HASH

HASH Engine LLD API. More...

Files
file	hw_hash.h
	Definition of API for the HASH Engine Low Level Driver.

Data Structures
struct	hw_hash_config_t
	HASH engine configuration structure. More...

Enumerations
enum	HW_HASH_ERROR
	HASH engine error codes.
enum	HW_HASH_TYPE { HW_HASH_TYPE_SHA_256_224 = 0, HW_HASH_TYPE_SHA_256 = 1 }
	HASH Type. More...
enum	HW_HASH_OUTPUT_LENGTH_MAX { HW_HASH_OUTPUT_LEN_MAX_SHA_256_224 = 28, HW_HASH_OUTPUT_LEN_MAX_SHA_256 = 32 }
	The maximum allowed output length of the HASH engine in bytes for all supported HASH types. More...

Functions
__STATIC_INLINE void	hw_hash_set_type (HW_HASH_TYPE hash_type)
	Set HASH type. More...
__STATIC_INLINE void	hw_hash_set_output_data_len (HW_HASH_TYPE hash_type, uint8_t output_data_len)
	Set HASH output length. More...
bool	hw_hash_check_input_data_len_restrictions (void)
	Check if the restrictions of the input data length are fulfilled. More...
HW_HASH_ERROR	hw_hash_init (const hw_hash_config_t *hash_cfg)
	HASH engine initialization function. More...

Detailed Description

HASH Engine LLD API.

Enumeration Type Documentation

HW_HASH_OUTPUT_LENGTH_MAX

enum HW_HASH_OUTPUT_LENGTH_MAX

The maximum allowed output length of the HASH engine in bytes for all supported HASH types.

Enumerator
HW_HASH_OUTPUT_LEN_MAX_SHA_256_224	The maximum allowed output length for HASH Type SHA-256/224
HW_HASH_OUTPUT_LEN_MAX_SHA_256	The maximum allowed output length for HASH Type SHA-256

HW_HASH_TYPE

enum HW_HASH_TYPE

HASH Type.

Enumerator
HW_HASH_TYPE_SHA_256_224	HASH Type SHA-256/224
HW_HASH_TYPE_SHA_256	HASH Type SHA-256

Function Documentation

hw_hash_check_input_data_len_restrictions()

bool hw_hash_check_input_data_len_restrictions

(

void

)

Check if the restrictions of the input data length are fulfilled.

There are some restrictions in terms of the acceptable values of the data_len with regards to Input Data Mode, indicated by the next table:

wait_more_input = true	wait_more_input = false
multiple of 8	no restrictions

Returns

true if the restrictions are fulfilled, otherwise false

hw_hash_init()

HW_HASH_ERROR hw_hash_init

(

const hw_hash_config_t *

hash_cfg

)

HASH engine initialization function.

Configure the HASH engine provided that the crypto engine is NOT locked by the AES engine. If the function returns HW_HASH_ERROR_NONE, the operation can be started by calling the hw_aes_hash_start().

Parameters

[in]

hash_cfg

Configuration structure for HASH engine.

Returns

HW_HASH_ERROR_NONE if the HASH engine has been successfully initialized, otherwise an error code.

Warning

When HASHing has been completed, the hw_aes_hash_deinit() should be called in order for the crypto engine to be unlocked from HASH. This is mandatory in case that both AES and HASH are used by the same application. The two blocks make use of the same hardware accelerator, thus they are mutually exclusive and cannot be used simultaneously. The functions hw_aes_init(), hw_hash_init() and hw_aes_hash_deinit() incorporate a mechanism which ensures mutual exclusion and prevents race condition, provided that the user doesn't call the functions hw_aes_hash_disable_clock(), hw_aes_hash_enable_clock(), hw_aes_set_mode() and hw_hash_set_type(). The aforementioned functions affect some AES/HASH register fields which are used by this mechanism and might violate it. Therefore, it is highly recommended to use the corresponding init/deinit functions instead.

See also

hw_hash_config_t

HW_HASH_ERROR

hw_hash_set_output_data_len()

__STATIC_INLINE void hw_hash_set_output_data_len	(	HW_HASH_TYPE	hash_type,
		uint8_t	output_data_len
	)

Set HASH output length.

There are restrictions with regards to the maximum length of the output data. If the selected output_data_len exceeds the maximum allowed length determined by HW_HASH_OUTPUT_LEN_MAX this function automatically equalizes the output length with the maximum allowed value.

Parameters

[in]	hash_type	HASH type
[in]	output_data_len	HASH output length

See also

HW_HASH_TYPE

HW_HASH_OUTPUT_LEN_MAX

hw_hash_set_type()

__STATIC_INLINE void hw_hash_set_type

(

HW_HASH_TYPE

hash_type

)

Set HASH type.

Parameters

[in]

hash_type

HASH type

See also

HW_HASH_TYPE