Arduino string encryption WIP

#include <AESLib.h>
#include <SPI.h>
#include <Adafruit_Sensor.h>
#include "DHT.h"
#include <RH_ASK.h>
#include <Base64.h>

#define DHTPIN 2     // what digital pin we're connected to

#define DHTTYPE DHT22   // DHT 22  (AM2302), AM2321
DHT dht(DHTPIN, DHTTYPE);
RH_ASK driver;

uint8_t key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};

uint8_t string_key[] = {97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112};
String test_message = "HelloIamamessag";
char data[16];

void setup() {
  driver.init();
  dht.begin();
  Serial.begin(9600);
}

void loop() {
  // Wait a few seconds between measurements.
  delay(5000);

  test_message.toCharArray(data, 16);
  Serial.print("data is:\t");
  Serial.print(data);

  aes128_enc_single(string_key, data);
  // Serial.print("\nEncrypted string is:\t");
  // Serial.println(data);
  int encryptedStringLength = sizeof(data);
  int encodedLength = Base64.encodedLength(encryptedStringLength);
  char encodedString[encodedLength];
  Base64.encode(encodedString, data, encryptedStringLength);
  Serial.print("\nEncoded string is:\t");
  Serial.println(encodedString);
}