1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
/*
* $Id: BASE64.java,v 1.4 2004/08/06 13:41:49 dog Exp $
* Copyright (C) 2003 The Free Software Foundation
*
* This file is part of GNU inetlib, a library.
*
* GNU inetlib is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GNU inetlib is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* As a special exception, if you link this library with other files to
* produce an executable, this library does not by itself cause the
* resulting executable to be covered by the GNU General Public License.
* This exception does not however invalidate any other reasons why the
* executable file might be covered by the GNU General Public License.
*/
package gnu.inet.util;
/**
* Encodes and decodes text according to the BASE64 encoding.
*
* @author <a href="mailto:dog@gnu.org">Chris Burdess</a>
* @version $Revision: 1.4 $ $Date: 2004/08/06 13:41:49 $
*/
public final class BASE64
{
private static final byte[] src = {
0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a,
0x4b, 0x4c, 0x4d, 0x4e, 0x4f, 0x50, 0x51, 0x52, 0x53, 0x54,
0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x61, 0x62, 0x63, 0x64,
0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e,
0x6f, 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
0x79, 0x7a, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
0x38, 0x39, 0x2b, 0x2f
};
private static final byte[] dst;
static
{
dst = new byte[0x100];
for (int i = 0x0; i < 0xff; i++)
{
dst[i] = -1;
}
for (int i = 0; i < src.length; i++)
{
dst[src[i]] = (byte) i;
}
}
private BASE64 ()
{
}
/**
* Encode the specified byte array using the BASE64 algorithm.
*
* @param bs the source byte array
*/
public static byte[] encode (byte[] bs)
{
int si = 0, ti = 0; // source/target array indices
byte[] bt = new byte[((bs.length + 2) * 4) / 3]; // target byte array
for (; si < bs.length; si += 3)
{
int buflen = bs.length - si;
if (buflen == 1)
{
byte b = bs[si];
int i = 0;
boolean flag = false;
bt[ti++] = src[b >>> 2 & 0x3f];
bt[ti++] = src[(b << 4 & 0x30) + (i >>> 4 & 0xf)];
}
else if (buflen == 2)
{
byte b1 = bs[si], b2 = bs[si + 1];
int i = 0;
bt[ti++] = src[b1 >>> 2 & 0x3f];
bt[ti++] = src[(b1 << 4 & 0x30) + (b2 >>> 4 & 0xf)];
bt[ti++] = src[(b2 << 2 & 0x3c) + (i >>> 6 & 0x3)];
}
else
{
byte b1 = bs[si], b2 = bs[si + 1], b3 = bs[si + 2];
bt[ti++] = src[b1 >>> 2 & 0x3f];
bt[ti++] = src[(b1 << 4 & 0x30) + (b2 >>> 4 & 0xf)];
bt[ti++] = src[(b2 << 2 & 0x3c) + (b3 >>> 6 & 0x3)];
bt[ti++] = src[b3 & 0x3f];
}
}
return bt;
}
/**
* Decode the specified byte array using the BASE64 algorithm.
*
* @param bs the source byte array
*/
public static byte[] decode(byte[] bs)
{
int srclen = bs.length;
while (srclen > 0 && bs[srclen - 1] == 0x3d)
{
srclen--; /* strip padding character */
}
byte[] buffer = new byte[srclen];
int buflen = 0;
int si = 0;
int len = srclen - si;
while (len > 0)
{
byte b0 = dst[bs[si++] & 0xff];
byte b2 = dst[bs[si++] & 0xff];
buffer[buflen++] = (byte) (b0 << 2 & 0xfc | b2 >>> 4 & 0x3);
if (len > 2)
{
b0 = b2;
b2 = dst[bs[si++] & 0xff];
buffer[buflen++] = (byte) (b0 << 4 & 0xf0 | b2 >>> 2 & 0xf);
if (len > 3)
{
b0 = b2;
b2 = dst[bs[si++] & 0xff];
buffer[buflen++] = (byte) (b0 << 6 & 0xc0 | b2 & 0x3f);
}
}
len = srclen - si;
}
byte[] bt = new byte[buflen];
System.arraycopy (buffer, 0, bt, 0, buflen);
return bt;
}
public static void main (String[] args)
{
boolean decode = false;
for (int i = 0; i < args.length; i++)
{
if (args[i].equals ("-d"))
{
decode = true;
}
else
{
try
{
byte[] in = args[i].getBytes ("US-ASCII");
byte[] out = decode ? decode (in) : encode (in);
System.out.println (args[i] + " = " +
new String (out, "US-ASCII"));
}
catch (java.io.UnsupportedEncodingException e)
{
e.printStackTrace (System.err);
}
}
}
}
}
|
