security patches & rate limits

LarpixServer/Account/Requests.cs

@@ -68,7 +68,7 @@ public class Requests
         string id = Utils.GetValidIdOrZero(idQuery.ToString());
         string password = await Utils.GetPassword(id);
         secret = await Utils.NonceDecryptBody(id, password, secret);
-        string auth = await Utils.Auth(id, password, secret);
+        string auth = await Utils.Auth(id, password, secret, context.Connection.RemoteIpAddress?.ToString() ?? "");
         if (auth != Utils.LOGIN_SUCCESS)
         {
             await context.Response.WriteAsync(auth);
@@ -103,9 +103,10 @@ public class Requests
         {
             case "init":
             {
-                //KEM keygen jest kosztowny - limit per IP
+                //check tylko: kwota jest zapisywana w finish po faktycznym utworzeniu konta,
+                //więc nieudane podejścia jej nie zjadają
                 string initIp = context.Connection.RemoteIpAddress?.ToString() ?? "";
-                if (RateLimited(AccountInitRateLimits, initIp, ACCOUNT_INIT_RATE_LIMIT))
+                if (IsRateLimitReached(AccountInitRateLimits, initIp, ACCOUNT_INIT_RATE_LIMIT))
                 {
                     await context.Response.WriteAsync("error:rate.limit");
                     return;
@@ -125,7 +126,12 @@ public class Requests
                 KeyExchangePayload payload = new KeyExchangePayload();
                 payload.pubX25519 = Convert.ToBase64String(serverInfo.pubX25519);
                 payload.pubMlKem = Convert.ToBase64String(serverInfo.pubMlKem);
-                payload.idKey = DateTimeOffset.UtcNow.ToUnixTimeSeconds() + "\n";
+                //losowy klucz: bez przejścia przez init nie da się odgadnąć idKey,
+                //więc register bez ważnego init robi tylko tani lookup
+                do
+                {
+                    payload.idKey = Convert.ToBase64String(RandomNumberGenerator.GetBytes(32));
+                } while (createHolder.ContainsKey(payload.idKey));
 
                 CreateHolder dataHolder = new();
                 dataHolder.date = DateTimeOffset.UtcNow;
@@ -134,11 +140,6 @@ public class Requests
                 dataHolder.KdfSalt = Convert.ToBase64String(RandomNumberGenerator.GetBytes(16));
                 payload.kdfSalt = dataHolder.KdfSalt;
 
-                while (createHolder.ContainsKey(payload.idKey))
-                {
-                    payload.idKey += Random.Shared.Next(0, 10).ToString();
-                }
-
                 createHolder.TryAdd(payload.idKey, dataHolder);
 
                 var serializedPayload = JsonSerializer.Serialize(
@@ -163,6 +164,14 @@ public class Requests
                     return;
                 }
 
+                //register jest jednorazowy w tej sesji: powtórka (albo równoległe żądanie)
+                //z tym samym idKey nie może drugi raz liczyć KEM
+                if (Interlocked.CompareExchange(ref entry.registerDone, 1, 0) != 0)
+                {
+                    await context.Response.WriteAsync("error:account.creation.request.expired");
+                    return;
+                }
+
                 entry.date = DateTimeOffset.UtcNow;
 
                 byte[] pubX25519Client = Convert.FromBase64String(serializedBody.pubX25519);
@@ -315,6 +324,9 @@ public class Requests
                         userLock.Release();
                     }
 
+                    //kwota liczona dopiero po faktycznym utworzeniu konta
+                    RecordRateLimitHit(AccountInitRateLimits,
+                        context.Connection.RemoteIpAddress?.ToString() ?? "", 3600);
                     await context.Response.WriteAsync("success:account.created");
                     return;
                 }
@@ -343,18 +355,11 @@ public class Requests
         }
 
         string id = Utils.GetValidIdOrZero(idQuery.ToString());
-
-        //rate limit prob logowania (konto+IP)
         string clientIp = context.Connection.RemoteIpAddress?.ToString() ?? "";
-        if (RateLimited(AuthRateLimits, $"{id}:{clientIp}", AUTH_RATE_LIMIT))
-        {
-            await context.Response.WriteAsync("error:rate.limit");
-            return;
-        }
 
         string password = await Utils.GetPassword(id);
         secret = await Utils.NonceDecryptBody(id, password, secret);
-        string auth = await Utils.Auth(id, password, secret);
+        string auth = await Utils.Auth(id, password, secret, clientIp);
 
         await context.Response.WriteAsync(auth);
         return;
@@ -511,7 +516,7 @@ public class Requests
         string bodyDecrypted = await Utils.NonceDecryptBody(id, password, body, false);
         secret = await Utils.NonceDecryptBody(id, password, secret);
 
-        string auth = await Utils.Auth(id, password, secret);
+        string auth = await Utils.Auth(id, password, secret, context.Connection.RemoteIpAddress?.ToString() ?? "");
 
         if (auth != Utils.LOGIN_SUCCESS)
         {
@@ -598,7 +603,7 @@ public class Requests
         body = await Utils.NonceDecryptBody(id, password, body, false);
         secret = await Utils.NonceDecryptBody(id, password, secret);
 
-        string auth = await Utils.Auth(id, secret, password);
+        string auth = await Utils.Auth(id, secret, password, context.Connection.RemoteIpAddress?.ToString() ?? "");
         if (auth != Utils.LOGIN_SUCCESS)
         {
             await context.Response.WriteAsync(auth);
@@ -726,7 +731,7 @@ public class Requests
             AppJsonSerializerContext.Default.Universal2String
         );
 
-        string auth = await Utils.Auth(id, secret, password);
+        string auth = await Utils.Auth(id, secret, password, context.Connection.RemoteIpAddress?.ToString() ?? "");
 
         if (auth != Utils.LOGIN_SUCCESS)
         {
@@ -1216,7 +1221,7 @@ public class Requests
         string target = await Utils.NonceDecryptBody(id, password, targetHeader, false);
         string secretStr = await Utils.NonceDecryptBody(id, password, secret, false);
         
-        string auth = await Utils.Auth(id, secretStr, password);
+        string auth = await Utils.Auth(id, secretStr, password, context.Connection.RemoteIpAddress?.ToString() ?? "");
 
         if (auth != Utils.LOGIN_SUCCESS)
         {
@@ -1276,7 +1281,7 @@ public class Requests
         //S9: jednorazowa akcja zapisu - konsumuj nonce (delEntry:false pozwalał
         //na nieograniczony replay przechwyconej pary secret+body)
         string secretStr = await Utils.NonceDecryptBody(id, password, secret, true);
-        string auth = await Utils.Auth(id, secretStr, password);
+        string auth = await Utils.Auth(id, secretStr, password, context.Connection.RemoteIpAddress?.ToString() ?? "");
 
         if (auth != Utils.LOGIN_SUCCESS)
         {
@@ -1340,7 +1345,7 @@ public class Requests
         string id = Utils.GetValidIdOrZero(idQuery.ToString());
         string password = await Utils.GetPassword(id);
         string secretStr = await Utils.NonceDecryptBody(id, password, secret, false);
-        string auth = await Utils.Auth(id, secretStr, password);
+        string auth = await Utils.Auth(id, secretStr, password, context.Connection.RemoteIpAddress?.ToString() ?? "");
 
         if (auth != Utils.LOGIN_SUCCESS) return; // Don't leak info
 
@@ -1381,7 +1386,7 @@ public class Requests
         string id = Utils.GetValidIdOrZero(idQuery.ToString());
         string password = await Utils.GetPassword(id);
         string secretStr = await Utils.NonceDecryptBody(id, password, secret, false);
-        string auth = await Utils.Auth(id, secretStr, password);
+        string auth = await Utils.Auth(id, secretStr, password, context.Connection.RemoteIpAddress?.ToString() ?? "");
 
         if (auth != Utils.LOGIN_SUCCESS) return;
 
@@ -1414,6 +1419,7 @@ public class Requests
 public class CreateHolder
 {
     public DateTimeOffset date;
+    public int registerDone;
     public string name;
     public string pass;
     public string captcha;

LarpixServer/Account/Utils.cs

@@ -151,17 +151,23 @@ public class Utils
         return Encoding.UTF8.GetString(await Fs.ReadFile(path));
     }
 
-    public static async Task<string> Auth(string id, string password, string password2)
+    public static async Task<string> Auth(string id, string password, string password2, string clientIp = "")
     {
+        if (IsAuthRateLimited(id, clientIp))
+        {
+            return "error:invalid.password";
+        }
         if (!Fs.Exists($"{ACCOUNTS_DATA_DIR}/{id}"))
         {
             return "error:invalid.username.or.password";
         }
         if (password != password2)
         {
+            RecordAuthFailure(id, clientIp);
             return "error:invalid.password";
         }
 
+        RecordAuthSuccess(id, clientIp);
         await UpdateLastLogin(id);
         return LOGIN_SUCCESS;
     }

LarpixServer/Program.cs

@@ -41,7 +41,7 @@ public class Program
                 {
                     if (entry.Value.resetAt <= nowSec) VoiceAuthLimits.TryRemove(entry.Key, out _);
                 }
-                //prune pozostałych rate limitów (okna 60s)
+                //prune pozostałych rate limitów (okna 60s / 1h)
                 PruneRateLimits(AuthRateLimits, nowSec);
                 PruneRateLimits(NonceRateLimits, nowSec);
                 PruneRateLimits(KdfSaltRateLimits, nowSec);

LarpixServer/Utils/Utils.cs

@@ -30,26 +30,85 @@ public class Utils
     // Fixed 60s window: (request count, window reset unix time).
     public static ConcurrentDictionary<string, (int count, long resetAt)> VoiceAuthLimits = new();
 
-    // Rate limity per-minute (okno 60s). Wszystkie konfigurowalne przez .env.
+    // Rate limity per IP/konto (okno stałe, domyślnie 60s). Wszystkie konfigurowalne przez .env.
     public static ConcurrentDictionary<string, (int count, long resetAt)> AuthRateLimits = new();
     public static ConcurrentDictionary<string, (int count, long resetAt)> NonceRateLimits = new();
     public static ConcurrentDictionary<string, (int count, long resetAt)> KdfSaltRateLimits = new();
     public static ConcurrentDictionary<string, (int count, long resetAt)> AccountInitRateLimits = new();
 
-    public static int AUTH_RATE_LIMIT = 10;          // próby logowania /auth + /ws na konto+IP
+    public static int AUTH_RATE_LIMIT = 10;              // failed password verifications per account+IP per minute
-    public static int NONCE_RATE_LIMIT = 240;        // pobrania nonce per konto
+    public static int NONCE_RATE_LIMIT = 240;            // pobrania nonce per konto per minute
-    public static int KDFSALT_RATE_LIMIT = 60;       // pobrania soli per IP
+    public static int KDFSALT_RATE_LIMIT = 60;           // pobrania soli per IP per minute
-    public static int ACCOUNT_INIT_RATE_LIMIT = 10;  // inicjalizacje rejestracji (KEM keygen) per IP
+    public static int ACCOUNT_INIT_RATE_LIMIT = 4;       // utworzone konta per IP per hour (check w init, zapis w finish)
 
-    // Zwraca true jeśli przekroczono limit. Okno stałe 60s.
+    // Zwraca true jeśli przekroczono limit. Okno stałe, domyślnie 60s.
-    public static bool RateLimited(ConcurrentDictionary<string, (int count, long resetAt)> store, string key, int limit)
+    public static bool RateLimited(ConcurrentDictionary<string, (int count, long resetAt)> store, string key, int limit, int windowSeconds = 60)
     {
         if (limit <= 0) return false; // <=0 wyłącza limit
         long nowSec = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
         var window = store.AddOrUpdate(key,
+            (1, nowSec + windowSeconds),
+            (_, old) => old.resetAt <= nowSec ? (1, nowSec + windowSeconds) : (old.count + 1, old.resetAt));
+        return window.count > limit;
+    }
+
+    //Sprawdzenie bez inkrementacji: true jeśli klucz osiągnął już limit w bieżącym oknie
+    public static bool IsRateLimitReached(ConcurrentDictionary<string, (int count, long resetAt)> store, string key, int limit)
+    {
+        if (limit <= 0) return false;
+        if (!store.TryGetValue(key, out var entry)) return false;
+
+        long nowSec = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+        if (entry.resetAt <= nowSec)
+        {
+            store.TryRemove(key, out _);
+            return false;
+        }
+        return entry.count >= limit;
+    }
+
+    //Zapis jednego zdarzenia; okno startuje przy pierwszym zapisie
+    public static void RecordRateLimitHit(ConcurrentDictionary<string, (int count, long resetAt)> store, string key, int windowSeconds = 60)
+    {
+        long nowSec = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+        store.AddOrUpdate(key,
+            (1, nowSec + windowSeconds),
+            (_, old) => old.resetAt <= nowSec ? (1, nowSec + windowSeconds) : (old.count + 1, old.resetAt));
+    }
+
+    // Failed password verifications only, keyed "{id}:{ip}". A success clears the
+    // counter unless the limit is already reached; then the 60s window must expire.
+    public static bool IsAuthRateLimited(string id, string clientIp)
+    {
+        if (AUTH_RATE_LIMIT <= 0) return false;
+        string key = $"{id}:{clientIp}";
+        if (!AuthRateLimits.TryGetValue(key, out var entry)) return false;
+
+        long nowSec = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+        if (entry.resetAt <= nowSec)
+        {
+            AuthRateLimits.TryRemove(key, out _);
+            return false;
+        }
+        return entry.count >= AUTH_RATE_LIMIT;
+    }
+
+    public static void RecordAuthFailure(string id, string clientIp)
+    {
+        if (AUTH_RATE_LIMIT <= 0) return;
+        long nowSec = DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+        AuthRateLimits.AddOrUpdate($"{id}:{clientIp}",
             (1, nowSec + 60),
             (_, old) => old.resetAt <= nowSec ? (1, nowSec + 60) : (old.count + 1, old.resetAt));
-        return window.count > limit;
+    }
+
+    public static void RecordAuthSuccess(string id, string clientIp)
+    {
+        string key = $"{id}:{clientIp}";
+        if (AuthRateLimits.TryGetValue(key, out var entry) && entry.count < AUTH_RATE_LIMIT)
+        {
+            AuthRateLimits.TryRemove(key, out _);
+        }
     }
     
     public static string DATA_DIR = "./data";
@@ -188,19 +247,12 @@ public class Utils
         }
 
         string id = Account.Utils.GetValidIdOrZero(authParams.string1);
-
-        //rate limit prób autoryzacji WS (konto+IP) - wspólny zasobnik z /auth
         string clientIp = context.Connection.RemoteIpAddress?.ToString() ?? "";
-        if (RateLimited(AuthRateLimits, $"{id}:{clientIp}", AUTH_RATE_LIMIT))
-        {
-            await webSocket.CloseAsync(System.Net.WebSockets.WebSocketCloseStatus.PolicyViolation, "Rate limited", CancellationToken.None);
-            return;
-        }
 
         string password = await Account.Utils.GetPassword(id);
         string secret = await Account.Utils.NonceDecryptBody(id, password, authParams.string2);
         
-        string auth = await Account.Utils.Auth(id, password, secret);
+        string auth = await Account.Utils.Auth(id, password, secret, clientIp);
         
         if (auth != Account.Utils.LOGIN_SUCCESS)
         {