public void TestAES128() { var key = "ad7a2bd03eac835a6f620fdcb506b345"; var iv = "12153524c0895e81b2c28465"; var aad = "d609b1f056637a0d46df998d88e52e00b2c2846512153524c0895e81"; var plaintext = "08000f101112131415161718191a1b1c1d1e1f202122232425262728292a2b2c2d2e2f303132333435363738393a0002"; var ciphertext = "701afa1cc039c0d765128a665dab69243899bf7318ccdc81c9931da17fbe8edd7d17cb8b4c26fc81e3284f2b7fba713d"; var tag = "4f8d55e7d3f06fd5a13c0c29b9d5b880"; var aes = new AESCipher(128); var gcm = new GCMCipher(aes); // encryption gcm.Init(new AADParameter(new IVParameter(new KeyParameter(HexConverter.FromHex(key)), HexConverter.FromHex(iv)), HexConverter.FromHex(aad))); var encryptInput = HexConverter.FromHex(plaintext); var encryptOutput = new byte[encryptInput.Length]; var encryptTag = new byte[16]; gcm.Encrypt(encryptInput, 0, encryptOutput, 0, encryptInput.Length); gcm.EncryptFinal(encryptTag, 0); Assert.AreEqual(ciphertext, HexConverter.ToHex(encryptOutput)); Assert.AreEqual(tag, HexConverter.ToHex(encryptTag)); // decryption gcm.Init(new AADParameter(new IVParameter(new KeyParameter(HexConverter.FromHex(key)), HexConverter.FromHex(iv)), HexConverter.FromHex(aad))); var decryptInput = HexConverter.FromHex(ciphertext + tag); var decryptOutput = new byte[decryptInput.Length - 16]; var offset = gcm.Decrypt(decryptInput, 0, decryptOutput, 0, decryptInput.Length); gcm.DecryptFinal(decryptInput, offset, decryptOutput, decryptInput.Length); Assert.AreEqual(plaintext, HexConverter.ToHex(decryptOutput)); }