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
 * 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,
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 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package sun.security.provider;

import java.io.*;
import java.security.*;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.security.cert.CertificateException;
import java.util.*;

import sun.security.pkcs.EncryptedPrivateKeyInfo;


This class provides the keystore implementation referred to as "JKS".

Author:Jan Luehe, David Brownell
See Also:
Since:1.2
/**
 * This class provides the keystore implementation referred to as "JKS".
 *
 * @author Jan Luehe
 * @author David Brownell
 *
 *
 * @see KeyProtector
 * @see java.security.KeyStoreSpi
 * @see KeyTool
 *
 * @since 1.2
 */

abstract class JavaKeyStore extends KeyStoreSpi {

    // regular JKS
    public static final class JKS extends JavaKeyStore {
        String convertAlias(String alias) {
            return alias.toLowerCase();
        }
    }

    // special JKS that uses case sensitive aliases
    public static final class CaseExactJKS extends JavaKeyStore {
        String convertAlias(String alias) {
            return alias;
        }
    }

    private static final int MAGIC = 0xfeedfeed;
    private static final int VERSION_1 = 0x01;
    private static final int VERSION_2 = 0x02;

    // Private keys and their supporting certificate chains
    private static class KeyEntry {
        Date date; // the creation date of this entry
        byte[] protectedPrivKey;
        Certificate chain[];
    };

    // Trusted certificates
    private static 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 final Hashtable<String, Object> entries;

    JavaKeyStore() {
        entries = new Hashtable<String, Object>();
    }

    // convert an alias to internal form, overridden in subclasses:
    // lower case for regular JKS
    // original string for CaseExactJKS
    abstract String convertAlias(String alias);

    
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
    {
        Object entry = entries.get(convertAlias(alias));

        if (entry == null || !(entry instanceof KeyEntry)) {
            return null;
        }
        if (password == null) {
            throw new UnrecoverableKeyException("Password must not be null");
        }

        KeyProtector keyProtector = new KeyProtector(password);
        byte[] encrBytes = ((KeyEntry)entry).protectedPrivKey;
        EncryptedPrivateKeyInfo encrInfo;
        byte[] plain;
        try {
            encrInfo = new EncryptedPrivateKeyInfo(encrBytes);
        } catch (IOException ioe) {
            throw new UnrecoverableKeyException("Private key not stored as "
                                                + "PKCS #8 "
                                                + "EncryptedPrivateKeyInfo");
        }
        return keyProtector.recover(encrInfo);
    }

    
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) {
        Object entry = entries.get(convertAlias(alias));

        if (entry != null && entry instanceof KeyEntry) {
            if (((KeyEntry)entry).chain == null) {
                return null;
            } else {
                return ((KeyEntry)entry).chain.clone();
            }
        } else {
            return null;
        }
    }

    
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) {
        Object entry = entries.get(convertAlias(alias));

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

    
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) {
        Object entry = entries.get(convertAlias(alias));

        if (entry != null) {
            if (entry instanceof TrustedCertEntry) {
                return new Date(((TrustedCertEntry)entry).date.getTime());
            } else {
                return new Date(((KeyEntry)entry).date.getTime());
            }
        } else {
            return null;
        }
    }

    
Assigns the given private key to the given alias, protecting
it with the given password as defined in PKCS8.

The given java.security.PrivateKey key 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 certificate
chain.

Params:
  • alias – the alias name
  • key – the private 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 is not a private key,
cannot be protected, or this operation fails for some other reason
/**
     * Assigns the given private key to the given alias, protecting
     * it with the given password as defined in PKCS8.
     *
     * <p>The given java.security.PrivateKey <code>key</code> 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 certificate
     * chain.
     *
     * @param alias the alias name
     * @param key the private 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 is not a private 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
    {
        KeyProtector keyProtector = null;

        if (!(key instanceof java.security.PrivateKey)) {
            throw new KeyStoreException("Cannot store non-PrivateKeys");
        }
        try {
            synchronized(entries) {
                KeyEntry entry = new KeyEntry();
                entry.date = new Date();

                // Protect the encoding of the key
                keyProtector = new KeyProtector(password);
                entry.protectedPrivKey = keyProtector.protect(key);

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

                entries.put(convertAlias(alias), entry);
            }
        } catch (NoSuchAlgorithmException nsae) {
            throw new KeyStoreException("Key protection algorithm not found");
        } finally {
            keyProtector = null;
        }
    }

    
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
underlying keystore implementation is of type jks,
key must be encoded as an
EncryptedPrivateKeyInfo as defined in the PKCS #8 standard.

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. If the
     * underlying keystore implementation is of type <code>jks</code>,
     * <code>key</code> must be encoded as an
     * <code>EncryptedPrivateKeyInfo</code> as defined in the PKCS #8 standard.
     *
     * <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) {
            // key must be encoded as EncryptedPrivateKeyInfo as defined in
            // PKCS#8
            try {
                new EncryptedPrivateKeyInfo(key);
            } catch (IOException ioe) {
                throw new KeyStoreException("key is not encoded as "
                                            + "EncryptedPrivateKeyInfo");
            }

            KeyEntry entry = new KeyEntry();
            entry.date = new Date();

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

            entries.put(convertAlias(alias), 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(convertAlias(alias));
            if ((entry != null) && (entry instanceof KeyEntry)) {
                throw new KeyStoreException
                    ("Cannot overwrite own certificate");
            }

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

    
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(convertAlias(alias));
    }

    
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) {
        Object entry = entries.get(convertAlias(alias));
        if ((entry != null) && (entry instanceof KeyEntry)) {
            return true;
        } else {
            return false;
        }
    }

    
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) {
        Object entry = entries.get(convertAlias(alias));
        if ((entry != null) && (entry instanceof TrustedCertEntry)) {
            return true;
        } else {
            return false;
        }
    }

    
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;

        for (Enumeration<String> e = entries.keys(); e.hasMoreElements(); ) {
            String alias = e.nextElement();
            Object entry = entries.get(alias);
            if (entry instanceof TrustedCertEntry) {
                certElem = ((TrustedCertEntry)entry).cert;
            } else if (((KeyEntry)entry).chain != null) {
                certElem = ((KeyEntry)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, then certs; for each cert,
             *          integer length followed by encoding)
             *     }
             *
             * or:
             *
             *     {
             *      tag=2 (big-endian integer)
             *      alias (UTF string)
             *      timestamp
             *      cert (integer length followed by encoding)
             *     }
             *
             * 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));

            dos.writeInt(MAGIC);
            // always write the latest version
            dos.writeInt(VERSION_2);

            dos.writeInt(entries.size());

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

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

                if (entry instanceof KeyEntry) {

                    // Store this entry as a KeyEntry
                    dos.writeInt(1);

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

                    // Write the (entry creation) date
                    dos.writeLong(((KeyEntry)entry).date.getTime());

                    // Write the protected private key
                    dos.writeInt(((KeyEntry)entry).protectedPrivKey.length);
                    dos.write(((KeyEntry)entry).protectedPrivKey);

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

                    // Store this entry as a certificate
                    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);
                }
            }

            /*
             * 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();
        }
    }

    
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);
            }

            // Body format: see store method

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

            if (xMagic!=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

                    KeyEntry entry = new KeyEntry();

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

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

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

                    // 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);
                        bais.close();
                    }

                    // 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);
                    bais.close();

                    // 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]) {
                        Throwable t = new UnrecoverableKeyException
                            ("Password verification failed");
                        throw (IOException)new IOException
                            ("Keystore was tampered with, or "
                            + "password was incorrect").initCause(t);
                    }
                }
            }
        }
    }

    
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;
    }
}