Radicade Public Code

Server/Auth/AdminLoginThrottle.cs

@@ -0,0 +1,108 @@
+using System.Collections.Concurrent;
+
+namespace RadicadeServer.Auth;
+
+
+
+
+
+
+
+
+public static class AdminLoginThrottle
+{
+
+	public const int MaxFailedAttempts = 5;
+
+
+	public static readonly TimeSpan LockoutDuration = TimeSpan.FromMinutes(15);
+
+	private sealed record Entry(int Failures, DateTime FirstFailureAt, DateTime LockedUntil);
+
+	private static readonly ConcurrentDictionary<string, Entry> Attempts = new();
+
+
+
+	public static bool IsLocked(string username, string ip, out TimeSpan remaining)
+	{
+		remaining = TimeSpan.Zero;
+		var byUser = LockedRemaining("u:" + username);
+		var byIp = LockedRemaining("ip:" + ip);
+
+		if (byUser == null && byIp == null) return false;
+		remaining = Max(byUser, byIp)!.Value;
+		return true;
+	}
+
+	public static void RecordFailure(string username, string ip)
+	{
+		var now = DateTime.UtcNow;
+		foreach (var key in Keys(username, ip))
+		{
+			Attempts.AddOrUpdate(key,
+				_ => new Entry(1, now, DateTime.MinValue),
+				(_, existing) =>
+				{
+
+
+					if (now - existing.FirstFailureAt > LockoutDuration)
+						return new Entry(1, now, DateTime.MinValue);
+
+					var failures = existing.Failures + 1;
+
+
+					var lockedUntil = failures >= MaxFailedAttempts ? now + LockoutDuration : DateTime.MinValue;
+					return new Entry(failures, existing.FirstFailureAt, lockedUntil);
+				});
+		}
+		Prune(now);
+	}
+
+	public static void Clear(string username, string ip)
+	{
+		foreach (var key in Keys(username, ip))
+			Attempts.TryRemove(key, out _);
+	}
+
+	private static TimeSpan? LockedRemaining(string key)
+	{
+		if (string.IsNullOrWhiteSpace(key)) return null;
+		if (!Attempts.TryGetValue(key, out var entry)) return null;
+
+
+		if (entry.Failures < MaxFailedAttempts) return null;
+
+		var now = DateTime.UtcNow;
+		if (now >= entry.LockedUntil)
+		{
+			Attempts.TryRemove(key, out _);
+			return null;
+		}
+		return entry.LockedUntil - now;
+	}
+
+	private static IEnumerable<string> Keys(string username, string ip)
+	{
+		if (!string.IsNullOrWhiteSpace(username)) yield return "u:" + username;
+		if (!string.IsNullOrWhiteSpace(ip)) yield return "ip:" + ip;
+	}
+
+	private static TimeSpan? Max(TimeSpan? a, TimeSpan? b)
+	{
+		if (a == null) return b;
+		if (b == null) return a;
+		return a > b ? a : b;
+	}
+
+	private static void Prune(DateTime now)
+	{
+
+		foreach (var kv in Attempts)
+		{
+			var e = kv.Value;
+			var lockActive = e.Failures >= MaxFailedAttempts && now < e.LockedUntil;
+			if (!lockActive && now - e.FirstFailureAt > LockoutDuration)
+				Attempts.TryRemove(kv.Key, out _);
+		}
+	}
+}