package gnu.crypto.keyring;  // -*- c-basic-offset: 3 -*-

// ---------------------------------------------------------------------------
// $Id: IKeyring.java,v 1.5 2005/10/06 04:24:16 rsdio Exp $
//
// Copyright (C) 2003 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.
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// General Public License for more details.
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//
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//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library.  Thus, the terms and
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import java.io.IOException;
import java.util.Enumeration;
import java.util.List;
import java.util.Map;

/**
 * <p>The top-level interface to a <i>keyring:</i> a file that is used to
 * store and protect public and private cryptographic keys.</p>
 *
 * <p>A <i>keyring</i> is modelled as a mapping of one <i>alias</i> to one or
 * more <i>entries</i> (optionally of different types).</p>
 *
 * <p>See also the sub-interfaces {@link IPublicKeyring} and
 * {@link IPrivateKeyring} for special types of <i>keyrings</i> --the difference
 * being in the type of entries they contain.</p>
 *
 * @version $Revision: 1.5 $
 */
public interface IKeyring {

   /**
    * <p>Property name for the source of data to load the keyring from. The
    * value mapped must be a {@link java.io.InputStream}.</p>
    */
   public static final String KEYRING_DATA_IN = "gnu.crypto.keyring.data.in";

   /**
    * <p>Property name for the data sink to store the keyring to. The value
    * mapped must be a {@link java.io.OutputStream}.</p>
    */
   public static final String KEYRING_DATA_OUT = "gun.crypto.keyring.data.out";

   /**
    * <p>Property name for the keyring's top-level password, used to
    * authenticate and/or transform the store itself. The mapped value must be a
    * char array.</p>
    */
   public static final String KEYRING_PASSWORD = "gnu.crypto.keyring.password";

   /**
    * <p>Loads a keyring into memory.</p>
    *
    * <p>What happens to the current contents of this keyring? are the new ones
    * merged with the current ones or do they simply replace them?</p>
    *
    * @param attributes The attributes that designate the source where the store
    * is to be loaded from. What happens
    * @throws IllegalArgumentException If the attributes are inappropriate.
    * @throws IOException If the keyring file cannot be read.
    * @throws SecurityException If the given password is incorrect, or if the
    * top-level authentication or decryption fails.
    */
   void load(Map attributes) throws IOException;

   /**
    * <p>Stores the contents of this keyring to persistent storage as specified
    * by the designated <code>attributes</code>.</p>
    *
    * @param attributes the attributes that define where the contents of this
    * keyring will be stored.
    * @throws IOException if an exception occurs during the process.
    */
   void store(Map attributes) throws IOException;

   /**
    * <p>Resets this keyring, clearing all sensitive data. This method always
    * suceeds.</p>
    */
   void reset();

   /**
    * <p>Returns the number of entries in this keyring.</p>
    *
    * @return The number of current entries in this keyring.
    */
   int size();

   /**
    * <p>Returns an {@link Enumeration} of all aliases (instances of
    * {@link String}) in this keyring.</p>
    *
    * @return The enumeration of {@link String}s each representing an
    * <i>alias</i> found in this keyring.
    */
   Enumeration aliases();

   /**
    * Tests whether or not this keyring contains the given alias.
    *
    * @param alias The alias to check.
    * @return true if this keyring contains the alias.
    */
   boolean containsAlias(String alias);

   /**
    * <p>Returns a {@link List} of entries (instances of {@link Entry}) for the
    * given <code>alias</code>, or <code>null</code> if there no such entry
    * exists.</p>
    *
    * @param alias The alias of the entry(ies) to return.
    * @return A list of all entries (instances of {@link Entry} that have the
    * given <code>alias</code>, or <code>null</code> if no one {@link Entry} can
    * be found with the designated <code>alias</code>.
    */
   List get(String alias);

   /**
    * <p>Adds a designated {@link Entry} to this keyring.</p>
    *
    * <p>What happens if there is already an entry with the same alias?</p>
    *
    * @param entry The entry to put in this keyring.
    */
   void add(Entry entry);

   /**
    * <p>Removes an entry with the designated <code>alias</code> from this
    * keyring. Does nothing if there was no such entry.</p>
    *
    * <p>What happens if there are more than one?</p>
    *
    * @param alias The alias of the entry to remove.
    */
   void remove(String alias);
}
