RSAPublicKey


1   package com.quadcap.crypto;
2   
3   /* Copyright 2002 - 2003 Quadcap Software.  All rights reserved.
4    *
5    * This software is distributed under the Quadcap Free Software License.
6    * This software may be used or modified for any purpose, personal or
7    * commercial.  Open Source redistributions are permitted.  Commercial
8    * redistribution of larger works derived from, or works which bundle
9    * this software requires a "Commercial Redistribution License"; see
10   * http://www.quadcap.com/purchase.
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12   * Redistributions qualify as "Open Source" under  one of the following terms:
13   *   
14   *    Redistributions are made at no charge beyond the reasonable cost of
15   *    materials and delivery.
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17   *    Redistributions are accompanied by a copy of the Source Code or by an
18   *    irrevocable offer to provide a copy of the Source Code for up to three
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20   *    must allow further use, modification, and redistribution of the Source
21   *    Code under substantially the same terms as this license.
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23   * Redistributions of source code must retain the copyright notices as they
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27   * Redistributions in binary form must reproduce this Copyright Notice,
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32   * The Software is provided on an "AS IS" basis.  No warranty is
33   * provided that the Software is free of defects, or fit for a
34   * particular purpose.  
35   *
36   * Limitation of Liability. Quadcap Software shall not be liable
37   * for any damages suffered by the Licensee or any third party resulting
38   * from use of the Software.
39   */
40  
41  import java.util.Random  ;
42  import java.math.BigInteger  ;
43  import java.nio.ByteBuffer  ;
44  
45  import com.quadcap.util.text.Text;
46  
47  /**
48   * RSA Public key implementation
49   *
50   * @author Stan Bailes
51   */
52  public class RSAPublicKey extends RSAKey implements PublicKey {
53      /**
54       * Default constructor
55       */
56      public RSAPublicKey() {}
57      
58      /**
59       * Construct from simple text representation
60       */
61      public void init(String   rep) {
62          String  [] s = Text.extractN(rep, "*:*:*");
63          super.init(s[3], Integer.parseInt(s[1]), new BigInteger  (s[2]));
64      }
65  
66      /**
67       * Convert to simple text representation
68       */
69      public String   toString() {
70          return "RSAPub:" + size + ":" + n + ":" + text;
71      }
72  
73      /**
74       * Return the textual identifier associated with this key
75       */
76      public String   getText() {
77          return text;
78      }
79  
80      /**
81       * Encrypt a buffer
82       */
83      public void f(ByteBuffer   plain, ByteBuffer   encrypted) {
84          engine(plain, encrypted);
85      }
86  
87      /**
88       * A single encryption operation for m < n
89       */
90      public BigInteger   engine(BigInteger   m) {
91          return m.modPow(e, n);
92      }
93  }
94
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