annotate src/ch/ethz/ssh2/crypto/cipher/CBCMode.java @ 435:9c6a269fabb5 stable-1.9.2

add bitcoin donation address
author Carl Byington <carl@five-ten-sg.com>
date Thu, 09 Apr 2015 11:32:38 -0700
parents 071eccdff8ea
children
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 * CBCMode.
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
9 *
273
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 */
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
13 public class CBCMode implements BlockCipher {
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
14 BlockCipher tc;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
15 int blockSize;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
16 boolean doEncrypt;
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
17
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
18 byte[] cbc_vector;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
19 byte[] tmp_vector;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
20
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
21 public void init(boolean forEncryption, byte[] key) {
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
22 }
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
23
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
24 public CBCMode(BlockCipher tc, byte[] iv, boolean doEncrypt)
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
25 throws IllegalArgumentException {
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
26 this.tc = tc;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
27 this.blockSize = tc.getBlockSize();
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
28 this.doEncrypt = doEncrypt;
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
29
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
30 if (this.blockSize != iv.length)
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
31 throw new IllegalArgumentException("IV must be " + blockSize
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
32 + " bytes long! (currently " + iv.length + ")");
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
33
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
34 this.cbc_vector = new byte[blockSize];
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
35 this.tmp_vector = new byte[blockSize];
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
36 System.arraycopy(iv, 0, cbc_vector, 0, blockSize);
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
37 }
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
38
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
39 public int getBlockSize() {
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
40 return blockSize;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
41 }
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
42
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
43 private void encryptBlock(byte[] src, int srcoff, byte[] dst, int dstoff) {
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
44 for (int i = 0; i < blockSize; i++)
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
45 cbc_vector[i] ^= src[srcoff + i];
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
46
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
47 tc.transformBlock(cbc_vector, 0, dst, dstoff);
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
48 System.arraycopy(dst, dstoff, cbc_vector, 0, blockSize);
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
49 }
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
50
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
51 private void decryptBlock(byte[] src, int srcoff, byte[] dst, int dstoff) {
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
52 /* Assume the worst, src and dst are overlapping... */
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
53 System.arraycopy(src, srcoff, tmp_vector, 0, blockSize);
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
54 tc.transformBlock(src, srcoff, dst, dstoff);
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
55
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
56 for (int i = 0; i < blockSize; i++)
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
57 dst[dstoff + i] ^= cbc_vector[i];
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
58
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
59 /* ...that is why we need a tmp buffer. */
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
60 byte[] swap = cbc_vector;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
61 cbc_vector = tmp_vector;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
62 tmp_vector = swap;
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
63 }
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
64
307
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
65 public void transformBlock(byte[] src, int srcoff, byte[] dst, int dstoff) {
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
66 if (doEncrypt)
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
67 encryptBlock(src, srcoff, dst, dstoff);
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
68 else
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
69 decryptBlock(src, srcoff, dst, dstoff);
071eccdff8ea fix java formatting
Carl Byington <carl@five-ten-sg.com>
parents: 273
diff changeset
70 }
273
91a31873c42a start conversion from trilead to ganymed
Carl Byington <carl@five-ten-sg.com>
parents:
diff changeset
71 }