package com.trilead.ssh2.crypto.digest;
/**
* MD5. Based on the example code in RFC 1321. Optimized (...a little).
*
* @author Christian Plattner, plattner@trilead.com
* @version $Id: MD5.java,v 1.1 2007/10/15 12:49:57 cplattne Exp $
*/
/*
* The following disclaimer has been copied from RFC 1321:
*
* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All rights
* reserved.
*
* License to copy and use this software is granted provided that it is
* identified as the "RSA Data Security, Inc. MD5 Message-Digest Algorithm" in
* all material mentioning or referencing this software or this function.
*
* License is also granted to make and use derivative works provided that such
* works are identified as "derived from the RSA Data Security, Inc. MD5
* Message-Digest Algorithm" in all material mentioning or referencing the
* derived work.
*
* RSA Data Security, Inc. makes no representations concerning either the
* merchantability of this software or the suitability of this software for any
* particular purpose. It is provided "as is" without express or implied
* warranty of any kind.
*
* These notices must be retained in any copies of any part of this
* documentation and/or software.
*
*/
public final class MD5 implements Digest
{
private int state0, state1, state2, state3;
private long count;
private final byte[] block = new byte[64];
private final int x[] = new int[16];
private static final byte[] padding = new byte[] { (byte) 128, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
public MD5()
{
reset();
}
private static final int FF(int a, int b, int c, int d, int x, int s, int ac)
{
a += ((b & c) | ((~b) & d)) + x + ac;
return ((a << s) | (a >>> (32 - s))) + b;
}
private static final int GG(int a, int b, int c, int d, int x, int s, int ac)
{
a += ((b & d) | (c & (~d))) + x + ac;
return ((a << s) | (a >>> (32 - s))) + b;
}
private static final int HH(int a, int b, int c, int d, int x, int s, int ac)
{
a += (b ^ c ^ d) + x + ac;
return ((a << s) | (a >>> (32 - s))) + b;
}
private static final int II(int a, int b, int c, int d, int x, int s, int ac)
{
a += (c ^ (b | (~d))) + x + ac;
return ((a << s) | (a >>> (32 - s))) + b;
}
private static final void encode(byte[] dst, int dstoff, int word)
{
dst[dstoff] = (byte) (word);
dst[dstoff + 1] = (byte) (word >> 8);
dst[dstoff + 2] = (byte) (word >> 16);
dst[dstoff + 3] = (byte) (word >> 24);
}
private final void transform(byte[] src, int pos)
{
int a = state0;
int b = state1;
int c = state2;
int d = state3;
for (int i = 0; i < 16; i++, pos += 4)
{
x[i] = (src[pos] & 0xff) | ((src[pos + 1] & 0xff) << 8) | ((src[pos + 2] & 0xff) << 16)
| ((src[pos + 3] & 0xff) << 24);
}
/* Round 1 */
a = FF(a, b, c, d, x[0], 7, 0xd76aa478); /* 1 */
d = FF(d, a, b, c, x[1], 12, 0xe8c7b756); /* 2 */
c = FF(c, d, a, b, x[2], 17, 0x242070db); /* 3 */
b = FF(b, c, d, a, x[3], 22, 0xc1bdceee); /* 4 */
a = FF(a, b, c, d, x[4], 7, 0xf57c0faf); /* 5 */
d = FF(d, a, b, c, x[5], 12, 0x4787c62a); /* 6 */
c = FF(c, d, a, b, x[6], 17, 0xa8304613); /* 7 */
b = FF(b, c, d, a, x[7], 22, 0xfd469501); /* 8 */
a = FF(a, b, c, d, x[8], 7, 0x698098d8); /* 9 */
d = FF(d, a, b, c, x[9], 12, 0x8b44f7af); /* 10 */
c = FF(c, d, a, b, x[10], 17, 0xffff5bb1); /* 11 */
b = FF(b, c, d, a, x[11], 22, 0x895cd7be); /* 12 */
a = FF(a, b, c, d, x[12], 7, 0x6b901122); /* 13 */
d = FF(d, a, b, c, x[13], 12, 0xfd987193); /* 14 */
c = FF(c, d, a, b, x[14], 17, 0xa679438e); /* 15 */
b = FF(b, c, d, a, x[15], 22, 0x49b40821); /* 16 */
/* Round 2 */
a = GG(a, b, c, d, x[1], 5, 0xf61e2562); /* 17 */
d = GG(d, a, b, c, x[6], 9, 0xc040b340); /* 18 */
c = GG(c, d, a, b, x[11], 14, 0x265e5a51); /* 19 */
b = GG(b, c, d, a, x[0], 20, 0xe9b6c7aa); /* 20 */
a = GG(a, b, c, d, x[5], 5, 0xd62f105d); /* 21 */
d = GG(d, a, b, c, x[10], 9, 0x2441453); /* 22 */
c = GG(c, d, a, b, x[15], 14, 0xd8a1e681); /* 23 */
b = GG(b, c, d, a, x[4], 20, 0xe7d3fbc8); /* 24 */
a = GG(a, b, c, d, x[9], 5, 0x21e1cde6); /* 25 */
d = GG(d, a, b, c, x[14], 9, 0xc33707d6); /* 26 */
c = GG(c, d, a, b, x[3], 14, 0xf4d50d87); /* 27 */
b = GG(b, c, d, a, x[8], 20, 0x455a14ed); /* 28 */
a = GG(a, b, c, d, x[13], 5, 0xa9e3e905); /* 29 */
d = GG(d, a, b, c, x[2], 9, 0xfcefa3f8); /* 30 */
c = GG(c, d, a, b, x[7], 14, 0x676f02d9); /* 31 */
b = GG(b, c, d, a, x[12], 20, 0x8d2a4c8a); /* 32 */
/* Round 3 */
a = HH(a, b, c, d, x[5], 4, 0xfffa3942); /* 33 */
d = HH(d, a, b, c, x[8], 11, 0x8771f681); /* 34 */
c = HH(c, d, a, b, x[11], 16, 0x6d9d6122); /* 35 */
b = HH(b, c, d, a, x[14], 23, 0xfde5380c); /* 36 */
a = HH(a, b, c, d, x[1], 4, 0xa4beea44); /* 37 */
d = HH(d, a, b, c, x[4], 11, 0x4bdecfa9); /* 38 */
c = HH(c, d, a, b, x[7], 16, 0xf6bb4b60); /* 39 */
b = HH(b, c, d, a, x[10], 23, 0xbebfbc70); /* 40 */
a = HH(a, b, c, d, x[13], 4, 0x289b7ec6); /* 41 */
d = HH(d, a, b, c, x[0], 11, 0xeaa127fa); /* 42 */
c = HH(c, d, a, b, x[3], 16, 0xd4ef3085); /* 43 */
b = HH(b, c, d, a, x[6], 23, 0x4881d05); /* 44 */
a = HH(a, b, c, d, x[9], 4, 0xd9d4d039); /* 45 */
d = HH(d, a, b, c, x[12], 11, 0xe6db99e5); /* 46 */
c = HH(c, d, a, b, x[15], 16, 0x1fa27cf8); /* 47 */
b = HH(b, c, d, a, x[2], 23, 0xc4ac5665); /* 48 */
/* Round 4 */
a = II(a, b, c, d, x[0], 6, 0xf4292244); /* 49 */
d = II(d, a, b, c, x[7], 10, 0x432aff97); /* 50 */
c = II(c, d, a, b, x[14], 15, 0xab9423a7); /* 51 */
b = II(b, c, d, a, x[5], 21, 0xfc93a039); /* 52 */
a = II(a, b, c, d, x[12], 6, 0x655b59c3); /* 53 */
d = II(d, a, b, c, x[3], 10, 0x8f0ccc92); /* 54 */
c = II(c, d, a, b, x[10], 15, 0xffeff47d); /* 55 */
b = II(b, c, d, a, x[1], 21, 0x85845dd1); /* 56 */
a = II(a, b, c, d, x[8], 6, 0x6fa87e4f); /* 57 */
d = II(d, a, b, c, x[15], 10, 0xfe2ce6e0); /* 58 */
c = II(c, d, a, b, x[6], 15, 0xa3014314); /* 59 */
b = II(b, c, d, a, x[13], 21, 0x4e0811a1); /* 60 */
a = II(a, b, c, d, x[4], 6, 0xf7537e82); /* 61 */
d = II(d, a, b, c, x[11], 10, 0xbd3af235); /* 62 */
c = II(c, d, a, b, x[2], 15, 0x2ad7d2bb); /* 63 */
b = II(b, c, d, a, x[9], 21, 0xeb86d391); /* 64 */
state0 += a;
state1 += b;
state2 += c;
state3 += d;
}
public final void reset()
{
count = 0;
state0 = 0x67452301;
state1 = 0xefcdab89;
state2 = 0x98badcfe;
state3 = 0x10325476;
/* Clear traces in memory... */
for (int i = 0; i < 16; i++)
x[i] = 0;
}
public final void update(byte b)
{
final int space = 64 - ((int) (count & 0x3f));
count++;
block[64 - space] = b;
if (space == 1)
transform(block, 0);
}
public final void update(byte[] buff, int pos, int len)
{
int space = 64 - ((int) (count & 0x3f));
count += len;
while (len > 0)
{
if (len < space)
{
System.arraycopy(buff, pos, block, 64 - space, len);
break;
}
if (space == 64)
{
transform(buff, pos);
}
else
{
System.arraycopy(buff, pos, block, 64 - space, space);
transform(block, 0);
}
pos += space;
len -= space;
space = 64;
}
}
public final void update(byte[] b)
{
update(b, 0, b.length);
}
public final void digest(byte[] dst, int pos)
{
byte[] bits = new byte[8];
encode(bits, 0, (int) (count << 3));
encode(bits, 4, (int) (count >> 29));
int idx = (int) count & 0x3f;
int padLen = (idx < 56) ? (56 - idx) : (120 - idx);
update(padding, 0, padLen);
update(bits, 0, 8);
encode(dst, pos, state0);
encode(dst, pos + 4, state1);
encode(dst, pos + 8, state2);
encode(dst, pos + 12, state3);
reset();
}
public final void digest(byte[] dst)
{
digest(dst, 0);
}
public final int getDigestLength()
{
return 16;
}
}