From a61e2bb7c4a7828039ea4b052f6d09ba73053d3b Mon Sep 17 00:00:00 2001
From: MayaTheShy <mayatheshy@gmail.com>
Date: Sat, 8 Nov 2025 17:52:52 -0500
Subject: [PATCH] feat: add protocol version handling and signature computation
 to NLPacket

---
 src/NLPacketCodec.cpp | 57 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/src/NLPacketCodec.cpp b/src/NLPacketCodec.cpp
index e6e2c76..61b6e96 100644
--- a/src/NLPacketCodec.cpp
+++ b/src/NLPacketCodec.cpp
@@ -3,6 +3,7 @@
 #include <arpa/inet.h>
 #include <cstring>
 #include <string>
+#include <openssl/md5.h>
 
 namespace Overte {
 
@@ -148,4 +149,60 @@ PacketType NLPacket::getType(const uint8_t* data, size_t size) {
     return static_cast<PacketType>(data[sizeof(uint32_t)]);
 }
 
+uint8_t NLPacket::versionForPacketType(PacketType type) {
+    // Based on Overte's PacketHeaders.cpp versionForPacketType()
+    // Returns the protocol version for each packet type
+    switch (type) {
+        case PacketType::DomainConnectRequest:
+            return PacketVersions::DomainConnectRequest_SocketTypes;
+        case PacketType::DomainListRequest:
+            return PacketVersions::DomainListRequest_SocketTypes;
+        case PacketType::DomainList:
+            return PacketVersions::DomainList_SocketTypes;
+        case PacketType::Ping:
+            return PacketVersions::Ping_IncludeConnectionID;
+        case PacketType::DomainConnectionDenied:
+            return 19;  // IncludesExtraInfo
+        case PacketType::DomainConnectRequestPending:
+            return 17;
+        case PacketType::PingReply:
+            return 17;
+        case PacketType::ICEServerPeerInformation:
+        case PacketType::ICEServerQuery:
+            return 17;
+        case PacketType::NodeIgnoreRequest:
+            return 18;
+        case PacketType::DomainServerAddedNode:
+            return 25;  // SocketTypes
+        // For other packet types, return a default version
+        // In real Overte, each has a specific version
+        default:
+            return 17;  // Default version for unspecified packets
+    }
+}
+
+std::vector<uint8_t> NLPacket::computeProtocolVersionSignature() {
+    // Compute MD5 hash of all packet type versions
+    // This matches Overte's ensureProtocolVersionsSignature() function
+    
+    std::vector<uint8_t> buffer;
+    
+    // Write number of packet types (256 max, but we'll use actual count)
+    uint8_t numPacketTypes = 128;  // Conservative estimate for now
+    buffer.push_back(numPacketTypes);
+    
+    // Write version for each packet type
+    for (uint8_t i = 0; i < numPacketTypes; i++) {
+        PacketType type = static_cast<PacketType>(i);
+        uint8_t version = versionForPacketType(type);
+        buffer.push_back(version);
+    }
+    
+    // Compute MD5 hash
+    std::vector<uint8_t> hash(MD5_DIGEST_LENGTH);
+    MD5(buffer.data(), buffer.size(), hash.data());
+    
+    return hash;
+}
+
 } // namespace Overte