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1   /**
2    *
3    *  Licensed to the Apache Software Foundation (ASF) under one or more
4    *  contributor license agreements.  See the NOTICE file distributed with
5    *  this work for additional information regarding copyright ownership.
6    *  The ASF licenses this file to You under the Apache License, Version 2.0
7    *  (the "License"); you may not use this file except in compliance with
8    *  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, software
13   *  distributed under the License is distributed on an "AS IS" BASIS,
14   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15   *  See the License for the specific language governing permissions and
16   *  limitations under the License.
17   */
18  
19  package org.apache.geronimo.util.crypto;
20  
21  /**
22   * interface that a message digest conforms to.
23   */
24  public interface Digest
25  {
26      /**
27       * return the algorithm name
28       *
29       * @return the algorithm name
30       */
31      public String getAlgorithmName();
32  
33      /**
34       * return the size, in bytes, of the digest produced by this message digest.
35       *
36       * @return the size, in bytes, of the digest produced by this message digest.
37       */
38      public int getDigestSize();
39  
40      /**
41       * update the message digest with a single byte.
42       *
43       * @param in the input byte to be entered.
44       */
45      public void update(byte in);
46  
47      /**
48       * update the message digest with a block of bytes.
49       *
50       * @param in the byte array containing the data.
51       * @param inOff the offset into the byte array where the data starts.
52       * @param len the length of the data.
53       */
54      public void update(byte[] in, int inOff, int len);
55  
56      /**
57       * close the digest, producing the final digest value. The doFinal
58       * call leaves the digest reset.
59       *
60       * @param out the array the digest is to be copied into.
61       * @param outOff the offset into the out array the digest is to start at.
62       */
63      public int doFinal(byte[] out, int outOff);
64  
65      /**
66       * reset the digest back to it's initial state.
67       */
68      public void reset();
69  }