update README and add .env.example

.env.example

@@ -0,0 +1 @@
+AES_KEY_GCM=<32-character-secret-key>

.gitignore

@@ -1,4 +1,7 @@
 # dont upload to github
+.env
+.env.*
+!.env.example
 bin
 
 # c++

README.md

@@ -34,6 +34,14 @@ make sure the go version shows up. otherwise just run manually.
 ```
 "31,0,0,360,0,200,200,60,100200200630013"
 ```
+### Environment Configuration
+
+Copy `.env.example` to `.env`, then set the `AES_KEY_GCM` value.
+
+> **Note**
+> - `AES_KEY_GCM` must be exactly **32 characters**.
+> - Use the **same key** on both the robot and the base station.
+> - Do not upload the `.env` file to GitHub.
 
 ### Author
 > <a href="https://me-danuandrean.github.io/">Danu andrean</a>

go.mod

@@ -2,4 +2,7 @@ module Basestation
 
 go 1.13
 
-require github.com/gorilla/websocket v1.5.0
+require (
+	github.com/gorilla/websocket v1.5.0
+	github.com/joho/godotenv v1.5.1
+)

go.sum

@@ -1,2 +1,4 @@
 github.com/gorilla/websocket v1.5.0 h1:PPwGk2jz7EePpoHN/+ClbZu8SPxiqlu12wZP/3sWmnc=
 github.com/gorilla/websocket v1.5.0/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=

source/manager.go

@@ -5,8 +5,8 @@ import (
 	"net"
 	"net/http"
 	"strconv"
-	"time"
 	"strings"
+	"time"
 
 	"github.com/gorilla/websocket"
 )
@@ -42,7 +42,7 @@ var gameController = GameController{}
 var timeout int64 = 5
 
 func Init() {
-	gameController.VERSION = 1
+	gameController.VERSION = 2
 	execute.robotExecute = "0"
 	execute.privilege = 10 // higher is lower
 }
@@ -76,94 +76,95 @@ func RefereeBoxHandler() {
 
 func ClientHandler() {
 
-    addr := net.UDPAddr{
-        Port: 8124,
-        IP:   net.ParseIP(GetIP()),
-    }
-
-    ser, err := net.ListenUDP("udp", &addr)
-    if err != nil {
-        fmt.Printf("Some error %v\n", err)
-        return
-    }
-
-    for {
-
-        bytes := make([]byte, 512)
-
-        n, remoteaddr, err := ser.ReadFromUDP(bytes)
-        if err != nil {
-            fmt.Printf("[ERROR] ReadFromUDP: %v\n", err)
-            continue
-        }
-
-        raw := strings.TrimSpace(string(bytes[:n]))
-        if raw == "" {
-            fmt.Println("[WARN] Received empty data")
-            continue
-        }
-
-        parts := strings.Split(raw, "|")
-        if len(parts) < 3 {
-            fmt.Printf("[ERROR] Incomplete encrypted data: %s\n", raw)
-            continue
-        }	
-
-		cipher := parts[0]
-		tag := parts[1]
-		iv := parts[2]
-		plaintext, err := DecryptAESGCM(iv, tag, cipher)
+	addr := net.UDPAddr{
+		Port: 8124,
+		IP:   net.ParseIP(GetIP()),
+	}
 
-        if err != nil {
-            fmt.Printf("[ERROR] Decryption failed: %v\n", err)
-            continue
-        }
+	ser, err := net.ListenUDP("udp", &addr)
+	if err != nil {
+		fmt.Printf("Some error %v\n", err)
+		return
+	}
 
-        fmt.Printf("[OK] Decrypted data: %s\n", plaintext)
+	for {
 
-        received := CleanString(plaintext)
-        dataAfterParseLoc := ParseLoc(received)
+		bytes := make([]byte, 512)
 
-        s := Split(received)
-        swap := Swap(s[10])
+		n, remoteaddr, err := ser.ReadFromUDP(bytes)
+		if err != nil {
+			fmt.Printf("[ERROR] ReadFromUDP: %v\n", err)
+			continue
+		}
 
-        var container string
-        for i := 0; i < 9; i++ {
-            container = container + s[i]
-        }
+		raw := strings.TrimSpace(string(bytes[:n]))
+		if raw == "" {
+			fmt.Println("[WARN] Received empty data")
+			continue
+		}
 
-        container = CleanString(container)
-        swap = CleanString(swap)
+		// panjang minimal: IV(24) + TAG(32)
+		if len(raw) < 56 {
+			fmt.Printf("[ERROR] Data terlalu pendek: %s\n", raw)
+			continue
+		}
 
-        if container == swap {
+		// slicing FIXED (HEX)
+		iv := raw[0:24]       // 12 byte
+		tag := raw[24:56]     // 16 byte
+		cipher := raw[56:]    // sisanya
 
-            id := GetID(dataAfterParseLoc)
+		plaintext, err := DecryptAESGCM(iv, tag, cipher)
+		if err != nil {
+			fmt.Printf("[ERROR] Decryption failed: %v\n", err)
+			continue
+		}
 
-            t := time.Now()
+		fmt.Printf("[OK] Decrypted data: %s\n", plaintext)
 
-            switch id[0] {
-            case '1':
-                times.timeR1 = t.Unix()
-                staging.R1 = dataAfterParseLoc
-            case '2':
-                times.timeR2 = t.Unix()
-                staging.R2 = dataAfterParseLoc
-            case '3':
-                times.timeR3 = t.Unix()
-                staging.R3 = dataAfterParseLoc
-            case '4':
-                times.timeR4 = t.Unix()
-                staging.R4 = dataAfterParseLoc
-            case '5':
-                times.timeR5 = t.Unix()
-                staging.R5 = dataAfterParseLoc
-            }
+		received := CleanString(plaintext)
+		dataAfterParseLoc := ParseLoc(received)
 
-            rvRobot := WhoIsExecute(id)
-            go ClientResponse(ser, remoteaddr, rvRobot)
-        }
+		s := Split(received)
+		swap := Swap(s[10])
 
-    }
+		var container string
+		for i := 0; i < 9; i++ {
+			container = container + s[i]
+		}
+
+		container = CleanString(container)
+		swap = CleanString(swap)
+
+		if container == swap {
+
+			id := GetID(dataAfterParseLoc)
+
+			t := time.Now()
+
+			switch id[0] {
+			case '1':
+				times.timeR1 = t.Unix()
+				staging.R1 = dataAfterParseLoc
+			case '2':
+				times.timeR2 = t.Unix()
+				staging.R2 = dataAfterParseLoc
+			case '3':
+				times.timeR3 = t.Unix()
+				staging.R3 = dataAfterParseLoc
+			case '4':
+				times.timeR4 = t.Unix()
+				staging.R4 = dataAfterParseLoc
+			case '5':
+				times.timeR5 = t.Unix()
+				staging.R5 = dataAfterParseLoc
+			}
+
+			rvRobot := WhoIsExecute(id)
+			go ClientResponse(ser, remoteaddr, rvRobot)
+		}
+
+	}
 }
 
 func ClientResponse(conn *net.UDPConn, addr *net.UDPAddr, rvRobot string) {
@@ -331,4 +332,4 @@ func GetPrivilegeRobot(data string) int {
 		return 5
 	}
 	return 10
-}
+}

source/utilities.go

@@ -9,6 +9,10 @@ import (
     "unicode"
 	"net"
 	"fmt"
+	"os"
+	"log"
+
+	"github.com/joho/godotenv"
 )
 
 func CleanString(data string) string {
@@ -85,8 +89,18 @@ func GetIP() string {
 }
 func DecryptAESGCM(ivHex, tagHex, cipherHex string) (string, error) {
 
-    key := []byte("R5C9u@D!A7xP#LQ2mZ8F$wKJH4S1ErT0")
+	err := godotenv.Load()
+	if err != nil {
+		log.Fatal(".env tidak ditemukan")
+	}
+
+	keyEnv := os.Getenv("AES_KEY_GCM")
 
+	if len(keyEnv) != 32 {
+		log.Fatal("AES_KEY_GCM tidak valid")
+	}
+
+	key := []byte(keyEnv)	
 
     // Convert HEX → BYTES
     iv, err := hex.DecodeString(ivHex)
@@ -129,4 +143,4 @@ func DecryptAESGCM(ivHex, tagHex, cipherHex string) (string, error) {
     }
 
     return string(plain), nil
-}
+}