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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *     http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.shiro.crypto.hash;
20  
21  import org.apache.shiro.util.ByteSource;
22  
23  /**
24   * A Cryptographic {@code Hash} represents a one-way conversion algorithm that transforms an input source to an
25   * underlying byte array.  Hex and Base64-encoding output of the hashed bytes are automatically supported by the
26   * inherited {@link #toHex() toHex()} and {@link #toBase64() toBase64()} methods.
27   * <p/>
28   * The bytes returned by the parent interface's {@link #getBytes() getBytes()} are the hashed value of the
29   * original input source, also known as the 'checksum' or 'digest'.
30   *
31   * @see Md2Hash
32   * @see Md5Hash
33   * @see Sha1Hash
34   * @see Sha256Hash
35   * @see Sha384Hash
36   * @see Sha512Hash
37   * @since 0.9
38   */
39  public interface Hash extends ByteSource {
40  
41      /**
42       * Returns the name of the algorithm used to hash the input source, for example, {@code SHA-256}, {@code MD5}, etc.
43       * <p/>
44       * The name is expected to be a {@link java.security.MessageDigest MessageDigest} algorithm name.
45       *
46       * @return the the name of the algorithm used to hash the input source, for example, {@code SHA-256}, {@code MD5}, etc.
47       * @since 1.1
48       */
49      String getAlgorithmName();
50  
51      /**
52       * Returns a salt used to compute the hash or {@code null} if no salt was used.
53       *
54       * @return a salt used to compute the hash or {@code null} if no salt was used.
55       * @since 1.2
56       */
57      ByteSource getSalt();
58  
59      /**
60       * Returns the number of hash iterations used to compute the hash.
61       *
62       * @return the number of hash iterations used to compute the hash.
63       * @since 1.2
64       */
65      int getIterations();
66  
67  }