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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements. See the NOTICE file distributed with this
4    * work for additional information regarding copyright ownership. The ASF
5    * licenses this file to you under the Apache License, Version 2.0 (the
6    * "License"); you may not use this file except in compliance with the License.
7    * You may obtain a copy of the License at
8    *
9    * http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
13   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
14   * License for the specific language governing permissions and limitations under
15   * the License.
16   */
17  package org.apache.hadoop.hbase.io.crypto;
18  
19  import java.io.IOException;
20  import java.io.InputStream;
21  import java.io.OutputStream;
22  import java.security.Key;
23  
24  import org.apache.hadoop.classification.InterfaceAudience;
25  import org.apache.hadoop.classification.InterfaceStability;
26  
27  /**
28   * A common interface for a cryptographic algorithm.
29   */
30  @InterfaceAudience.Public
31  @InterfaceStability.Evolving
32  public abstract class Cipher {
33  
34    private final CipherProvider provider;
35  
36    public Cipher(CipherProvider provider) {
37      this.provider = provider;
38    }
39  
40    /**
41     * Return the provider for this Cipher
42     */
43    public CipherProvider getProvider() {
44      return provider;
45    }
46  
47    /**
48     * Return this Cipher's name
49     */
50    public abstract String getName();
51  
52    /**
53     * Return the key length required by this cipher, in bytes
54     */
55    public abstract int getKeyLength();
56  
57    /**
58     * Return the expected initialization vector length, in bytes, or 0 if not applicable
59     */
60    public abstract int getIvLength();
61  
62    /**
63     * Create a random symmetric key
64     * @return the random symmetric key
65     */
66    public abstract Key getRandomKey();
67  
68    /**
69     * Get an encryptor for encrypting data.
70     */
71    public abstract Encryptor getEncryptor();
72  
73    /**
74     * Return a decryptor for decrypting data.
75     */
76    public abstract Decryptor getDecryptor();
77  
78    /**
79     * Create an encrypting output stream given a context and IV
80     * @param out the output stream to wrap
81     * @param context the encryption context
82     * @param iv initialization vector
83     * @return the encrypting wrapper
84     * @throws IOException
85     */
86    public abstract OutputStream createEncryptionStream(OutputStream out, Context context,
87        byte[] iv)
88      throws IOException;
89  
90    /**
91     * Create an encrypting output stream given an initialized encryptor
92     * @param out the output stream to wrap
93     * @param encryptor the encryptor
94     * @return the encrypting wrapper
95     * @throws IOException
96     */
97    public abstract OutputStream createEncryptionStream(OutputStream out, Encryptor encryptor)
98      throws IOException;
99  
100   /**
101    * Create a decrypting input stream given a context and IV
102    * @param in the input stream to wrap
103    * @param context the encryption context
104    * @param iv initialization vector
105    * @return the decrypting wrapper
106    * @throws IOException
107    */
108   public abstract InputStream createDecryptionStream(InputStream in, Context context,
109       byte[] iv)
110     throws IOException;
111 
112   /**
113    * Create a decrypting output stream given an initialized decryptor
114    * @param in the input stream to wrap
115    * @param decryptor the decryptor
116    * @return the decrypting wrapper
117    * @throws IOException
118    */
119   public abstract InputStream createDecryptionStream(InputStream in, Decryptor decryptor)
120     throws IOException;
121 
122 }