Adding symmetric encryption

[luigigubello]

I have added user-friendly (I hope) support to symmetric encryption. In particular, you can run DES and AES128 now.

How to use

AES128

runEnc()

Giving the secret key, the initialization vector and the plain text, this method returns the encrypted one.

Syntax

AES128.runEnc(key, keyLength, input, inputLengh, iv);

Parameters

• key: the secret key used to encrypt the plain text. The variable type is uint8_t;
• keyLength: the secret key's length. It is always 16. The variable type is size_t;
• input: the plain text. The variable type is uint8_t;
• inputLengh: the plain text's length. It must be always a multiple of 16. The variable type is size_t;
• iv: the initialization vector. It must have always 16 bytes. The variable type is uint8_t;

Example

#include <ArduinoBearSSL.h>
uint8_t key[16] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x02};
uint8_t iv[16] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x01};
uint8_t input[16] = "ArduinoArduino";
void setup() {
  AES128.runEnc(key, 16, input, 16, iv);
}
void loop() {}

runDec()

Giving the secret key, the initialization vector and the encrypted text, this method returns the decrypted one.

Sintax

AES128.runDec(key, keyLength, input, inputLengh, iv);

Parameters

• key: the secret key used to encrypt the plain text. The variable type is uint8_t;
• keyLength: the secret key's length. It is always 16. The variable type is size_t;
• input: the encrypted text. The variable type is uint8_t;
• inputLengh: the encrypted text's length. It must be always a multiple of 16. The variable type is size_t;
• iv: the initialization vector. It must have always 16 bytes. The variable type is uint8_t;

Example

#include <ArduinoBearSSL.h>
uint8_t key[16] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x02};
uint8_t iv[16] = {0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x01,0x01};
uint8_t input[16] = {0x65,0xD0,0xF7,0x75,0x8B,0x09,0x41,0x14,0xAF,0xA6,0xD3,0x3A,0x5E,0xA0,0x71,0x6A};
void setup() {
  AES128.runDec(key, 16, input, 16, iv);
}
void loop() {}

(similar for DES)

I have tested the examples with Arduino Nano 33 IoT (SAMD21), Arduino Uno WiFi Rev2 (ATmega4809) and Arduino Nano 33 BLE Sense.

[aentinger]

LGTM 👍 Thank you @luigigubello 🚀