1   /**
2    * Logback: the reliable, generic, fast and flexible logging framework.
3    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
4    *
5    * This program and the accompanying materials are dual-licensed under
6    * either the terms of the Eclipse Public License v1.0 as published by
7    * the Eclipse Foundation
8    *
9    *   or (per the licensee's choosing)
10   *
11   * under the terms of the GNU Lesser General Public License version 2.1
12   * as published by the Free Software Foundation.
13   */
14  package ch.qos.logback.core.net.ssl;
15  
16  import java.security.NoSuchAlgorithmException;
17  import java.security.NoSuchProviderException;
18  import java.security.SecureRandom;
19  
20  /**
21   * A factory bean for a JCA {@link SecureRandom} generator.
22   * <p>
23   * This object holds the configurable properties of a secure random generator
24   * and uses them to create and load a {@link SecureRandom} instance.
25   *
26   * @author Carl Harris
27   */
28  public class SecureRandomFactoryBean {
29  
30      private String algorithm;
31      private String provider;
32  
33      /**
34       * Creates a new {@link SecureRandom} generator using the receiver's
35       * configuration.
36       * 
37       * @return secure random generator instance
38       * @throws NoSuchProviderException  if the provider name specified by
39       *                                  {@link #setProvider(String)} is not known to
40       *                                  the platform
41       * @throws NoSuchAlgorithmException if the algorithm name specified by
42       *                                  {@link #setAlgorithm(String)} is not
43       *                                  recognized by the specified provider (or the
44       *                                  platform's default provider if the provider
45       *                                  isn't specified)
46       */
47      public SecureRandom createSecureRandom() throws NoSuchProviderException, NoSuchAlgorithmException {
48          try {
49              return getProvider() != null ? SecureRandom.getInstance(getAlgorithm(), getProvider())
50                      : SecureRandom.getInstance(getAlgorithm());
51          } catch (NoSuchProviderException ex) {
52              throw new NoSuchProviderException("no such secure random provider: " + getProvider());
53          } catch (NoSuchAlgorithmException ex) {
54              throw new NoSuchAlgorithmException("no such secure random algorithm: " + getAlgorithm());
55          }
56      }
57  
58      /**
59       * Gets the secure random generator algorithm name.
60       * 
61       * @return an algorithm name (e.g. {@code SHA1PRNG}); the
62       *         {@link SSL#DEFAULT_SECURE_RANDOM_ALGORITHM} is returned if no
63       *         algorithm has been specified
64       */
65      public String getAlgorithm() {
66          if (algorithm == null) {
67              return SSL.DEFAULT_SECURE_RANDOM_ALGORITHM;
68          }
69          return algorithm;
70      }
71  
72      /**
73       * Sets the secure random generator algorithm name.
74       * 
75       * @param algorithm an algorithm name, which must be recognized by the provider
76       *                  specified via {@link #setProvider(String)} or by the
77       *                  platform's default provider if no provider is specified.
78       */
79      public void setAlgorithm(String algorithm) {
80          this.algorithm = algorithm;
81      }
82  
83      /**
84       * Gets the JCA provider name for the secure random generator.
85       * 
86       * @return provider name
87       */
88      public String getProvider() {
89          return provider;
90      }
91  
92      /**
93       * Sets the JCA provider name for the secure random generator.
94       * 
95       * @param provider name of the JCA provider to utilize in creating the secure
96       *                 random generator
97       */
98      public void setProvider(String provider) {
99          this.provider = provider;
100     }
101 
102 }