Mercurial > 510Connectbot

annotate src/ch/ethz/ssh2/crypto/cipher/CTRMode.java @ 297:c1f929cb3dd0 ganymed

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
start conversion from trilead to ganymed
author Carl Byington <carl@five-ten-sg.com>
date Tue, 29 Jul 2014 16:43:12 -0700
parents 91a31873c42a
children 071eccdff8ea
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
1 /*
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
2 * Copyright (c) 2006-2011 Christian Plattner. All rights reserved.
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
3 * Please refer to the LICENSE.txt for licensing details.
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
4 */
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
5 package ch.ethz.ssh2.crypto.cipher;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
6
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
7 /**
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
8 * This is CTR mode as described in draft-ietf-secsh-newmodes-XY.txt
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
9 *
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
10 * @author Christian Plattner
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
11 * @version 2.50, 03/15/10
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
12 */
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
13 public class CTRMode implements BlockCipher
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
14 {
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
15 byte[] X;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
16 byte[] Xenc;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
17
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
18 BlockCipher bc;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
19 int blockSize;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
20 boolean doEncrypt;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
21
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
22 int count = 0;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
23
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
24 public void init(boolean forEncryption, byte[] key)
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
25 {
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
26 }
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
27
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
28 public CTRMode(BlockCipher tc, byte[] iv, boolean doEnc) throws IllegalArgumentException
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
29 {
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
30 bc = tc;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
31 blockSize = bc.getBlockSize();
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
32 doEncrypt = doEnc;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
33
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
34 if (blockSize != iv.length)
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
35 throw new IllegalArgumentException("IV must be " + blockSize + " bytes long! (currently " + iv.length + ")");
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
36
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
37 X = new byte[blockSize];
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
38 Xenc = new byte[blockSize];
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
39
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
40 System.arraycopy(iv, 0, X, 0, blockSize);
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
41 }
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
42
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
43 public final int getBlockSize()
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
44 {
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
45 return blockSize;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
46 }
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
47
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
48 public final void transformBlock(byte[] src, int srcoff, byte[] dst, int dstoff)
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
49 {
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
50 bc.transformBlock(X, 0, Xenc, 0);
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
51
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
52 for (int i = 0; i < blockSize; i++)
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
53 {
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
54 dst[dstoff + i] = (byte) (src[srcoff + i] ^ Xenc[i]);
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
55 }
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
56
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
57 for (int i = (blockSize - 1); i >= 0; i--)
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
58 {
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
59 X[i]++;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
60 if (X[i] != 0)
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
61 break;
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
62
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
63 }
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
64 }
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
65 }