/// <inheritdoc />
public string Solve(string input)
{
// Convert input string to bytes
byte[] bytes = input.GetBytes();
// Run Oracle against the input data multiple times (with different random byte keys)
int totalTests = 50;
int testFailCount = 0;
for (int i = 0; i < totalTests; i++)
{
// Encrypt data using a random key
int keySize = 16;
Tuple <byte[], EncryptionTypeEnum> encryptionResult = EncryptWithUnknownKey(bytes, keySize);
// Detect which encryption type was used
EncryptionTypeEnum oracleEncryption = DetectEncryptionType(encryptionResult.Item1);
// Get the actual encryption type that was used
EncryptionTypeEnum actualEncryption = encryptionResult.Item2;
// If the determination does not match, the test failed so increment the count
if (!oracleEncryption.Equals(actualEncryption))
{
testFailCount++;
}
}
// Format the result of the tests and return it
return(FormatOutput(totalTests, testFailCount));
}
/// <summary>
/// Selects the right algorithem by looking at the enum
/// </summary>
/// <param name="algorithm">Tells what algorithm to use</param>
public void SelectAlgorithm(EncryptionTypeEnum algorithm)
{
symmetric = algorithm switch
{
EncryptionTypeEnum.AES => Aes.Create(),
EncryptionTypeEnum.DES => DES.Create(),
EncryptionTypeEnum.TripleDES => TripleDES.Create(),
EncryptionTypeEnum.Rijndael => Rijndael.Create(),
_ => new AesManaged(),
};
symmetric.Padding = PaddingMode.PKCS7;
symmetric.Mode = CipherMode.CBC;
}
/// <summary>
/// Encrypt bytes using ECB and CBC randomly
/// </summary>
/// <param name="bytes">The bytes to encrypt</param>
/// <param name="key">The key used to encrypt</param>
/// <returns>A tuple containing the encrypted bytes and the encryption type used (ECB or CBC)</returns>
private Tuple <byte[], EncryptionTypeEnum> EncryptBytesRandomly(byte[] bytes, byte[] key)
{
// Encrypt with ECB or CBC randomly
byte[] encryptedBytes = new byte[bytes.Length];
EncryptionTypeEnum encryptionType = (EncryptionTypeEnum)random.Next(1, 3);
// Encrypt
if (encryptionType.Equals(EncryptionTypeEnum.ECB))
{
// Encrypt using ECB
encryptedBytes = Cryptography.AES_ECB(bytes, key);
}
else if (encryptionType.Equals(EncryptionTypeEnum.CBC))
{
// Create an initialization vector (use random IV)
byte[] iv = GenerateRandomASCIIBytes(key.Length);
// Encrypt using CBC
encryptedBytes = challenge10.AES_CBC(true, bytes, key, iv);
}
return(new Tuple <byte[], EncryptionTypeEnum>(encryptedBytes, encryptionType));
}
public AuthEncryption(AuthenticationTypeEnum authentication, EncryptionTypeEnum encryption, bool useOneX = false)
{
Authentication = authentication;
Encryption = encryption;
UseOneX = useOneX;
}
