Post date: Mar 7, 2011 10:55:16 AM
using System;
using System.Collections.Generic;
using System.Security;
using System.Text;
using System.Security.Cryptography;
using System.IO;
using Microsoft.CSharp;
using System.CodeDom.Compiler;
namespace RSACryptography
{
public class Cryptography{
public static string SUCCESS = "Success";
//Function to Encrypt the Data using Public Key Encrytion
public static string EncryptData(string publicKeyPath,string data2Encrypt)
{
StreamReader reader=null;
RSACryptoServiceProvider rsa;
try
{
//Initialize the parameters
const int PROVIDER_RSA_FULL = 1;
const string CONTAINER_NAME = "License";
//perform Cryptography computation
CspParameters cspParams;
//initialize the CSP parameters
cspParams = new CspParameters(PROVIDER_RSA_FULL);
//Key Name
cspParams.KeyContainerName = CONTAINER_NAME;
//use information from computer's store
cspParams.Flags = CspProviderFlags.UseMachineKeyStore;
//Provider Name
cspParams.ProviderName = "Microsoft Strong Cryptographic Provider";
//Configure the RAS Provider
rsa = new RSACryptoServiceProvider(cspParams);
//Reader to read xml file
reader = new StreamReader(publicKeyPath);
string publicOnlyKeyXML = reader.ReadToEnd();
//initialize the public key for encryption
rsa.FromXmlString(publicOnlyKeyXML);
reader.Close();
//read plaintext, encrypt it to ciphertext
byte[] plainbytes = System.Text.Encoding.UTF8.GetBytes(data2Encrypt);
//Encrypt the Given data
byte[] cipherbytes = rsa.Encrypt(plainbytes, false);
//Ciper text to caller
return Convert.ToBase64String(cipherbytes);
}
catch
{
try
{
reader.Close();
}
catch { }
return null;
}
}
//Create New Files
public static bool AssignNewKey(string privateKeyPath, string publicKeyPath)
{
//Ture when file is created successfully
bool isFileCreated = false;
StreamWriter writer=null;
RSACryptoServiceProvider rsa;
try
{
//InitializeParameter;
//Initialize the parameters
const int PROVIDER_RSA_FULL = 1;
const string CONTAINER_NAME = "License";
//perform Cryptography computation
CspParameters cspParams;
//initialize the CSP parameters
cspParams = new CspParameters(PROVIDER_RSA_FULL);
//Key Name
cspParams.KeyContainerName = CONTAINER_NAME;
//use information from computer's store
cspParams.Flags = CspProviderFlags.UseMachineKeyStore;
//Provider Name
cspParams.ProviderName = "Microsoft Strong Cryptographic Provider";
//Configure the RAS Provider
rsa = new RSACryptoServiceProvider(cspParams);
//provide public and private RSA params
writer= new StreamWriter(privateKeyPath);
string publicPrivateKeyXML = rsa.ToXmlString(true);
writer.Write(publicPrivateKeyXML);
writer.Close();
//provide public only RSA params
writer = new StreamWriter(publicKeyPath);
string publicOnlyKeyXML = rsa.ToXmlString(false);
writer.Write(publicOnlyKeyXML);
writer.Close();
isFileCreated = true;
return isFileCreated;
}//Incase any error occured when read or writing the file
catch
{
try
{
//close the file
writer.Close();
}
catch
{
}
return isFileCreated;
}
}
public static string DecryptData(string privateKey,string data2Decrypt)
{
StreamReader reader=null;
try
{
//Initialize the parameters
//InitializeParameter();
RSACryptoServiceProvider rsa;
//Initialize the parameters
const int PROVIDER_RSA_FULL = 1;
const string CONTAINER_NAME = "License";
//perform Cryptography computation
CspParameters cspParams;
//initialize the CSP parameters
cspParams = new CspParameters(PROVIDER_RSA_FULL);
//Key Name
cspParams.KeyContainerName = CONTAINER_NAME;
//use information from computer's store
cspParams.Flags = CspProviderFlags.UseMachineKeyStore;
//Provider Name
cspParams.ProviderName = "Microsoft Strong Cryptographic Provider";
//Configure the RAS Provider
rsa = new RSACryptoServiceProvider(cspParams);
//Convert into 8-bit Unsignned integer array
byte[] getpassword = Convert.FromBase64String(data2Decrypt);
//Reader to read XML file
reader= new StreamReader(privateKey);
string publicPrivateKeyXML = reader.ReadToEnd();
//initialize the RSA by using the key string
rsa.FromXmlString(publicPrivateKeyXML);
reader.Close();
//read ciphertext, decrypt it to plaintext
byte[] plain = rsa.Decrypt(getpassword, false);
//convert byte into character string
return Encoding.UTF8.GetString(plain);
}
catch
{
try
{
reader.Close();
}
catch
{
}
return null;
}
}
}
}