feat: Implement QuickLZ decompression, fragment reassembly, and voice echo

internal/client/client.go

@@ -576,31 +576,57 @@ func (c *Client) getCryptoState() (key, nonce, mac []byte, isHandshake bool) {
 // This starts AFTER clientek? Or WITH clientek? "clientek already has the packet id 1"
 
 func (c *Client) handleVoice(pkt *protocol.Packet) {
-	// Parse Voice Header
-	// 2 bytes VID, 1 byte Codec, Data
-	if len(pkt.Data) < 3 {
+	// Parse Voice Header (Server -> Client)
+	// VID(2) + CID(2) + Codec(1) + Data
+	if len(pkt.Data) < 5 {
 		return
 	}
 
-	// vid := binary.BigEndian.Uint16(pkt.Data[0:2])
-	// codec := pkt.Data[2]
-	voiceData := pkt.Data[3:]
+	vid := binary.BigEndian.Uint16(pkt.Data[0:2])
+	// cid := binary.BigEndian.Uint16(pkt.Data[2:4]) // Talking client ID (not needed for echo)
+	codec := pkt.Data[4]
+	voiceData := pkt.Data[5:]
 
-	// Calculate "Volume" (RMS of encrypted/compressed data is meaningless, but existing requirement asks for it)
-	// To do this properly, we need to decrypt -> decode[Opus] -> PCM -> RMS.
-	// For "Eco" (Echo), we can just re-wrap this data and send it back.
+	log.Printf("Voice Packet received. VID=%d, Codec=%d, Size=%d", vid, codec, len(voiceData))
 
-	vol := len(voiceData) // Placeholder "volume"
-	log.Printf("Voice Packet received. Approx Size/Vol: %d", vol)
+	// Build echo packet (Client -> Server)
+	// Format: VID(2) + Codec(1) + Data
+	echoData := make([]byte, 2+1+len(voiceData))
+	binary.BigEndian.PutUint16(echoData[0:2], vid)
+	echoData[2] = codec
+	copy(echoData[3:], voiceData)
 
-	// Echo back
-	// Client -> Server Voice Packet
-	// VID + Codec + Data
-	// We can reuse the data payload structure mostly?
-	// C->S: VID(2) + Codec(1) + Data
+	echoPkt := protocol.NewPacket(protocol.PacketTypeVoice, echoData)
+	echoPkt.Header.PacketID = pkt.Header.PacketID // Use same ID for voice
+	echoPkt.Header.ClientID = c.ClientID
+
+	// Encrypt voice packet with SharedSecret
+	if c.Handshake != nil && len(c.Handshake.SharedIV) > 0 {
+		crypto := &protocol.CryptoState{
+			SharedIV:     c.Handshake.SharedIV,
+			SharedMac:    c.Handshake.SharedMac,
+			GenerationID: 0,
+		}
+		key, nonce := crypto.GenerateKeyNonce(&echoPkt.Header, true)
+
+		// Meta for Client->Server: PID(2) + CID(2) + PT(1)
+		meta := make([]byte, 5)
+		binary.BigEndian.PutUint16(meta[0:2], echoPkt.Header.PacketID)
+		binary.BigEndian.PutUint16(meta[2:4], echoPkt.Header.ClientID)
+		meta[4] = echoPkt.Header.Type
+
+		encData, mac, err := protocol.EncryptEAX(key, nonce, meta, echoPkt.Data)
+		if err != nil {
+			log.Printf("Voice encryption failed: %v", err)
+			return
+		}
+		echoPkt.Data = encData
+		copy(echoPkt.Header.MAC[:], mac)
+	} else {
+		// If no encryption keys, use SharedMac
+		echoPkt.Header.MAC = protocol.HandshakeMac
+	}
 
-	echoPkt := protocol.NewPacket(protocol.PacketTypeVoice, pkt.Data)
-	// ID Counter handling?
 	c.Conn.SendPacket(echoPkt)
 }