public void ValidateOtp_test_validates_within_50_second_validity_period()
 {
     var key = Sha1ReferenceKey;
     var generator = new TimeBasedOtpGenerator(key, 8);
     var currentTime = new DateTime(2033, 5, 18, 3, 33, 20, DateTimeKind.Utc);
     var fiftySeconds = TimeSpan.FromSeconds(50);
     Assert.IsFalse(generator.ValidateOtp("69279037", currentTime.AddSeconds(-90), fiftySeconds), "90 seconds prior should be invalid");
     Assert.IsFalse(generator.ValidateOtp("69279037", currentTime.AddSeconds(-60), fiftySeconds), "60 seconds prior should be invalid");
     Assert.IsTrue(generator.ValidateOtp("69279037", currentTime.AddSeconds(-30), fiftySeconds), "30 seconds prior should be valid");
     Assert.IsTrue(generator.ValidateOtp("69279037", currentTime.AddSeconds(+00), fiftySeconds), "The exact time should be valid");
     Assert.IsTrue(generator.ValidateOtp("69279037", currentTime.AddSeconds(+30), fiftySeconds), "30 seconds after should be valid");
     Assert.IsFalse(generator.ValidateOtp("69279037", currentTime.AddSeconds(+60), fiftySeconds), "60 seconds after should be invalid");
     Assert.IsFalse(generator.ValidateOtp("69279037", currentTime.AddSeconds(+90), fiftySeconds), "90 seconds after should be invalid");
 }
 public void ValidateOtp_test_validates_with_an_empty_validity_period()
 {
     var key = Sha1ReferenceKey;
     var generator = new TimeBasedOtpGenerator(key, 8);
     var currentTime = new DateTime(2033, 5, 18, 3, 33, 20, DateTimeKind.Utc);
     var zeroSeconds = TimeSpan.FromSeconds(0);
     Assert.IsFalse(generator.ValidateOtp("69279037", currentTime.AddSeconds(-30), zeroSeconds), "30 seconds prior should be invalid");
     Assert.IsTrue(generator.ValidateOtp("69279037", currentTime.AddSeconds(-01), zeroSeconds), "1 second prior should be valid (due to a 30-second precision)");
     Assert.IsTrue(generator.ValidateOtp("69279037", currentTime.AddSeconds(+00), zeroSeconds), "The exact time should be valid");
     Assert.IsTrue(generator.ValidateOtp("69279037", currentTime.AddSeconds(+01), zeroSeconds), "1 seconds after should be valid (due to a 30-second precision)");
     Assert.IsFalse(generator.ValidateOtp("69279037", currentTime.AddSeconds(+30), zeroSeconds), "30 seconds after should be invalid");
 }
 public void ValidateOtp_test_validates_within_60_second_validity_period()
 {
     var key = Sha1ReferenceKey;
     var generator = new TimeBasedOtpGenerator(key, 8);
     var currentTime = new DateTime(2009, 2, 13, 23, 31, 30, DateTimeKind.Utc);
     var sixtySeconds = TimeSpan.FromSeconds(60);
     Assert.IsFalse(generator.ValidateOtp("89005924", currentTime.AddSeconds(-90), sixtySeconds), "90 seconds prior should be invalid");
     Assert.IsTrue(generator.ValidateOtp("89005924", currentTime.AddSeconds(-60), sixtySeconds), "60 seconds prior should be valid");
     Assert.IsTrue(generator.ValidateOtp("89005924", currentTime.AddSeconds(-15), sixtySeconds), "15 seconds prior should be valid");
     Assert.IsTrue(generator.ValidateOtp("89005924", currentTime.AddSeconds(+00), sixtySeconds), "The exact time should be valid");
     Assert.IsTrue(generator.ValidateOtp("89005924", currentTime.AddSeconds(+15), sixtySeconds), "15 seconds after should be valid");
     Assert.IsTrue(generator.ValidateOtp("89005924", currentTime.AddSeconds(+60), sixtySeconds), "60 seconds after should be valid");
     Assert.IsFalse(generator.ValidateOtp("89005924", currentTime.AddSeconds(+90), sixtySeconds), "90 seconds after should be invalid");
 }