protected override void Dispose(bool disposing)
{
if (disposing)
{
_symmetricAlgorithm.Dispose();
}
base.Dispose(disposing);
}
/// <summary>
///
/// </summary>
/// <param name="secretKey"></param>
/// <param name="plainData"></param>
/// <returns></returns>
public static ProtectedMemory EncryptData(ProtectedString secretKey, ProtectedMemory plainData)
{
ProtectedMemory returnValue = null;
System.Byte[] encryptedData = null;
#region Check protection of secret key
if (!secretKey.IsProtected)
{
throw new UnsecureException();
}
#endregion
#region Check protection of plain data
if (!plainData.IsProtected)
{
throw new UnsecureException();
}
#endregion
#region Prepare encryption provider
// Unprotect memory containing secret key
secretKey.Unprotect();
// Create encryption provider
System.Security.Cryptography.SymmetricAlgorithm encryptionProvider = System.Security.Cryptography.Aes.Create();
encryptionProvider.Mode = System.Security.Cryptography.CipherMode.CBC;
encryptionProvider.Key = secretKey.GetBytes();
encryptionProvider.GenerateIV();
// Reprotect memory containing secret key
secretKey.Protect();
#endregion
// Create encryptor
System.Security.Cryptography.ICryptoTransform encryptor = encryptionProvider.CreateEncryptor(encryptionProvider.Key, encryptionProvider.IV);
// Create handle to stream data into memory
using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream())
{
// Write IV to temp memory (IV length is static => 16 )
memoryStream.Write(encryptionProvider.IV, 0, 16);
// Create handle for data encryption; data streamed to this stream will be automatically encrypted and streamed to memory
using (System.Security.Cryptography.CryptoStream cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream, encryptor, System.Security.Cryptography.CryptoStreamMode.Write))
{
// Create handle to write data to a stream; data written to this stream will be automatically encrypted and streamed to memory
using (System.IO.StreamWriter streamWriter = new System.IO.StreamWriter(cryptoStream))
{
// Unprotect plain data
plainData.Unprotect();
#region Write and encrypt plain data to temp memory
foreach (System.Byte b in plainData.GetBytes())
{
streamWriter.Write((System.Char)b);
}
#endregion
// Reprotect plain data
plainData.Protect();
}
}
// Save content of temp memory in temp buffer
encryptedData = memoryStream.ToArray();
}
// Dispose encryptor
encryptor.Dispose();
// Dispose encryption provider
encryptionProvider.Dispose();
#region Save cyphered data in protected memory
// Create protected memory for cyphered data
returnValue = new ProtectedMemory(encryptedData.Length);
// Unprotect memory for cyphered data
returnValue.Unprotect();
// Copy cyphered data in encrypted memory
for (System.Int32 i = 0; i < encryptedData.Length; i++)
{
returnValue.SetByte(i, encryptedData[i]);
}
// Reprotect memory with cyphered data
returnValue.Protect();
#endregion
return(returnValue);
}
/// <summary>
///
/// </summary>
/// <param name="secretKey"></param>
/// <param name="cypheredData"></param>
/// <returns></returns>
public static ProtectedMemory DecryptData(ProtectedString secretKey, ProtectedMemory cypheredData)
{
ProtectedMemory returnValue = null;
System.Byte[] encryptedData = null;
System.Byte[] ivData = null;
#region Check protection of secret key
if (!secretKey.IsProtected)
{
throw new UnsecureException();
}
#endregion
#region Check protection of cyphered data
if (!cypheredData.IsProtected)
{
throw new UnsecureException();
}
#endregion
#region Split cyphered data
// Unprotect cyphered memory
cypheredData.Unprotect();
// extract iv data (IV length is static => 16)
ivData = new System.Byte[16];
System.Array.Copy(cypheredData.GetBytes(), 0, ivData, 0, 16);
// extract encrypted data
encryptedData = new System.Byte[cypheredData.SizeInByte - 16];
System.Array.Copy(cypheredData.GetBytes(), 16, encryptedData, 0, (cypheredData.SizeInByte - 16));
// Reprotect cyphered memory
cypheredData.Protect();
#endregion
#region Prepare encryption provider
// Unprotect memory containing secret key
secretKey.Unprotect();
// Create encryption provider
System.Security.Cryptography.SymmetricAlgorithm encryptionProvider = System.Security.Cryptography.Aes.Create();
encryptionProvider.Mode = System.Security.Cryptography.CipherMode.CBC;
encryptionProvider.Key = secretKey.GetBytes();
encryptionProvider.IV = ivData;
// Reprotect memory containing secret key
secretKey.Protect();
#endregion
// Create decryptor
System.Security.Cryptography.ICryptoTransform decryptor = encryptionProvider.CreateDecryptor(encryptionProvider.Key, encryptionProvider.IV);
// Create handle to memory of encrypted data
using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(encryptedData))
{
// Create handle for data decryption; data streamed by this stream will be automatically decrypted
using (System.Security.Cryptography.CryptoStream cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream, decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
{
// Create handle to read data of a strea,; data readed by this stream will be automatically decrypted
using (System.IO.StreamReader streamReader = new System.IO.StreamReader(cryptoStream))
{
#region Save plain data in protected memory
// Save plain data in temp buffer
System.String plainData = streamReader.ReadToEnd();
// Create protected memory for plain data
returnValue = new ProtectedMemory(plainData.Length);
// Unprotect memory for plain data
returnValue.Unprotect();
// Copy plain data in encrypted memory
for (System.Int32 i = 0; i < plainData.Length; i++)
{
returnValue.SetByte(i, (System.Byte)plainData[i]);
}
// Reprotect memory with plain data
returnValue.Protect();
// Save erase temp buffer
plainData = null;
System.GC.Collect();
#endregion
}
}
}
// Dispose decryptor
decryptor.Dispose();
// Dispose encryption provider
encryptionProvider.Dispose();
return(returnValue);
}
