keystore to the given output stream, and protects its
     * integrity with the given password.
     *
     * @param stream the output stream to which this keystore is written.
     * @param password the password to generate the keystore integrity check
     *
     * @exception IOException if there was an I/O problem with data
     * @exception NoSuchAlgorithmException if the appropriate data integrity
     * algorithm could not be found
     * @exception CertificateException if any of the certificates included in
     * the keystore data could not be stored
     */
    public void engineStore(OutputStream stream, char[] password)
        throws IOException, NoSuchAlgorithmException, CertificateException
    {
        synchronized(entries) {
            /*
             * KEYSTORE FORMAT:
             *
             * Magic number (big-endian integer),
             * Version of this file format (big-endian integer),
             *
             * Count (big-endian integer),
             * followed by "count" instances of either:
             *
             *     {
             *      tag=1 (big-endian integer)
             *      alias (UTF string)
             *      timestamp
             *      encrypted private-key info according to PKCS #8
             *          (integer length followed by encoding)
             *      cert chain (integer count followed by certs;
             *          for each cert: type UTF string, followed by integer
             *              length, followed by encoding)
             *     }
             *
             * or:
             *
             *     {
             *      tag=2 (big-endian integer)
             *      alias (UTF string)
             *      timestamp
             *      cert (type UTF string, followed by integer length,
             *          followed by encoding)
             *     }
             *
             * or:
             *
             *     {
             *      tag=3 (big-endian integer)
             *      alias (UTF string)
             *      timestamp
             *      sealed secret key (in serialized form)
             *     }
             *
             * ended by a keyed SHA1 hash (bytes only) of
             *     { password + whitener + preceding body }
             */

            // password is mandatory when storing
            if (password == null) {
                throw new IllegalArgumentException("password can't be null");
            }

            byte[] encoded; // the certificate encoding

            MessageDigest md = getPreKeyedHash(password);
            DataOutputStream dos
                = new DataOutputStream(new DigestOutputStream(stream, md));
            // NOTE: don't pass dos to oos at this point or it'll corrupt
            // the keystore!!!
            ObjectOutputStream oos = null;
            try {
                dos.writeInt(JCEKS_MAGIC);
                dos.writeInt(VERSION_2); // always write the latest version

                dos.writeInt(entries.size());

                Enumeration<String> e = entries.keys();
                while (e.hasMoreElements()) {

                    String alias = e.nextElement();
                    Object entry = entries.get(alias);

                    if (entry instanceof PrivateKeyEntry) {

                        PrivateKeyEntry pentry = (PrivateKeyEntry)entry;

                        // write PrivateKeyEntry tag
                        dos.writeInt(1);

                        // write the alias
                        dos.writeUTF(alias);

                        // write the (entry creation) date
                        dos.writeLong(pentry.date.getTime());

                        // write the protected private key
                        dos.writeInt(pentry.protectedKey.length);
                        dos.write(pentry.protectedKey);

                        // write the certificate chain
                        int chainLen;
                        if (pentry.chain == null) {
                            chainLen = 0;
                        } else {
                            chainLen = pentry.chain.length;
                        }
                        dos.writeInt(chainLen);
                        for (int i = 0; i < chainLen; i++) {
                            encoded = pentry.chain[i].getEncoded();
                            dos.writeUTF(pentry.chain[i].getType());
                            dos.writeInt(encoded.length);
                            dos.write(encoded);
                        }

                    } else if (entry instanceof TrustedCertEntry) {

                        // write TrustedCertEntry tag
                        dos.writeInt(2);

                        // write the alias
                        dos.writeUTF(alias);

                        // write the (entry creation) date
                        dos.writeLong(((TrustedCertEntry)entry).date.getTime());

                        // write the trusted certificate
                        encoded = ((TrustedCertEntry)entry).cert.getEncoded();
                        dos.writeUTF(((TrustedCertEntry)entry).cert.getType());
                        dos.writeInt(encoded.length);
                        dos.write(encoded);

                    } else {

                        // write SecretKeyEntry tag
                        dos.writeInt(3);

                        // write the alias
                        dos.writeUTF(alias);

                        // write the (entry creation) date
                        dos.writeLong(((SecretKeyEntry)entry).date.getTime());

                        // write the sealed key
                        oos = new ObjectOutputStream(dos);
                        oos.writeObject(((SecretKeyEntry)entry).sealedKey);
                        // NOTE: don't close oos here since we are still
                        // using dos!!!
                    }
                }

                /*
                 * Write the keyed hash which is used to detect tampering with
                 * the keystore (such as deleting or modifying key or
                 * certificate entries).
                 */
                byte digest[] = md.digest();

                dos.write(digest);
                dos.flush();
            } finally {
                if (oos != null) {
                    oos.close();
                } else {
                    dos.close();
                }
            }
        }
    }

    
Loads the keystore from the given input stream.

If a password is given, it is used to check the integrity of the
keystore data. Otherwise, the integrity of the keystore is not checked.

Params:
  • stream – the input stream from which the keystore is loaded
  • password – the (optional) password used to check the integrity of
the keystore.
Throws:
/**
     * Loads the keystore from the given input stream.
     *
     * <p>If a password is given, it is used to check the integrity of the
     * keystore data. Otherwise, the integrity of the keystore is not checked.
     *
     * @param stream the input stream from which the keystore is loaded
     * @param password the (optional) password used to check the integrity of
     * the keystore.
     *
     * @exception IOException if there is an I/O or format problem with the
     * keystore data
     * @exception NoSuchAlgorithmException if the algorithm used to check
     * the integrity of the keystore cannot be found
     * @exception CertificateException if any of the certificates in the
     * keystore could not be loaded
     */
    public void engineLoad(InputStream stream, char[] password)
        throws IOException, NoSuchAlgorithmException, CertificateException
    {
        synchronized(entries) {
            DataInputStream dis;
            MessageDigest md = null;
            CertificateFactory cf = null;
            Hashtable<String, CertificateFactory> cfs = null;
            ByteArrayInputStream bais = null;
            byte[] encoded = null;

            if (stream == null)
                return;

            if (password != null) {
                md = getPreKeyedHash(password);
                dis = new DataInputStream(new DigestInputStream(stream, md));
            } else {
                dis = new DataInputStream(stream);
            }
            // NOTE: don't pass dis to ois at this point or it'll fail to load
            // the keystore!!!
            ObjectInputStream ois = null;

            try {
                // Body format: see store method

                int xMagic = dis.readInt();
                int xVersion = dis.readInt();

                // Accept the following keystore implementations:
                // - JCEKS (this implementation), versions 1 and 2
                // - JKS (Sun's keystore implementation in JDK 1.2),
                //   versions 1 and 2
                if (((xMagic != JCEKS_MAGIC) && (xMagic != JKS_MAGIC)) ||
                    ((xVersion != VERSION_1) && (xVersion != VERSION_2))) {
                    throw new IOException("Invalid keystore format");
                }

                if (xVersion == VERSION_1) {
                    cf = CertificateFactory.getInstance("X509");
                } else {
                    // version 2
                    cfs = new Hashtable<String, CertificateFactory>(3);
                }

                entries.clear();
                int count = dis.readInt();

                for (int i = 0; i < count; i++) {
                    int tag;
                    String alias;

                    tag = dis.readInt();

                    if (tag == 1) { // private-key entry

                        PrivateKeyEntry entry = new PrivateKeyEntry();

                        // read the alias
                        alias = dis.readUTF();

                        // read the (entry creation) date
                        entry.date = new Date(dis.readLong());

                        // read the private key
                        try {
                            entry.protectedKey = new byte[dis.readInt()];
                        } catch (OutOfMemoryError e) {
                            throw new IOException("Keysize too big");
                        }
                        dis.readFully(entry.protectedKey);

                        // read the certificate chain
                        int numOfCerts = dis.readInt();
                        try {
                            if (numOfCerts > 0) {
                                entry.chain = new Certificate[numOfCerts];
                            }
                        } catch (OutOfMemoryError e) {
                            throw new IOException("Too many certificates in "
                                                  + "chain");
                        }
                        for (int j = 0; j < numOfCerts; j++) {
                            if (xVersion == 2) {
                                // read the certificate type, and instantiate a
                                // certificate factory of that type (reuse
                                // existing factory if possible)
                                String certType = dis.readUTF();
                                if (cfs.containsKey(certType)) {
                                // reuse certificate factory
                                    cf = cfs.get(certType);
                                } else {
                                // create new certificate factory
                                    cf = CertificateFactory.getInstance(certType);
                                // store the certificate factory so we can
                                // reuse it later
                                    cfs.put(certType, cf);
                                }
                            }
                            // instantiate the certificate
                            try {
                                encoded = new byte[dis.readInt()];
                            } catch (OutOfMemoryError e) {
                                throw new IOException("Certificate too big");
                            }
                            dis.readFully(encoded);
                            bais = new ByteArrayInputStream(encoded);
                            entry.chain[j] = cf.generateCertificate(bais);
                        }

                        // Add the entry to the list
                        entries.put(alias, entry);

                    } else if (tag == 2) { // trusted certificate entry

                        TrustedCertEntry entry = new TrustedCertEntry();

                        // read the alias
                        alias = dis.readUTF();

                        // read the (entry creation) date
                        entry.date = new Date(dis.readLong());

                        // read the trusted certificate
                        if (xVersion == 2) {
                            // read the certificate type, and instantiate a
                            // certificate factory of that type (reuse
                            // existing factory if possible)
                            String certType = dis.readUTF();
                            if (cfs.containsKey(certType)) {
                                // reuse certificate factory
                                cf = cfs.get(certType);
                            } else {
                                // create new certificate factory
                                cf = CertificateFactory.getInstance(certType);
                                // store the certificate factory so we can
                                // reuse it later
                                cfs.put(certType, cf);
                            }
                        }
                        try {
                            encoded = new byte[dis.readInt()];
                        } catch (OutOfMemoryError e) {
                            throw new IOException("Certificate too big");
                        }
                        dis.readFully(encoded);
                        bais = new ByteArrayInputStream(encoded);
                        entry.cert = cf.generateCertificate(bais);

                        // Add the entry to the list
                        entries.put(alias, entry);

                    } else if (tag == 3) { // secret-key entry

                        SecretKeyEntry entry = new SecretKeyEntry();

                        // read the alias
                        alias = dis.readUTF();

                        // read the (entry creation) date
                        entry.date = new Date(dis.readLong());

                        // read the sealed key
                        try {
                            ois = new ObjectInputStream(dis);
                            final ObjectInputStream ois2 = ois;
                            // Set a deserialization checker
                            AccessController.doPrivileged(
                                    new PrivilegedAction<Void>() {
                                        @Override
                                        public Void run() {
                                            ObjectInputFilter.Config.setObjectInputFilter(
                                                    ois2, new DeserializationChecker());
                                            return null;
                                        }
                                    });
                            entry.sealedKey = (SealedObject)ois.readObject();
                            // NOTE: don't close ois here since we are still
                            // using dis!!!
                        } catch (ClassNotFoundException cnfe) {
                            throw new IOException(cnfe.getMessage());
                        } catch (InvalidClassException ice) {
                            throw new IOException("Invalid secret key format");
                        }

                        // Add the entry to the list
                        entries.put(alias, entry);

                    } else {
                        throw new IOException("Unrecognized keystore entry");
                    }
                }

                /*
                 * If a password has been provided, we check the keyed digest
                 * at the end. If this check fails, the store has been tampered
                 * with
                 */
                if (password != null) {
                    byte computed[], actual[];
                    computed = md.digest();
                    actual = new byte[computed.length];
                    dis.readFully(actual);
                    for (int i = 0; i < computed.length; i++) {
                        if (computed[i] != actual[i]) {
                            throw new IOException("Keystore was tampered with, or "
                                                  + "password was incorrect");
                        }
                    }
                }
            }  finally {
                if (ois != null) {
                    ois.close();
                } else {
                    dis.close();
                }
            }
        }
    }

    
To guard against tampering with the keystore, we append a keyed
hash with a bit of whitener.

/**
     * To guard against tampering with the keystore, we append a keyed
     * hash with a bit of whitener.
     */
    private MessageDigest getPreKeyedHash(char[] password)
    throws NoSuchAlgorithmException, UnsupportedEncodingException {
        int i, j;

        MessageDigest md = MessageDigest.getInstance("SHA");
        byte[] passwdBytes = new byte[password.length * 2];
        for (i=0, j=0; i<password.length; i++) {
            passwdBytes[j++] = (byte)(password[i] >> 8);
            passwdBytes[j++] = (byte)password[i];
        }
        md.update(passwdBytes);
        for (i=0; i<passwdBytes.length; i++)
            passwdBytes[i] = 0;
        md.update("Mighty Aphrodite".getBytes("UTF8"));
        return md;
    }

    /*
     * An ObjectInputFilter that checks the format of the secret key being
     * deserialized.
     */
    private static class DeserializationChecker implements ObjectInputFilter {
        private static final int MAX_NESTED_DEPTH = 2;

        @Override
        public ObjectInputFilter.Status
            checkInput(ObjectInputFilter.FilterInfo info) {

            // First run a custom filter
            long nestedDepth = info.depth();
            if ((nestedDepth == 1 &&
                        info.serialClass() != SealedObjectForKeyProtector.class) ||
                    (nestedDepth > MAX_NESTED_DEPTH &&
                        info.serialClass() != null &&
                        info.serialClass() != Object.class)) {
                return Status.REJECTED;
            }

            // Next run the default filter, if available
            ObjectInputFilter defaultFilter =
                ObjectInputFilter.Config.getSerialFilter();
            if (defaultFilter != null) {
                return defaultFilter.checkInput(info);
            }

            return Status.UNDECIDED;
        }
    }
}