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comparison src/ch/ethz/ssh2/crypto/KeyMaterial.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
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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;
6
7 import java.io.IOException;
8 import java.math.BigInteger;
9
10 import ch.ethz.ssh2.crypto.digest.HashForSSH2Types;
11
12 /**
13 * Establishes key material for iv/key/mac (both directions).
14 *
15 * @author Christian Plattner
16 * @version 2.50, 03/15/10
17 */
18 public class KeyMaterial {
19 public byte[] initial_iv_client_to_server;
20 public byte[] initial_iv_server_to_client;
21 public byte[] enc_key_client_to_server;
22 public byte[] enc_key_server_to_client;
23 public byte[] integrity_key_client_to_server;
24 public byte[] integrity_key_server_to_client;
25
26 private static byte[] calculateKey(HashForSSH2Types sh, BigInteger K, byte[] H, byte type, byte[] SessionID,
27 int keyLength) throws IOException {
28 byte[] res = new byte[keyLength];
29
30 int dglen = sh.getDigestLength();
31 int numRounds = (keyLength + dglen - 1) / dglen;
32
33 byte[][] tmp = new byte[numRounds][];
34
35 sh.reset();
36 sh.updateBigInt(K);
37 sh.updateBytes(H);
38 sh.updateByte(type);
39 sh.updateBytes(SessionID);
40
41 tmp[0] = sh.getDigest();
42
43 int off = 0;
44 int produced = Math.min(dglen, keyLength);
45
46 System.arraycopy(tmp[0], 0, res, off, produced);
47
48 keyLength -= produced;
49 off += produced;
50
51 for(int i = 1; i < numRounds; i++) {
52 sh.updateBigInt(K);
53 sh.updateBytes(H);
54
55 for(int j = 0; j < i; j++) {
56 sh.updateBytes(tmp[j]);
57 }
58
59 tmp[i] = sh.getDigest();
60
61 produced = Math.min(dglen, keyLength);
62 System.arraycopy(tmp[i], 0, res, off, produced);
63 keyLength -= produced;
64 off += produced;
65 }
66
67 return res;
68 }
69
70 public static KeyMaterial create(String hashType, byte[] H, BigInteger K, byte[] SessionID, int keyLengthCS,
71 int blockSizeCS, int macLengthCS, int keyLengthSC, int blockSizeSC, int macLengthSC)
72 throws IOException {
73 KeyMaterial km = new KeyMaterial();
74
75 HashForSSH2Types sh = new HashForSSH2Types(hashType);
76
77 km.initial_iv_client_to_server = calculateKey(sh, K, H, (byte) 'A', SessionID, blockSizeCS);
78
79 km.initial_iv_server_to_client = calculateKey(sh, K, H, (byte) 'B', SessionID, blockSizeSC);
80
81 km.enc_key_client_to_server = calculateKey(sh, K, H, (byte) 'C', SessionID, keyLengthCS);
82
83 km.enc_key_server_to_client = calculateKey(sh, K, H, (byte) 'D', SessionID, keyLengthSC);
84
85 km.integrity_key_client_to_server = calculateKey(sh, K, H, (byte) 'E', SessionID, macLengthCS);
86
87 km.integrity_key_server_to_client = calculateKey(sh, K, H, (byte) 'F', SessionID, macLengthSC);
88
89 return km;
90 }
91 }