public string Encrypt(string message)
{
byte[] result = null;
StringBuilder hash = new StringBuilder();
switch (HashSize)
{
case HashFunctionSize.Bits224:
result = Sha3.Sha3224().ComputeHash(Encoding.UTF8.GetBytes(message));
break;
case HashFunctionSize.Bits256:
result = Sha3.Sha3256().ComputeHash(Encoding.UTF8.GetBytes(message));
break;
case HashFunctionSize.Bits384:
result = Sha3.Sha3384().ComputeHash(Encoding.UTF8.GetBytes(message));
break;
case HashFunctionSize.Bits512:
result = Sha3.Sha3512().ComputeHash(Encoding.UTF8.GetBytes(message));
break;
}
for (int i = 0; i < result.Length; i++)
{
hash.Append(result[i].ToString("x2"));
}
return(hash.ToString());
}
public TicketScanResult CheckTicket(DigitalTicket scannedTicket, Ticket actualTicket)
{
if (scannedTicket is null)
{
throw new ArgumentNullException(nameof(scannedTicket), "Cannot check null ticket");
}
if (!scannedTicket.Seat.Equals(actualTicket.Seat))
{
throw new ArgumentException(nameof(actualTicket), "Seats do not match");
}
byte[] scannedSecretHash;
try
{
using var hasher = Sha3.Sha3224();
scannedSecretHash = hasher.ComputeHash(scannedTicket.Secret);
}
catch (ArgumentException e)
{
_logger.LogWarning(e.Message);
return(null);
}
if (!actualTicket.Secret.SequenceEqual(scannedSecretHash))
{
return(new TicketScanResult(false, string.Empty));
}
if (actualTicket.CustomerIdentifier is null)
{
return(new TicketScanResult(true, string.Empty));
}
string plainTextCustomerIdentifier;
try
{
using var aes = _cipherFactory.CreateCbcProvider();
plainTextCustomerIdentifier = aes.Decrypt(actualTicket.CustomerIdentifier, scannedTicket.NameKey, scannedTicket.NameIV);
}
catch (CryptographicException e)
{
_logger.LogDebug(e.Message);
return(new TicketScanResult(true, string.Empty));
}
catch (ArgumentException e)
{
_logger.LogWarning(e.Message);
return(null);
}
return(new TicketScanResult(true, plainTextCustomerIdentifier));
}
public void CheckTicket_ProvidedSecretMatchesCustomerIdentifierDecrypted_ReturnsResultOwnsTicketNameMatchesDecryptedValue()
{
// Arrange
var plainTextSecret = "f09aIm3-hH9379c";
byte[] hashedSecret;
using (var hasher = Sha3.Sha3224())
{
hashedSecret = hasher.ComputeHash(plainTextSecret);
}
var customerIdentifier = new byte[16] {
33, 93, 23, 252, 24, 38, 43, 94, 224, 10, 12, 232, 28, 211, 64, 99
};
var name = "Benjamin Swift";
var scannedTicket = new DigitalTicket
{
Seat = new Seat {
Number = 1, Letter = 'A'
},
Secret = plainTextSecret
};
var actualTicket = new Ticket
{
Seat = new Seat {
Number = 1, Letter = 'A'
},
Secret = hashedSecret,
CustomerIdentifier = customerIdentifier
};
_cbc.Setup(callTo => callTo.Decrypt(customerIdentifier, It.IsAny <byte[]>(), It.IsAny <byte[]>())).Returns(name);
// Act
var result = _ticketChecker.CheckTicket(scannedTicket, actualTicket);
// Assert
Assert.Multiple(() =>
{
Assert.That(result.OwnsTicket, Is.True, nameof(TicketScanResult.OwnsTicket));
Assert.That(result.Name, Is.EqualTo(name), nameof(TicketScanResult.Name));
});
}
public void CheckTicket_ProvidedSecretMatchesDecryptCustomerIdentifierThrowsArgumentException_ReturnsNull()
{
// Arrange
var plainTextSecret = "f09aIm3-hH9379c";
byte[] hashedSecret;
using (var hasher = Sha3.Sha3224())
{
hashedSecret = hasher.ComputeHash(plainTextSecret);
}
var customerIdentifier = new byte[16] {
33, 93, 23, 252, 24, 38, 43, 94, 224, 10, 12, 232, 28, 211, 64, 99
};
var scannedTicket = new DigitalTicket
{
Seat = new Seat {
Number = 1, Letter = 'A'
},
Secret = plainTextSecret
};
var actualTicket = new Ticket
{
Seat = new Seat {
Number = 1, Letter = 'A'
},
Secret = hashedSecret,
CustomerIdentifier = customerIdentifier
};
_cbc.Setup(callTo => callTo.Decrypt(customerIdentifier, It.IsAny <byte[]>(), It.IsAny <byte[]>())).Throws <ArgumentException>();
// Act
var result = _ticketChecker.CheckTicket(scannedTicket, actualTicket);
// Assert
Assert.That(result, Is.Null);
}
public void CheckTicket_ProvidedSecretMatchesCustomerIdentifierNull_ReturnsResultOwnsTicketNameEmpty()
{
// Arrange
var plainTextSecret = "f09aIm3-hH9379c";
byte[] hashedSecret;
using (var hasher = Sha3.Sha3224())
{
hashedSecret = hasher.ComputeHash(plainTextSecret);
}
var scannedTicket = new DigitalTicket
{
Seat = new Seat {
Number = 1, Letter = 'A'
},
Secret = plainTextSecret
};
var actualTicket = new Ticket
{
Seat = new Seat {
Number = 1, Letter = 'A'
},
Secret = hashedSecret
};
// Act
var result = _ticketChecker.CheckTicket(scannedTicket, actualTicket);
// Assert
Assert.Multiple(() =>
{
Assert.That(result.OwnsTicket, Is.True, nameof(TicketScanResult.OwnsTicket));
Assert.That(result.Name, Is.Empty, nameof(TicketScanResult.Name));
});
}
public void Sha3224ComputeHash_WithControlledInput_ResultMatchesExpected(string input, string expected)
{
var hash = Sha3.Sha3224().ComputeHash(Encoding.UTF8.GetBytes(input));
hash.ToHexString().Should().Be(expected);
}
