net.java.truevfs.driver.zip.raes.KeyManagerRaesParameters Maven / Gradle / Ivy

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Provides a file system driver for accessing the RAES encrypted ZIP file format, alias ZIP.RAES or TZP. Add the JAR artifact of this module to the run time class path to make its file system drivers available for service location in the client API modules.

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/*
 * Copyright (C) 2005-2015 Schlichtherle IT Services.
 * All rights reserved. Use is subject to license terms.
 */
package net.java.truevfs.driver.zip.raes;

import java.net.URI;
import java.util.Objects;
import javax.annotation.concurrent.ThreadSafe;
import net.java.truevfs.driver.zip.raes.crypto.RaesKeyException;
import net.java.truevfs.driver.zip.raes.crypto.RaesParameters;
import net.java.truevfs.driver.zip.raes.crypto.RaesParametersProvider;
import net.java.truevfs.driver.zip.raes.crypto.Type0RaesParameters;
import net.java.truecommons.key.spec.KeyManager;
import net.java.truecommons.key.spec.KeyManagerMap;
import net.java.truecommons.key.spec.KeyProvider;
import net.java.truecommons.key.spec.UnknownKeyException;
import net.java.truecommons.key.spec.common.AesKeyStrength;
import net.java.truecommons.key.spec.common.AesPbeParameters;

/**
 * An adapter which provides {@link RaesParameters} by using a
 * {@link KeyManager} for {@link AesPbeParameters}.
 * 
 * The current implementation supports only {@link Type0RaesParameters}.
 *
 * @author Christian Schlichtherle
 */
@ThreadSafe
public class KeyManagerRaesParameters
implements RaesParametersProvider {

    /** The key manager for accessing RAES encrypted data. */
    protected final KeyManager manager;

    /** The resource URI of the RAES file. */
    protected final URI raes;

    /**
     * Constructs RAES parameters using the given key manager provider.
     *
     * @param  container the container of the key manager for accessing RAES
     *         encrypted data.
     * @param  raes the absolute URI of the RAES file.
     */
    public KeyManagerRaesParameters(
            final KeyManagerMap container,
            final URI raes) {
        this(container.manager(AesPbeParameters.class), raes);
    }

    /**
     * Constructs new RAES parameters.
     *
     * @param  manager the key manager for accessing RAES encrypted data.
     * @param  raes the resource URI of the RAES file.
     */
    public KeyManagerRaesParameters(
            final KeyManager manager,
            final URI raes) {
        this.manager = Objects.requireNonNull(manager);
        this.raes = Objects.requireNonNull(raes);
    }

    /**
     * {@inheritDoc}
     * 

     * If {@code type} is assignable from {@link Type0RaesParameters}, then the
     * {@link KeyManager} for {@link AesPbeParameters} will getKeyManager used which
     * has been provided to the constructor.
     * 

     * Otherwise, {@code null} gets returned.
     */
    @Override
    public 
 P get(Class type) {
        if (type.isAssignableFrom(Type0RaesParameters.class))
            return type.cast(new Type0());
        return null;
    }

    /**
     * Adapts a {@code KeyProvider} for {@link  AesPbeParameters} obtained
     * from the {@link #manager} to {@code Type0RaesParameters}.
     */
    private class Type0 implements Type0RaesParameters {

        private volatile KeyProvider provider;

        private KeyProvider provider() {
            final KeyProvider p = provider;
            return null != p ? p : (provider = manager.provider(raes));
        }

        @Override
        public char[] getPasswordForWriting()
        throws RaesKeyException {
            try {
                return provider().getKeyForWriting().getPassword();
            } catch (final UnknownKeyException ex) {
                throw new RaesKeyException(ex);
            }
        }

        @Override
        public char[] getPasswordForReading(final boolean invalid)
        throws RaesKeyException {
            try {
                return provider().getKeyForReading(invalid).getPassword();
            } catch (final UnknownKeyException ex) {
                throw new RaesKeyException(ex);
            }
        }

        @Override
        public AesKeyStrength getKeyStrength()
        throws RaesKeyException {
            try {
                return provider().getKeyForWriting().getKeyStrength();
            } catch (final UnknownKeyException ex) {
                throw new RaesKeyException(ex);
            }
        }

        @Override
        public void setKeyStrength(final AesKeyStrength keyStrength)
        throws RaesKeyException {
            final KeyProvider p = provider();
            final AesPbeParameters k;
            try {
                k = p.getKeyForReading(false);
            } catch (final UnknownKeyException ex) {
                throw new RaesKeyException(ex);
            }
            k.setKeyStrength(keyStrength);
            p.setKey(k);
        }
    } // Type0
}