Low-level crypto API for an AES unit implemented in ATxmega MCUs .

#include "sal_types.h"
#include <stdio.h>
#include <string.h>
#include "sal.h"
#include "sysclk.h"

Macros
#define	AES_DIR_VOID (AES_DIR_ENCRYPT + AES_DIR_DECRYPT + 1)

#define	COMP_SR(SUB, val) (((val) << SUB ## _bp) & SUB ## _bm)

Functions
void	sal_aes_exec (uint8_t *data)
	En/decrypt one AES block. More...

void	sal_aes_read (uint8_t *data)
	Reads the result of previous AES en/decryption. More...

void	sal_aes_restart (void)
	Re-inits key and state after a sleep or chip reset. More...

bool	sal_aes_setup (uint8_t *key, uint8_t enc_mode, uint8_t dir)
	Setup AES unit. More...

void	sal_init (void)
	Initialization of SAL. More...

Variables
static bool	dec_initialized = false

static uint8_t	dec_key [AES_KEYSIZE]

static uint8_t	enc_key [AES_KEYSIZE]

static uint8_t *	keyp

static uint8_t	last_dir = AES_DIR_VOID

static uint8_t	mode_byte

#define AES_DIR_VOID (AES_DIR_ENCRYPT + AES_DIR_DECRYPT + 1)

Referenced by sal_aes_setup().

#define COMP_SR	(	SUB,
		val
	)	(((val) << SUB ## _bp) & SUB ## _bm)

Referenced by sal_aes_setup(), and sal_init().

void sal_aes_exec ( uint8_t * data )

En/decrypt one AES block.

The function returns after the AES operation is finished.

Parameters

[in] data AES block to be en/decrypted

References AES_BLOCKSIZE, and keyp.

Referenced by compute_mic(), encrypt_with_padding(), and sal_aes_setup().

void sal_aes_read ( uint8_t * data )

Reads the result of previous AES en/decryption.

This function returns the result of the previous AES operation.

Parameters

[out] data - result of previous operation

References AES_BLOCKSIZE.

Referenced by compute_mic(), and encrypt_pldmic().

void sal_aes_restart ( void )

Re-inits key and state after a sleep or chip reset.

Re-inits key and state after a sleep or TRX reset.

This function is void for ATxmega since the key must be re-initialized before every block encryption anyway.

Referenced by stb_ccm_secure().

bool sal_aes_setup	(	uint8_t *	key,
		uint8_t	enc_mode,
		uint8_t	dir
	)

Setup AES unit.

This function performs the following tasks as part of the setup of the AES unit: key initialization, set encryption direction and encryption mode.

In general, the contents of SRAM buffer is destroyed. When using sal_aes_wrrd(), sal_aes_read() needs to be called in order to get the result of the last AES operation before you may call sal_aes_setup() again.

Parameters