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1 package com.quikj.server.framework;
2
3 import java.security.*;
4 import javax.crypto.*;
5 import javax.crypto.spec.*;
6
11 public final class Encryption
12 {
13 private javax.crypto.SecretKey secretKey = null;
14
15
18 public Encryption()
19 throws
20 InvalidKeyException,
21 NoSuchAlgorithmException,
22 java.security.spec.InvalidKeySpecException 
23 {
24 super();
25
26 Provider sun_jce = new com.sun.crypto.provider.SunJCE();
27 Security.addProvider(sun_jce);
28 }
29
35 public static String byteToString(byte[] inp)
36 {
37 StringBuffer buffer = new StringBuffer ();
38 for (int i = 0; i < inp.length; i++)
39 {
40 String n = Byte.toString(inp[i]);
41 int len = n.length();
42
43 if (len == 1)
44 {
45 buffer.append("$$$" + n);
46 }
47 else if (len == 2)
48 {
49 buffer.append("$$" + n);
50 }
51 else if (len == 3)
52 {
53 buffer.append("$" + n);
54 }
55 else
56 {
57 buffer.append(n);
58 }
59 }
60
61 return buffer.toString();
62
63 }
64
70 public String decrypt(String text, String secret)
71 {
72 try
73 {
74 DESKeySpec des_key_spec = new DESKeySpec(secret.getBytes());
75 SecretKeyFactory key_factory = SecretKeyFactory.getInstance("DES");
76 javax.crypto.SecretKey secret_key = key_factory.generateSecret(des_key_spec);
77
78 byte[] input = stringToByte(text);
79 if (input == null)
80 {
81 return null;
82 }
83
84 Cipher cipher = Cipher.getInstance("DES");
85 cipher.init(Cipher.DECRYPT_MODE, secret_key);
86 byte[] decrypt_text = cipher.doFinal(input);
87 return new String (decrypt_text);
88 }
89 catch (Exception ex)
90 {
91 return null;
92 }
93 }
94
100 public String encrypt(String text, String secret)
101 {
102 try
103 {
104 byte[] secret_bytes = secret.getBytes();
105 DESKeySpec des_key_spec = new DESKeySpec(secret_bytes);
106 SecretKeyFactory key_factory = SecretKeyFactory.getInstance("DES");
107 javax.crypto.SecretKey secret_key = key_factory.generateSecret(des_key_spec);
108
109 Cipher cipher = Cipher.getInstance("DES");
110 cipher.init(Cipher.ENCRYPT_MODE, secret_key);
111 byte[] cipher_text = cipher.doFinal(text.getBytes());
112
113 return byteToString(cipher_text);
114 }
115 catch (Exception ex)
116 {
117 return null;
118 }
119 }
120
125 public static void main(String [] args)
126 {
127 try
128 {
129 if (args.length < 3)
130 {
131 System.err.println("Usage <-e/-d> text secret");
132 System.exit(1);
133 }
134
135 Encryption enc = new Encryption();
136 if (args[0].equals("-e") == true)
137 {
138 System.out.println("Result: " + enc.encrypt(args[1], args[2]));
139
140 }
141 else if (args[0].equals("-d") == true)
142 {
143 System.out.println("Result: " + enc.decrypt(args[1], args[2]));
144 }
145 else
146 {
147 System.err.println("Unknown option " + args[0]);
148 System.exit(2);
149 }
150 }
151 catch (Exception ex)
152 {
153 System.err.println(ex.getClass().getName() + ": " + ex.getMessage());
154 System.exit(3);
155 }
156
157 System.exit(0);
158 }
159
165 public static byte[] stringToByte(String text)
166 {
167 int len = text.length();
168 if ((len % 4) > 0)
169 {
170 return null;
171 }
172
173 byte[] input = new byte[len / 4];
174 for (int i = 0; i < len; i += 4)
175 {
176 String element = text.substring(i, i + 4);
177
178 if (element.startsWith("$$$") == true)
179 {
180 element = element.substring(3);
181 }
182 else if (element.startsWith("$$") == true)
183 {
184 element = element.substring(2);
185 }
186 else if (element.startsWith("$") == true)
187 {
188 element = element.substring(1);
189 }
190
191 try
192 {
193 input[i / 4] = Byte.parseByte(element);
194 }
195 catch (NumberFormatException ex)
196 {
197 return null;
198 }
199 }
200 return input;
201 }
202 }
203 |
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