public static EncryptedLoaderFrame Create(byte[] unencryptedData)
{
int length = unencryptedData.Length;
if (length % BootLoaderCryptoAlgorithm.DecryptedBlockSize != 0)
{
throw new ArgumentException("Unencrypted data is not a multiple of 50 byte block size.");
}
int blockCount = length / BootLoaderCryptoAlgorithm.DecryptedBlockSize;
if (blockCount == 0 || blockCount > 5)
{
throw new ArgumentException("Unencrypted data must be 1 to 5 blocks of 50 bytes.");
}
EncryptedLoaderFrame frame = new EncryptedLoaderFrame(blockCount);
frame.Encrypt(unencryptedData);
return(frame);
}
public static EncryptedLoaderFrame Load(Stream encryptedStream)
{
byte header = (byte)encryptedStream.ReadByte();
if (!IsValidHeader(header))
{
throw new ArgumentException("Invalid header information in stream.");
}
int frameLength = GetBlockCount(header) * BootLoaderCryptoAlgorithm.EncryptedBlockSize;
byte[] data = new byte[frameLength];
int bytesRead = encryptedStream.Read(data, 0, frameLength);
if (bytesRead != frameLength)
{
throw new ArgumentException("Stream does not contain enough data.");
}
EncryptedLoaderFrame frame = new EncryptedLoaderFrame(data);
return(frame);
}
