protected void TryEncryptOneShot_DestinationJustRightTest(byte[] plaintext, byte[] ciphertext, PaddingMode padding, CipherMode mode, int feedbackSize = 0) { using (SymmetricAlgorithm alg = CreateAlgorithm()) { int paddingSizeBytes = mode == CipherMode.CFB ? feedbackSize / 8 : alg.BlockSize / 8; alg.Key = Key; int expectedCiphertextSize = mode switch { CipherMode.ECB => alg.GetCiphertextLengthEcb(plaintext.Length, padding), CipherMode.CBC => alg.GetCiphertextLengthCbc(plaintext.Length, padding), CipherMode.CFB => alg.GetCiphertextLengthCfb(plaintext.Length, padding, feedbackSize), _ => throw new NotImplementedException(), }; Span <byte> destinationBuffer = new byte[expectedCiphertextSize]; int bytesWritten; bool result = mode switch { CipherMode.ECB => alg.TryEncryptEcb(plaintext, destinationBuffer, padding, out bytesWritten), CipherMode.CBC => alg.TryEncryptCbc(plaintext, IV, destinationBuffer, out bytesWritten, padding), CipherMode.CFB => alg.TryEncryptCfb(plaintext, IV, destinationBuffer, out bytesWritten, padding, feedbackSize), _ => throw new NotImplementedException(), }; Assert.True(result, "TryEncrypt"); Assert.Equal(expectedCiphertextSize, bytesWritten); AssertCiphertexts(ciphertext, destinationBuffer, padding, paddingSizeBytes); } }