sal.c File Reference

Low-level crypto API for an AES unit implemented in AT86RFA1.

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

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

Macros
#define	_SR_MASK(addr, mask, pos, val)   (((uint8_t)val << pos) & mask)
#define	_trx_bit_read(addr, mask, pos)   (((*(volatile uint8_t *)(addr)) & (mask)) >> (pos))
#define	AES_COMPLETED   (1)
	Constant AES_COMPLETED for sub-register SR_AES_DONE in register AES_STATUS. More...
#define	AES_DIR_DECRYPT   (1)
	Constant AES_DIR_DECRYPT for sub-register SR_AES_DIR in register AES_CTRL. More...
#define	AES_DIR_ENCRYPT   (0)
	Constant AES_DIR_ENCRYPT for sub-register SR_AES_DIR in register AES_CTRL. More...
#define	AES_DIR_VOID   (AES_DIR_ENCRYPT + AES_DIR_DECRYPT + 1)
#define	AES_NOT_COMPLETED   (0)
	Constant AES_NOT_COMPLETED for sub-register SR_AES_DONE in register AES_STATUS. More...
#define	AES_START   (1)
	Constant AES_START for sub-register SR_AES_REQUEST in register AES_CTRL. More...
#define	AES_START   (1)
	Constant AES_START for sub-register SR_AES_REQUEST in register AES_CTRL. More...
#define	RG_AES_CTRL   (0x13C)
	Offset for register AES_CTRL. More...
#define	RG_AES_KEY   (0x13F)
	Offset for register AES_KEY. More...
#define	RG_AES_STATE   (0x13E)
	Offset for register AES_STATE. More...
#define	RG_AES_STATUS   (0x13D)
	Offset for register AES_STATUS. More...
#define	RG_TRX_STATUS   (0x141)
	Offset for register TRX_STATUS. More...
#define	SR_AES_DIR   0x13C, 0x08, 3
	Access parameters for sub-register AES_DIR in register RG_AES_CTRL. More...
#define	SR_AES_DONE   0x13D, 0x01, 0
	Sub-registers of Register RG_AES_STATUS. More...
#define	SR_AES_ER   0x13D, 0x80, 7
	Access parameters for sub-register AES_ER in register RG_AES_STATUS. More...
#define	SR_AES_IM   0x13C, 0x04, 2
	Sub-registers of Register RG_AES_CTRL. More...
#define	SR_AES_MODE   0x13C, 0x20, 5
	Access parameters for sub-register AES_MODE in register RG_AES_CTRL. More...
#define	SR_AES_REQUEST   0x13C, 0x80, 7
	Access parameters for sub-register AES_REQUEST in register RG_AES_CTRL. More...
#define	SR_MASK(SR, val)   _SR_MASK(SR, val)
#define	trx_bit_read(arg)   _trx_bit_read(arg)
	Subregister read. More...
#define	trx_reg_read(addr)   (*(volatile uint8_t *)(addr))
	Reads current value from a transceiver register. More...
#define	trx_reg_write(addr, data)   (*(volatile uint8_t *)(addr)) = (data)
	Writes data into a transceiver register. More...

Functions
void	_sal_aes_clean_up (void)
	Cleans up the SAL/AES after STB has been finished. 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_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	last_dir = AES_DIR_VOID
static uint8_t	mode_byte

#define _SR_MASK	(		addr,
			mask,
			pos,
			val
	)		(((uint8_t)val << pos) & mask)

#define _trx_bit_read	(		addr,
			mask,
			pos
	)		(((*(volatile uint8_t *)(addr)) & (mask)) >> (pos))

#define AES_COMPLETED   (1)

Constant AES_COMPLETED for sub-register SR_AES_DONE in register AES_STATUS.

#define AES_DIR_DECRYPT   (1)

Constant AES_DIR_DECRYPT for sub-register SR_AES_DIR in register AES_CTRL.

Referenced by sal_aes_setup().

#define AES_DIR_ENCRYPT   (0)

Constant AES_DIR_ENCRYPT for sub-register SR_AES_DIR in register AES_CTRL.

Referenced by sal_aes_restart(), and sal_aes_setup().

#define AES_DIR_VOID   (AES_DIR_ENCRYPT + AES_DIR_DECRYPT + 1)

Author

Microchip Technology Inc: http://www.microchip.com Support: https://www.microchip.com/support/

Referenced by sal_aes_setup().

#define AES_NOT_COMPLETED   (0)

Constant AES_NOT_COMPLETED for sub-register SR_AES_DONE in register AES_STATUS.

#define AES_START   (1)

Constant AES_START for sub-register SR_AES_REQUEST in register AES_CTRL.

#define AES_START   (1)

Constant AES_START for sub-register SR_AES_REQUEST in register AES_CTRL.

#define RG_AES_CTRL   (0x13C)

Offset for register AES_CTRL.

Referenced by sal_aes_exec(), sal_aes_restart(), and sal_aes_setup().

#define RG_AES_KEY   (0x13F)

Offset for register AES_KEY.

Referenced by sal_aes_restart(), and sal_aes_setup().

#define RG_AES_STATE   (0x13E)

Offset for register AES_STATE.

Referenced by sal_aes_exec(), and sal_aes_read().

#define RG_AES_STATUS   (0x13D)

Offset for register AES_STATUS.

#define RG_TRX_STATUS   (0x141)

Offset for register TRX_STATUS.

#define SR_AES_DIR   0x13C, 0x08, 3

Access parameters for sub-register AES_DIR in register RG_AES_CTRL.

Referenced by sal_aes_setup().

#define SR_AES_DONE   0x13D, 0x01, 0

Sub-registers of Register RG_AES_STATUS.

Access parameters for sub-register AES_DONE in register RG_AES_STATUS

Referenced by sal_aes_exec().

#define SR_AES_ER   0x13D, 0x80, 7

Access parameters for sub-register AES_ER in register RG_AES_STATUS.

#define SR_AES_IM   0x13C, 0x04, 2

Sub-registers of Register RG_AES_CTRL.

Access parameters for sub-register AES_IM in register RG_AES_CTRL

#define SR_AES_MODE   0x13C, 0x20, 5

Access parameters for sub-register AES_MODE in register RG_AES_CTRL.

Referenced by sal_aes_setup().

#define SR_AES_REQUEST   0x13C, 0x80, 7

Access parameters for sub-register AES_REQUEST in register RG_AES_CTRL.

Referenced by sal_aes_exec().

#define SR_MASK	(		SR,
			val
	)		_SR_MASK(SR, val)

Referenced by sal_aes_exec(), and sal_aes_setup().

#define trx_bit_read

(

arg

)

_trx_bit_read(arg)

Subregister read.

Parameters

arg	Subregister

Returns

Value of the read subregister

Referenced by sal_aes_exec().

#define trx_reg_read

(

addr

)

(*(volatile uint8_t *)(addr))

Reads current value from a transceiver register.

This macro reads the current value from a transceiver register.

Parameters

addr	Specifies the address of the trx register from which the data shall be read

Returns

value of the register read

Referenced by sal_aes_read(), and sal_aes_setup().

#define trx_reg_write	(		addr,
			data
	)		(*(volatile uint8_t *)(addr)) = (data)

Writes data into a transceiver register.

This macro writes a value into transceiver register.

Parameters

addr	Address of the trx register
data	Data to be written to trx register

Referenced by sal_aes_exec(), sal_aes_restart(), and sal_aes_setup().

void _sal_aes_clean_up

(

void

)

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

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

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, AES_START, mode_byte, RG_AES_CTRL, RG_AES_STATE, SR_AES_DONE, SR_AES_REQUEST, SR_MASK, trx_bit_read, and trx_reg_write.

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, 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

References AES_BLOCKSIZE, RG_AES_STATE, and trx_reg_read.

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

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.

References AES_BLOCKSIZE, AES_DIR_ENCRYPT, dec_key, enc_key, last_dir, mode_byte, RG_AES_CTRL, RG_AES_KEY, and trx_reg_write.

Referenced by stb_ccm_secure().

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 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_BLOCKSIZE, AES_DIR_DECRYPT, AES_DIR_ENCRYPT, AES_DIR_VOID, AES_KEYSIZE, AES_MODE_CBC, AES_MODE_ECB, dec_initialized, dec_key, enc_key, last_dir, mode_byte, NULL, RG_AES_CTRL, RG_AES_KEY, sal_aes_exec(), SR_AES_DIR, SR_AES_MODE, SR_MASK, trx_reg_read, and trx_reg_write.

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

void sal_init

(

void

)

Initialization of SAL.

This functions initializes the SAL.

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_restart(), and sal_aes_setup().

uint8_t enc_key[AES_KEYSIZE]

static

Referenced by sal_aes_restart(), and sal_aes_setup().

uint8_t last_dir = AES_DIR_VOID

static

Referenced by sal_aes_restart(), and sal_aes_setup().

uint8_t mode_byte

static

Referenced by sal_aes_exec(), sal_aes_restart(), and sal_aes_setup().