// $Id: MD2.java 54 2007-01-24 16:22:09Z tp $
package fr.cryptohash;
/**
* <p>This class implements the MD2 digest algorithm under the
* <code>Digest</code> API, using the <code>DigestEngine</code> class.
* MD4 is described in RFC 1319.</p>
*
* <pre>
* ==========================(LICENSE BEGIN)============================
*
* Copyright (c) 2007 Projet RNRT SAPHIR
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* ===========================(LICENSE END)=============================
* </pre>
*
* @version $Revision: 54 $
* @author Thomas Pornin <thomas.pornin@cryptolog.com>
*/
public class MD2 extends DigestEngine {
/**
* Create the object.
*/
public MD2()
{
}
/** Internal "magic" table. */
private static final int[] S = {
41, 46, 67, 201, 162, 216, 124, 1,
61, 54, 84, 161, 236, 240, 6, 19,
98, 167, 5, 243, 192, 199, 115, 140,
152, 147, 43, 217, 188, 76, 130, 202,
30, 155, 87, 60, 253, 212, 224, 22,
103, 66, 111, 24, 138, 23, 229, 18,
190, 78, 196, 214, 218, 158, 222, 73,
160, 251, 245, 142, 187, 47, 238, 122,
169, 104, 121, 145, 21, 178, 7, 63,
148, 194, 16, 137, 11, 34, 95, 33,
128, 127, 93, 154, 90, 144, 50, 39,
53, 62, 204, 231, 191, 247, 151, 3,
255, 25, 48, 179, 72, 165, 181, 209,
215, 94, 146, 42, 172, 86, 170, 198,
79, 184, 56, 210, 150, 164, 125, 182,
118, 252, 107, 226, 156, 116, 4, 241,
69, 157, 112, 89, 100, 113, 135, 32,
134, 91, 207, 101, 230, 45, 168, 2,
27, 96, 37, 173, 174, 176, 185, 246,
28, 70, 97, 105, 52, 64, 126, 15,
85, 71, 163, 35, 221, 81, 175, 58,
195, 92, 249, 206, 186, 197, 234, 38,
44, 83, 13, 110, 133, 40, 132, 9,
211, 223, 205, 244, 65, 129, 77, 82,
106, 220, 55, 200, 108, 193, 171, 250,
36, 225, 123, 8, 12, 189, 177, 74,
120, 136, 149, 139, 227, 99, 232, 109,
233, 203, 213, 254, 59, 0, 29, 57,
242, 239, 183, 14, 102, 88, 208, 228,
166, 119, 114, 248, 235, 117, 75, 10,
49, 68, 80, 180, 143, 237, 31, 26,
219, 153, 141, 51, 159, 17, 131, 20
};
private int[] X, C;
private byte[] D;
private int L;
/** @see Digest */
public Digest copy()
{
MD2 d = new MD2();
System.arraycopy(X, 0, d.X, 0, X.length);
System.arraycopy(C, 0, d.C, 0, C.length);
d.L = L;
return copyState(d);
}
/** @see Digest */
public int getDigestLength()
{
return 16;
}
/** @see Digest */
public int getBlockLength()
{
return 16;
}
/** @see DigestEngine */
protected void engineReset()
{
for (int i = 0; i < 16; i ++) {
X[i] = 0;
C[i] = 0;
}
L = 0;
}
/** @see DigestEngine */
protected void doPadding(byte[] output, int outputOffset)
{
int pending = flush();
for (int i = 0; i < (16 - pending); i ++)
update((byte)(16 - pending));
flush();
for (int i = 0; i < 16; i ++)
D[i] = (byte)(C[i]);
processBlock(D);
for (int i = 0; i < 16; i ++)
output[outputOffset + i] = (byte)(X[i]);
}
/** @see DigestEngine */
protected void doInit()
{
X = new int[48];
C = new int[16];
D = new byte[16];
engineReset();
}
/** @see DigestEngine */
protected void processBlock(byte[] data)
{
int tL = L;
for (int i = 0; i < 16; i ++) {
int u = data[i] & 0xFF;
X[16 + i] = u;
X[32 + i] = X[i] ^ u;
tL = (C[i] ^= S[u ^ tL]);
}
L = tL;
int t = 0;
for (int j = 0; j < 18; j ++) {
for (int k = 0; k < 48; k += 8) {
t = (X[k + 0] ^= S[t]);
t = (X[k + 1] ^= S[t]);
t = (X[k + 2] ^= S[t]);
t = (X[k + 3] ^= S[t]);
t = (X[k + 4] ^= S[t]);
t = (X[k + 5] ^= S[t]);
t = (X[k + 6] ^= S[t]);
t = (X[k + 7] ^= S[t]);
}
t = (t + j) & 0xFF;
}
}
}