/// <summary>
/// Serialize the cookie container into a byte array.
/// </summary>
/// <returns>Byte array that represents the Cookie Container</returns>
public byte[] Serialize(CookieContainer cookieContainer)
{
// First turn the encryptedSymmetricKey.Length into a byte array
byte[] keyLength = DataBitsConverter.ToBytes(cookieContainer.EncryptedSymmetricKey.Length);
// Allocate the total buffer required.
int bufferSize = keyLength.Length + cookieContainer.EncryptedSymmetricKey.Length + cookieContainer.IV.Length + cookieContainer.EncryptedCookie.Length;
byte[] buffer = new byte[bufferSize];
// Copy SymmetricKeyLength to the buffer.
Array.Copy(keyLength, buffer, keyLength.Length);
// Keep track of the next available space in the buffer.
int index = keyLength.Length;
// Copy the encrypted symmetric key to the buffer.
Array.Copy(cookieContainer.EncryptedSymmetricKey, 0, buffer, index, cookieContainer.EncryptedSymmetricKey.Length);
index += cookieContainer.EncryptedSymmetricKey.Length;
// Copy the IV to the buffer
Array.Copy(cookieContainer.IV, 0, buffer, index, cookieContainer.IV.Length);
index += cookieContainer.IV.Length;
// The rest of the buffer contains the encrypted SCT Cookie.
Array.Copy(cookieContainer.EncryptedCookie, 0, buffer, index, cookieContainer.EncryptedCookie.Length);
return(buffer);
}
/// <summary>
/// Turns a byte array back into a CookieContainer.
/// </summary>
/// <param name="rsaKey">The protection RSA key to decrypt the symmetric key.</param>
/// <param name="aesAlg">The symmetric key algorithm to use to decrypt the cookie block.</param>
/// <param name="data">The byte array to deserialize.</param>
/// <returns>The deserialized cookie container instance.</returns>
public CookieContainer Deserialize(RSACryptoServiceProvider rsaKey, RijndaelManaged aesAlg, byte[] data)
{
CookieContainer cookieContainer = new CookieContainer(rsaKey, aesAlg);
// Length of the IV according to the AES algorithm (in bytes).
int ivLength = aesAlg.BlockSize / 8;
// Determine how much buffer to read to retrieve the symmetric key.
int symmetricKeyLength = DataBitsConverter.ToInt(data, 0, sizeof(int));
// Perform some basic data validation
if (symmetricKeyLength <= 0)
{
throw new InvalidOperationException("symmetricKeyLength must be greater than zero.");
}
checked
{
if (sizeof(int) + symmetricKeyLength + ivLength > data.Length)
{
throw new InvalidOperationException("symmetricKeyLength + encryptedSymmetricKey + IV (in bytes) exceeds the data buffer length.");
}
}
// Use an index to track the next byte to read in the data buffer.
int index = sizeof(int);
// Retrieve the encrypted symmetric key.
cookieContainer.EncryptedSymmetricKey = new byte[symmetricKeyLength];
Array.Copy(data, index, cookieContainer.EncryptedSymmetricKey, 0, symmetricKeyLength);
index += symmetricKeyLength;
// Retrieve the IV.
cookieContainer.IV = new byte[ivLength];
Array.Copy(data, index, cookieContainer.IV, 0, ivLength);
index += ivLength;
// Retrieve the encrypted cookie.
cookieContainer.EncryptedCookie = new byte[data.Length - index];
Array.Copy(data, index, cookieContainer.EncryptedCookie, 0, data.Length - index);
// Re-create the encryptor / decryptor with the new symmetric key and IV.
cookieContainer.CreateCryptoTransformers();
return(cookieContainer);
}
