public void Test_GetPlaintextLength_ReturnsCorrectLength(int ciphertextLength, int expectedPlaintextLength)
{
var aeadCipher = new XChaChaAeadCipher();
var plaintextLength = aeadCipher.GetPlaintextLength(ciphertextLength);
Assert.Equal(expectedPlaintextLength, plaintextLength);
}
public void Test_Encrypt_WithAdditionalData_ReturnsNonZeroOutput()
{
using (var key = XChaChaKey.Generate())
{
var aeadCipher = new XChaChaAeadCipher();
var nonce = XChaChaNonce.Generate();
var additionalData = Encoding.UTF8.GetBytes(DateTime.Now.ToString());
var message = RandomBytesGenerator.NextBytes(1024 * 1024);
var ciphertext = aeadCipher.Encrypt(message, key, nonce, additionalData);
Assert.False(ciphertext.All(b => b == 0));
}
}
public void Test_Decrypt_WithAdditionalData_Success()
{
using (var key = XChaChaKey.Generate())
{
var aeadCipher = new XChaChaAeadCipher();
var nonce = XChaChaNonce.Generate();
var additionalData = Encoding.UTF8.GetBytes(DateTime.Now.ToString());
const int messageLength = 1024 * 1024;
var message = RandomBytesGenerator.NextBytes(messageLength);
var ciphertext = aeadCipher.Encrypt(message, key, nonce, additionalData);
var result = aeadCipher.Decrypt(ciphertext, key, nonce, additionalData);
Assert.Equal(message, result);
}
}
public void Test_Decrypt_WithInvalidAdditionalData_Fails()
{
using (var key = XChaChaKey.Generate())
{
var aeadCipher = new XChaChaAeadCipher();
var nonce = XChaChaNonce.Generate().ToArray();
var additionalData = Encoding.UTF8.GetBytes(DateTime.Now.ToString());
const int messageLength = 1024 * 1024;
var message = RandomBytesGenerator.NextBytes(messageLength);
var ciphertext = aeadCipher.Encrypt(message, key, new XChaChaNonce(nonce), additionalData);
var invalidAdditionalData = Encoding.UTF8.GetBytes("banana");
Action action = () => { aeadCipher.Decrypt(ciphertext, key, new XChaChaNonce(nonce), invalidAdditionalData); };
var exception = Assert.Throws <CryptographicException>(action);
Assert.Equal("decryption failed", exception.Message);
}
}
public void Test_EncryptWithReturn_MaxMessageLengthExceeded_ThrowsException()
{
unsafe
{
using (var key = XChaChaKey.Generate())
{
var aeadCipher = new XChaChaAeadCipher();
Action action = () =>
{
var message = new ReadOnlySpan <byte>(IntPtr.Zero.ToPointer(), int.MaxValue);
var additionalData = Encoding.UTF8.GetBytes(DateTime.Now.ToString());
var nonce = XChaChaNonce.Generate();
aeadCipher.Encrypt(message, key, nonce, additionalData);
};
var exception = Assert.Throws <ArgumentException>(action);
Assert.Equal("message is too long", exception.Message);
}
}
}