private Result GetDecryptor(out ICipher decryptor, long offset)
{
if (offset == 0)
{
// Use the IV directly
decryptor = Aes.CreateCbcDecryptor(_key, _iv);
return(Result.Success);
}
decryptor = default;
// Need to get the output of the previous block
Span <byte> prevBlock = stackalloc byte[BlockSize];
Result rc = BaseStorage.Read(offset - BlockSize, prevBlock);
if (rc.IsFailure())
{
return(rc);
}
ICipher tmpDecryptor = Aes.CreateCbcDecryptor(_key, _iv);
tmpDecryptor.Transform(prevBlock, prevBlock);
decryptor = tmpDecryptor;
return(Result.Success);
}
private static void RegisterAesSequentialBenchmarks(MultiBenchmark bench)
{
var input = new byte[BatchCipherBenchSize];
var output = new byte[BatchCipherBenchSize];
Func <double, string> resultPrinter = time => GetPerformanceString(time, BatchCipherBenchSize);
// Skip the first benchmark set if we don't have AES-NI intrinsics
for (int i = Aes.IsAesNiSupported() ? 0 : 1; i < 2; i++)
{
// Prefer .NET crypto on the second set
string nameSuffix = i == 1 ? "built-in " : string.Empty;
bool preferDotNetImpl = i == 1;
RegisterCipher($"AES-ECB {nameSuffix}encrypt",
() => Aes.CreateEcbEncryptor(new byte[0x10], preferDotNetImpl));
RegisterCipher($"AES-ECB {nameSuffix}decrypt",
() => Aes.CreateEcbDecryptor(new byte[0x10], preferDotNetImpl));
RegisterCipher($"AES-CBC {nameSuffix}encrypt",
() => Aes.CreateCbcEncryptor(new byte[0x10], new byte[0x10], preferDotNetImpl));
RegisterCipher($"AES-CBC {nameSuffix}decrypt",
() => Aes.CreateCbcDecryptor(new byte[0x10], new byte[0x10], preferDotNetImpl));
RegisterCipher($"AES-CTR {nameSuffix}decrypt",
() => Aes.CreateCtrDecryptor(new byte[0x10], new byte[0x10], preferDotNetImpl));
RegisterCipher($"AES-XTS {nameSuffix}encrypt",
() => Aes.CreateXtsEncryptor(new byte[0x10], new byte[0x10], new byte[0x10], preferDotNetImpl));
RegisterCipher($"AES-XTS {nameSuffix}decrypt",
() => Aes.CreateXtsDecryptor(new byte[0x10], new byte[0x10], new byte[0x10], preferDotNetImpl));
}
void RegisterCipher(string name, Func <ICipher> cipherGenerator)
{
ICipher cipher = null;
Action setup = () => cipher = cipherGenerator();
Action action = () => cipher.Transform(input, output);
bench.Register(name, setup, action, resultPrinter);
}
}
//[Theory, MemberData(nameof(DecryptTestVectors_Individual))]
public static void Decrypt_Individual(EncryptionTestVector tv)
{
Common.CipherTestCore(tv.CipherText, tv.PlainText, Aes.CreateCbcDecryptor(tv.Key, tv.Iv, true));
}
public static void DecryptMultiIntrinsics()
{
Common.DecryptCipherTest(DecryptMultiTestVectors, (key, iv) => Aes.CreateCbcDecryptor(key, iv));
}
public static void Decrypt()
{
Common.DecryptCipherTest(DecryptTestVectors, (key, iv) => Aes.CreateCbcDecryptor(key, iv, true));
}
public static void DecryptMultiIntrinsics(EncryptionTestVector tv)
{
Common.CipherTestCore(tv.CipherText, tv.PlainText, Aes.CreateCbcDecryptor(tv.Key, tv.Iv));
}