//readonly MemoryProtectionScope scope;
#region static initializers
/// <summary>
/// Static method to create a protected key from a plaintext key. It will wipe the reference that was passed in once the protected key instance is initialized
/// </summary>
/// <param name="plaintextKey">The key</param>
/// <returns>A protected key instance from the provided key</returns>
public static InMemoryKey CreateProtectedKeyAndDestroyPlaintextKey(byte[] plaintextKey)
{
var key = new InMemoryKey(plaintextKey);
// the protected key creates a copy of the key and pads it as needed for in memory protection.
// Thus the reference that was passed in isn't needed. Overwrite it with random garbage.
KeyUtilities.Destroy(plaintextKey);
return(key);
}
/// <summary>
/// Uses the key to get an HMAC using the specified algorithm and data
/// </summary>
/// <param name="mode">The HMAC algorithm to use</param>
/// <param name="data">The data used to compute the HMAC</param>
/// <returns>HMAC of the key and data</returns>
public byte[] ComputeHmac(OtpHashMode mode, byte[] data)
{
byte[] hashedValue = null;
using (HMAC hmac = CreateHmacHash(mode))
{
byte[] key = this.GetCopyOfKey();
try
{
hmac.Key = key;
hashedValue = hmac.ComputeHash(data);
}
finally
{
KeyUtilities.Destroy(key);
}
}
return(hashedValue);
}