APIs for Secure link configuration and usage.

Data Structures
struct	sl_wfx_set_securelink_mac_key_req_body_t
	Set the Secure Link MAC key.

struct	sl_wfx_set_securelink_mac_key_cnf_body_t
	Confirmation for the Secure Link MAC key setting.

struct	sl_wfx_securelink_exchange_pub_keys_req_body_t
	Exchange Secure Link Public Keys.

struct	sl_wfx_securelink_exchange_pub_keys_cnf_body_t
	Confirmation for exchange of Secure Link Public Keys.

struct	sl_wfx_securelink_exchange_pub_keys_ind_body_t
	Indication for exchange of Secure Link Public Keys.

struct	sl_wfx_securelink_configure_req_body_t
	Configure Secure Link Layer.

struct	sl_wfx_securelink_configure_cnf_body_t
	Confirmation of Secure Link Layer configuration sl_wfx_securelink_configure_req_body_t .

Macros
#define	SL_WFX_SESSION_KEY_PROTECTION_DISABLE_MAGIC 0xfa21e603
	Magic word used to disable Session Key protection.

Enumerations
enum	sl_wfx_secure_link_state_t { SECURE_LINK_NA_MODE = 0x0, SECURE_LINK_UNTRUSTED_MODE = 0x1, SECURE_LINK_TRUSTED_MODE = 0x2, SECURE_LINK_TRUSTED_ACTIVE_ENFORCED = 0x3 }
	*Secure Link' device state

enum	sl_wfx_securelink_mac_key_dest_t { SECURE_LINK_MAC_KEY_DEST_OTP = 0x78, SECURE_LINK_MAC_KEY_DEST_RAM = 0x87 }
	destination of the Secure Link MAC key , used by request message sl_wfx_set_securelink_mac_key_req_body_t

enum	sl_wfx_secure_link_session_key_alg_t { SECURE_LINK_CURVE25519 = 0x01, SECURE_LINK_KDF = 0x02 }
	Session Key computation algorithms.

Detailed Description

APIs for Secure link configuration and usage.

WFX family of product have the ability to encrypt the SDIO or SPI link.

Link to more detailed documentation about the Secure Link feature : SecureLink

Data Structure Documentation

◆ sl_wfx_set_securelink_mac_key_req_body_t

struct sl_wfx_set_securelink_mac_key_req_body_t

Set the Secure Link MAC key.

This API can be used for Trusted Eval devices in two contexts:

to set a temporary SecureLink MAC key in RAM.
to permanently burn the SecureLink MAC key in OTP memory. In that case, the OTP SecureLink mode will switch to Trusted Enforced mode

Definition at line 553 of file sl_wfx_general_api.h .

Data Fields
uint8_t	key_value[32]	Secure Link MAC Key value.
uint8_t	otp_or_ram	Key destination - OTP or RAM (see enum sl_wfx_securelink_mac_key_dest_t)

◆ sl_wfx_set_securelink_mac_key_cnf_body_t

struct sl_wfx_set_securelink_mac_key_cnf_body_t

Confirmation for the Secure Link MAC key setting.

Definition at line 566 of file sl_wfx_general_api.h .

Data Fields
uint32_t	status	Key upload status (see enum sl_wfx_status_t)

◆ sl_wfx_securelink_exchange_pub_keys_req_body_t

struct sl_wfx_securelink_exchange_pub_keys_req_body_t

Exchange Secure Link Public Keys.

This API is used by the Host to send its curve25519 public key to Device, and get back Device public key in the confirmation message. Once keys are exchanged and authenticated (using their respective MAC), each peer computes the Secure Link session key that will be used to encrypt/decrypt future Host<->Device messages.

Definition at line 594 of file sl_wfx_general_api.h .

Data Fields
uint32_t	algorithm	Choice of the cryptographic algorithm used in the session key computation (see enum sl_wfx_secure_link_session_key_alg_t)
uint8_t	host_pub_key[32]	Host Public Key.
uint8_t	host_pub_key_mac[64]	Host Public Key MAC.

◆ sl_wfx_securelink_exchange_pub_keys_cnf_body_t

struct sl_wfx_securelink_exchange_pub_keys_cnf_body_t

Confirmation for exchange of Secure Link Public Keys.

Definition at line 608 of file sl_wfx_general_api.h .

Data Fields
uint32_t	status	Request status (see enum sl_wfx_status_t)

◆ sl_wfx_securelink_exchange_pub_keys_ind_body_t

struct sl_wfx_securelink_exchange_pub_keys_ind_body_t

Indication for exchange of Secure Link Public Keys.

Definition at line 622 of file sl_wfx_general_api.h .

Data Fields
uint8_t	ncp_pub_key[32]	Device Public Key.
uint8_t	ncp_pub_key_mac[64]	Device Public Key MAC.
uint32_t	status	Request status (see enum sl_wfx_status_t)

◆ sl_wfx_securelink_configure_req_body_t

struct sl_wfx_securelink_configure_req_body_t

Configure Secure Link Layer.

This API can be used to:

Set/update the Secure Link encryption bitmap
Disable Session Key Protection

About the Session Key protection: SecureLink underlying encryption algorithm is AES CCM. This algorithm is using an internal Nonce counter incremented each time a message is encrypted/decrypted. This counter is not supposed to go beyond a given limit to guarantee AES CCM security properties. This is why Host Driver is responsible for renegotiating the session key once the message counter is approaching the limit. Disabling the Session Key protection will disable the check performed by the firmware that the Nonce counter is crossing the limit, allowing Host Driver to use the same session key during the same power cycle, even during a very long time. This behavior is not recommended.

To disable the protection, a given magic word (SL_WFX_SESSION_KEY_PROTECTION_DISABLE_MAGIC) must be provided as DisableSessionKeyProtection parameter value. Any other value will let the protection set.

Note: When SecureLink is activated, SL Configure API must be called right after the key exchange.; It is not recommended to call this API a second time during the same power cycle.

Definition at line 657 of file sl_wfx_general_api.h .

Data Fields
uint32_t	disable_session_key_protection	Force the firmware to authorize the use of the same session key during a complete power cycle, even very long. NOT RECOMMENDED.
uint8_t	encr_bmp[32]	Encryption bitmap.

◆ sl_wfx_securelink_configure_cnf_body_t

struct sl_wfx_securelink_configure_cnf_body_t

Confirmation of Secure Link Layer configuration sl_wfx_securelink_configure_req_body_t .

The following situation will lead to a SL_WFX_STATUS_FAILURE return value:

Bitmap is set to 1 for SL_WFX_SEND_FRAME_REQ_ID (since encryption is not supported for TX frames)

Definition at line 673 of file sl_wfx_general_api.h .

Data Fields
uint32_t	status	Request status (see enum wsm_status)

Enumeration Type Documentation

◆ sl_wfx_secure_link_session_key_alg_t

enum sl_wfx_secure_link_session_key_alg_t

Session Key computation algorithms.

Enumerator
SECURE_LINK_CURVE25519	Session key is computed using curve25519 algorithm.
SECURE_LINK_KDF	Session key is computed using KDF algorithm (not available yet)

Definition at line 582 of file sl_wfx_general_api.h .

◆ sl_wfx_secure_link_state_t

enum sl_wfx_secure_link_state_t

*Secure Link' device state

Enumerator
SECURE_LINK_NA_MODE	Reserved.
SECURE_LINK_UNTRUSTED_MODE	Untrusted mode - SecureLink not available.
SECURE_LINK_TRUSTED_MODE	Trusted (Evaluation) mode.
SECURE_LINK_TRUSTED_ACTIVE_ENFORCED	Trusted (Enforced) mode.

Definition at line 528 of file sl_wfx_general_api.h .

◆ sl_wfx_securelink_mac_key_dest_t

enum sl_wfx_securelink_mac_key_dest_t

destination of the Secure Link MAC key , used by request message sl_wfx_set_securelink_mac_key_req_body_t

Enumerator
SECURE_LINK_MAC_KEY_DEST_OTP	Key will be stored in OTP.
SECURE_LINK_MAC_KEY_DEST_RAM	Key will be stored in RAM.

Definition at line 538 of file sl_wfx_general_api.h .

Secure_LinkGENERAL_API

Data Structures

Macros

Enumerations