Data Structures
struct	puf_config_t

Functions
void	PUF_GetDefaultConfig (puf_config_t *conf)
	Sets the default configuration of PUF.

status_t	PUF_Init (PUF_Type base, puf_config_t conf)
	Initialize PUF.

void	PUF_Deinit (PUF_Type base, puf_config_t conf)
	Denitialize PUF.

status_t	PUF_Enroll (PUF_Type base, uint8_t activationCode, size_t activationCodeSize)
	Enroll PUF.

status_t	PUF_Start (PUF_Type base, const uint8_t activationCode, size_t activationCodeSize)
	Start PUF.

status_t	PUF_SetIntrinsicKey (PUF_Type base, puf_key_index_register_t keyIndex, size_t keySize, uint8_t keyCode, size_t keyCodeSize)
	Set intrinsic key.

status_t	PUF_SetUserKey (PUF_Type base, puf_key_index_register_t keyIndex, const uint8_t userKey, size_t userKeySize, uint8_t *keyCode, size_t keyCodeSize)
	Set user key.

status_t	PUF_GetKey (PUF_Type base, const uint8_t keyCode, size_t keyCodeSize, uint8_t *key, size_t keySize)
	Reconstruct key from a key code.

status_t	PUF_GetHwKey (PUF_Type base, const uint8_t keyCode, size_t keyCodeSize, puf_key_slot_t keySlot, uint32_t keyMask)
	Reconstruct hw bus key from a key code.

status_t	PUF_Zeroize (PUF_Type *base)
	Zeroize PUF.

bool	PUF_IsGetKeyAllowed (PUF_Type *base)
	Checks if Get Key operation is allowed.

status_t	PUF_PowerCycle (PUF_Type base, puf_config_t conf)
	Powercycle PUF.

Variables
uint32_t	puf_config_t::dischargeTimeMsec

uint32_t	puf_config_t::coreClockFrequencyHz

Driver version
enum	_puf_key_index_register { kPUF_KeyIndex_00 = 0x00U , kPUF_KeyIndex_01 = 0x01U , kPUF_KeyIndex_02 = 0x02U , kPUF_KeyIndex_03 = 0x03U , kPUF_KeyIndex_04 = 0x04U , kPUF_KeyIndex_05 = 0x05U , kPUF_KeyIndex_06 = 0x06U , kPUF_KeyIndex_07 = 0x07U , kPUF_KeyIndex_08 = 0x08U , kPUF_KeyIndex_09 = 0x09U , kPUF_KeyIndex_10 = 0x0AU , kPUF_KeyIndex_11 = 0x0BU , kPUF_KeyIndex_12 = 0x0CU , kPUF_KeyIndex_13 = 0x0DU , kPUF_KeyIndex_14 = 0x0EU , kPUF_KeyIndex_15 = 0x0FU }

enum	_puf_min_max { kPUF_KeySizeMin = 8u , kPUF_KeySizeMax = 512u , kPUF_KeyIndexMax = kPUF_KeyIndex_15 }

enum	_puf_key_slot { kPUF_KeySlot0 = 0U , kPUF_KeySlot1 = 1U }
	PUF key slot. More...

enum	{ kStatus_EnrollNotAllowed = MAKE_STATUS(kStatusGroup_PUF, 1) , kStatus_StartNotAllowed = MAKE_STATUS(kStatusGroup_PUF, 2) }

typedef enum _puf_key_index_register	puf_key_index_register_t

typedef enum _puf_min_max	puf_min_max_t

typedef enum _puf_key_slot	puf_key_slot_t
	PUF key slot.

#define	FSL_PUF_DRIVER_VERSION (MAKE_VERSION(2, 1, 6))
	PUF driver version. Version 2.1.6.

#define	PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(x) ((160u + (((((x) << 3) + 255u) >> 8) << 8)) >> 3)
	Get Key Code size in bytes from key size in bytes at compile time.

#define	PUF_MIN_KEY_CODE_SIZE PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(8UL)

#define	PUF_ACTIVATION_CODE_SIZE 1192U

#define	KEYSTORE_PUF_DISCHARGE_TIME_FIRST_TRY_MS 50

#define	KEYSTORE_PUF_DISCHARGE_TIME_MAX_MS 400

Detailed Description

Macro Definition Documentation

◆ FSL_PUF_DRIVER_VERSION

#define FSL_PUF_DRIVER_VERSION (MAKE_VERSION(2, 1, 6))

PUF driver version. Version 2.1.6.

Current version: 2.1.6

Change log:

2.0.0
- Initial version.
2.0.1
- Fixed puf_wait_usec function optimization issue.
2.0.2
- Add PUF configuration structure and support for PUF SRAM controller. Remove magic constants.
2.0.3
- Fix MISRA C-2012 issue.
2.1.0
- Align driver with PUF SRAM controller registers on LPCXpresso55s16.
- Update initizalition logic .
2.1.1
- Fix ARMGCC build warning .
2.1.2
- Update: Add automatic big to little endian swap for user (pre-shared) keys destinated to secret hardware bus (PUF key index 0).
2.1.3
- Fix MISRA C-2012 issue.
2.1.4
- Replace register uint32_t ticksCount with volatile uint32_t ticksCount in puf_wait_usec() to prevent optimization out delay loop.
2.1.5
- Use common SDK delay in puf_wait_usec()
2.1.6
- Changed wait time in PUF_Init(), when initialization fails it will try PUF_Powercycle() with shorter time. If this shorter time will also fail, initialization will be tried with worst case time as before.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

PUF status return codes.

◆ _puf_key_slot

enum _puf_key_slot

PUF key slot.

Enumerator
kPUF_KeySlot0	PUF key slot 0
kPUF_KeySlot1	PUF key slot 1

Function Documentation

◆ PUF_Deinit()

void PUF_Deinit	(	PUF_Type *	base,
		puf_config_t *	conf
	)

Denitialize PUF.

This function disables power to PUF SRAM and peripheral clock.

Parameters

base	PUF peripheral base address
conf	PUF configuration structure

brief Denitialize PUF

This function disables power to PUF SRAM and peripheral clock.

param base PUF peripheral base address param conf PUF configuration structure

◆ PUF_Enroll()

status_t PUF_Enroll	(	PUF_Type *	base,
		uint8_t *	activationCode,
		size_t	activationCodeSize
	)

Enroll PUF.

This function derives a digital fingerprint, generates the corresponding Activation Code (AC) and returns it to be stored in an NVM or a file. This step needs to be performed only once for each device. This function may be permanently disallowed by a fuse.

Parameters

	base	PUF peripheral base address
[out]	activationCode	Word aligned address of the resulting activation code.
	activationCodeSize	Size of the activationCode buffer in bytes. Shall be 1192 bytes.

Returns: Status of enroll operation.

brief Enroll PUF

This function derives a digital fingerprint, generates the corresponding Activation Code (AC) and returns it to be stored in an NVM or a file. This step needs to be performed only once for each device. This function may be permanently disallowed by a fuse.

param base PUF peripheral base address param[out] activationCode Word aligned address of the resulting activation code. param activationCodeSize Size of the activationCode buffer in bytes. Shall be 1192 bytes. return Status of enroll operation.

◆ PUF_GetDefaultConfig()

void PUF_GetDefaultConfig ( puf_config_t * conf )

Sets the default configuration of PUF.

This function initialize PUF config structure to default values.

Parameters

conf	PUF configuration structure

brief Sets the default configuration of PUF

This function initialize PUF config structure to default values.

param conf PUF configuration structure

◆ PUF_GetHwKey()

status_t PUF_GetHwKey	(	PUF_Type *	base,
		const uint8_t *	keyCode,
		size_t	keyCodeSize,
		puf_key_slot_t	keySlot,
		uint32_t	keyMask
	)

Reconstruct hw bus key from a key code.

The digital fingerprint generated during the Start operation and the KC generated during a Set Key operation (Set intrinsic key or Set user key) are used to retrieve a stored key. This operation needs to be done every time a key is needed. This function accepts only Key Codes created for PUF index register kPUF_KeyIndex_00. Such a key is output directly to a dedicated hardware bus. The reconstructed key is not exposed to system memory.

Parameters

base	PUF peripheral base address
keyCode	Word aligned address of the input key code.
keyCodeSize	Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(keySize).
keySlot	key slot to output on hw bus. Parameter is ignored on devices with less than two key slots.
keyMask	key masking value. Shall be random for each POR/reset. Value does not have to be cryptographicaly secure.

Returns: Status of get key operation.

brief Reconstruct hw bus key from a key code

The digital fingerprint generated during the Start operation and the KC generated during a Set Key operation (Set intrinsic key or Set user key) are used to retrieve a stored key. This operation needs to be done every time a key is needed. This function accepts only Key Codes created for PUF index register kPUF_KeyIndex_00. Such a key is output directly to a dedicated hardware bus. The reconstructed key is not exposed to system memory.

param base PUF peripheral base address param keyCode Word aligned address of the input key code. param keyCodeSize Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(keySize). param keySlot key slot to output on hw bus. Parameter is ignored on devices with less than two key slots. param keyMask key masking value. Shall be random for each POR/reset. Value does not have to be cryptographicaly secure. return Status of get key operation.

◆ PUF_GetKey()

status_t PUF_GetKey	(	PUF_Type *	base,
		const uint8_t *	keyCode,
		size_t	keyCodeSize,
		uint8_t *	key,
		size_t	keySize
	)

Reconstruct key from a key code.

The digital fingerprint generated during the Start operation and the KC generated during a Set Key operation (Set intrinsic key or Set user key) are used to retrieve a stored key. This operation needs to be done every time a key is needed. This function accepts only Key Codes created for PUF index registers kPUF_KeyIndex_01 to kPUF_KeyIndex_15.

Parameters

	base	PUF peripheral base address
	keyCode	Word aligned address of the input key code.
	keyCodeSize	Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(keySize).
[out]	key	Word aligned address of output key.
	keySize	Size of the output key in bytes.

Returns: Status of get key operation.

brief Reconstruct key from a key code

The digital fingerprint generated during the Start operation and the KC generated during a Set Key operation (Set intrinsic key or Set user key) are used to retrieve a stored key. This operation needs to be done every time a key is needed. This function accepts only Key Codes created for PUF index registers kPUF_KeyIndex_01 to kPUF_KeyIndex_15.

param base PUF peripheral base address param keyCode Word aligned address of the input key code. param keyCodeSize Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(keySize). param[out] key Word aligned address of output key. param keySize Size of the output key in bytes. return Status of get key operation.

◆ PUF_Init()

status_t PUF_Init	(	PUF_Type *	base,
		puf_config_t *	conf
	)

Initialize PUF.

This function enables power to PUF block and waits until the block initializes.

Parameters

base	PUF peripheral base address
conf	PUF configuration structure

Returns: Status of the init operation

brief Initialize PUF

This function enables power to PUF block and waits until the block initializes.

param base PUF peripheral base address param conf PUF configuration structure return Status of the init operation

◆ PUF_IsGetKeyAllowed()

bool PUF_IsGetKeyAllowed ( PUF_Type * base )

Checks if Get Key operation is allowed.

This function returns true if get key operation is allowed.

Parameters

base	PUF peripheral base address

Returns: true if get key operation is allowed

brief Checks if Get Key operation is allowed.

This function returns true if get key operation is allowed.

param base PUF peripheral base address return true if get key operation is allowed

◆ PUF_PowerCycle()

status_t PUF_PowerCycle	(	PUF_Type *	base,
		puf_config_t *	conf
	)

Powercycle PUF.

This function make powercycle.

Parameters

base	PUF peripheral base address
conf	PUF configuration structure

Returns: Status of the powercycle operation.

brief Powercycle PUF

This function make powercycle of PUF.

param base PUF peripheral base address param conf PUF configuration structure return Status of the powercycle operation.

◆ PUF_SetIntrinsicKey()

status_t PUF_SetIntrinsicKey	(	PUF_Type *	base,
		puf_key_index_register_t	keyIndex,
		size_t	keySize,
		uint8_t *	keyCode,
		size_t	keyCodeSize
	)

Set intrinsic key.

The digital fingerprint generated during the Enroll/Start operations is used to generate a Key Code (KC) that defines a unique intrinsic key. This KC is returned to be stored in an NVM or a file. This operation needs to be done only once for each intrinsic key. Each time a Set Intrinsic Key operation is executed a new unique key is generated.

Parameters

	base	PUF peripheral base address
	keyIndex	PUF key index register
	keySize	Size of the intrinsic key to generate in bytes.
[out]	keyCode	Word aligned address of the resulting key code.
	keyCodeSize	Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(keySize).

Returns: Status of set intrinsic key operation.

brief Set intrinsic key

The digital fingerprint generated during the Enroll/Start operations is used to generate a Key Code (KC) that defines a unique intrinsic key. This KC is returned to be stored in an NVM or a file. This operation needs to be done only once for each intrinsic key. Each time a Set Intrinsic Key operation is executed a new unique key is generated.

param base PUF peripheral base address param keyIndex PUF key index register param keySize Size of the intrinsic key to generate in bytes. param[out] keyCode Word aligned address of the resulting key code. param keyCodeSize Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(keySize). return Status of set intrinsic key operation.

◆ PUF_SetUserKey()

status_t PUF_SetUserKey	(	PUF_Type *	base,
		puf_key_index_register_t	keyIndex,
		const uint8_t *	userKey,
		size_t	userKeySize,
		uint8_t *	keyCode,
		size_t	keyCodeSize
	)

Set user key.

The digital fingerprint generated during the Enroll/Start operations and a user key (UK) provided as input are used to generate a Key Code (KC). This KC is sent returned to be stored in an NVM or a file. This operation needs to be done only once for each user key.

Parameters

	base	PUF peripheral base address
	keyIndex	PUF key index register
	userKey	Word aligned address of input user key.
	userKeySize	Size of the input user key in bytes.
[out]	keyCode	Word aligned address of the resulting key code.
	keyCodeSize	Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(userKeySize).

Returns: Status of set user key operation.

brief Set user key

The digital fingerprint generated during the Enroll/Start operations and a user key (UK) provided as input are used to generate a Key Code (KC). This KC is sent returned to be stored in an NVM or a file. This operation needs to be done only once for each user key.

param base PUF peripheral base address param keyIndex PUF key index register param userKey Word aligned address of input user key. param userKeySize Size of the input user key in bytes. param[out] keyCode Word aligned address of the resulting key code. param keyCodeSize Size of the keyCode buffer in bytes. Shall be PUF_GET_KEY_CODE_SIZE_FOR_KEY_SIZE(userKeySize). return Status of set user key operation.

◆ PUF_Start()

status_t PUF_Start	(	PUF_Type *	base,
		const uint8_t *	activationCode,
		size_t	activationCodeSize
	)

Start PUF.

The Activation Code generated during the Enroll operation is used to reconstruct the digital fingerprint. This needs to be done after every power-up and reset.

Parameters

base	PUF peripheral base address
activationCode	Word aligned address of the input activation code.
activationCodeSize	Size of the activationCode buffer in bytes. Shall be 1192 bytes.

Returns: Status of start operation.

brief Start PUF

The Activation Code generated during the Enroll operation is used to reconstruct the digital fingerprint. This needs to be done after every power-up and reset.

param base PUF peripheral base address param activationCode Word aligned address of the input activation code. param activationCodeSize Size of the activationCode buffer in bytes. Shall be 1192 bytes. return Status of start operation.

◆ PUF_Zeroize()

status_t PUF_Zeroize ( PUF_Type * base )

Zeroize PUF.

This function clears all PUF internal logic and puts the PUF to error state.

Parameters

base	PUF peripheral base address

Returns: Status of the zeroize operation.

brief Zeroize PUF

This function clears all PUF internal logic and puts the PUF to error state.

param base PUF peripheral base address return Status of the zeroize operation.

Data Structures

Functions

Variables

Driver version

Detailed Description

Macro Definition Documentation

◆ FSL_PUF_DRIVER_VERSION

Enumeration Type Documentation

◆ anonymous enum

◆ _puf_key_slot

Function Documentation

◆ PUF_Deinit()

◆ PUF_Enroll()

◆ PUF_GetDefaultConfig()

◆ PUF_GetHwKey()

◆ PUF_GetKey()

◆ PUF_Init()

◆ PUF_IsGetKeyAllowed()

◆ PUF_PowerCycle()

◆ PUF_SetIntrinsicKey()

◆ PUF_SetUserKey()

◆ PUF_Start()

◆ PUF_Zeroize()