using System;
namespace Org.BouncyCastle.Crypto.Digests{
/**
* implementation of MD5 as outlined in "Handbook of Applied Cryptography", pages 346 - 347.
*/
public class MD5Digest
: GeneralDigest
{
private const int DigestLength = 16;
private int H1, H2, H3, H4; // IV's
private int[] X = new int[16];
private int xOff;
public MD5Digest()
{
Reset();
}
/**
* Copy constructor. This will copy the state of the provided
* message digest.
*/
public MD5Digest(MD5Digest t)
: base(t)
{
H1 = t.H1;
H2 = t.H2;
H3 = t.H3;
H4 = t.H4;
Array.Copy(t.X, 0, X, 0, t.X.Length);
xOff = t.xOff;
}
public override string AlgorithmName
{
get { return "MD5"; }
}
public override int GetDigestSize()
{
return DigestLength;
}
internal override void ProcessWord(
byte[] input,
int inOff)
{
X[xOff++] = (input[inOff] & 0xff) | ((input[inOff + 1] & 0xff) << 8)
| ((input[inOff + 2] & 0xff) << 16) | ((input[inOff + 3] & 0xff) << 24);
if (xOff == 16)
{
ProcessBlock();
}
}
internal override void ProcessLength(
long bitLength)
{
if (xOff > 14)
{
ProcessBlock();
}
X[14] = (int)(bitLength & 0xffffffff);
X[15] = (int)((ulong) bitLength >> 32);
}
private void UnpackWord(
int word,
byte[] outBytes,
int outOff)
{
outBytes[outOff] = (byte)word;
outBytes[outOff + 1] = (byte)((uint) word >> 8);
outBytes[outOff + 2] = (byte)((uint) word >> 16);
outBytes[outOff + 3] = (byte)((uint) word >> 24);
}
public override int DoFinal(
byte[] output,
int outOff)
{
Finish();
UnpackWord(H1, output, outOff);
UnpackWord(H2, output, outOff + 4);
UnpackWord(H3, output, outOff + 8);
UnpackWord(H4, output, outOff + 12);
Reset();
return DigestLength;
}
/**
* reset the chaining variables to the IV values.
*/
public override void Reset()
{
base.Reset();
H1 = unchecked((int) 0x67452301);
H2 = unchecked((int) 0xefcdab89);
H3 = unchecked((int) 0x98badcfe);
H4 = unchecked((int) 0x10325476);
xOff = 0;
for (int i = 0; i != X.Length; i++)
{
X[i] = 0;
}
}
//
// round 1 left rotates
//
private static readonly int S11 = 7;
private static readonly int S12 = 12;
private static readonly int S13 = 17;
private static readonly int S14 = 22;
//
// round 2 left rotates
//
private static readonly int S21 = 5;
private static readonly int S22 = 9;
private static readonly int S23 = 14;
private static readonly int S24 = 20;
//
// round 3 left rotates
//
private static readonly int S31 = 4;
private static readonly int S32 = 11;
private static readonly int S33 = 16;
private static readonly int S34 = 23;
//
// round 4 left rotates
//
private static readonly int S41 = 6;
private static readonly int S42 = 10;
private static readonly int S43 = 15;
private static readonly int S44 = 21;
/*
* rotate int x left n bits.
*/
private int RotateLeft(
int x,
int n)
{
return (x << n) | (int) ((uint) 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);
}
internal override 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] + unchecked((int) 0xd76aa478)), S11) + b;
d = RotateLeft((d + F(a, b, c) + X[ 1] + unchecked((int) 0xe8c7b756)), S12) + a;
c = RotateLeft((c + F(d, a, b) + X[ 2] + unchecked((int) 0x242070db)), S13) + d;
b = RotateLeft((b + F(c, d, a) + X[ 3] + unchecked((int) 0xc1bdceee)), S14) + c;
a = RotateLeft((a + F(b, c, d) + X[ 4] + unchecked((int) 0xf57c0faf)), S11) + b;
d = RotateLeft((d + F(a, b, c) + X[ 5] + unchecked((int) 0x4787c62a)), S12) + a;
c = RotateLeft((c + F(d, a, b) + X[ 6] + unchecked((int) 0xa8304613)), S13) + d;
b = RotateLeft((b + F(c, d, a) + X[ 7] + unchecked((int) 0xfd469501)), S14) + c;
a = RotateLeft((a + F(b, c, d) + X[ 8] + unchecked((int) 0x698098d8)), S11) + b;
d = RotateLeft((d + F(a, b, c) + X[ 9] + unchecked((int) 0x8b44f7af)), S12) + a;
c = RotateLeft((c + F(d, a, b) + X[10] + unchecked((int) 0xffff5bb1)), S13) + d;
b = RotateLeft((b + F(c, d, a) + X[11] + unchecked((int) 0x895cd7be)), S14) + c;
a = RotateLeft((a + F(b, c, d) + X[12] + unchecked((int) 0x6b901122)), S11) + b;
d = RotateLeft((d + F(a, b, c) + X[13] + unchecked((int) 0xfd987193)), S12) + a;
c = RotateLeft((c + F(d, a, b) + X[14] + unchecked((int) 0xa679438e)), S13) + d;
b = RotateLeft((b + F(c, d, a) + X[15] + unchecked((int) 0x49b40821)), S14) + c;
//
// Round 2 - G cycle, 16 times.
//
a = RotateLeft((a + G(b, c, d) + X[ 1] + unchecked((int) 0xf61e2562)), S21) + b;
d = RotateLeft((d + G(a, b, c) + X[ 6] + unchecked((int) 0xc040b340)), S22) + a;
c = RotateLeft((c + G(d, a, b) + X[11] + unchecked((int) 0x265e5a51)), S23) + d;
b = RotateLeft((b + G(c, d, a) + X[ 0] + unchecked((int) 0xe9b6c7aa)), S24) + c;
a = RotateLeft((a + G(b, c, d) + X[ 5] + unchecked((int) 0xd62f105d)), S21) + b;
d = RotateLeft((d + G(a, b, c) + X[10] + unchecked((int) 0x02441453)), S22) + a;
c = RotateLeft((c + G(d, a, b) + X[15] + unchecked((int) 0xd8a1e681)), S23) + d;
b = RotateLeft((b + G(c, d, a) + X[ 4] + unchecked((int) 0xe7d3fbc8)), S24) + c;
a = RotateLeft((a + G(b, c, d) + X[ 9] + unchecked((int) 0x21e1cde6)), S21) + b;
d = RotateLeft((d + G(a, b, c) + X[14] + unchecked((int) 0xc33707d6)), S22) + a;
c = RotateLeft((c + G(d, a, b) + X[ 3] + unchecked((int) 0xf4d50d87)), S23) + d;
b = RotateLeft((b + G(c, d, a) + X[ 8] + unchecked((int) 0x455a14ed)), S24) + c;
a = RotateLeft((a + G(b, c, d) + X[13] + unchecked((int) 0xa9e3e905)), S21) + b;
d = RotateLeft((d + G(a, b, c) + X[ 2] + unchecked((int) 0xfcefa3f8)), S22) + a;
c = RotateLeft((c + G(d, a, b) + X[ 7] + unchecked((int) 0x676f02d9)), S23) + d;
b = RotateLeft((b + G(c, d, a) + X[12] + unchecked((int) 0x8d2a4c8a)), S24) + c;
//
// Round 3 - H cycle, 16 times.
//
a = RotateLeft((a + H(b, c, d) + X[ 5] + unchecked((int) 0xfffa3942)), S31) + b;
d = RotateLeft((d + H(a, b, c) + X[ 8] + unchecked((int) 0x8771f681)), S32) + a;
c = RotateLeft((c + H(d, a, b) + X[11] + unchecked((int) 0x6d9d6122)), S33) + d;
b = RotateLeft((b + H(c, d, a) + X[14] + unchecked((int) 0xfde5380c)), S34) + c;
a = RotateLeft((a + H(b, c, d) + X[ 1] + unchecked((int) 0xa4beea44)), S31) + b;
d = RotateLeft((d + H(a, b, c) + X[ 4] + unchecked((int) 0x4bdecfa9)), S32) + a;
c = RotateLeft((c + H(d, a, b) + X[ 7] + unchecked((int) 0xf6bb4b60)), S33) + d;
b = RotateLeft((b + H(c, d, a) + X[10] + unchecked((int) 0xbebfbc70)), S34) + c;
a = RotateLeft((a + H(b, c, d) + X[13] + unchecked((int) 0x289b7ec6)), S31) + b;
d = RotateLeft((d + H(a, b, c) + X[ 0] + unchecked((int) 0xeaa127fa)), S32) + a;
c = RotateLeft((c + H(d, a, b) + X[ 3] + unchecked((int) 0xd4ef3085)), S33) + d;
b = RotateLeft((b + H(c, d, a) + X[ 6] + unchecked((int) 0x04881d05)), S34) + c;
a = RotateLeft((a + H(b, c, d) + X[ 9] + unchecked((int) 0xd9d4d039)), S31) + b;
d = RotateLeft((d + H(a, b, c) + X[12] + unchecked((int) 0xe6db99e5)), S32) + a;
c = RotateLeft((c + H(d, a, b) + X[15] + unchecked((int) 0x1fa27cf8)), S33) + d;
b = RotateLeft((b + H(c, d, a) + X[ 2] + unchecked((int) 0xc4ac5665)), S34) + c;
//
// Round 4 - K cycle, 16 times.
//
a = RotateLeft((a + K(b, c, d) + X[ 0] + unchecked((int) 0xf4292244)), S41) + b;
d = RotateLeft((d + K(a, b, c) + X[ 7] + unchecked((int) 0x432aff97)), S42) + a;
c = RotateLeft((c + K(d, a, b) + X[14] + unchecked((int) 0xab9423a7)), S43) + d;
b = RotateLeft((b + K(c, d, a) + X[ 5] + unchecked((int) 0xfc93a039)), S44) + c;
a = RotateLeft((a + K(b, c, d) + X[12] + unchecked((int) 0x655b59c3)), S41) + b;
d = RotateLeft((d + K(a, b, c) + X[ 3] + unchecked((int) 0x8f0ccc92)), S42) + a;
c = RotateLeft((c + K(d, a, b) + X[10] + unchecked((int) 0xffeff47d)), S43) + d;
b = RotateLeft((b + K(c, d, a) + X[ 1] + unchecked((int) 0x85845dd1)), S44) + c;
a = RotateLeft((a + K(b, c, d) + X[ 8] + unchecked((int) 0x6fa87e4f)), S41) + b;
d = RotateLeft((d + K(a, b, c) + X[15] + unchecked((int) 0xfe2ce6e0)), S42) + a;
c = RotateLeft((c + K(d, a, b) + X[ 6] + unchecked((int) 0xa3014314)), S43) + d;
b = RotateLeft((b + K(c, d, a) + X[13] + unchecked((int) 0x4e0811a1)), S44) + c;
a = RotateLeft((a + K(b, c, d) + X[ 4] + unchecked((int) 0xf7537e82)), S41) + b;
d = RotateLeft((d + K(a, b, c) + X[11] + unchecked((int) 0xbd3af235)), S42) + a;
c = RotateLeft((c + K(d, a, b) + X[ 2] + unchecked((int) 0x2ad7d2bb)), S43) + d;
b = RotateLeft((b + K(c, d, a) + X[ 9] + unchecked((int) 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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