From 0801887236c82240ad2fee8c9c52089f71ed8ccf Mon Sep 17 00:00:00 2001
From: Joren Schipman <joren.schipman@student.howest.be>
Date: Tue, 30 Apr 2024 17:09:14 +0200
Subject: [PATCH] If the data is to big chunk it

---
 Connect.kt | 37 ++++++++++++++++---------------------
 main.go    | 54 +++++++++++++++++-------------------------------------
 2 files changed, 33 insertions(+), 58 deletions(-)

diff --git a/Connect.kt b/Connect.kt
index 0b12a8b..21c9863 100644
--- a/Connect.kt
+++ b/Connect.kt
@@ -39,18 +39,19 @@ class Connect {
         suspend fun main() {
             val host = "192.168.90.151"
             val port = 8080
-
             val secureRandom = SecureRandom()
             val keyBytes = ByteArray(16)
-            secureRandom.nextBytes(keyBytes)
-            val key = SecretKeySpec(keyBytes, "AES")
-
             val ivBytes = ByteArray(16)
+            secureRandom.nextBytes(keyBytes)
             secureRandom.nextBytes(ivBytes)
+            val key = SecretKeySpec(keyBytes, "AES")
             val iv = IvParameterSpec(ivBytes)
-
             val algorithm = "AES/CBC/PKCS5Padding"
-            val inputText = "abcdefghigklmnopqrstuvwxyz0123456789"
+
+            var sendData = "Hello, World!"
+
+            val chunkSize = 45
+            val chunks = sendData.chunked(chunkSize)
 
             withContext(Dispatchers.IO) {
                 Socket(host, port).use { socket ->
@@ -58,30 +59,24 @@ class Connect {
                     val reader = BufferedReader(InputStreamReader(socket.getInputStream()))
 
                     val encodedKey = encodeBase64(keyBytes)
-                    println(keyBytes.toHexString())
                     writer.println(encodedKey)
-
-                    println(reader.readLine())
-
+                    reader.readLine()
                     val encodedIV = encodeBase64(ivBytes)
-                    println(ivBytes.toHexString())
                     writer.println(encodedIV)
+                    reader.readLine()
 
-                    println(reader.readLine())
-
-                    val cipherText = encrypt(algorithm, inputText, key, iv)
-                    println(cipherText)
-                    writer.println(cipherText)
+                    for (chunk in chunks) {
+                        val cipherText = encrypt(algorithm, chunk, key, iv)
+                        writer.println(cipherText)
+                        reader.readLine()
+                    }
 
                     writer.println("END_OF_COMMUNICATION")
-
-                    println(reader.readLine())
+                    reader.readLine()
 
                     println("Client: Ready for next operation")
-
                     writer.println("Ready for next operation")
-
-                    println(reader.readLine())
+                    reader.readLine()
                 }
             }
         }
diff --git a/main.go b/main.go
index 4b3754f..6baa675 100644
--- a/main.go
+++ b/main.go
@@ -16,7 +16,6 @@ func main() {
 	host := "0.0.0.0"
 	port := 8080
 
-	// Listen for incoming connections
 	listener, err := net.Listen("tcp", fmt.Sprintf("%s:%d", host, port))
 	if err != nil {
 		log.Fatalf("Error listening: %v", err)
@@ -46,65 +45,46 @@ func handleConnection(conn net.Conn) {
         log.Printf("Error reading key: %v", err)
         return
     }
-
-    key, err := base64.StdEncoding.DecodeString(keyData[:len(keyData)-1])
-    if err != nil {
-        log.Printf("Error decoding key: %v", err)
-        return
-    }
-
-    fmt.Printf("Key: %x\n", key)
-    conn.Write([]byte("Received key\n"))
+    key, _ := base64.StdEncoding.DecodeString(strings.TrimSpace(keyData))
     conn.Write([]byte("Received key\n"))
 
-    ivData, err := bufio.NewReader(conn).ReadString('\n')
-    if err != nil {
-        log.Printf("Error reading iv: %v", err)
-        return
-    }
-
-    iv, err := base64.StdEncoding.DecodeString(ivData[:len(ivData)-1])
-    if err != nil {
-        log.Printf("Error decoding iv: %v", err)
-        return
-    }
-
-    fmt.Printf("IV: %x\n", iv)
+    ivData, _ := bufio.NewReader(conn).ReadString('\n')
+    iv, _ := base64.StdEncoding.DecodeString(strings.TrimSpace(ivData))
     conn.Write([]byte("Received IV\n"))
 
+    var ciphertext []byte
+    var chunk string
+    var plaintext []byte
+
     for {
-        textData, err := bufio.NewReader(conn).ReadString('\n')
+        chunk, err = bufio.NewReader(conn).ReadString('\n')
         if err != nil {
-            log.Printf("Error reading text: %v", err)
+            log.Printf("Error reading chunk: %v", err)
             return
         }
-
-        if strings.TrimSpace(textData) == "END_OF_COMMUNICATION" {
+        if strings.TrimSpace(chunk) == "END_OF_COMMUNICATION" {
             fmt.Println("Client ended communication")
             break
         }
+        ciphertext, _ = base64.StdEncoding.DecodeString(strings.TrimSpace(chunk))
 
-        cipherText, err := base64.StdEncoding.DecodeString(textData[:len(textData)-1])
+        plaintextChunk, err := decrypt(ciphertext, key, iv)
         if err != nil {
-            log.Printf("Error decoding text: %v", err)
+            log.Printf("Error decrypting chunk: %v", err)
             return
         }
+        plaintext = append(plaintext, plaintextChunk...)
 
-        plaintext, err := decrypt(cipherText, key, iv)
-        if err != nil {
-            log.Printf("Error decrypting text: %v", err)
-            return
-        }
-
-        fmt.Println("Decrypted text:", string(plaintext))
-        conn.Write([]byte("Received and decrypted text\n"))
+        conn.Write([]byte("Received and decrypted chunk\n"))
     }
 
+    fmt.Println("Decrypted text:", string(plaintext))
     conn.Write([]byte("Ready for next operation\n"))
 }
 
 
 
+
 func decrypt(cipherText []byte, key []byte, iv []byte) ([]byte, error) {
 	block, err := aes.NewCipher(key)
 	if err != nil {