001/**
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v1.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014package ch.qos.logback.core.net.ssl;
015
016import java.security.NoSuchAlgorithmException;
017import java.security.NoSuchProviderException;
018import java.security.SecureRandom;
019
020/**
021 * A factory bean for a JCA {@link SecureRandom} generator.
022 * <p>
023 * This object holds the configurable properties of a secure random generator
024 * and uses them to create and load a {@link SecureRandom} instance.
025 *
026 * @author Carl Harris
027 */
028public class SecureRandomFactoryBean {
029
030    private String algorithm;
031    private String provider;
032
033    /**
034     * Creates a new {@link SecureRandom} generator using the receiver's
035     * configuration.
036     * 
037     * @return secure random generator instance
038     * @throws NoSuchProviderException  if the provider name specified by
039     *                                  {@link #setProvider(String)} is not known to
040     *                                  the platform
041     * @throws NoSuchAlgorithmException if the algorithm name specified by
042     *                                  {@link #setAlgorithm(String)} is not
043     *                                  recognized by the specified provider (or the
044     *                                  platform's default provider if the provider
045     *                                  isn't specified)
046     */
047    public SecureRandom createSecureRandom() throws NoSuchProviderException, NoSuchAlgorithmException {
048        try {
049            return getProvider() != null ? SecureRandom.getInstance(getAlgorithm(), getProvider())
050                    : SecureRandom.getInstance(getAlgorithm());
051        } catch (NoSuchProviderException ex) {
052            throw new NoSuchProviderException("no such secure random provider: " + getProvider());
053        } catch (NoSuchAlgorithmException ex) {
054            throw new NoSuchAlgorithmException("no such secure random algorithm: " + getAlgorithm());
055        }
056    }
057
058    /**
059     * Gets the secure random generator algorithm name.
060     * 
061     * @return an algorithm name (e.g. {@code SHA1PRNG}); the
062     *         {@link SSL#DEFAULT_SECURE_RANDOM_ALGORITHM} is returned if no
063     *         algorithm has been specified
064     */
065    public String getAlgorithm() {
066        if (algorithm == null) {
067            return SSL.DEFAULT_SECURE_RANDOM_ALGORITHM;
068        }
069        return algorithm;
070    }
071
072    /**
073     * Sets the secure random generator algorithm name.
074     * 
075     * @param algorithm an algorithm name, which must be recognized by the provider
076     *                  specified via {@link #setProvider(String)} or by the
077     *                  platform's default provider if no provider is specified.
078     */
079    public void setAlgorithm(String algorithm) {
080        this.algorithm = algorithm;
081    }
082
083    /**
084     * Gets the JCA provider name for the secure random generator.
085     * 
086     * @return provider name
087     */
088    public String getProvider() {
089        return provider;
090    }
091
092    /**
093     * Sets the JCA provider name for the secure random generator.
094     * 
095     * @param provider name of the JCA provider to utilize in creating the secure
096     *                 random generator
097     */
098    public void setProvider(String provider) {
099        this.provider = provider;
100    }
101
102}