late night chnges

android-app/app/src/main/java/org/pupes/tabletpccontrol/helper_funcs.kt

@@ -0,0 +1,28 @@
+package org.pupes.tabletpccontrol
+import javax.crypto.Cipher
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.SecretKeySpec
+import android.util.Base64
+
+fun decrypt(base64CipherText: String, key: String, iv: String): String {
+    val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")
+
+    val secretKey = SecretKeySpec(key.toByteArray(Charsets.UTF_8), "AES")
+    val ivParams = IvParameterSpec(iv.toByteArray(Charsets.UTF_8))
+
+    cipher.init(Cipher.DECRYPT_MODE, secretKey, ivParams)
+
+    val decryptedBytes = cipher.doFinal(Base64.decode(base64CipherText, Base64.DEFAULT))
+
+    return String(decryptedBytes, Charsets.UTF_8)
+}
+
+// Example usage
+fun main() {
+    val base64CipherText = "YOUR_BASE64_ENCRYPTED_TEXT_HERE"
+    val key = "key123456789101" // Must match the C++ key length
+    val iv = "iv1234567891111"  // Must match the C++ IV length
+
+    val decryptedText = decrypt(base64CipherText, key, iv)
+    println("Decrypted Text: $decryptedText")
+}

cpp-server/src/crypt.cpp

@@ -1,19 +1,24 @@
+#include "helper_funcs.h"
 #include <cryptopp/aes.h>
 #include <cryptopp/base64.h>
 #include <cryptopp/filters.h>
 #include <cryptopp/modes.h>
 #include <iomanip>
 #include <iostream>
+#include <nlohmann/json.hpp>
 #include <string>
 
-int main() {
+using nlohmann::json;
+
+int encrypt() {
   // Key and IV (Initialization Vector) for AES
   CryptoPP::byte key[CryptoPP::AES::DEFAULT_KEYLENGTH] = {
       'k', 'e', 'y', '1', '2', '3', '4', '5',
       '6', '7', '8', '9', '1', '0', '1', '1'};
-  CryptoPP::byte iv[CryptoPP::AES::BLOCKSIZE] = {'i', 'v', '1', '2', '3', '4',
+  CryptoPP::byte iv[CryptoPP::AES::BLOCKSIZE];
-                                                 '5', '6', '7', '8', '9', '1',
+  for (int i = 0; i < 16; i++) {
-                                                 '0', '1', '1', '1'};
+    iv[i] = static_cast<char>(get_random_num(33, 126));
+  }
 
   // Message to be encrypted
   std::string plainText = "Hello, AES!";
@@ -36,3 +41,40 @@ int main() {
 
   return 0;
 }
+
+int decrypt() {
+  // Key and IV (Initialization Vector) for AES
+  CryptoPP::byte key[CryptoPP::AES::DEFAULT_KEYLENGTH] = {
+      'k', 'e', 'y', '1', '2', '3', '4', '5',
+      '6', '7', '8', '9', '1', '0', '1', '1'};
+  CryptoPP::byte iv[CryptoPP::AES::BLOCKSIZE] = {'i', 'v', '1', '2', '3', '4',
+                                                 '5', '6', '7', '8', '9', '1',
+                                                 '0', '1', '1', '1'};
+
+  // Base64 encoded encrypted message (replace with actual encrypted message)
+  std::string base64EncodedCipherText = "PgKnjjHY2xz/LRWgg1ob1Q==";
+  std::string cipherText;
+
+  // Decode the Base64 encoded message
+  CryptoPP::StringSource(
+      base64EncodedCipherText, true,
+      new CryptoPP::Base64Decoder(new CryptoPP::StringSink(cipherText)));
+
+  // Decrypt using AES in CBC mode
+  std::string decryptedText;
+  CryptoPP::CBC_Mode<CryptoPP::AES>::Decryption decryptor(key, sizeof(key), iv);
+
+  CryptoPP::StringSource(
+      cipherText, true,
+      new CryptoPP::StreamTransformationFilter(
+          decryptor, new CryptoPP::StringSink(decryptedText)));
+
+  // Display the decrypted message
+  std::cout << "Decrypted Text: " << decryptedText << std::endl;
+
+  return 0;
+}
+int main() {
+  decrypt();
+  return 0;
+}

cpp-server/src/helper_funcs.cpp

@@ -1,6 +1,8 @@
 #include "main.h"
 #include <iostream>
+#include <random>
 #include <unistd.h>
+
 void safe_exit(int code) {
   try {
     std::clog << "Exiting\n";
@@ -9,4 +11,13 @@ void safe_exit(int code) {
   } catch (...) {
   }
   exit(code);
+}
+
+int get_random_num(int min, int max) {
+  std::random_device dev;
+  std::mt19937 rng(dev());
+  std::uniform_int_distribution<std::mt19937::result_type> dist(
+      min, max); // set range
+
+  return dist(rng);
 }

cpp-server/src/helper_funcs.h

@@ -1 +1,2 @@
-void safe_exit(int code);
+void safe_exit(int code);
+int get_random_num(int min, int max);