private static bool removePadding = true; // can be set to false by HandleConfigurationArguments
public static void Main(String[] args)
{
Console.WriteLine("~~ Padding Oracle Attack Demo ~~");
HandleConfigurationArguments(args);
Console.WriteLine("Oracle response delay set to {0} ms.", oracle.OracleDelayMilliseconds);
Console.WriteLine("\nEnter plaintext:");
string plaintext = Console.ReadLine();
byte[] encrypted = oracle.Encrypt(plaintext);
var blocks = ByteUtils.SliceIntoBlocks(encrypted);
Console.WriteLine("\nCiphertext blocks (base64):\n{0}", String.Join("\n", blocks.ConvertAll(block => Convert.ToBase64String(block))));
Console.WriteLine("\nPadding oracle attack results:");
Console.WriteLine("(first block cannot be decrypted)");
var stopwatch = new Stopwatch();
var lastBlockIndex = blocks.Count - 1;
for (int blockIndex = 1; blockIndex <= lastBlockIndex; ++blockIndex)
{
stopwatch.Start();
var decrypted = decryptor.DecryptBlock(blocks[blockIndex], blocks[blockIndex - 1]);
stopwatch.Stop();
if (removePadding && blockIndex == lastBlockIndex)
{
decrypted = PaddingUtils.GetPaddingRemoverFromMode(oracle.Padding).Invoke(decrypted);
}
var decryptedPlaintext = Encoding.UTF8.GetString(decrypted, 0, decrypted.Length);
Console.WriteLine(decryptedPlaintext.Length > 0 ? decryptedPlaintext : "(padding-only block)");
}
var decodedBlocksCount = blocks.Count - 1;
Console.WriteLine("\nDecoded {0} blocks.", decodedBlocksCount);
if (decodedBlocksCount > 0)
{
var timeElapsed = stopwatch.Elapsed;
Console.WriteLine("Time elapsed: {0}, avg {1:0.000} s per block", timeElapsed.ToString(), timeElapsed.Divide(decodedBlocksCount).TotalMilliseconds / 1000);
}
}
public PaddingOracleDecryptor(RemoteServerMock oracle)
{
this.oracle = oracle;
paddingValueProvider = PaddingUtils.GetPaddingValueProviderFromMode(oracle.Padding);
}