xxtea.c File Reference

XXTEA block cipher. More...

#include <lib/random/xxtea.h>
#include <assert.h>

Include dependency graph for xxtea.c:

Macros
#define	XXTEA_DELTA   UINT32_C(0x9e3779b9)
	XXTEA magic number.

Functions
static uint32_t	xxtea_mx (uint32_t y, uint32_t z, uint32_t sum, unsigned p, unsigned e, const uint32_t key[4])
	Main XXTEA Feistel network based routine. More...
void	xxtea_encode (uint32_t *restrict v, unsigned n, uint32_t const key[restrict 4])
	Encode a array of data with the XXTEA algorithm Encoding is done in place. More...
void	xxtea_decode (uint32_t *restrict v, unsigned n, uint32_t const key[restrict 4])
	Decode a array of data with the XXTEA algorithm Decoding is done in place. More...

Detailed Description

XXTEA block cipher.

An implementation of the XXTEA block cipher (code based on "Correction to xtea" by David J. Wheeler and Roger M. Needham)

Copyright

Copyright (C) 2008-2022 HPDCS Group https://hpdcs.github.io

Function Documentation

xxtea_decode()

void xxtea_decode	(	uint32_t *restrict	v,
		unsigned	n,
		uint32_t const	key[restrict 4]
	)

Decode a array of data with the XXTEA algorithm Decoding is done in place.

Parameters

v	a pointer to the array of data to decode
n	the number of 32 bits blocks in v
key	the key used to perform the decoding

xxtea_encode()

void xxtea_encode	(	uint32_t *restrict	v,
		unsigned	n,
		uint32_t const	key[restrict 4]
	)

Encode a array of data with the XXTEA algorithm Encoding is done in place.

Parameters

v	a pointer to the array of data to encode
n	the number of 32 bits blocks in v
key	the key used to perform the encoding

xxtea_mx()

static uint32_t xxtea_mx ( uint32_t  y, uint32_t  z, uint32_t  sum, unsigned  p, unsigned  e, const uint32_t  key[4]  )

inlinestatic

Main XXTEA Feistel network based routine.

Parameters

y	the y block to mix
z	the z block to mix
sum	the cumulative sum of XXTEA delta values
p	an helper key block selector value
e	an helper key block selector value
key	the key used for encoding/decoding

Returns

the value of the next y/z block