/* KeyStoreSpi.java --- Key Store Service Provider Interface
   Copyright (C) 1999, 2004  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
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General Public License for more details.

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02111-1307 USA.

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making a combined work based on this library.  Thus, the terms and
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permission to link this library with independent modules to produce an
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package java.security;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.cert.CertificateException;
import java.util.Date;
import java.util.Enumeration;

/**
 * KeyStoreSpi is the Service Provider Interface (SPI) for the 
 * KeyStore class. This is the interface for providers to 
 * supply to implement a keystore for a particular keystore 
 * type.
 *
 * @since 1.2
 * @author Mark Benvenuto
 */
public abstract class KeyStoreSpi
{
  /**
   * Constructs a new KeyStoreSpi
   */
  public KeyStoreSpi()
  {
  }

  /**
   * Returns the key associated with given alias using the 
   * supplied password.
   *
   * @param alias an alias for the key to get
   * @param password password to access key with
   *
   * @return the requested key, or null otherwise
   *
   * @throws NoSuchAlgorithmException if there is no algorithm
   * for recovering the key
   * @throws UnrecoverableKeyException key cannot be reocovered
   * (wrong password).
   */
  public abstract Key engineGetKey(String alias, char[]password)
    throws NoSuchAlgorithmException, UnrecoverableKeyException;

  /**
   * Gets a Certificate chain for the specified alias.
   *
   * @param alias the alias name
   *
   * @return a chain of Certificates ( ordered from the user's 
   * certificate to the Certificate Authority's ) or 
   * null if the alias does not exist or there is no
   * certificate chain for the alias ( the alias refers
   * to a trusted certificate entry or there is no entry).
   */
  public abstract java.security.cert.
    Certificate[] engineGetCertificateChain(String alias);


  /**
   * Gets a Certificate for the specified alias.
   *
   * If there is a trusted certificate entry then that is returned.
   * it there is a key entry with a certificate chain then the
   * first certificate is return or else null.
   *
   * @param alias the alias name
   *
   * @return a Certificate or null if the alias does not exist 
   * or there is no certificate for the alias
   */
  public abstract java.security.cert.
    Certificate engineGetCertificate(String alias);

  /**
   * Gets entry creation date for the specified alias.
   *
   * @param alias the alias name
   *
   * @returns the entry creation date or null
   */
  public abstract Date engineGetCreationDate(String alias);

  /**
   * Assign the key to the alias in the keystore, protecting it
   * with the given password. It will overwrite an existing 
   * entry and if the key is a PrivateKey, also add the 
   * certificate chain representing the corresponding public key.
   *
   * @param alias the alias name
   * @param key the key to add
   * @password the password to protect with
   * @param chain the certificate chain for the corresponding
   * public key
   *
   * @throws KeyStoreException if it fails
   */
  public abstract void engineSetKeyEntry(String alias, Key key,
					 char[]password,
					 java.security.cert.
					 Certificate[]chain) throws
    KeyStoreException;

  /**
   * Assign the key to the alias in the keystore. It will overwrite
   * an existing entry and if the key is a PrivateKey, also 
   * add the certificate chain representing the corresponding 
   * public key.
   *
   * @param alias the alias name
   * @param key the key to add
   * @param chain the certificate chain for the corresponding
   * public key
   *
   * @throws KeyStoreException if it fails
   */
  public abstract void engineSetKeyEntry(String alias, byte[]key,
					 java.security.cert.
					 Certificate[]chain) throws
    KeyStoreException;


  /**
   * Assign the certificate to the alias in the keystore. It 
   * will overwrite an existing entry.
   *
   * @param alias the alias name
   * @param cert the certificate to add
   *
   * @throws KeyStoreException if it fails
   */
  public abstract void engineSetCertificateEntry(String alias,
						 java.security.cert.
						 Certificate cert) throws
    KeyStoreException;

  /**
   * Deletes the entry for the specified entry.
   *
   * @param alias the alias name
   *
   * @throws KeyStoreException if it fails
   */
  public abstract void engineDeleteEntry(String alias)
    throws KeyStoreException;

  /**
   * Generates a list of all the aliases in the keystore.
   *
   * @return an Enumeration of the aliases
   */
  public abstract Enumeration engineAliases();

  /**
   * Determines if the keystore contains the specified alias.
   *
   * @param alias the alias name
   *
   * @return true if it contains the alias, false otherwise
   */
  public abstract boolean engineContainsAlias(String alias);

  /**
   * Returns the number of entries in the keystore.
   *
   * @returns the number of keystore entries.
   */
  public abstract int engineSize();

  /**
   * Determines if the keystore contains a key entry for 
   * the specified alias.
   *
   * @param alias the alias name
   *
   * @return true if it is a key entry, false otherwise
   */
  public abstract boolean engineIsKeyEntry(String alias);

  /**
   * Determines if the keystore contains a certificate entry for 
   * the specified alias.
   *
   * @param alias the alias name
   *
   * @return true if it is a certificate entry, false otherwise
   */
  public abstract boolean engineIsCertificateEntry(String alias);

  /**
   * Determines if the keystore contains the specified certificate 
   * entry and returns the alias.
   *
   * It checks every entry and for a key entry checks only the
   * first certificate in the chain.
   *
   * @param cert Certificate to look for
   *
   * @return alias of first matching certificate, null if it 
   * does not exist.
   */
  public abstract String engineGetCertificateAlias(java.security.cert.
						   Certificate cert);

  /**
   * Stores the keystore in the specified output stream and it
   * uses the specified key it keep it secure.
   *
   * @param stream the output stream to save the keystore to
   * @param password the password to protect the keystore integrity with
   *
   * @throws IOException if an I/O error occurs.
   * @throws NoSuchAlgorithmException the data integrity algorithm 
   * used cannot be found.
   * @throws CertificateException if any certificates could not be
   * stored in the output stream.
   */
  public abstract void engineStore(OutputStream stream, char[]password)
    throws IOException, NoSuchAlgorithmException, CertificateException;


  /**
   * Loads the keystore from the specified input stream and it
   * uses the specified password to check for integrity if supplied.
   *
   * @param stream the input stream to load the keystore from
   * @param password the password to check the keystore integrity with
   *
   * @throws IOException if an I/O error occurs.
   * @throws NoSuchAlgorithmException the data integrity algorithm 
   * used cannot be found.
   * @throws CertificateException if any certificates could not be
   * stored in the output stream.
   */
  public abstract void engineLoad(InputStream stream, char[]password)
    throws IOException, NoSuchAlgorithmException, CertificateException;
}