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Java > Open Source Codes > org > apache > geronimo > util > crypto > DSA


1 /**
2  * Licensed to the Apache Software Foundation (ASF) under one or more
3  * contributor license agreements. See the NOTICE file distributed with
4  * this work for additional information regarding copyright ownership.
5  * The ASF licenses this file to You under the Apache License, Version 2.0
6  * (the "License"); you may not use this file except in compliance with
7  * the License. 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,
13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14  * See the License for the specific language governing permissions and
15  * limitations under the License.
16  */
17
18 package org.apache.geronimo.util.crypto;
19
20 import java.math.BigInteger JavaDoc;
21
22 /**
23  * interface for classes implementing algorithms modeled similar to the Digital Signature Alorithm.
24  */
25 public interface DSA
26 {
27     /**
28      * initialise the signer for signature generation or signature
29      * verification.
30      *
31      * @param forSigning true if we are generating a signature, false
32      * otherwise.
33      * @param param key parameters for signature generation.
34      */
35     public void init(boolean forSigning, CipherParameters param);
36
37     /**
38      * sign the passed in message (usually the output of a hash function).
39      *
40      * @param message the message to be signed.
41      * @return two big integers representing the r and s values respectively.
42      */
43     public BigInteger JavaDoc[] generateSignature(byte[] message);
44
45     /**
46      * verify the message message against the signature values r and s.
47      *
48      * @param message the message that was supposed to have been signed.
49      * @param r the r signature value.
50      * @param s the s signature value.
51      */
52     public boolean verifySignature(byte[] message, BigInteger JavaDoc r, BigInteger JavaDoc s);
53 }
54
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