sal.h File Reference

Declarations for low-level security API.

Copyright (c) 2013-2018 Microchip Technology Inc. and its subsidiaries.

#include "sal_types.h"
#include "sal_generic.h"
#include "stdbool.h"
#include <stdint.h>

Macros
#define	AES_DIR_DECRYPT   (1)
	Defines AES direction as decryption. More...
#define	AES_DIR_ENCRYPT   (0)
	Defines AES direction as encryption. More...
#define	AES_MODE_CBC   (2)
	Defines AES mode as CBC. More...
#define	AES_MODE_ECB   (0)
	Defines AES mode as ECB. More...
#define	sal_aes_clean_up()   _sal_aes_clean_up()
	Route function macro to the corresponding function. More...

Functions
void	_sal_aes_clean_up (void)
	Cleans up the SAL/AES after STB has been completed. More...
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 TRX reset. More...
bool	sal_aes_setup (uint8_t *key, uint8_t enc_mode, uint8_t dir)
	Setup AES unit. More...
void	sal_aes_wrrd (uint8_t *idata, uint8_t *odata)
	Writes data, reads previous result and does the AES en/decryption. More...
void	sal_init (void)
	Initialization of SAL. More...

#define AES_DIR_DECRYPT   (1)

Defines AES direction as decryption.

#define AES_DIR_ENCRYPT   (0)

Defines AES direction as encryption.

#define AES_MODE_CBC   (2)

Defines AES mode as CBC.

#define AES_MODE_ECB   (0)

Defines AES mode as ECB.

#define sal_aes_clean_up

(

)

_sal_aes_clean_up()

Route function macro to the corresponding function.

Referenced by stb_ccm_secure().

void _sal_aes_clean_up

(

void

)

Cleans up the SAL/AES after STB has been completed.

This function puts the radio to SLEEP if it has been in SLEEP before sal_aes_restart().

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, so this function is needed in order to get the last result of a series of sal_aes_wrrd() calls.

Parameters

[out]

data

- result of previous operation

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 TRX reset.

This function re-initializes the AES key and the state of the AES engine after TRX sleep or reset. The contents of AES register AES_CON is restored, the next AES operation started with sal_aes_exec() will be executed correctly.

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.

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

Setup AES unit.

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

Parameters

[in]	key	AES key or NULL (NULL: use last key)
[in]	enc_mode	AES_MODE_ECB or AES_MODE_CBC
[in]	dir	must be AES_DIR_ENCRYPT

Returns

False if some parameter was illegal, true else

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]	key	AES key or NULL (NULL: use last key)
[in]	enc_mode	AES_MODE_ECB or AES_MODE_CBC
[in]	dir	AES_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(), and stb_ccm_secure().

void sal_aes_wrrd	(	uint8_t *	idata,
		uint8_t *	odata
	)

Writes data, reads previous result and does the AES en/decryption.

The function returns after the AES operation is finished.

When sal_aes_wrrd() is called several times in sequence, from the second call onwards, odata contains the result of the previous operation. To obtain the last result, you must call sal_aes_read() at the end. Please note that any call of sal_aes_setup() as well as putting the transceiver to sleep state destroys the SRAM contents, i.e. the next call of sal_aes_wrrd() yields no meaningful result.

Parameters

[in]	idata	AES block to be en/decrypted
[out]	odata	Result of previous operation (odata may be NULL or equal to idata)

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

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().