public void BadSignatureEmptyLength(string badSignature)
{
//Online HMAC tester: https://www.devglan.com/online-tools/hmac-sha256-online
var input = new TestModelInclusive();
var calculator = new HMACSHA256SignatureCalculator();
var sut = new InstanceSignatureBuilder(calculator);
sut.VerifyHex(input, badSignature, knownKey).Should().BeFalse();
}
public void PropertiesImplicitlyIncludedInCalculation()
{
//Online HMAC tester: https://www.devglan.com/online-tools/hmac-sha256-online
const string signature = "8feda6b02259091f6d58b53f5bf5645586fe38694c43d50c4e06f51265ed84a9";
var input = new TestModelInclusive();
var calculator = new HMACSHA256SignatureCalculator();
var sut = new InstanceSignatureBuilder(calculator);
sut.VerifyHex(input, signature, knownKey).Should().BeTrue();
}
public void BuildSignatureAndVerifyExample_Hex()
{
// Any input. Even an anonymous type will do.
var input = new
{
Id = 1,
Name = "Hello World",
CreatedDate = DateTime.MaxValue
};
// Secret key shared between the sender and receiver.
var sharedSecretKey = "This is the key shared between the signature creator and signature verifier";
// Sender computes signature.
var signatureBuilder = new InstanceSignatureBuilder(new HMACSHA256SignatureCalculator());
var signatureResult = signatureBuilder.Compute(input, sharedSecretKey);
_output.WriteLine($"ASCII Payload used to calculate signature: {signatureResult.PayloadAsASCIIString()}");
_output.WriteLine($"Signature in Hex: {signatureResult.SignatureAsHexString()}");
// receiver verifies signature, positive verification when sender and receiver key matches.
var verificationStatus = signatureBuilder.VerifyHex(input, signatureResult.SignatureAsHexString(), sharedSecretKey)
? "verified"
: "incorrect";
_output.WriteLine($"Signature Validity: {verificationStatus}");
// receiver verifies signature, negative verification.
// This test should fail in the case where either the signature or the key is different from original provided values.
// In the example below, a different key is used when comparing signatures.
var verificationStatusForcedFailure = signatureBuilder.VerifyHex(input, signatureResult.SignatureAsHexString(), "Any different key will force an incorrect verification.")
? "verified"
: "incorrect";
_output.WriteLine($"Signature Validity: {verificationStatusForcedFailure}");
}