Decrypting data. : ICryptoStream « Development Class « C# / C Sharp

Home
C# / C Sharp
1.2D Graphics
2.Class Interface
3.Collections Data Structure
4.Components
5.Data Types
6.Database ADO.net
7.Design Patterns
8.Development Class
9.Event
10.File Stream
11.Generics
12.GUI Windows Form
13.Language Basics
14.LINQ
15.Network
16.Office
17.Reflection
18.Regular Expressions
19.Security
20.Services Event
21.Thread
22.Web Services
23.Windows
24.Windows Presentation Foundation
25.XML
26.XML LINQ
C# / C Sharp by API
C# / CSharp Tutorial
C# / CSharp Open Source
C# / C Sharp » Development Class » ICryptoStreamScreenshots 
Decrypting data.
 


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

public class StoreCryptoStream : ICryptoStream {
    static byte[] tag1 = {(byte)'[',(byte)'S',(byte)'a',(byte)'u' ,(byte)'d' ,(byte)'e',(byte)'s' ,(byte)']'};
    static byte[] tag2 = {(byte)'[',(byte)'S',(byte)'a',(byte)'u' ,(byte)'r' ,(byte)'c',(byte)'2' ,(byte)']'};

    FileStream fs;

    public StoreCryptoStream(FileStream fout) {
        fs = fout;
    }

    public virtual void CloseStream() { fs.Close()}
    public virtual void CloseStream(Object obj) { fs.Close()}
    public virtual void SetSink(ICryptoStream pstm) { }
    public virtual void SetSource(CryptographicObject co) { }
    public virtual ICryptoStream GetSink() { return null}

    public virtual void Write(byte[] bin) {
        int len = bin.GetLength(0);
        Write(bin, 0, len);
    }

    public virtual void Write(byte[] bin, int start, int len) {
        fs.Write(bin, start, len);
    }

}

public class MainClass {
    static byte[] symKey;
    static byte[] symIV;

    private static bool GenerateKey(string password) {
            int len;
            char[] cp = password.ToCharArray();
            len = cp.GetLength(0);
            byte[] bt = new byte[len];

            for (int i = 0; i < len; i++) {
                bt[i(byte)cp[i];
            }
            symKey = new byte[8];
            symIV = new byte[8];
            SHA1_CSP sha = new SHA1_CSP();
            sha.Write(bt);
            sha.CloseStream();
            for (int i = 0; i < 8; i++) {
                symKey[i= sha.Hash[i];
            }
            for (int i = 8; i < 16; i++) {
                symIV[i - 8= sha.Hash[i];
            }

            return true;

    }

    private static void DecryptData(string infile, string outfile) {
            FileStream fin = new FileStream(infile, FileMode.Open, FileAccess.Read);
            FileStream fout = new FileStream(outfile, FileMode.OpenOrCreate, FileAccess.Write);
            fout.SetLength(0);

            byte[] bin = new byte[4096];
            long totlen = fin.Length;
            long rdlen = 8;
            int len;

            SymmetricAlgorithm des = new DES_CSP();

            StoreCryptoStream scs = new StoreCryptoStream(fout);
            SymmetricStreamDecryptor ssd = des.CreateDecryptor(symKey, symIV);

            ssd.SetSink(scs);
            scs.SetSource(ssd);

            while (rdlen < totlen) {
                len = fin.Read(bin, 04096);
                ssd.Write(bin, 0, len);
                rdlen = rdlen + len;
            }
            ssd.CloseStream();
            fin.Close();
            fout.Close();

    }

    public static void Main(string[] args) {
        GenerateKey(args[0]);
        DecryptData(args[1], args[2]);
    }
}

 
Related examples in the same category
1.Encrypting data.
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.