#include <AESLib>

AESLib aesLib;

// AES Encryption Key (same key used for Encryption and Decryption)
const char* key = "0123456789ABCDEF"; // Must be a 16, 24 or 32 character string

// General initialization vector (same as in node-js example) (you must use your own IV's in production for full security!!!)
byte iv[N_BLOCK] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };

// Generate IV (once)
void aes_init() {
  aesLib.gen_iv(iv);
  aesLib.set_paddingmode((paddingMode)0); // AES_PADDING_MODE_ZERO (default is PKCS7)
}

// Encrypts a string and returns the size of the encrypted data
int encrypt(char *msg, byte *encMsg) {
  int msgLen = strlen(msg);
  int paddedLen = aesLib.get_padded_len(msgLen);
  aesLib.encrypt((byte*)msg, paddedLen, encMsg, (byte*)key, sizeof(key), iv);
  return paddedLen;
}

// Decrypts a byte array and returns the original string
String decrypt(byte *encMsg, int encMsgLen) {
  char msg[encMsgLen];
  aesLib.decrypt(encMsg, encMsgLen, (byte*)key, sizeof(key), iv);
  return String(msg);
}

void setup() {
  Serial.begin(115200);

  aes_init(); // Initialize AES

  char msg[] = "This is a secret message"; // Message to be encrypted
  byte encMsg[256]; // Buffer to hold the encrypted message

  // Encrypt
  int encMsgLen = encrypt(msg, encMsg);

  // Decrypt
  String decMsg = decrypt(encMsg, encMsgLen);

  // Print encrypted and decrypted messages
  Serial.println("Encrypted Message:");
  for (int i = 0; i < encMsgLen; i++) {
    Serial.print(encMsg[i], HEX);
    Serial.print(" ");
  }
  Serial.println();
  
  Serial.print("Decrypted Message: ");
  Serial.println(decMsg);
}