1/* Copyright (c) 2002,2003, Stefan Haustein, Oberhausen, Rhld., Germany
2 *
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to deal
5 * in the Software without restriction, including without limitation the rights
6 * to use, copy, modify, merge, publish, distribute, sublicense, and/or
7 * sell copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
9 *
10 * The  above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
18 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
19 * IN THE SOFTWARE. */
20
21package org.ksoap2.kobjects.base64;
22
23import java.io.*;
24
25public class Base64 {
26
27    static final char[] charTab =
28            "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
29                    .toCharArray();
30
31    public static String encode(byte[] data) {
32        return encode(data, 0, data.length, null).toString();
33    }
34
35    /** Encodes the part of the given byte array denoted by start and
36    len to the Base64 format.  The encoded data is appended to the
37    given StringBuffer. If no StringBuffer is given, a new one is
38    created automatically. The StringBuffer is the return value of
39    this method. */
40
41    public static StringBuffer encode(
42            byte[] data,
43            int start,
44            int len,
45            StringBuffer buf) {
46
47        if (buf == null)
48            buf = new StringBuffer(data.length * 3 / 2);
49
50        int end = len - 3;
51        int i = start;
52        int n = 0;
53
54        while (i <= end) {
55            int d =
56                    ((((int) data[i]) & 0x0ff) << 16)
57                            | ((((int) data[i + 1]) & 0x0ff) << 8)
58                            | (((int) data[i + 2]) & 0x0ff);
59
60            buf.append(charTab[(d >> 18) & 63]);
61            buf.append(charTab[(d >> 12) & 63]);
62            buf.append(charTab[(d >> 6) & 63]);
63            buf.append(charTab[d & 63]);
64
65            i += 3;
66
67            if (n++ >= 14) {
68                n = 0;
69                buf.append("\r\n");
70            }
71        }
72
73        if (i == start + len - 2) {
74            int d =
75                    ((((int) data[i]) & 0x0ff) << 16)
76                            | ((((int) data[i + 1]) & 255) << 8);
77
78            buf.append(charTab[(d >> 18) & 63]);
79            buf.append(charTab[(d >> 12) & 63]);
80            buf.append(charTab[(d >> 6) & 63]);
81            buf.append("=");
82        }
83        else if (i == start + len - 1) {
84            int d = (((int) data[i]) & 0x0ff) << 16;
85
86            buf.append(charTab[(d >> 18) & 63]);
87            buf.append(charTab[(d >> 12) & 63]);
88            buf.append("==");
89        }
90
91        return buf;
92    }
93
94    static int decode(char c) {
95        if (c >= 'A' && c <= 'Z')
96            return ((int) c) - 65;
97        else if (c >= 'a' && c <= 'z')
98            return ((int) c) - 97 + 26;
99        else if (c >= '0' && c <= '9')
100            return ((int) c) - 48 + 26 + 26;
101        else
102            switch (c) {
103                case '+':
104                    return 62;
105                case '/':
106                    return 63;
107                case '=':
108                    return 0;
109                default:
110                    throw new RuntimeException(
111                            "unexpected code: " + c);
112            }
113    }
114
115    /** Decodes the given Base64 encoded String to a new byte array.
116    The byte array holding the decoded data is returned. */
117
118    public static byte[] decode(String s) {
119
120        ByteArrayOutputStream bos = new ByteArrayOutputStream();
121        try {
122            decode(s, bos);
123        } catch (IOException e) {
124            throw new RuntimeException();
125        }
126        return bos.toByteArray();
127    }
128
129    public static void decode(String s, OutputStream os)
130            throws IOException {
131        int i = 0;
132
133        int len = s.length();
134
135        while (true) {
136            while (i < len && s.charAt(i) <= ' ')
137                i++;
138
139            if (i == len)
140                break;
141
142            int tri =
143                    (decode(s.charAt(i)) << 18)
144                            + (decode(s.charAt(i + 1)) << 12)
145                            + (decode(s.charAt(i + 2)) << 6)
146                            + (decode(s.charAt(i + 3)));
147
148            os.write((tri >> 16) & 255);
149            if (s.charAt(i + 2) == '=')
150                break;
151            os.write((tri >> 8) & 255);
152            if (s.charAt(i + 3) == '=')
153                break;
154            os.write(tri & 255);
155
156            i += 4;
157        }
158    }
159}
160