cc2538 AES-CBC-MAC

Driver for the cc2538 AES-CBC-MAC mode of the security core. More...

Files
file	cbc-mac.c
	Implementation of the cc2538 AES-CBC-MAC driver.
file	cbc-mac.h
	Header file for the cc2538 AES-CBC-MAC driver.

AES-CBC-MAC constants
#define	CBC_MAC_MAC_LEN   AES_TAG_LEN

AES-CBC-MAC functions
uint8_t	cbc_mac_auth_start (uint8_t key_area, const void *mdata, uint16_t mdata_len, struct process *process)
	Starts a CBC-MAC authentication operation. More...
uint8_t	cbc_mac_auth_get_result (const void *mac_in, void *mac_out)
	Gets the result of the CBC-MAC authentication operation. More...
#define	cbc_mac_auth_check_status   aes_auth_crypt_check_status
	Checks the status of the CBC-MAC authentication operation. More...

Detailed Description

Driver for the cc2538 AES-CBC-MAC mode of the security core.

Macro Definition Documentation

#define cbc_mac_auth_check_status   aes_auth_crypt_check_status

Checks the status of the CBC-MAC authentication operation.

Return values

false	Result not yet available, and no error occurred
true	Result available, or error occurred

Definition at line 81 of file cbc-mac.h.

Function Documentation

uint8_t cbc_mac_auth_get_result	(	const void *	mac_in,
		void *	mac_out
	)

Gets the result of the CBC-MAC authentication operation.

Parameters

mac_in	Pointer to 128-bit input MAC, or NULL
mac_out	Pointer to 128-bit output MAC, or NULL

Returns

CRYPTO_SUCCESS if successful, or CRYPTO/AES/CBC-MAC error code

Note

This function must be called only after cbc_mac_auth_start().

Definition at line 66 of file cbc-mac.c.

References aes_auth_crypt_get_result(), and NULL.

uint8_t cbc_mac_auth_start	(	uint8_t	key_area,
		const void *	mdata,
		uint16_t	mdata_len,
		struct process *	process
	)

Starts a CBC-MAC authentication operation.

Parameters

key_area	Area in Key RAM where the key is stored (0 to AES_KEY_AREAS - 1)
mdata	Pointer to message to authenticate in SRAM
mdata_len	Length of message to authenticate in octets
process	Process to be polled upon completion of the operation, or NULL

Returns

CRYPTO_SUCCESS if successful, or CRYPTO/AES/CBC-MAC error code

Warning

CBC-MAC is not secure for variable-length messages. There are a few workarounds that can be implemented by the caller, like prepending the message length to the first block of the message before passing it.

Definition at line 46 of file cbc-mac.c.

References AES_AES_CTRL_CBC_MAC, AES_AES_CTRL_DIRECTION_ENCRYPT, AES_AES_CTRL_SAVE_CONTEXT, aes_auth_crypt_start(), and NULL.