fahhh

App/security/FuzzyTokens.h

@@ -0,0 +1,86 @@
+#pragma once
+#include "boost/thread/mutex.hpp"
+
+namespace RBX
+{
+    // This is designed to be an anti-tamper security reporting mechanism.
+    // Add flag is based on the number of bits in the flag, and succeeds
+    // with probability 1 - 0.5**N per transmitted packet.  This might
+    // seem like an issue, but most of the checks will re-trigger an addition
+    // meaning an exploiter is unlikely to be in the game for more than 30
+    // seconds.  Attempts to modify the packet are very likely to fail.
+
+    namespace Security
+    {
+        unsigned long long teaDecrypt(unsigned long long inTag);
+        unsigned long long teaEncrypt(unsigned long long inTag);
+    }
+
+    namespace Tokens
+    {
+        union binaryTag
+        {
+            unsigned int asHalf[2];
+            unsigned long long asFull;
+        };
+    }
+
+    class ClientFuzzySecurityToken 
+    {
+        Tokens::binaryTag tag;
+        Tokens::binaryTag prevTag;
+        Tokens::binaryTag savedTag;
+        boost::mutex tokenMutex;
+    public:
+        ClientFuzzySecurityToken(unsigned long long inTag);
+        void set(unsigned long long inTag);
+
+#ifdef WIN32
+        __forceinline
+#else
+        inline
+#endif
+        void addFlagFast(unsigned long long flags)
+        {
+            tag.asFull |= flags;
+        }
+
+#ifdef WIN32
+        __forceinline
+#else
+        inline
+#endif
+        void addFlagSafe(unsigned long long flags)
+        {
+            boost::mutex::scoped_lock lock(tokenMutex);
+            tag.asFull |= flags;
+        }
+        unsigned long long crypt();
+        unsigned long long getPrev()
+        {
+            return prevTag.asFull;
+        }
+    };
+
+    // The server can check this.  Each '1' transmitted from the client has
+    // a 50% chance of being a '0' here, thus it it fuzzy.
+    class ServerFuzzySecurityToken
+    {
+        Tokens::binaryTag lastTag;
+        Tokens::binaryTag tag;
+        unsigned int ignoreFlags;
+    public:
+        ServerFuzzySecurityToken(unsigned long long inTag, unsigned int ignoreFlags = 0);
+        void setLastTag(unsigned long long tag) { lastTag.asFull = tag;}
+        unsigned long long decrypt(unsigned long long inTag);
+    };
+
+    namespace Tokens
+    {
+        extern ClientFuzzySecurityToken sendStatsToken;
+        extern unsigned int simpleToken;
+        extern ClientFuzzySecurityToken apiToken;
+    }
+
+}
+