jellyfin/Emby.Common.Implementations/IO/SharpCifs/Util/MD4.cs

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2017-04-02 00:36:06 +00:00
// This code is derived from jcifs smb client library <jcifs at samba dot org>
// Ported by J. Arturo <webmaster at komodosoft dot net>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
using System;
using SharpCifs.Util.Sharpen;
namespace SharpCifs.Util
{
/// <summary>Implements the MD4 message digest algorithm in Java.</summary>
/// <remarks>
/// Implements the MD4 message digest algorithm in Java.
/// <p>
/// <b>References:</b>
/// <ol>
/// <li> Ronald L. Rivest,
/// "<a href="http://www.roxen.com/rfc/rfc1320.html">
/// The MD4 Message-Digest Algorithm</a>",
/// IETF RFC-1320 (informational).
/// </ol>
/// <p><b>$Revision: 1.2 $</b>
/// </remarks>
/// <author>Raif S. Naffah</author>
public class Md4 : MessageDigest
{
/// <summary>The size in bytes of the input block to the tranformation algorithm.</summary>
/// <remarks>The size in bytes of the input block to the tranformation algorithm.</remarks>
private const int BlockLength = 64;
/// <summary>4 32-bit words (interim result)</summary>
private int[] _context = new int[4];
/// <summary>Number of bytes processed so far mod.</summary>
/// <remarks>Number of bytes processed so far mod. 2 power of 64.</remarks>
private long _count;
/// <summary>512 bits input buffer = 16 x 32-bit words holds until reaches 512 bits.</summary>
/// <remarks>512 bits input buffer = 16 x 32-bit words holds until reaches 512 bits.</remarks>
private byte[] _buffer = new byte[BlockLength];
/// <summary>512 bits work buffer = 16 x 32-bit words</summary>
private int[] _x = new int[16];
public Md4()
{
// This file is currently unlocked (change this line if you lock the file)
//
// $Log: MD4.java,v $
// Revision 1.2 1998/01/05 03:41:19 iang
// Added references only.
//
// Revision 1.1.1.1 1997/11/03 22:36:56 hopwood
// + Imported to CVS (tagged as 'start').
//
// Revision 0.1.0.0 1997/07/14 R. Naffah
// + original version
//
// $Endlog$
// MD4 specific object variables
//...........................................................................
// = 512 / 8;
// Constructors
//...........................................................................
EngineReset();
}
/// <summary>This constructor is here to implement cloneability of this class.</summary>
/// <remarks>This constructor is here to implement cloneability of this class.</remarks>
private Md4(Md4 md) : this()
{
_context = (int[])md._context.Clone();
_buffer = (byte[])md._buffer.Clone();
_count = md._count;
}
// Cloneable method implementation
//...........................................................................
/// <summary>Returns a copy of this MD object.</summary>
/// <remarks>Returns a copy of this MD object.</remarks>
public object Clone()
{
return new Md4(this);
}
// JCE methods
//...........................................................................
/// <summary>
/// Resets this object disregarding any temporary data present at the
/// time of the invocation of this call.
/// </summary>
/// <remarks>
/// Resets this object disregarding any temporary data present at the
/// time of the invocation of this call.
/// </remarks>
protected void EngineReset()
{
// initial values of MD4 i.e. A, B, C, D
// as per rfc-1320; they are low-order byte first
_context[0] = unchecked(0x67452301);
_context[1] = unchecked((int)(0xEFCDAB89));
_context[2] = unchecked((int)(0x98BADCFE));
_context[3] = unchecked(0x10325476);
_count = 0L;
for (int i = 0; i < BlockLength; i++)
{
_buffer[i] = 0;
}
}
/// <summary>Continues an MD4 message digest using the input byte.</summary>
/// <remarks>Continues an MD4 message digest using the input byte.</remarks>
protected void EngineUpdate(byte b)
{
// compute number of bytes still unhashed; ie. present in buffer
int i = (int)(_count % BlockLength);
_count++;
// update number of bytes
_buffer[i] = b;
if (i == BlockLength - 1)
{
Transform(_buffer, 0);
}
}
/// <summary>MD4 block update operation.</summary>
/// <remarks>
/// MD4 block update operation.
/// <p>
/// Continues an MD4 message digest operation, by filling the buffer,
/// transform(ing) data in 512-bit message block(s), updating the variables
/// context and count, and leaving (buffering) the remaining bytes in buffer
/// for the next update or finish.
/// </remarks>
/// <param name="input">input block</param>
/// <param name="offset">start of meaningful bytes in input</param>
/// <param name="len">count of bytes in input block to consider</param>
protected void EngineUpdate(byte[] input, int offset, int len)
{
// make sure we don't exceed input's allocated size/length
if (offset < 0 || len < 0 || (long)offset + len > input.Length)
{
throw new IndexOutOfRangeException();
}
// compute number of bytes still unhashed; ie. present in buffer
int bufferNdx = (int)(_count % BlockLength);
_count += len;
// update number of bytes
int partLen = BlockLength - bufferNdx;
int i = 0;
if (len >= partLen)
{
Array.Copy(input, offset, _buffer, bufferNdx, partLen);
Transform(_buffer, 0);
for (i = partLen; i + BlockLength - 1 < len; i += BlockLength)
{
Transform(input, offset + i);
}
bufferNdx = 0;
}
// buffer remaining input
if (i < len)
{
Array.Copy(input, offset + i, _buffer, bufferNdx, len - i);
}
}
/// <summary>
/// Completes the hash computation by performing final operations such
/// as padding.
/// </summary>
/// <remarks>
/// Completes the hash computation by performing final operations such
/// as padding. At the return of this engineDigest, the MD engine is
/// reset.
/// </remarks>
/// <returns>the array of bytes for the resulting hash value.</returns>
protected byte[] EngineDigest()
{
// pad output to 56 mod 64; as RFC1320 puts it: congruent to 448 mod 512
int bufferNdx = (int)(_count % BlockLength);
int padLen = (bufferNdx < 56) ? (56 - bufferNdx) : (120 - bufferNdx);
// padding is alwas binary 1 followed by binary 0s
byte[] tail = new byte[padLen + 8];
tail[0] = unchecked(unchecked(0x80));
// append length before final transform:
// save number of bits, casting the long to an array of 8 bytes
// save low-order byte first.
for (int i = 0; i < 8; i++)
{
tail[padLen + i] = unchecked((byte)((long)(((ulong)(_count * 8)) >> (8 * i))));
}
EngineUpdate(tail, 0, tail.Length);
byte[] result = new byte[16];
// cast this MD4's context (array of 4 ints) into an array of 16 bytes.
for (int i1 = 0; i1 < 4; i1++)
{
for (int j = 0; j < 4; j++)
{
result[i1 * 4 + j] = unchecked((byte)((int)(((uint)_context[i1]) >> (8 * j))));
}
}
// reset the engine
EngineReset();
return result;
}
// own methods
//...........................................................................
/// <summary>MD4 basic transformation.</summary>
/// <remarks>
/// MD4 basic transformation.
/// <p>
/// Transforms context based on 512 bits from input block starting
/// from the offset'th byte.
/// </remarks>
/// <param name="block">input sub-array.</param>
/// <param name="offset">starting position of sub-array.</param>
private void Transform(byte[] block, int offset)
{
// encodes 64 bytes from input block into an array of 16 32-bit
// entities. Use A as a temp var.
for (int i = 0; i < 16; i++)
{
_x[i] = (block[offset++] & unchecked(0xFF)) | (block[offset++] & unchecked(
0xFF)) << 8 | (block[offset++] & unchecked(0xFF)) << 16 | (block[offset
++] & unchecked(0xFF)) << 24;
}
int a = _context[0];
int b = _context[1];
int c = _context[2];
int d = _context[3];
a = Ff(a, b, c, d, _x[0], 3);
d = Ff(d, a, b, c, _x[1], 7);
c = Ff(c, d, a, b, _x[2], 11);
b = Ff(b, c, d, a, _x[3], 19);
a = Ff(a, b, c, d, _x[4], 3);
d = Ff(d, a, b, c, _x[5], 7);
c = Ff(c, d, a, b, _x[6], 11);
b = Ff(b, c, d, a, _x[7], 19);
a = Ff(a, b, c, d, _x[8], 3);
d = Ff(d, a, b, c, _x[9], 7);
c = Ff(c, d, a, b, _x[10], 11);
b = Ff(b, c, d, a, _x[11], 19);
a = Ff(a, b, c, d, _x[12], 3);
d = Ff(d, a, b, c, _x[13], 7);
c = Ff(c, d, a, b, _x[14], 11);
b = Ff(b, c, d, a, _x[15], 19);
a = Gg(a, b, c, d, _x[0], 3);
d = Gg(d, a, b, c, _x[4], 5);
c = Gg(c, d, a, b, _x[8], 9);
b = Gg(b, c, d, a, _x[12], 13);
a = Gg(a, b, c, d, _x[1], 3);
d = Gg(d, a, b, c, _x[5], 5);
c = Gg(c, d, a, b, _x[9], 9);
b = Gg(b, c, d, a, _x[13], 13);
a = Gg(a, b, c, d, _x[2], 3);
d = Gg(d, a, b, c, _x[6], 5);
c = Gg(c, d, a, b, _x[10], 9);
b = Gg(b, c, d, a, _x[14], 13);
a = Gg(a, b, c, d, _x[3], 3);
d = Gg(d, a, b, c, _x[7], 5);
c = Gg(c, d, a, b, _x[11], 9);
b = Gg(b, c, d, a, _x[15], 13);
a = Hh(a, b, c, d, _x[0], 3);
d = Hh(d, a, b, c, _x[8], 9);
c = Hh(c, d, a, b, _x[4], 11);
b = Hh(b, c, d, a, _x[12], 15);
a = Hh(a, b, c, d, _x[2], 3);
d = Hh(d, a, b, c, _x[10], 9);
c = Hh(c, d, a, b, _x[6], 11);
b = Hh(b, c, d, a, _x[14], 15);
a = Hh(a, b, c, d, _x[1], 3);
d = Hh(d, a, b, c, _x[9], 9);
c = Hh(c, d, a, b, _x[5], 11);
b = Hh(b, c, d, a, _x[13], 15);
a = Hh(a, b, c, d, _x[3], 3);
d = Hh(d, a, b, c, _x[11], 9);
c = Hh(c, d, a, b, _x[7], 11);
b = Hh(b, c, d, a, _x[15], 15);
_context[0] += a;
_context[1] += b;
_context[2] += c;
_context[3] += d;
}
// The basic MD4 atomic functions.
private int Ff(int a, int b, int c, int d, int x, int s)
{
int t = a + ((b & c) | (~b & d)) + x;
return t << s | (int)(((uint)t) >> (32 - s));
}
private int Gg(int a, int b, int c, int d, int x, int s)
{
int t = a + ((b & (c | d)) | (c & d)) + x + unchecked(0x5A827999);
return t << s | (int)(((uint)t) >> (32 - s));
}
private int Hh(int a, int b, int c, int d, int x, int s)
{
int t = a + (b ^ c ^ d) + x + unchecked(0x6ED9EBA1);
return t << s | (int)(((uint)t) >> (32 - s));
}
public override byte[] Digest()
{
return EngineDigest();
}
public override int GetDigestLength()
{
return EngineDigest().Length;
}
public override void Reset()
{
EngineReset();
}
public override void Update(byte[] b)
{
EngineUpdate(b, 0, b.Length);
}
public override void Update(byte b)
{
EngineUpdate(b);
}
public override void Update(byte[] b, int offset, int len)
{
EngineUpdate(b, offset, len);
}
}
}