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comparison src/ch/ethz/ssh2/crypto/cipher/CipherOutputStream.java @ 273:91a31873c42a ganymed

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start conversion from trilead to ganymed
author Carl Byington <carl@five-ten-sg.com>
date Fri, 18 Jul 2014 11:21:46 -0700
parents
children 071eccdff8ea
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272:ce2f4e397703 273:91a31873c42a
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.cipher;
6
7 import java.io.IOException;
8 import java.io.OutputStream;
9
10 /**
11 * CipherOutputStream.
12 *
13 * @author Christian Plattner
14 * @version $Id: CipherOutputStream.java 85 2014-04-07 14:05:09Z dkocher@sudo.ch $
15 */
16 public class CipherOutputStream
17 {
18 BlockCipher currentCipher;
19 OutputStream bo;
20 byte[] buffer;
21 byte[] enc;
22 int blockSize;
23 int pos;
24
25 /*
26 * We cannot use java.io.BufferedOutputStream, since that is not available
27 * in J2ME. Everything could be improved here alot.
28 */
29
30 private static final int BUFF_SIZE = 8192;
31 byte[] out_buffer = new byte[BUFF_SIZE];
32 int out_buffer_pos = 0;
33
34 public CipherOutputStream(BlockCipher tc, OutputStream bo)
35 {
36 this.bo = bo;
37 changeCipher(tc);
38 }
39
40 private void internal_write(byte[] src, int off, int len) throws IOException
41 {
42 while (len > 0)
43 {
44 int space = BUFF_SIZE - out_buffer_pos;
45 int copy = (len > space) ? space : len;
46
47 System.arraycopy(src, off, out_buffer, out_buffer_pos, copy);
48
49 off += copy;
50 out_buffer_pos += copy;
51 len -= copy;
52
53 if (out_buffer_pos >= BUFF_SIZE)
54 {
55 bo.write(out_buffer, 0, BUFF_SIZE);
56 out_buffer_pos = 0;
57 }
58 }
59 }
60
61 private void internal_write(int b) throws IOException
62 {
63 out_buffer[out_buffer_pos++] = (byte) b;
64 if (out_buffer_pos >= BUFF_SIZE)
65 {
66 bo.write(out_buffer, 0, BUFF_SIZE);
67 out_buffer_pos = 0;
68 }
69 }
70
71 public void flush() throws IOException
72 {
73 if (pos != 0)
74 {
75 throw new IOException("FATAL: cannot flush since crypto buffer is not aligned.");
76 }
77
78 if (out_buffer_pos > 0)
79 {
80 bo.write(out_buffer, 0, out_buffer_pos);
81 out_buffer_pos = 0;
82 }
83 bo.flush();
84 }
85
86 public void changeCipher(BlockCipher bc)
87 {
88 this.currentCipher = bc;
89 blockSize = bc.getBlockSize();
90 buffer = new byte[blockSize];
91 enc = new byte[blockSize];
92 pos = 0;
93 }
94
95 private void writeBlock() throws IOException
96 {
97 try
98 {
99 currentCipher.transformBlock(buffer, 0, enc, 0);
100 }
101 catch (Exception e)
102 {
103 throw new IOException("Error while decrypting block.", e);
104 }
105
106 internal_write(enc, 0, blockSize);
107 pos = 0;
108 }
109
110 public void write(byte[] src, int off, int len) throws IOException
111 {
112 while (len > 0)
113 {
114 int avail = blockSize - pos;
115 int copy = Math.min(avail, len);
116
117 System.arraycopy(src, off, buffer, pos, copy);
118 pos += copy;
119 off += copy;
120 len -= copy;
121
122 if (pos >= blockSize)
123 {
124 writeBlock();
125 }
126 }
127 }
128
129 public void write(int b) throws IOException
130 {
131 buffer[pos++] = (byte) b;
132 if (pos >= blockSize)
133 {
134 writeBlock();
135 }
136 }
137
138 public void writePlain(int b) throws IOException
139 {
140 if (pos != 0)
141 {
142 throw new IOException("Cannot write plain since crypto buffer is not aligned.");
143 }
144 internal_write(b);
145 }
146
147 public void writePlain(byte[] b, int off, int len) throws IOException
148 {
149 if (pos != 0)
150 {
151 throw new IOException("Cannot write plain since crypto buffer is not aligned.");
152 }
153 internal_write(b, off, len);
154 }
155 }