See Quick start guide for XMEGA AES driver.

This is a driver for the AVR XMEGA AES crypto module. It provides functions for configuring the AES modules, reseting and starting AES encryption and decryption operations.

Note

After the AES has been configured, data and key must be loaded into register before any operations can be done.
The functions for loading configurations/data/key are not protected against interrupts.

Quick start guide

See Quick start guide for XMEGA AES driver

Modules
	Related Project(s)
	In this section you can find all the projects related to the Advanced Encryption Standard (AES).

	Quick Start Guide(s)
	In this section you can find a list of all Quick Start guides related to the Advanced Encryption Standard (AES).

AES Configuration Define
enum	aes_dec { AES_ENCRYPT, AES_DECRYPT = AES_DECRYPT_bm }
	AES encryption/decryption direction settings. More...

enum	aes_auto { AES_MANUAL, AES_AUTO = AES_AUTO_bm }
	AES Auto Start Trigger settings. More...

enum	aes_xor { AES_XOR_OFF, AES_XOR_ON = AES_XOR_bm }
	AES State XOR Load Enable settings. More...

enum	aes_intlvl { AES_INTLVL_OFF = AES_INTLVL_OFF_gc, AES_INTLVL_LO = AES_INTLVL_LO_gc, AES_INTLVL_MED = AES_INTLVL_MED_gc, AES_INTLVL_HI = AES_INTLVL_HI_gc }
	AES Interrupt Enable / Level settings. More...

typedef uint8_t	t_key [AES_KEY_SIZE]
	AES key block type. More...

typedef uint8_t	t_data [AES_DATA_SIZE]
	AES data block type. More...

typedef void(*	aes_callback_t )(void)
	AES interrupt callback function pointer. More...

#define	AES_KEY_SIZE 16
	Length of one key block. More...

#define	AES_DATA_SIZE 16
	Length of one data block. More...

AES Function Define
static void	aes_start (void)
	Start a decryption/encryption operation. More...

static void	aes_software_reset (void)
	Reset all registers in AES module. More...

static bool	aes_is_busy (void)
	Check if the AES module is busy. More...

static bool	aes_is_error (void)
	Check if the AES module has encountered an error. More...

static void	aes_clear_interrupt_flag (void)
	Clear the AES state ready interrupt flag. More...

static void	aes_clear_error_flag (void)
	Clear the AES error flag. More...

void	aes_configure (enum aes_dec decrypt, enum aes_auto auto_start, enum aes_xor xor_mode)
	AES control register settings. More...

void	aes_set_key (t_key k_in)
	Load key memory. More...

void	aes_get_key (t_key k_out)
	Get key memory. More...

void	aes_write_inputdata (t_data d_in)
	Load state memory. More...

void	aes_read_outputdata (t_data d_out)
	Get state memory. More...

void	aes_isr_configure (enum aes_intlvl intlvl)
	AES interrupt settings. More...

void	aes_set_callback (aes_callback_t callback)
	Set AES interrupt callback function. More...

#define AES_DATA_SIZE 16

Length of one data block.

Always 128-bits (16 bytes).

Referenced by aes_read_outputdata(), aes_write_inputdata(), and compare_data_block().

#define AES_KEY_SIZE 16

Length of one key block.

Always 128-bits (16 bytes).

Referenced by aes_get_key(), and aes_set_key().

typedef void(* aes_callback_t)(void)

AES interrupt callback function pointer.

typedef uint8_t t_data[AES_DATA_SIZE]

AES data block type.

typedef uint8_t t_key[AES_KEY_SIZE]

AES key block type.

enum aes_auto

AES Auto Start Trigger settings.

Enumerator
AES_MANUAL	manual start mode.
AES_AUTO	auto start mode.

enum aes_dec

AES encryption/decryption direction settings.

Enumerator
AES_ENCRYPT	encryption.
AES_DECRYPT	decryption.

enum aes_intlvl

AES Interrupt Enable / Level settings.

Enumerator
AES_INTLVL_OFF	Interrupt Disabled.
AES_INTLVL_LO	Low Level.
AES_INTLVL_MED	Medium Level.
AES_INTLVL_HI	High Level.

enum aes_xor

AES State XOR Load Enable settings.

Enumerator
AES_XOR_OFF	state direct load.
AES_XOR_ON	state XOR load.

static void aes_clear_error_flag ( void )

inlinestatic

Clear the AES error flag.

See Also: aes_software_reset() to reset entire module and all flags.

Referenced by aes_lastsubkey_generate(), and run_aes_state_interface_test().

static void aes_clear_interrupt_flag ( void )

inlinestatic

Clear the AES state ready interrupt flag.

See Also: aes_software_reset() to reset entire module and all flags.

Referenced by aes_lastsubkey_generate(), and run_aes_state_interface_test().

void aes_configure	(	enum aes_dec	decrypt,
		enum aes_auto	auto_start,
		enum aes_xor	xor_mode
	)

AES control register settings.

Note: Set AES CTRL register. Refer to the device manual for detailed information.

Parameters

decrypt	encryption/decryption direction.
auto_start	Auto Start Trigger.
xor_mode	AES State XOR Load Enable.

Referenced by aes_isr_cbc_decrypt_handler(), aes_lastsubkey_generate(), main(), run_aes_decryption_test(), run_aes_encrypt_and_decrypt_test(), run_aes_encryption_test(), and run_aes_state_interface_test().

void aes_get_key ( t_key key_out )

Get key memory.

Note: The key is a user defined value of 16 bytes in AVR XMEGA Crypto Engine.

Parameters

key_out Pointer to AES key output.

References AES_KEY_SIZE.

Referenced by aes_lastsubkey_generate(), and run_aes_set_and_get_key_test().

static bool aes_is_busy ( void )

inlinestatic

Check if the AES module is busy.

This functions determines whether the AES module is busy by checking if it is currently performing a encryption/decryption operation or an error has occurred. If neither of these cases are true, the module is determined to be busy.

If an error has occurred, the flag must be cleared with the function aes_clear_error_flag().

Referenced by aes_lastsubkey_generate(), main(), run_aes_decryption_test(), run_aes_encryption_test(), and run_aes_state_interface_test().

static bool aes_is_error ( void )

inlinestatic

Check if the AES module has encountered an error.

Referenced by aes_isr_handler(), aes_lastsubkey_generate(), main(), and run_aes_state_interface_test().

void aes_isr_configure ( enum aes_intlvl intlvl )

AES interrupt settings.