michpro / xtea-cipher

XTEA cipher library, with MAC support, for the Arduino environment.

XTEA-Cipher library for Arduino

XTEA cipher library with MAC code calculation support for Arduino environment. Supported encryption modes are: ECB, CFB and OCB and for generating message authentication codes is CFB-MAC. 'C' code of this library was optimized for lowest possible use of program memory. Contrary to reference implementation, base data type is uint8_t[] instead of uint32_t.

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Constants

Configure library settings in file xtea.h, or better in your sketch, by adding directive #define XTEA_ROUNDS n or/and #define XTEA_MAC_ROUNDS n before directive including this cipher library e.g.:

...
#define XTEA_ROUNDS 48
#define XTEA_MAC_ROUNDS 24

#include "XTEA-Cipher.h"
...

• XTEA_ROUNDS

  actual number of Feistel rounds during cipher is 2 * XTEA_ROUNDS

  [default value is 32]

• XTEA_MAC_ROUNDS

  actual number of Feistel rounds during MAC calculation is 2 * XTEA_MAC_ROUNDS

  [default value is 32]

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  known attack is on 36 Feistel rounds (18 XTEA_ROUNDS or XTEA_MAC_ROUNDS)

• XTEA_BLOCK_SIZE

  data block size = 64-bit [8 bytes]

  [Do NOT change its value]

• XTEA_IV_SIZE

  size of initialization vector [IV] (a.k.a. NONCE) = 64-bit [8 bytes]

  [Do NOT change its value]

• XTEA_KEY_SIZE

  key size = 128-bit [16 bytes]

  [Do NOT change its value]

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Library Content

Read the source code for details.

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Examples

• XTEA Test 'C' style

  Sketch shows examples of calling 'C' code functions and validating them with test vectors.

• XTEA Test Arduino style

  This sketch shows examples of calling methods of a c++ class and validating them with test vectors.

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Installation Guide

Arduino IDE - Additional libraries installation guide.

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Reporting bugs

Create an issue on GitHub.

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License

Copyright © 2020-2021 Michal Protasowicki

Source: https://github.com/michpro/XTEA-Cipher

This project is released under MIT License.

Support

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