5 private static final byte[] encodingTable = {
6 (byte)'A', (byte)'B', (byte)'C', (byte)'D', (byte)'E', (byte)'F', (byte)'G',
7 (byte)'H', (byte)'I', (byte)'J', (byte)'K', (byte)'L', (byte)'M', (byte)'N',
8 (byte)'O', (byte)'P', (byte)'Q', (byte)'R', (byte)'S', (byte)'T', (byte)'U',
9 (byte)'V', (byte)'W', (byte)'X', (byte)'Y', (byte)'Z',
10 (byte)'a', (byte)'b', (byte)'c', (byte)'d', (byte)'e', (byte)'f', (byte)'g',
11 (byte)'h', (byte)'i', (byte)'j', (byte)'k', (byte)'l', (byte)'m', (byte)'n',
12 (byte)'o', (byte)'p', (byte)'q', (byte)'r', (byte)'s', (byte)'t', (byte)'u',
13 (byte)'v', (byte)'w', (byte)'x', (byte)'y', (byte)'z', (byte)'0', (byte)'1',
14 (byte)'2', (byte)'3', (byte)'4', (byte)'5', (byte)'6', (byte)'7', (byte)'8',
15 (byte)'9', (byte)'+', (byte)'/'
18 // FIXME could be far more efficient
19 public static class InputStream extends java.io.ByteArrayInputStream {
20 public InputStream(String s) { super(decode(s.getBytes())); }
24 * encode the input data producong a base 64 encoded byte array.
26 * @return a byte array containing the base 64 encoded data.
28 public static byte[] encode(byte[] data) {
31 int modulus = data.length % 3;
33 bytes = new byte[4 * data.length / 3];
35 bytes = new byte[4 * ((data.length / 3) + 1)];
38 int dataLength = (data.length - modulus);
40 for (int i = 0, j = 0; i < dataLength; i += 3, j += 4) {
42 a2 = data[i + 1] & 0xff;
43 a3 = data[i + 2] & 0xff;
45 bytes[j] = encodingTable[(a1 >>> 2) & 0x3f];
46 bytes[j + 1] = encodingTable[((a1 << 4) | (a2 >>> 4)) & 0x3f];
47 bytes[j + 2] = encodingTable[((a2 << 2) | (a3 >>> 6)) & 0x3f];
48 bytes[j + 3] = encodingTable[a3 & 0x3f];
55 case 0: /* nothing left to do */
58 d1 = data[data.length - 1] & 0xff;
59 b1 = (d1 >>> 2) & 0x3f;
60 b2 = (d1 << 4) & 0x3f;
62 bytes[bytes.length - 4] = encodingTable[b1];
63 bytes[bytes.length - 3] = encodingTable[b2];
64 bytes[bytes.length - 2] = (byte)'=';
65 bytes[bytes.length - 1] = (byte)'=';
68 d1 = data[data.length - 2] & 0xff;
69 d2 = data[data.length - 1] & 0xff;
71 b1 = (d1 >>> 2) & 0x3f;
72 b2 = ((d1 << 4) | (d2 >>> 4)) & 0x3f;
73 b3 = (d2 << 2) & 0x3f;
75 bytes[bytes.length - 4] = encodingTable[b1];
76 bytes[bytes.length - 3] = encodingTable[b2];
77 bytes[bytes.length - 2] = encodingTable[b3];
78 bytes[bytes.length - 1] = (byte)'=';
85 private static final byte[] decodingTable;
88 decodingTable = new byte[128];
89 for (int i = 'A'; i <= 'Z'; i++) decodingTable[i] = (byte)(i - 'A');
90 for (int i = 'a'; i <= 'z'; i++) decodingTable[i] = (byte)(i - 'a' + 26);
91 for (int i = '0'; i <= '9'; i++) decodingTable[i] = (byte)(i - '0' + 52);
92 decodingTable['+'] = 62;
93 decodingTable['/'] = 63;
97 * decode the base 64 encoded input data.
99 * @return a byte array representing the decoded data.
101 public static byte[] decode(byte[] data) {
105 if (data[data.length - 2] == '=') bytes = new byte[(((data.length / 4) - 1) * 3) + 1];
106 else if (data[data.length - 1] == '=') bytes = new byte[(((data.length / 4) - 1) * 3) + 2];
107 else bytes = new byte[((data.length / 4) * 3)];
109 for (int i = 0, j = 0; i < data.length - 4; i += 4, j += 3) {
110 b1 = decodingTable[data[i]];
111 b2 = decodingTable[data[i + 1]];
112 b3 = decodingTable[data[i + 2]];
113 b4 = decodingTable[data[i + 3]];
115 bytes[j] = (byte)((b1 << 2) | (b2 >> 4));
116 bytes[j + 1] = (byte)((b2 << 4) | (b3 >> 2));
117 bytes[j + 2] = (byte)((b3 << 6) | b4);
120 if (data[data.length - 2] == '=') {
121 b1 = decodingTable[data[data.length - 4]];
122 b2 = decodingTable[data[data.length - 3]];
123 bytes[bytes.length - 1] = (byte)((b1 << 2) | (b2 >> 4));
124 } else if (data[data.length - 1] == '=') {
125 b1 = decodingTable[data[data.length - 4]];
126 b2 = decodingTable[data[data.length - 3]];
127 b3 = decodingTable[data[data.length - 2]];
128 bytes[bytes.length - 2] = (byte)((b1 << 2) | (b2 >> 4));
129 bytes[bytes.length - 1] = (byte)((b2 << 4) | (b3 >> 2));
131 b1 = decodingTable[data[data.length - 4]];
132 b2 = decodingTable[data[data.length - 3]];
133 b3 = decodingTable[data[data.length - 2]];
134 b4 = decodingTable[data[data.length - 1]];
135 bytes[bytes.length - 3] = (byte)((b1 << 2) | (b2 >> 4));
136 bytes[bytes.length - 2] = (byte)((b2 << 4) | (b3 >> 2));
137 bytes[bytes.length - 1] = (byte)((b3 << 6) | b4);
143 * decode the base 64 encoded String data.
145 * @return a byte array representing the decoded data.
147 public static byte[] decode(String data) {
151 if (data.charAt(data.length() - 2) == '=')
152 bytes = new byte[(((data.length() / 4) - 1) * 3) + 1];
153 else if (data.charAt(data.length() - 1) == '=')
154 bytes = new byte[(((data.length() / 4) - 1) * 3) + 2];
156 bytes = new byte[((data.length() / 4) * 3)];
158 for (int i = 0, j = 0; i < data.length() - 4; i += 4, j += 3) {
159 b1 = decodingTable[data.charAt(i)];
160 b2 = decodingTable[data.charAt(i + 1)];
161 b3 = decodingTable[data.charAt(i + 2)];
162 b4 = decodingTable[data.charAt(i + 3)];
164 bytes[j] = (byte)((b1 << 2) | (b2 >> 4));
165 bytes[j + 1] = (byte)((b2 << 4) | (b3 >> 2));
166 bytes[j + 2] = (byte)((b3 << 6) | b4);
169 if (data.charAt(data.length() - 2) == '=') {
170 b1 = decodingTable[data.charAt(data.length() - 4)];
171 b2 = decodingTable[data.charAt(data.length() - 3)];
172 bytes[bytes.length - 1] = (byte)((b1 << 2) | (b2 >> 4));
173 } else if (data.charAt(data.length() - 1) == '=') {
174 b1 = decodingTable[data.charAt(data.length() - 4)];
175 b2 = decodingTable[data.charAt(data.length() - 3)];
176 b3 = decodingTable[data.charAt(data.length() - 2)];
177 bytes[bytes.length - 2] = (byte)((b1 << 2) | (b2 >> 4));
178 bytes[bytes.length - 1] = (byte)((b2 << 4) | (b3 >> 2));
180 b1 = decodingTable[data.charAt(data.length() - 4)];
181 b2 = decodingTable[data.charAt(data.length() - 3)];
182 b3 = decodingTable[data.charAt(data.length() - 2)];
183 b4 = decodingTable[data.charAt(data.length() - 1)];
184 bytes[bytes.length - 3] = (byte)((b1 << 2) | (b2 >> 4));
185 bytes[bytes.length - 2] = (byte)((b2 << 4) | (b3 >> 2));
186 bytes[bytes.length - 1] = (byte)((b3 << 6) | b4);