Enterprise Library Test Guide - Willy .Net

148
Enterprise Library Test Guide
Check
Yes
Description
Clear sensitive data from memory as soon as possible. The Cryptography Application
Block byte arrays contain unencrypted keys. The application block clears them from
memory as soon as it uses them. The following example shows how the application
block uses a key and then removes it.
public byte[] Encrypt(byte[] plaintext)
{
byte[] output = null;
byte[] cipherText = null;
this.algorithm.Key = Key;
using (ICryptoTransform transform =
this.algorithm.CreateEncryptor())
{
cipherText = Transform(transform, plaintext);
}
output = new byte[IVLength + cipherText.Length];
Buffer.BlockCopy(this.algorithm.IV, 0, output, 0,
IVLength);
Buffer.BlockCopy(cipherText, 0, output, IVLength,
cipherText.Length);
CryptographyUtility.ZeroOutBytes(this.algorithm.Key);
}
return output;
public static void ZeroOutBytes(byte[] bytes)
{
if (bytes == null)
{
return;
}
Array.Clear(bytes, 0, bytes.Length);
}
Exception Management Checklist
Table 36 lists the general exception management recommendations.