clsEasyMD5.cs

// C# ClassLib
// http://csharp-classlib.sourceforge.net
//
//
// Copyright (C) 2005 Marcel Joachim Kloubert
// 
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
// 
// This program 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 General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
//

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace CSharp_ClassLib.Cryptography
{
        public class EasyMD5 : System.Object
        {
                private System.Security.Cryptography.MD5CryptoServiceProvider m_oMD5;
        private byte[] m_bChecksum;
        private System.Text.ASCIIEncoding m_oASCII;
                
                public EasyMD5()
                {
                        this.IntRest();
                        
                        return;
                }
                
                public EasyMD5(byte[] Expression)
                {
                        this.IntRest();
                        this.ExpressionBytes = Expression;
                        
                        return;
                }
                
                public EasyMD5(System.IO.Stream stream)
                {
                        this.IntRest();
                        this.Stream = stream;
                        
                        return;
                }
                
                public EasyMD5(string filename)
                {
                        this.IntRest();
                        this.Filename = filename;
                        
                        return;
                }
                
                public byte[] ChecksumBytes { get { return this.m_bChecksum; } }
                
                public string ChecksumString { get { return this.ToHexString(this.ChecksumBytes); } }
                
                public byte[] ExpressionBytes
                {
                        set
                        {
                                this.m_oMD5 = new System.Security.Cryptography.MD5CryptoServiceProvider();                                                      
                                this.m_bChecksum = this.m_oMD5.ComputeHash(value);
                        }
                }
                
                public string ExpressionString { set { this.ExpressionBytes = m_oASCII.GetBytes(value); } }
                
                public string Filename
                {
                        set
                        {
                                if (!System.IO.File.Exists(value.Trim()))
                                        // file does not exist!
                                        throw ( new System.IO.FileNotFoundException("File was not found!", value.Trim()) );
                                
                                this.Stream = ( new System.IO.FileStream(value.Trim(), System.IO.FileMode.Open) );
                        }
                }
                
                public System.IO.Stream Stream
                {
                        set
                        {
                                this.m_oMD5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
                                this.m_bChecksum = this.m_oMD5.ComputeHash(value);
                        }
                }
                
                private void IntRest()
                {
                        this.m_oMD5 = null;
                        this.m_bChecksum = new byte[0];
                        
                        this.m_oASCII = new System.Text.ASCIIEncoding();
                        
                        return;
                }
                
                private string ToHexString (byte[] Expression)
                {
                        if (null == Expression)
                                return "";
                                
                        int i = 0;
                        byte bHigh = 0;
                        byte bLow = 0;
                        string strBuffer = "";
                        string strHexString = "0123456789ABCDEF";

                        for (i = 0; i < Expression.GetLength(0); i++)
                        {
                                // calc the high & the low byte
                                bHigh = (byte)System.Math.Floor((double)Expression[i] / 16.0);
                                bLow = (byte)(Expression[i] % 16);
        
                                // add the character as 2-character-hex-expression
                                strBuffer += strHexString.Substring(bHigh, 1) + strHexString.Substring(bLow, 1);
                        }
                
                        return strBuffer;
                }

                public void Clear ()
                {
                        this.m_bChecksum = new byte[0];
                        
                        return;
                }
                
        }
}

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