CAAM RNG driver

Overview

This section describes the programming interface of the CAAM RNG driver.

Data Structures
struct	caam_rng_config_t
	CAAM RNG configuration. More...

Typedefs
typedef uint32_t	caam_rng_generic256_t [256/sizeof(uint32_t)]
	256-bit value used as optional additional entropy input

Enumerations
enum	caam_rng_state_handle_t {   kCAAM_RngStateHandle0 = 0u,   kCAAM_RngStateHandle1 = 1u }
	CAAM RNG state handle. More...
enum	caam_rng_random_type_t {   kCAAM_RngDataAny = 0u,   kCAAM_RngDataOddParity = 1u,   kCAAM_RngDataNonZero = 2u }
	Type of random data to generate. More...

Functions
status_t	CAAM_RNG_GetDefaultConfig (caam_rng_config_t *config)
	Initializes user configuration structure to default. More...
status_t	CAAM_RNG_Init (CAAM_Type *base, caam_handle_t *handle, caam_rng_state_handle_t stateHandle, const caam_rng_config_t *config)
	Instantiate the CAAM RNG state handle. More...
status_t	CAAM_RNG_Deinit (CAAM_Type *base, caam_handle_t *handle, caam_rng_state_handle_t stateHandle)
	Uninstantiate the CAAM RNG state handle. More...
status_t	CAAM_RNG_GenerateSecureKey (CAAM_Type *base, caam_handle_t *handle, caam_rng_generic256_t additionalEntropy)
	Generate Secure Key. More...
status_t	CAAM_RNG_Reseed (CAAM_Type *base, caam_handle_t *handle, caam_rng_state_handle_t stateHandle, caam_rng_generic256_t additionalEntropy)
	Reseed the CAAM RNG state handle. More...
status_t	CAAM_RNG_GetRandomData (CAAM_Type *base, caam_handle_t *handle, caam_rng_state_handle_t stateHandle, void *data, size_t dataSize, caam_rng_random_type_t dataType, caam_rng_generic256_t additionalEntropy)
	Get random data. More...

---

Data Structure Documentation

struct caam_rng_config_t

Data Fields
uint32_t	autoReseedInterval
	Automatic reseed internal. More...
caam_rng_generic256_t *	personalString
	NULL or pointer to optional personalization string.

Field Documentation

uint32_t caam_rng_config_t::autoReseedInterval

If set to zero, CAAM RNG will use hardware default interval of 10.000.000 generate requests.

Enumeration Type Documentation

enum caam_rng_state_handle_t

Enumerator
kCAAM_RngStateHandle0	CAAM RNG state handle 0.
kCAAM_RngStateHandle1	CAAM RNG state handle 1.

enum caam_rng_random_type_t

Enumerator
kCAAM_RngDataAny	CAAM RNG any random data bytes.
kCAAM_RngDataOddParity	CAAM RNG odd parity random data bytes.
kCAAM_RngDataNonZero	CAAM RNG non zero random data bytes.

Function Documentation

status_t CAAM_RNG_GetDefaultConfig

(

caam_rng_config_t *

config

)

This function initializes the configure structure to default value. the default value are:

*     config->autoReseedInterval = 0;
*     config->personalString = NULL;
* 

Parameters

config

User configuration structure.

Returns

status of the request

status_t CAAM_RNG_Init	(	CAAM_Type *	base,
		caam_handle_t *	handle,
		caam_rng_state_handle_t	stateHandle,
		const caam_rng_config_t *	config
	)

This function instantiates CAAM RNG state handle. The function is blocking and returns after CAAM has processed the request.

Parameters

base	CAAM peripheral base address
handle	CAAM jobRing used for this request
stateHandle	RNG state handle to instantiate
config	Pointer to configuration structure.

Returns

Status of the request

status_t CAAM_RNG_Deinit	(	CAAM_Type *	base,
		caam_handle_t *	handle,
		caam_rng_state_handle_t	stateHandle
	)

This function uninstantiates CAAM RNG state handle. The function is blocking and returns after CAAM has processed the request.

Parameters

base	CAAM peripheral base address
handle	jobRing used for this request.
stateHandle	RNG state handle to uninstantiate

Returns

Status of the request

status_t CAAM_RNG_GenerateSecureKey	(	CAAM_Type *	base,
		caam_handle_t *	handle,
		caam_rng_generic256_t	additionalEntropy
	)

This function generates random data writes it to Secure Key registers. The function is blocking and returns after CAAM has processed the request. RNG state handle 0 is always used.

Parameters

base	CAAM peripheral base address
handle	jobRing used for this request
additionalEntropy	NULL or Pointer to optional 256-bit additional entropy.

Returns

Status of the request

status_t CAAM_RNG_Reseed	(	CAAM_Type *	base,
		caam_handle_t *	handle,
		caam_rng_state_handle_t	stateHandle,
		caam_rng_generic256_t	additionalEntropy
	)

This function reseeds the CAAM RNG state handle. For a state handle in nondeterministic mode, the DRNG is seeded with 384 bits of entropy from the TRNG and an optional 256-bit additional input from the descriptor via the Class 1 Context Register.

The function is blocking and returns after CAAM has processed the request.

Parameters

base	CAAM peripheral base address
handle	jobRing used for this request
stateHandle	RNG state handle to reseed
additionalEntropy	NULL or Pointer to optional 256-bit additional entropy.

Returns

Status of the request

status_t CAAM_RNG_GetRandomData	(	CAAM_Type *	base,
		caam_handle_t *	handle,
		caam_rng_state_handle_t	stateHandle,
		void *	data,
		size_t	dataSize,
		caam_rng_random_type_t	dataType,
		caam_rng_generic256_t	additionalEntropy
	)

This function gets random data from CAAM RNG.

The function is blocking and returns after CAAM has generated the requested data or an error occured.

Parameters

	base	CAAM peripheral base address
	handle	jobRing used for this request
	stateHandle	RNG state handle used to generate random data
[out]	data	Pointer address used to store random data
	dataSize	Size of the buffer pointed by the data parameter
	dataType	Type of random data to be generated
	additionalEntropy	NULL or Pointer to optional 256-bit additional entropy.

Returns

Status of the request