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SimpleEncryptor.cs
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SimpleEncryptor.cs
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using System;
using System.Security.Cryptography;
using System.IO;
namespace Mob.Core
{
public class SimpleEncryptor
{
// Change these keys. Used for encryption
private readonly byte[] _key = { 25, 213, 73, 255, 138, 133, 37, 11, 77, 28, 44, 124, 129, 217, 199, 101, 18, 31, 178, 144, 82, 80, 111, 52, 34, 33, 35, 1, 155, 184, 74, 201 };
private readonly byte[] _vector = { 35, 57, 177, 111, 33, 3, 17, 237, 119, 121, 88, 114, 79, 34, 77, 134 };
private readonly ICryptoTransform _encryptorTransform;
private readonly ICryptoTransform _decryptorTransform;
private readonly System.Text.UTF8Encoding _utfEncoder;
public SimpleEncryptor()
{
//This is our encryption method
RijndaelManaged rm = new RijndaelManaged();
//Create an encryptor and a decryptor using our encryption method, key, and vector.
_encryptorTransform = rm.CreateEncryptor(this._key, this._vector);
_decryptorTransform = rm.CreateDecryptor(this._key, this._vector);
//Used to translate bytes to text and vice versa
_utfEncoder = new System.Text.UTF8Encoding();
}
/// -------------- Two Utility Methods (not used but may be useful) -----------
/// Generates an encryption key.
static public byte[] GenerateEncryptionKey()
{
//Generate a Key.
RijndaelManaged rm = new RijndaelManaged();
rm.GenerateKey();
return rm.Key;
}
/// Generates a unique encryption vector
static public byte[] GenerateEncryptionVector()
{
//Generate a Vector
RijndaelManaged rm = new RijndaelManaged();
rm.GenerateIV();
return rm.IV;
}
/// ----------- The commonly used methods ------------------------------
/// Encrypt some text and return a string suitable for passing in a URL.
public string EncryptToString(string textValue)
{
return ByteArrToString(Encrypt(textValue));
}
/// Encrypt some text and return an encrypted byte array.
public byte[] Encrypt(string textValue)
{
//Translates our text value into a byte array.
Byte[] bytes = _utfEncoder.GetBytes(textValue);
//Used to stream the data in and out of the CryptoStream.
MemoryStream memoryStream = new MemoryStream();
/*
* We will have to write the unencrypted bytes to the stream,
* then read the encrypted result back from the stream.
*/
#region Write the decrypted value to the encryption stream
CryptoStream cs = new CryptoStream(memoryStream, _encryptorTransform, CryptoStreamMode.Write);
cs.Write(bytes, 0, bytes.Length);
cs.FlushFinalBlock();
#endregion
#region Read encrypted value back out of the stream
memoryStream.Position = 0;
byte[] encrypted = new byte[memoryStream.Length];
memoryStream.Read(encrypted, 0, encrypted.Length);
#endregion
//Clean up.
cs.Close();
memoryStream.Close();
return encrypted;
}
/// The other side: Decryption methods
public string DecryptString(string encryptedString)
{
return Decrypt(StrToByteArray(encryptedString));
}
/// Decryption when working with byte arrays.
public string Decrypt(byte[] encryptedValue)
{
#region Write the encrypted value to the decryption stream
MemoryStream encryptedStream = new MemoryStream();
CryptoStream decryptStream = new CryptoStream(encryptedStream, _decryptorTransform, CryptoStreamMode.Write);
decryptStream.Write(encryptedValue, 0, encryptedValue.Length);
decryptStream.FlushFinalBlock();
#endregion
#region Read the decrypted value from the stream.
encryptedStream.Position = 0;
Byte[] decryptedBytes = new Byte[encryptedStream.Length];
encryptedStream.Read(decryptedBytes, 0, decryptedBytes.Length);
encryptedStream.Close();
#endregion
return _utfEncoder.GetString(decryptedBytes);
}
/// Convert a string to a byte array. NOTE: Normally we'd create a Byte Array from a string using an ASCII encoding (like so).
// System.Text.ASCIIEncoding encoding = new System.Text.ASCIIEncoding();
// return encoding.GetBytes(str);
// However, this results in character values that cannot be passed in a URL. So, instead, I just
// lay out all of the byte values in a long string of numbers (three per - must pad numbers less than 100).
public byte[] StrToByteArray(string str)
{
if (str.Length == 0)
throw new Exception("Invalid string value in StrToByteArray");
byte val;
byte[] byteArr = new byte[str.Length / 3];
int i = 0;
int j = 0;
do
{
val = byte.Parse(str.Substring(i, 3));
byteArr[j++] = val;
i += 3;
}
while (i < str.Length);
return byteArr;
}
// Same comment as above. Normally the conversion would use an ASCII encoding in the other direction:
// System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
// return enc.GetString(byteArr);
public string ByteArrToString(byte[] byteArr)
{
byte val;
string tempStr = "";
for (int i = 0; i <= byteArr.GetUpperBound(0); i++)
{
val = byteArr[i];
if (val < (byte)10)
tempStr += "00" + val.ToString();
else if (val < (byte)100)
tempStr += "0" + val.ToString();
else
tempStr += val.ToString();
}
return tempStr;
}
}
}