Arduino AESLib

This project is just an Arduino ready extract from the AVR-Crypto-Lib.

It only packages the ASM implementations of AES into a library ready to use in Arduino IDE.

See the LICENSE file for details of the GPLv3 license in which the AVR-Crypo-Lib is licensed.

Installation

Download the files in this repository (using either clone or the download button)
Copy the AESLib folder into libraries folder (same level as your sketch folder)
add #include <AESLib.h> in your sketch.

Usage

At the moment only 128bit and 256bit keys are supported, the blocksize is fixed at 128bit. This means that the key array should contain exactly 16 bytes (uint8_t or byte) or 32 bytes, respectively. The iv array should be exactly 16 bytes long. Moreover the amount of bytes to encrypt should be mod 16. (this means you have to take care of padding yourself).

The library supports 3 kinds of operations.

single block encryption/decryption

multiple block encryption/decryption using CBC (single call)
multiple block encryption/decryption using CBC (multiple calls)

The single block enc/decryption are the following methods:

void aes128_enc_single(const uint8_t* key, void* data);
void aes128_dec_single(const uint8_t* key, void* data);
void aes256_enc_single(const uint8_t* key, void* data);
void aes256_dec_single(const uint8_t* key, void* data);

Methods for the CBC mode of operation (encryption):

void aes128_cbc_enc(const uint8_t* key, const uint8_t* iv, void* data, const uint16_t data_len);
aes_context aes128_cbc_enc_start(const uint8_t* key, const void* iv);
aes_context aes256_cbc_enc_start(const uint8_t* key, const void* iv);
void aes_cbc_enc_continue(const aes_context ctx, void* data, const uint16_t data_len);
void aes_cbc_enc_finish(const aes_context ctx);

Methods for the CBC mode of operation (decryption). Right now, only 128bit is supported:

aes_context aes128_cbc_dec_start(const uint8_t* key, const void* iv);
void aes128_cbc_dec_continue(const aes_context ctx, void* data, const uint16_t data_len);
void aes128_cbc_dec_finish(const aes_context ctx);

Usage example:

Serial.begin(57600);
uint8_t key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
char data[] = "0123456789012345"; //16 chars == 16 bytes
aes128_enc_single(key, data);
Serial.print("encrypted:");
Serial.println(data);
aes128_dec_single(key, data);
Serial.print("decrypted:");
Serial.println(data);

Usage example for AES256:

Serial.begin(57600);
uint8_t key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31};
char data[] = "0123456789012345";
aes256_enc_single(key, data);
Serial.print("encrypted:");
Serial.println(data);
aes256_dec_single(key, data);
Serial.print("decrypted:");
Serial.println(data);

Usage example for AES256-CBC:

uint8_t key[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31};
uint8_t iv[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
char data[] = "0123456789012345ABCDEF6789012345";
aes_context ctx;

Serial.begin(57600);
ctx = aes256_cbc_enc_start(key, iv);
aes_cbc_enc_continue(ctx, data, 32);
aes_cbc_enc_finish(ctx);
Serial.print("encrypted-cbc:");
Serial.println(data);

slintak/AESLib

Arduino AESLib

Installation

Usage