Gazell Pairing API. More...

Pairing configuration defines
#define	GZP_PAIRING_PIPE 0
	Pipe reserved for initial pairing communication.

#define	GZP_DATA_PIPE 1
	Pipe reserved for GZP encrypted data communication (one pipe only).

#define	GZP_TX_RX_TRANS_DELAY 10
	Time to wait between request and fetch packets in RX_PERIODS (2 timeslot periods)

#define	GZP_SYSTEM_ADDRESS_WIDTH 4
	Must equal Gazell base address length.

#define	GZP_VALIDATION_ID {0x32, 0x53, 0x66}
	Validation ID. Required to be shared by Host and Device. Not a secret.

#define	GZP_VALIDATION_ID_LENGTH 3
	Validation ID length in bytes.

#define	GZP_HOST_ID_LENGTH 5
	Host ID length in bytes.

#define	GZP_SESSION_TOKEN_LENGTH GZP_HOST_ID_LENGTH
	Session token length in bytes.

#define	GZP_DYN_KEY_LENGTH (16 - GZP_VALIDATION_ID_LENGTH)
	Dynamic key length in bytes.

#define	GZP_HOST_RX_POWER_THRESHOLD -64
	RSSI threshold for when signal strength in RX packet power is high enough.

Device -> Host packet definitions
#define	GZP_CMD_HOST_ADDRESS_REQ_PAYLOAD_LENGTH 1
	"Host address request" packet, payload length

#define	GZP_CMD_HOST_ADDRESS_FETCH_PAYLOAD_LENGTH 1
	"Host address fetch" packet, payload length

#define	GZP_CMD_HOST_ID_REQ_SESSION_TOKEN 1
	"Host ID request" packet, session token position

#define	GZP_CMD_HOST_ID_REQ_PAYLOAD_LENGTH (GZP_CMD_HOST_ID_REQ_SESSION_TOKEN + GZP_SESSION_TOKEN_LENGTH)
	"Host ID request" payload length

#define	GZP_CMD_HOST_ID_FETCH_VALIDATION_ID 1
	"Host ID fetch" packet

#define	GZP_CMD_HOST_ID_FETCH_PAYLOAD_LENGTH (GZP_CMD_HOST_ID_FETCH_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH)
	"Host ID fetch" payload length

#define	GZP_CMD_KEY_UPDATE_PREPARE_PAYLOAD_LENGTH 1
	"Key update prepare" payload length

#define	GZP_CMD_KEY_UPDATE_VALIDATION_ID 1
	"Key update" packet, validation ID position

#define	GZP_CMD_KEY_UPDATE_NEW_KEY (GZP_CMD_KEY_UPDATE_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH)
	"Key update" packet, new key position

#define	GZP_CMD_KEY_UPDATE_PAYLOAD_LENGTH (GZP_CMD_KEY_UPDATE_NEW_KEY + GZP_DYN_KEY_LENGTH)
	"Key update" packet, payload length

#define	GZP_CMD_ENCRYPTED_USER_DATA_VALIDATION_ID 1
	"Encrypted user data" packet, validation ID position

#define	GZP_CMD_ENCRYPTED_USER_DATA_PAYLOAD ((GZP_CMD_ENCRYPTED_USER_DATA_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH))
	"Encrypted user data" packet, user data position

#define	GZP_ENCRYPTED_USER_DATA_PACKET_OVERHEAD ( GZP_CMD_ENCRYPTED_USER_DATA_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH)
	"Encrypted user data" packet, packet overhead length

#define	GZP_ENCRYPTED_USER_DATA_MAX_LENGTH (17 - GZP_ENCRYPTED_USER_DATA_PACKET_OVERHEAD)
	"Encrypted user data" packet, max payload length

#define	GZP_CMD_FETCH_RESP_PAYLOAD_LENGTH 1
	General "fetch response" packet, payload_length.

Host -> Device packet definitions
#define	GZP_CMD_HOST_ADDRESS_RESP_ADDRESS 1
	"Host address fetch" response packet, address position

#define	GZP_CMD_HOST_ADDRESS_RESP_PAYLOAD_LENGTH (GZP_CMD_HOST_ADDRESS_RESP_ADDRESS + GZP_SYSTEM_ADDRESS_WIDTH)
	///< "Host address fetch" response packet, payload length

#define	GZP_CMD_HOST_ID_FETCH_RESP_VALIDATION_ID 1
	"Host ID fetch" response packet, validation ID position

#define	GZP_CMD_HOST_ID_FETCH_RESP_STATUS (GZP_CMD_HOST_ID_FETCH_RESP_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH)
	"Host ID fetch" response packet, status position

#define	GZP_CMD_HOST_ID_FETCH_RESP_HOST_ID (GZP_CMD_HOST_ID_FETCH_RESP_STATUS + 1)
	"Host ID fetch" response packet, Host ID position

#define	GZP_CMD_HOST_ID_FETCH_RESP_PAYLOAD_LENGTH (GZP_CMD_HOST_ID_FETCH_RESP_HOST_ID + GZP_HOST_ID_LENGTH)
	"Host ID fetch" response packet, payload length

#define	GZP_CMD_KEY_UPDATE_PREPARE_RESP_SESSION_TOKEN 1
	"Key update prepare" response packet, session token position

#define	GZP_CMD_KEY_UPDATE_PREPARE_RESP_PAYLOAD_LENGTH (GZP_CMD_KEY_UPDATE_PREPARE_RESP_SESSION_TOKEN + GZP_SESSION_TOKEN_LENGTH)
	"Key update prepare" response packet, payload length position

#define	GZP_CMD_ENCRYPTED_USER_DATA_RESP_SESSION_TOKEN 1
	"Encrypted user data" response packet, session token position

#define	GZP_CMD_ENCRYPTED_USER_DATA_RESP_VALIDATION_ID (GZP_CMD_ENCRYPTED_USER_DATA_RESP_SESSION_TOKEN + GZP_SESSION_TOKEN_LENGTH)
	"Encrypted user data" response packet, validation ID position

#define	GZP_CMD_ENCRYPTED_USER_DATA_RESP_PAYLOAD_LENGTH (GZP_CMD_ENCRYPTED_USER_DATA_RESP_VALIDATION_ID + GZP_VALIDATION_ID_LENGTH)
	"Encrypted user data" response packet, payload length position

Typedefs
enum	gzp_key_select_t { GZP_ID_EXCHANGE, GZP_KEY_EXCHANGE, GZP_DATA_EXCHANGE }
	Enumerator used for selecting the key to be used for encryption. More...

enum	gzp_cmd_t { GZP_CMD_HOST_ADDRESS_REQ = 0, GZP_CMD_HOST_ADDRESS_FETCH, GZP_CMD_HOST_ID_REQ, GZP_CMD_HOST_ID_FETCH, GZP_CMD_KEY_UPDATE_PREPARE, GZP_CMD_KEY_UPDATE, GZP_CMD_ENCRYPTED_USER_DATA, GZP_CMD_FETCH_RESP, GZP_CMD_HOST_ADDRESS_RESP, GZP_CMD_HOST_ID_FETCH_RESP, GZP_CMD_KEY_UPDATE_PREPARE_RESP, GZP_CMD_ENCRYPTED_USER_DATA_RESP }
	Enumerator used in the first payload byte of each packet to indicate the packet type. More...

enum	gzp_id_req_res_t { GZP_ID_RESP_PENDING, GZP_ID_RESP_GRANTED, GZP_ID_RESP_REJECTED, GZP_ID_RESP_FAILED, GZP_ID_RESP_NO_REQUEST }
	Enumerator used to identify the state of the current Host ID request. More...

Misc. function prototypes
void	gzp_crypt_set_session_token (const uint8_t *token)

void	gzp_crypt_get_session_token (uint8_t *dst_token)

void	gzp_crypt_set_dyn_key (const uint8_t *dyn_key)

void	gzp_crypt_get_dyn_key (uint8_t *dst_key)

static void	gzp_set_host_id (const uint8_t *src)

void	gzp_get_host_id (uint8_t *dst)

void	gzp_crypt_select_key (gzp_key_select_t key_select)

void	gzp_crypt (uint8_t dst, const uint8_t src, uint8_t length)

bool	gzp_validate_id (const uint8_t *src_id)

void	gzp_add_validation_id (uint8_t *dst_id)

void	gzp_random_numbers_generate (uint8_t *dst, uint8_t n)

bool	gzp_update_radio_params (const uint8_t *system_address)

void	gzp_generate_channels (uint8_t ch_dst, const uint8_t address, uint8_t channel_set_size)

void	gzp_xor_cipher (uint8_t dst, const uint8_t src, const uint8_t *pad, uint8_t length)

Common Device and Host functions
void	gzp_init (void)

void	gzp_erase_pairing_data (void)

void	nrf_gzp_disable_gzll (void)

void	gzp_id_req_cancel (void)

void	nrf_gzp_flush_rx_fifo (uint32_t pipe)

Device functions
bool	nrf_gzp_tx_complete (void)

bool	nrf_gzp_tx_success (void)

void	nrf_gzp_reset_tx_complete (void)

void	nrf_gzp_reset_tx_success (void)

int8_t	gzp_get_pairing_status (void)

bool	gzp_address_req_send (void)

gzp_id_req_res_t	gzp_id_req_send (void)

bool	gzp_crypt_data_send (const uint8_t *src, uint8_t length)

Host functions
void	gzp_pairing_enable (bool enable)

void	gzp_host_execute (void)

bool	gzp_address_exchanged (void)

bool	gzp_id_req_received (void)

void	gzp_id_req_reject (void)

void	gzp_id_req_grant (void)

bool	gzp_crypt_user_data_received (void)

bool	gzp_crypt_user_data_read (uint8_t dst, uint8_t length)

void	gzll_rx_start (void)

Detailed Description

Gazell Pairing API.

Enumeration Type Documentation

enum gzp_cmd_t

Enumerator used in the first payload byte of each packet to indicate the packet type.

Enumerator
GZP_CMD_HOST_ADDRESS_REQ	Host address request.
GZP_CMD_HOST_ADDRESS_FETCH	Host address fetch.
GZP_CMD_HOST_ID_REQ	Host ID request.
GZP_CMD_HOST_ID_FETCH	Host ID fetch request.
GZP_CMD_KEY_UPDATE_PREPARE	Key update prepare.
GZP_CMD_KEY_UPDATE	Key update.
GZP_CMD_ENCRYPTED_USER_DATA	Encrypted user data.
GZP_CMD_FETCH_RESP	Fetch response.
GZP_CMD_HOST_ADDRESS_RESP	Host address response.
GZP_CMD_HOST_ID_FETCH_RESP	Host ID fetch response.
GZP_CMD_KEY_UPDATE_PREPARE_RESP	Key update prepare.
GZP_CMD_ENCRYPTED_USER_DATA_RESP	Encrypted user data response.

enum gzp_id_req_res_t

Enumerator used to identify the state of the current Host ID request.

Enumerator
GZP_ID_RESP_PENDING	ID response pending.
GZP_ID_RESP_GRANTED	ID response granted.
GZP_ID_RESP_REJECTED	ID response rejected.
GZP_ID_RESP_FAILED	ID response failed.
GZP_ID_RESP_NO_REQUEST	Default value. No ID request has yet been received.

enum gzp_key_select_t

Enumerator used for selecting the key to be used for encryption.

Enumerator
GZP_ID_EXCHANGE	"Secret key" only
GZP_KEY_EXCHANGE	"Secret key" and "Host ID"
GZP_DATA_EXCHANGE	"Dynamic key" and "Host ID"

Function Documentation

void gzll_rx_start ( void )

Function emulating behavior of gzll_rx_start() in legeacy nRF24xx Gaell linbrary.

This functions sets Gazell in Host mode and starts reception (enable).

void gzp_add_validation_id ( uint8_t * dst_id )

Add the pre-defined validation ID to dst_id. GZP_VALIDATION_ID_LENGTH bytes will be added.

Parameters

dst_id Pointer to add the GZP validation ID to.

bool gzp_address_exchanged ( void )

Address exchanged check.

Return values

true	If a "system address" was delivered to a requesting Device during the previous call to gzp_host_execute();
false	Otherwise.

bool gzp_address_req_send ( void )

Function for sending a "system address" request to a Host.

When calling this function the Device will attempt acquiring the "system address" from any Host within close proximity.

If a host is located within close proximity and pairing is enabled in the Host, a "system address" will be sent in return to the Device.

The new "system address" will apply immediately in the Device, and the new "system address" will be stored in non volatile (NV) memory.

Note. Using OTP devices limits the number of times a new "system address" can be stored in NV memory.

Returns

Return values

true	if new "system address" was received from a Host.
false	if no "system address" was received from a Host.

void gzp_crypt	(	uint8_t *	dst,
		const uint8_t *	src,
		uint8_t	length
	)

Encypt / decrypt data.

The current "session token" will be used as initialization vector (IV). The AES key to be used is selected by gzp_crypt_select_key(). AES is a symmetric encryption scheme, this function can be used to perform both encryption and decryption.

Parameters

dst	Destination to write encrypted data to. Should be 16 bytes long.
src	Source data to encrypt.
length	Length in bytes of src.

bool gzp_crypt_data_send	(	const uint8_t *	src,
		uint8_t	length
	)

Function for sending encrypted user data to the Host.

Before any data can be sent the Device must acquire both the Host's "system address" by using gzp_address_req_send() and the "Host ID" by using gzp_id_req_send().

Parameters

*src	is a pointer to the data packet to be sent.
length	is the length of the data packet to be sent.

Returns

Return values

true	if the data was successfully transmitted and decrypted by the Host.
false	if data transmission failed or Host failed to decryption data correctly.

void gzp_crypt_get_dyn_key ( uint8_t * dst_key )

Get the dynamic key.

Parameters

dst_key Pointer to write the dynamic key too.

void gzp_crypt_get_session_token ( uint8_t * dst_token )

Get the session token.

Parameters

dst_token Pointer to write the session token.

void gzp_crypt_select_key ( gzp_key_select_t key_select )

Selecting what key-set that should be used when encrypting data using gzp_crypt().

Parameters

key_select Key-set to use.

void gzp_crypt_set_dyn_key ( const uint8_t * dyn_key )

Set the dynamic key.

Parameters

dyn_key Pointer to the dynamic key to set.

void gzp_crypt_set_session_token ( const uint8_t * token )

Set the session token.

Parameters

token Pointer to the session token to set.

bool gzp_crypt_user_data_read	(	uint8_t *	dst,
		uint8_t *	length
	)

Function for reading encrypted user data.

Note that the read user data will be automatically decrypted. Only data that was decrypted correctly will be presented.

Parameters

dst*	is a pointer to where the received data will be written.
length*	is a pointer for returning the number of bytes received. Only 1 byte will be writtem to length*.

Returns

Return values

true	if data has been received and is written to dst*
false	if no data has been received.

bool gzp_crypt_user_data_received ( void )

Check if user data has been received.

Return values

true	If encrypted user data has been received.
false	Otherwise.

void gzp_erase_pairing_data ( void )

Function for erasing all pairing data.

void gzp_generate_channels	(	uint8_t *	ch_dst,
		const uint8_t *	address,
		uint8_t	channel_set_size
	)

Generate a set of channels from a 4 byte address.

Parameters

ch_dst	Destination to write the channel set to. The channel set includes GZP_CHANNEL_MAX and GZP_CHANNEL_MIN.
address	Four byte address to generate the channel set from.
channel_set_size	Size of the channel set to generate.

void gzp_get_host_id ( uint8_t * dst )

Get the Host ID.

Parameters

dst	Pointer to write the Host ID to.

int8_t gzp_get_pairing_status ( void )

Function to check whether a Device has existing pairing data, implying that it is paired to a Host.

Return values

-2	The pairing database is empty.
-1	The device has a system address but no Host ID.
>=0	The device has a system address and HostID at this index value in the database.

void gzp_host_execute ( void )

Execute the Gazell Pairing Library Host operation.

This function must be called regularly by the Host application.

void gzp_id_req_cancel ( void )

Function for cancelling an ongoing (pending) "Host ID request".

After calling this function the "Host ID request" status will go to "ID request Idle".

void gzp_id_req_grant ( void )

Function for granting the previously received "Host ID request". This function should be called only when a "Host ID request" has been received (internal state is "ID request pending").

The internal state of the Pairing library will remain "ID request pending" until the "Host ID" has been successfully transmitted to the requesting Device. After this the internal state will change to "ID request idle".

bool gzp_id_req_received ( void )

Function for checking if a "Host ID request" has been received from a Device.

If a request has been received, the Pairing library will enter "ID request pending" state.

The application is responsible for responding to this request by calling one of the following functions:

Return values

true	if a "Host ID request" has been received (internal state is "ID request pending")
false	if no "Host ID request" has been received (internal state is "ID request idle")

void gzp_id_req_reject ( void )

Function for rejecting the previously received "Host ID request". This function should be called only when a "Host ID request" has been received (internal state is "ID request pending").

The internal state of the Pairing library will remain "ID request pending" until the a "reject" message has been successfully transmitted to the requesting Device. After this the internal state will change to "ID request idle".

gzp_id_req_res_t gzp_id_req_send ( void )

Function for sending a "Host ID request" to a Host.

The "Host ID" is needed to be able to send encrypted data using gzp_crypt_data_send().

The request will be sent using the "system address" previously received using gzp_address_req_send().

It is not required that the Host is within close proximity in order to acquire the "Host ID".

The new "Host ID" will apply immediately for the Device, and the new "Host ID" will be stored in non volatile (NV) memory.

Note. Using OTP devices limits the number of times a new "Host ID" can be stored in NV memory.

Returns

Return values

GZP_ID_RESP_PENDING	if a "Host ID request" has been sent to the Host, but the Host application has not yet decided whether to Grant or Reject the "ID request".
GZP_ID_RESP_GRANTED	if the "Host ID" has been received from the Host. The received "Host ID" will be stored in non volatile memory.
GZP_ID_RESP_REJECTED	if the Host application has rejected the "Host ID request".
GZP_ID_RESP_FAILED	if failing to send a request or receive a response from the Host.

void gzp_init ( void )

Initialization function. This function initializes the Gazell Pairing Library.

This function must be called before any of the other Gazell Pairing Library functions are used and must be called after gzll_init() is called.

void gzp_pairing_enable ( bool enable )

Function for enabling/disabling pairing in a host. When pairing is enabled the host will be monitoring for "system address" and "Host ID" requests from Devices.

A "system address request" received from a Device will always be granted. When a "host ID request" has been received, the Host application have to grant, reject or cancel this by using one of the following functions:

Parameters

enable

true enables pairing.
false disables pairing.

void gzp_random_numbers_generate	(	uint8_t *	dst,
		uint8_t	n
	)

Generate random bytes.

Parameters

dst	Destination to write the random bytes to.
n	Number of bytes to generate.

static void gzp_set_host_id ( const uint8_t * src )

static

Set the Host ID.

Parameters

src	Pointer to the Host ID to set.

bool gzp_update_radio_params ( const uint8_t * system_address )

Update the channel table and the system address.

The channel table is updated to pseudo-random set generated using the system address. The channel table still includes GZP_CHANNEL_MAX and GZP_CHANNEL_MIN. The system address is applied to base address 1 and therefore applies to pipes 1-7.

Parameters

system_address Pointer to the system_address to set.

Return values

true	If theradio parameters were updated successfully.
false	If there was an error updated the radio parameters.

bool gzp_validate_id ( const uint8_t * src_id )

Compare the *src_id with a pre-defined validation ID.

Parameters

src_id Pointer to the source validation ID to compare to.

Return values

true	If *src_id equals the pre-defined ID.
false	If *src_id does not equal the pre-defined ID.

void gzp_xor_cipher	(	uint8_t *	dst,
		const uint8_t *	src,
		const uint8_t *	pad,
		uint8_t	length
	)

Perform an XOR on two byte strings.

Parameters

dst	Destination to write the result to. Should be of size length.
src
pad
length	Number of bytes to perform the XOR operation on.

void nrf_gzp_disable_gzll ( void )

Disable Gazell and sleep while waiting for nrf_gzll_disabled callback.

void nrf_gzp_flush_rx_fifo ( uint32_t pipe )

Flush the GZLL RX FIFO for a specific pipe while GZLL is disabled.

Parameters

pipe Pipe.

void nrf_gzp_reset_tx_complete ( void )

Reset tx_complete status.

void nrf_gzp_reset_tx_success ( void )

Reset tx_success status.

bool nrf_gzp_tx_complete ( void )

Check whether current GZP packet transaction has completed.

Return values

true
false

bool nrf_gzp_tx_success ( void )

Check whether previous GZP packet transaction was successful.

Return values

true
false

Pairing configuration defines

Device -> Host packet definitions

Host -> Device packet definitions

Typedefs

Misc. function prototypes

Common Device and Host functions

Device functions

Host functions

Detailed Description

Enumeration Type Documentation

Function Documentation