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comparison app/src/main/java/ch/ethz/ssh2/crypto/Base64.java @ 438:d29cce60f393

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migrate from Eclipse to Android Studio
author Carl Byington <carl@five-ten-sg.com>
date Thu, 03 Dec 2015 11:23:55 -0800
parents src/ch/ethz/ssh2/crypto/Base64.java@071eccdff8ea
children
comparison
equal deleted inserted replaced
437:208b31032318 438:d29cce60f393
1 /*
2 * Copyright (c) 2006-2011 Christian Plattner. All rights reserved.
3 * Please refer to the LICENSE.txt for licensing details.
4 */
5 package ch.ethz.ssh2.crypto;
6
7 import java.io.CharArrayWriter;
8 import java.io.IOException;
9
10 /**
11 * Basic Base64 Support.
12 *
13 * @author Christian Plattner
14 * @version 2.50, 03/15/10
15 */
16 public class Base64 {
17 static final char[] alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray();
18
19 public static char[] encode(byte[] content) {
20 CharArrayWriter cw = new CharArrayWriter((4 * content.length) / 3);
21 int idx = 0;
22 int x = 0;
23
24 for (int i = 0; i < content.length; i++) {
25 if (idx == 0)
26 x = (content[i] & 0xff) << 16;
27 else if (idx == 1)
28 x = x | ((content[i] & 0xff) << 8);
29 else
30 x = x | (content[i] & 0xff);
31
32 idx++;
33
34 if (idx == 3) {
35 cw.write(alphabet[x >> 18]);
36 cw.write(alphabet[(x >> 12) & 0x3f]);
37 cw.write(alphabet[(x >> 6) & 0x3f]);
38 cw.write(alphabet[x & 0x3f]);
39 idx = 0;
40 }
41 }
42
43 if (idx == 1) {
44 cw.write(alphabet[x >> 18]);
45 cw.write(alphabet[(x >> 12) & 0x3f]);
46 cw.write('=');
47 cw.write('=');
48 }
49
50 if (idx == 2) {
51 cw.write(alphabet[x >> 18]);
52 cw.write(alphabet[(x >> 12) & 0x3f]);
53 cw.write(alphabet[(x >> 6) & 0x3f]);
54 cw.write('=');
55 }
56
57 return cw.toCharArray();
58 }
59
60 public static byte[] decode(char[] message) throws IOException {
61 byte buff[] = new byte[4];
62 byte dest[] = new byte[message.length];
63 int bpos = 0;
64 int destpos = 0;
65
66 for (int i = 0; i < message.length; i++) {
67 int c = message[i];
68
69 if ((c == '\n') || (c == '\r') || (c == ' ') || (c == '\t'))
70 continue;
71
72 if ((c >= 'A') && (c <= 'Z')) {
73 buff[bpos++] = (byte)(c - 'A');
74 }
75 else if ((c >= 'a') && (c <= 'z')) {
76 buff[bpos++] = (byte)((c - 'a') + 26);
77 }
78 else if ((c >= '0') && (c <= '9')) {
79 buff[bpos++] = (byte)((c - '0') + 52);
80 }
81 else if (c == '+') {
82 buff[bpos++] = 62;
83 }
84 else if (c == '/') {
85 buff[bpos++] = 63;
86 }
87 else if (c == '=') {
88 buff[bpos++] = 64;
89 }
90 else {
91 throw new IOException("Illegal char in base64 code.");
92 }
93
94 if (bpos == 4) {
95 bpos = 0;
96
97 if (buff[0] == 64)
98 break;
99
100 if (buff[1] == 64)
101 throw new IOException("Unexpected '=' in base64 code.");
102
103 if (buff[2] == 64) {
104 int v = (((buff[0] & 0x3f) << 6) | ((buff[1] & 0x3f)));
105 dest[destpos++] = (byte)(v >> 4);
106 break;
107 }
108 else if (buff[3] == 64) {
109 int v = (((buff[0] & 0x3f) << 12) | ((buff[1] & 0x3f) << 6) | ((buff[2] & 0x3f)));
110 dest[destpos++] = (byte)(v >> 10);
111 dest[destpos++] = (byte)(v >> 2);
112 break;
113 }
114 else {
115 int v = (((buff[0] & 0x3f) << 18) | ((buff[1] & 0x3f) << 12) | ((buff[2] & 0x3f) << 6) | ((buff[3] & 0x3f)));
116 dest[destpos++] = (byte)(v >> 16);
117 dest[destpos++] = (byte)(v >> 8);
118 dest[destpos++] = (byte)(v);
119 }
120 }
121 }
122
123 byte[] res = new byte[destpos];
124 System.arraycopy(dest, 0, res, 0, destpos);
125 return res;
126 }
127 }