?? md5digest.java
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package org.bouncycastle.crypto.digests;
/**
* implementation of MD5 as outlined in "Handbook of Applied Cryptography", pages 346 - 347.
*/
public class MD5Digest
extends GeneralDigest
{
private static final int DIGEST_LENGTH = 16;
private int H1, H2, H3, H4; // IV's
private int[] X = new int[16];
private int xOff;
/**
* Standard constructor
*/
public MD5Digest()
{
reset();
}
/**
* Copy constructor. This will copy the state of the provided
* message digest.
*/
public MD5Digest(MD5Digest t)
{
super(t);
H1 = t.H1;
H2 = t.H2;
H3 = t.H3;
H4 = t.H4;
System.arraycopy(t.X, 0, X, 0, t.X.length);
xOff = t.xOff;
}
public String getAlgorithmName()
{
return "MD5";
}
public int getDigestSize()
{
return DIGEST_LENGTH;
}
protected void processWord(
byte[] in,
int inOff)
{
X[xOff++] = (in[inOff] & 0xff) | ((in[inOff + 1] & 0xff) << 8)
| ((in[inOff + 2] & 0xff) << 16) | ((in[inOff + 3] & 0xff) << 24);
if (xOff == 16)
{
processBlock();
}
}
protected void processLength(
long bitLength)
{
if (xOff > 14)
{
processBlock();
}
X[14] = (int)(bitLength & 0xffffffff);
X[15] = (int)(bitLength >>> 32);
}
private void unpackWord(
int word,
byte[] out,
int outOff)
{
out[outOff] = (byte)word;
out[outOff + 1] = (byte)(word >>> 8);
out[outOff + 2] = (byte)(word >>> 16);
out[outOff + 3] = (byte)(word >>> 24);
}
public int doFinal(
byte[] out,
int outOff)
{
finish();
unpackWord(H1, out, outOff);
unpackWord(H2, out, outOff + 4);
unpackWord(H3, out, outOff + 8);
unpackWord(H4, out, outOff + 12);
reset();
return DIGEST_LENGTH;
}
/**
* reset the chaining variables to the IV values.
*/
public void reset()
{
super.reset();
H1 = 0x67452301;
H2 = 0xefcdab89;
H3 = 0x98badcfe;
H4 = 0x10325476;
xOff = 0;
for (int i = 0; i != X.length; i++)
{
X[i] = 0;
}
}
//
// round 1 left rotates
//
private static final int S11 = 7;
private static final int S12 = 12;
private static final int S13 = 17;
private static final int S14 = 22;
//
// round 2 left rotates
//
private static final int S21 = 5;
private static final int S22 = 9;
private static final int S23 = 14;
private static final int S24 = 20;
//
// round 3 left rotates
//
private static final int S31 = 4;
private static final int S32 = 11;
private static final int S33 = 16;
private static final int S34 = 23;
//
// round 4 left rotates
//
private static final int S41 = 6;
private static final int S42 = 10;
private static final int S43 = 15;
private static final int S44 = 21;
/*
* rotate int x left n bits.
*/
private int rotateLeft(
int x,
int n)
{
return (x << n) | (x >>> (32 - n));
}
/*
* F, G, H and I are the basic MD5 functions.
*/
private int F(
int u,
int v,
int w)
{
return (u & v) | (~u & w);
}
private int G(
int u,
int v,
int w)
{
return (u & w) | (v & ~w);
}
private int H(
int u,
int v,
int w)
{
return u ^ v ^ w;
}
private int K(
int u,
int v,
int w)
{
return v ^ (u | ~w);
}
protected void processBlock()
{
int a = H1;
int b = H2;
int c = H3;
int d = H4;
//
// Round 1 - F cycle, 16 times.
//
a = rotateLeft((a + F(b, c, d) + X[ 0] + 0xd76aa478), S11) + b;
d = rotateLeft((d + F(a, b, c) + X[ 1] + 0xe8c7b756), S12) + a;
c = rotateLeft((c + F(d, a, b) + X[ 2] + 0x242070db), S13) + d;
b = rotateLeft((b + F(c, d, a) + X[ 3] + 0xc1bdceee), S14) + c;
a = rotateLeft((a + F(b, c, d) + X[ 4] + 0xf57c0faf), S11) + b;
d = rotateLeft((d + F(a, b, c) + X[ 5] + 0x4787c62a), S12) + a;
c = rotateLeft((c + F(d, a, b) + X[ 6] + 0xa8304613), S13) + d;
b = rotateLeft((b + F(c, d, a) + X[ 7] + 0xfd469501), S14) + c;
a = rotateLeft((a + F(b, c, d) + X[ 8] + 0x698098d8), S11) + b;
d = rotateLeft((d + F(a, b, c) + X[ 9] + 0x8b44f7af), S12) + a;
c = rotateLeft((c + F(d, a, b) + X[10] + 0xffff5bb1), S13) + d;
b = rotateLeft((b + F(c, d, a) + X[11] + 0x895cd7be), S14) + c;
a = rotateLeft((a + F(b, c, d) + X[12] + 0x6b901122), S11) + b;
d = rotateLeft((d + F(a, b, c) + X[13] + 0xfd987193), S12) + a;
c = rotateLeft((c + F(d, a, b) + X[14] + 0xa679438e), S13) + d;
b = rotateLeft((b + F(c, d, a) + X[15] + 0x49b40821), S14) + c;
//
// Round 2 - G cycle, 16 times.
//
a = rotateLeft((a + G(b, c, d) + X[ 1] + 0xf61e2562), S21) + b;
d = rotateLeft((d + G(a, b, c) + X[ 6] + 0xc040b340), S22) + a;
c = rotateLeft((c + G(d, a, b) + X[11] + 0x265e5a51), S23) + d;
b = rotateLeft((b + G(c, d, a) + X[ 0] + 0xe9b6c7aa), S24) + c;
a = rotateLeft((a + G(b, c, d) + X[ 5] + 0xd62f105d), S21) + b;
d = rotateLeft((d + G(a, b, c) + X[10] + 0x02441453), S22) + a;
c = rotateLeft((c + G(d, a, b) + X[15] + 0xd8a1e681), S23) + d;
b = rotateLeft((b + G(c, d, a) + X[ 4] + 0xe7d3fbc8), S24) + c;
a = rotateLeft((a + G(b, c, d) + X[ 9] + 0x21e1cde6), S21) + b;
d = rotateLeft((d + G(a, b, c) + X[14] + 0xc33707d6), S22) + a;
c = rotateLeft((c + G(d, a, b) + X[ 3] + 0xf4d50d87), S23) + d;
b = rotateLeft((b + G(c, d, a) + X[ 8] + 0x455a14ed), S24) + c;
a = rotateLeft((a + G(b, c, d) + X[13] + 0xa9e3e905), S21) + b;
d = rotateLeft((d + G(a, b, c) + X[ 2] + 0xfcefa3f8), S22) + a;
c = rotateLeft((c + G(d, a, b) + X[ 7] + 0x676f02d9), S23) + d;
b = rotateLeft((b + G(c, d, a) + X[12] + 0x8d2a4c8a), S24) + c;
//
// Round 3 - H cycle, 16 times.
//
a = rotateLeft((a + H(b, c, d) + X[ 5] + 0xfffa3942), S31) + b;
d = rotateLeft((d + H(a, b, c) + X[ 8] + 0x8771f681), S32) + a;
c = rotateLeft((c + H(d, a, b) + X[11] + 0x6d9d6122), S33) + d;
b = rotateLeft((b + H(c, d, a) + X[14] + 0xfde5380c), S34) + c;
a = rotateLeft((a + H(b, c, d) + X[ 1] + 0xa4beea44), S31) + b;
d = rotateLeft((d + H(a, b, c) + X[ 4] + 0x4bdecfa9), S32) + a;
c = rotateLeft((c + H(d, a, b) + X[ 7] + 0xf6bb4b60), S33) + d;
b = rotateLeft((b + H(c, d, a) + X[10] + 0xbebfbc70), S34) + c;
a = rotateLeft((a + H(b, c, d) + X[13] + 0x289b7ec6), S31) + b;
d = rotateLeft((d + H(a, b, c) + X[ 0] + 0xeaa127fa), S32) + a;
c = rotateLeft((c + H(d, a, b) + X[ 3] + 0xd4ef3085), S33) + d;
b = rotateLeft((b + H(c, d, a) + X[ 6] + 0x04881d05), S34) + c;
a = rotateLeft((a + H(b, c, d) + X[ 9] + 0xd9d4d039), S31) + b;
d = rotateLeft((d + H(a, b, c) + X[12] + 0xe6db99e5), S32) + a;
c = rotateLeft((c + H(d, a, b) + X[15] + 0x1fa27cf8), S33) + d;
b = rotateLeft((b + H(c, d, a) + X[ 2] + 0xc4ac5665), S34) + c;
//
// Round 4 - K cycle, 16 times.
//
a = rotateLeft((a + K(b, c, d) + X[ 0] + 0xf4292244), S41) + b;
d = rotateLeft((d + K(a, b, c) + X[ 7] + 0x432aff97), S42) + a;
c = rotateLeft((c + K(d, a, b) + X[14] + 0xab9423a7), S43) + d;
b = rotateLeft((b + K(c, d, a) + X[ 5] + 0xfc93a039), S44) + c;
a = rotateLeft((a + K(b, c, d) + X[12] + 0x655b59c3), S41) + b;
d = rotateLeft((d + K(a, b, c) + X[ 3] + 0x8f0ccc92), S42) + a;
c = rotateLeft((c + K(d, a, b) + X[10] + 0xffeff47d), S43) + d;
b = rotateLeft((b + K(c, d, a) + X[ 1] + 0x85845dd1), S44) + c;
a = rotateLeft((a + K(b, c, d) + X[ 8] + 0x6fa87e4f), S41) + b;
d = rotateLeft((d + K(a, b, c) + X[15] + 0xfe2ce6e0), S42) + a;
c = rotateLeft((c + K(d, a, b) + X[ 6] + 0xa3014314), S43) + d;
b = rotateLeft((b + K(c, d, a) + X[13] + 0x4e0811a1), S44) + c;
a = rotateLeft((a + K(b, c, d) + X[ 4] + 0xf7537e82), S41) + b;
d = rotateLeft((d + K(a, b, c) + X[11] + 0xbd3af235), S42) + a;
c = rotateLeft((c + K(d, a, b) + X[ 2] + 0x2ad7d2bb), S43) + d;
b = rotateLeft((b + K(c, d, a) + X[ 9] + 0xeb86d391), S44) + c;
H1 += a;
H2 += b;
H3 += c;
H4 += d;
//
// reset the offset and clean out the word buffer.
//
xOff = 0;
for (int i = 0; i != X.length; i++)
{
X[i] = 0;
}
}
}
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