Updates

SVSim.EmulatedEntrypoint/Services/SteamSessionService.cs

@@ -0,0 +1,56 @@
+using System.Collections.Concurrent;
+using System.Globalization;
+using Microsoft.Extensions.Caching.Memory;
+using Steamworks;
+
+namespace SVSim.EmulatedEntrypoint.Services;
+
+public class SteamSessionService : IDisposable
+{
+    private readonly ConcurrentDictionary<string, ulong> _validatedSessionTickets;
+
+    private const int ShadowVerseAppId = 453480;
+    
+    public SteamSessionService()
+    {
+        _validatedSessionTickets = new ConcurrentDictionary<string, ulong>();
+        SteamServer.Init(ShadowVerseAppId, new SteamServerInit
+        {
+            GamePort = default,
+            QueryPort = default
+        });
+    }
+
+    /// <summary>
+    /// Validates if a given session ticket is valid, and matches up with the given steamid.
+    /// </summary>
+    /// <param name="ticket">the ticket, represented as a hexadecimal string</param>
+    /// <param name="steamId">the steamid that should be associated with the ticket</param>
+    /// <returns>whether the ticket is valid for the given steamid</returns>
+    public bool IsTicketValidForUser(string ticket, ulong steamId)
+    {
+        if (_validatedSessionTickets.TryGetValue(ticket, out ulong storedSteamId))
+        {
+            return storedSteamId == steamId;
+        }
+
+        List<byte> ticketBytes = new List<byte>();
+        for (int i = 0; i < ticket.Length; i += 2)
+        {
+            ticketBytes.Add(Convert.ToByte(ticket.Substring(i, 2), 16));
+        }
+
+        var steamCheckResults = SteamServer.BeginAuthSession(ticketBytes.ToArray(), new SteamId { Value = steamId });
+        if (steamCheckResults)
+        {
+            _validatedSessionTickets.TryAdd(ticket, storedSteamId);
+        }
+        
+        return steamCheckResults;
+    }
+
+    public void Dispose()
+    {
+        SteamServer.Shutdown();
+    }
+}