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1   /*
2    * Copyright 2001-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.codehaus.xfire.util ;
17  
18  import java.io.IOException;
19  import java.io.OutputStream;
20  import java.io.Writer;
21  
22  /***
23   *
24   * @author TAMURA Kent <kent@trl.ibm.co.jp>
25   */
26  public class Base64 {
27      private static final char[] S_BASE64CHAR = {
28          'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 
29          'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 
30          'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 
31          'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 
32          'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 
33          'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', 
34          '8', '9', '+', '/'
35      };
36      private static final char S_BASE64PAD = '=';
37      private static final byte[] S_DECODETABLE = new byte[128];
38      static {
39          for (int i = 0;  i < S_DECODETABLE.length;  i ++)
40              S_DECODETABLE[i] = Byte.MAX_VALUE;  // 127
41          for (int i = 0;  i < S_BASE64CHAR.length;  i ++) // 0 to 63
42              S_DECODETABLE[S_BASE64CHAR[i]] = (byte)i;
43      }
44  
45      private static int decode0(char[] ibuf, byte[] obuf, int wp) {
46          int outlen = 3;
47          if (ibuf[3] == S_BASE64PAD)  outlen = 2;
48          if (ibuf[2] == S_BASE64PAD)  outlen = 1;
49          int b0 = S_DECODETABLE[ibuf[0]];
50          int b1 = S_DECODETABLE[ibuf[1]];
51          int b2 = S_DECODETABLE[ibuf[2]];
52          int b3 = S_DECODETABLE[ibuf[3]];
53          switch (outlen) {
54          case 1:
55              obuf[wp] = (byte)(b0 << 2 & 0xfc | b1 >> 4 & 0x3);
56              return 1;
57          case 2:
58              obuf[wp++] = (byte)(b0 << 2 & 0xfc | b1 >> 4 & 0x3);
59              obuf[wp] = (byte)(b1 << 4 & 0xf0 | b2 >> 2 & 0xf);
60              return 2;
61          case 3:
62              obuf[wp++] = (byte)(b0 << 2 & 0xfc | b1 >> 4 & 0x3);
63              obuf[wp++] = (byte)(b1 << 4 & 0xf0 | b2 >> 2 & 0xf);
64              obuf[wp] = (byte)(b2 << 6 & 0xc0 | b3 & 0x3f);
65              return 3;
66          default:
67              throw new RuntimeException("Couldn't decode.");
68          }
69      }
70  
71      /***
72       *
73       */
74      public static byte[] decode(char[] data, int off, int len) {
75          char[] ibuf = new char[4];
76          int ibufcount = 0;
77          byte[] obuf = new byte[len/4*3+3];
78          int obufcount = 0;
79          for (int i = off;  i < off+len;  i ++) {
80              char ch = data[i];
81              if (ch == S_BASE64PAD
82                  || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
83                  ibuf[ibufcount++] = ch;
84                  if (ibufcount == ibuf.length) {
85                      ibufcount = 0;
86                      obufcount += decode0(ibuf, obuf, obufcount);
87                  }
88              }
89          }
90          if (obufcount == obuf.length)
91              return obuf;
92          byte[] ret = new byte[obufcount];
93          System.arraycopy(obuf, 0, ret, 0, obufcount);
94          return ret;
95      }
96  
97      /***
98       *
99       */
100     public static byte[] decode(String data) {
101         char[] ibuf = new char[4];
102         int ibufcount = 0;
103         byte[] obuf = new byte[data.length()/4*3+3];
104         int obufcount = 0;
105         for (int i = 0;  i < data.length();  i ++) {
106             char ch = data.charAt(i);
107             if (ch == S_BASE64PAD
108                 || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
109                 ibuf[ibufcount++] = ch;
110                 if (ibufcount == ibuf.length) {
111                     ibufcount = 0;
112                     obufcount += decode0(ibuf, obuf, obufcount);
113                 }
114             }
115         }
116         if (obufcount == obuf.length)
117             return obuf;
118         byte[] ret = new byte[obufcount];
119         System.arraycopy(obuf, 0, ret, 0, obufcount);
120         return ret;
121     }
122 
123     /***
124      *
125      */
126     public static void decode(char[] data, int off, int len, OutputStream ostream) throws IOException {
127         char[] ibuf = new char[4];
128         int ibufcount = 0;
129         byte[] obuf = new byte[3];
130         for (int i = off;  i < off+len;  i ++) {
131             char ch = data[i];
132             if (ch == S_BASE64PAD
133                 || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
134                 ibuf[ibufcount++] = ch;
135                 if (ibufcount == ibuf.length) {
136                     ibufcount = 0;
137                     int obufcount = decode0(ibuf, obuf, 0);
138                     ostream.write(obuf, 0, obufcount);
139                 }
140             }
141         }
142     }
143 
144     /***
145      *
146      */
147     public static void decode(String data, OutputStream ostream) throws IOException {
148         char[] ibuf = new char[4];
149         int ibufcount = 0;
150         byte[] obuf = new byte[3];
151         for (int i = 0;  i < data.length();  i ++) {
152             char ch = data.charAt(i);
153             if (ch == S_BASE64PAD
154                 || ch < S_DECODETABLE.length && S_DECODETABLE[ch] != Byte.MAX_VALUE) {
155                 ibuf[ibufcount++] = ch;
156                 if (ibufcount == ibuf.length) {
157                     ibufcount = 0;
158                     int obufcount = decode0(ibuf, obuf, 0);
159                     ostream.write(obuf, 0, obufcount);
160                 }
161             }
162         }
163     }
164 
165     /***
166      * Returns base64 representation of specified byte array.
167      */
168     public static String encode(byte[] data) {
169         return encode(data, 0, data.length);
170     }
171 
172     /***
173      * Returns base64 representation of specified byte array.
174      */
175     public static String encode(byte[] data, int off, int len) {
176         if (len <= 0)  return "";
177         char[] out = new char[len/3*4+4];
178         int rindex = off;
179         int windex = 0;
180         int rest = len-off;
181         while (rest >= 3) {
182             int i = ((data[rindex]&0xff)<<16)
183                     +((data[rindex+1]&0xff)<<8)
184                     +(data[rindex+2]&0xff);
185             out[windex++] = S_BASE64CHAR[i>>18];
186             out[windex++] = S_BASE64CHAR[(i>>12)&0x3f];
187             out[windex++] = S_BASE64CHAR[(i>>6)&0x3f];
188             out[windex++] = S_BASE64CHAR[i&0x3f];
189             rindex += 3;
190             rest -= 3;
191         }
192         if (rest == 1) {
193             int i = data[rindex]&0xff;
194             out[windex++] = S_BASE64CHAR[i>>2];
195             out[windex++] = S_BASE64CHAR[(i<<4)&0x3f];
196             out[windex++] = S_BASE64PAD;
197             out[windex++] = S_BASE64PAD;
198         } else if (rest == 2) {
199             int i = ((data[rindex]&0xff)<<8)+(data[rindex+1]&0xff);
200             out[windex++] = S_BASE64CHAR[i>>10];
201             out[windex++] = S_BASE64CHAR[(i>>4)&0x3f];
202             out[windex++] = S_BASE64CHAR[(i<<2)&0x3f];
203             out[windex++] = S_BASE64PAD;
204         }
205         return new String(out, 0, windex);
206     }
207 
208     /***
209      * Outputs base64 representation of the specified byte array to a byte stream.
210      */
211     public static void encode(byte[] data, int off, int len, OutputStream ostream) throws IOException {
212         if (len <= 0)  return;
213         byte[] out = new byte[4];
214         int rindex = off;
215         int rest = len-off;
216         while (rest >= 3) {
217             int i = ((data[rindex]&0xff)<<16)
218                     +((data[rindex+1]&0xff)<<8)
219                     +(data[rindex+2]&0xff);
220             out[0] = (byte)S_BASE64CHAR[i>>18];
221             out[1] = (byte)S_BASE64CHAR[(i>>12)&0x3f];
222             out[2] = (byte)S_BASE64CHAR[(i>>6)&0x3f];
223             out[3] = (byte)S_BASE64CHAR[i&0x3f];
224             ostream.write(out, 0, 4);
225             rindex += 3;
226             rest -= 3;
227         }
228         if (rest == 1) {
229             int i = data[rindex]&0xff;
230             out[0] = (byte)S_BASE64CHAR[i>>2];
231             out[1] = (byte)S_BASE64CHAR[(i<<4)&0x3f];
232             out[2] = (byte)S_BASE64PAD;
233             out[3] = (byte)S_BASE64PAD;
234             ostream.write(out, 0, 4);
235         } else if (rest == 2) {
236             int i = ((data[rindex]&0xff)<<8)+(data[rindex+1]&0xff);
237             out[0] = (byte)S_BASE64CHAR[i>>10];
238             out[1] = (byte)S_BASE64CHAR[(i>>4)&0x3f];
239             out[2] = (byte)S_BASE64CHAR[(i<<2)&0x3f];
240             out[3] = (byte)S_BASE64PAD;
241             ostream.write(out, 0, 4);
242         }
243     }
244 
245     /***
246      * Outputs base64 representation of the specified byte array to a character stream.
247      */
248     public static void encode(byte[] data, int off, int len, Writer writer) throws IOException {
249         if (len <= 0)  return;
250         char[] out = new char[4];
251         int rindex = off;
252         int rest = len-off;
253         int output = 0;
254         while (rest >= 3) {
255             int i = ((data[rindex]&0xff)<<16)
256                     +((data[rindex+1]&0xff)<<8)
257                     +(data[rindex+2]&0xff);
258             out[0] = S_BASE64CHAR[i>>18];
259             out[1] = S_BASE64CHAR[(i>>12)&0x3f];
260             out[2] = S_BASE64CHAR[(i>>6)&0x3f];
261             out[3] = S_BASE64CHAR[i&0x3f];
262             writer.write(out, 0, 4);
263             rindex += 3;
264             rest -= 3;
265             output += 4;
266             if (output % 76 == 0)
267                 writer.write("\n");
268         }
269         if (rest == 1) {
270             int i = data[rindex]&0xff;
271             out[0] = S_BASE64CHAR[i>>2];
272             out[1] = S_BASE64CHAR[(i<<4)&0x3f];
273             out[2] = S_BASE64PAD;
274             out[3] = S_BASE64PAD;
275             writer.write(out, 0, 4);
276         } else if (rest == 2) {
277             int i = ((data[rindex]&0xff)<<8)+(data[rindex+1]&0xff);
278             out[0] = S_BASE64CHAR[i>>10];
279             out[1] = S_BASE64CHAR[(i>>4)&0x3f];
280             out[2] = S_BASE64CHAR[(i<<2)&0x3f];
281             out[3] = S_BASE64PAD;
282             writer.write(out, 0, 4);
283         }
284     }
285 }