How to solve this Timeslot issue in C#

asp.net, c#

Solution

You could store a list of attempt timestamps and use that to determine if the user is locked out. This is not complete code, but here's the basic idea:

// Store a list of attempts
var attempts = new List<DateTime>();

// Determine if 10 or more attempts have been made in the last 5 minutes
bool lockout = attempts.Where(a => (DateTime.Now - a).TotalMinutes <= 5).Count() >= 10;

// Register an attempt
attempts.Add(DateTime.Now);

// Remove attempts older than 5 minutes
attempts.Where(a => (DateTime.Now - a).TotalMinutes > 5).ToList()
    .ForEach(a => attempts.Remove(a));

You could also store the attempts in a database, which would give you a papertrail for security purposes. The same methodology would apply -- count the records less than 5 minutes old.

Problem

I am trying to solve this business issue: - A user gets 10 attempts to login every 5 minutes - If a user exceeds 10 attempts, I display a "You need to wait to login" message - Once 5 minutes have elapsed, I need to reset the number of attempts and let the user attempt 10 more times. I'd like to do this without using a `Timer` and I am storing most of this info in the `Session` ``` public class LoginExp { public DateTime FirstAttempt; public int NumOfAttempts; } ``` I store the `FirstAttempt` DateTime on Page Load. On the Login button click: - I increment `NumOfAttempts` - I need to check if NumOfAttempts < 10 within the same 5 minute time slot. I could get the number of minutes elapsed between `FirstAttempt` and `DateTime.Now` and do a mod of 5, but that won't tell me which timeslot this is in (In other words, a user may have attempted 3 times as of the 2nd minute and then comes back in the 7th minute to do an attempt again. The `mod` would give me the same value. Any thoughts on how I could do this?

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