Atmel Software Framework

sal.c File Reference

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

Copyright (c) 2013-2015 Atmel Corporation. All rights reserved.

#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]dataAES block to be en/decrypted

References AES_BLOCKSIZE, and keyp.

Referenced by compute_mic(), encrypt_with_padding(), PHY_EncryptReq(), 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(), encrypt_pldmic(), and PHY_EncryptReq().

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
[in]keyAES key or NULL (NULL: use last key)
[in]enc_modeAES_MODE_ECB or AES_MODE_CBC
[in]dirAES_DIR_ENCRYPT or AES_DIR_DECRYPT
Returns
False if some parameter was illegal, true else

References AES_AUTO, AES_BLOCKSIZE, AES_DECRYPT, AES_DIR_DECRYPT, AES_DIR_ENCRYPT, AES_DIR_VOID, AES_KEYSIZE, AES_MODE_CBC, AES_MODE_ECB, COMP_SR, dec_initialized, dec_key, enc_key, keyp, last_dir, mode_byte, and sal_aes_exec().

Referenced by compute_mic(), encrypt_pldmic(), PHY_EncryptReq(), and stb_ccm_secure().

void sal_init ( void  )

Initialization of SAL.

This functions initializes the SAL.

References COMP_SR, SYSCLK_AES, sysclk_enable_module(), and SYSCLK_PORT_GEN.

Referenced by stb_init(), and SYS_Init().

bool dec_initialized = false
static

Referenced by sal_aes_setup().

uint8_t dec_key[AES_KEYSIZE]
static

Referenced by sal_aes_setup().

uint8_t enc_key[AES_KEYSIZE]
static

Referenced by sal_aes_setup().

uint8_t* keyp
static

Referenced by sal_aes_exec(), and sal_aes_setup().

uint8_t last_dir = AES_DIR_VOID
static

Referenced by sal_aes_setup().

uint8_t mode_byte
static

Referenced by sal_aes_setup().