Security Manager#

Security Manager.


Modules
sl_bt_evt_sm_passkey_display
Indicates a request to display the passkey to the user.
sl_bt_evt_sm_passkey_request
Indicates a request for the passkey prompt displayed on the remote device.
sl_bt_evt_sm_confirm_passkey
Indicates a request for passkey display and confirmation by the user.
sl_bt_evt_sm_bonded
Triggered after the pairing or bonding procedure is successfully completed.
sl_bt_evt_sm_bonding_failed
This event is triggered if the pairing or bonding procedure fails.
sl_bt_evt_sm_confirm_bonding
Indicates a user request to display that the new bonding request is received and for the user to confirm the request.
sl_bt_evt_sm_list_bonding_entry
Triggered by the command sl_bt_sm_list_all_bondings if bondings exist in the local database.
sl_bt_evt_sm_list_all_bondings_complete
Triggered by the sl_bt_sm_list_all_bondings and follows sl_bt_evt_sm_list_bonding_entry events.


Enumerations
enum	sl_bt_sm_io_capability_t { sl_bt_sm_io_capability_displayonly = 0x0, sl_bt_sm_io_capability_displayyesno = 0x1, sl_bt_sm_io_capability_keyboardonly = 0x2, sl_bt_sm_io_capability_noinputnooutput = 0x3, sl_bt_sm_io_capability_keyboarddisplay = 0x4 }
	SMP I/O Capabilities.


Functions
sl_status_t	sl_bt_sm_configure (uint8_t flags, uint8_t io_capabilities)
sl_status_t	sl_bt_sm_set_minimum_key_size (uint8_t minimum_key_size)
sl_status_t	sl_bt_sm_set_debug_mode ()
sl_status_t	sl_bt_sm_add_to_whitelist (bd_addr address, uint8_t address_type)
sl_status_t	sl_bt_sm_store_bonding_configuration (uint8_t max_bonding_count, uint8_t policy_flags)
sl_status_t	sl_bt_sm_set_bondable_mode (uint8_t bondable)
sl_status_t	sl_bt_sm_set_passkey (int32_t passkey)
sl_status_t	sl_bt_sm_set_oob_data (size_t oob_data_len, const uint8_t *oob_data)
sl_status_t	sl_bt_sm_use_sc_oob (uint8_t enable, size_t max_oob_data_size, size_t oob_data_len, uint8_t oob_data)
sl_status_t	sl_bt_sm_set_sc_remote_oob_data (size_t oob_data_len, const uint8_t *oob_data)
sl_status_t	sl_bt_sm_increase_security (uint8_t connection)
sl_status_t	sl_bt_sm_enter_passkey (uint8_t connection, int32_t passkey)
sl_status_t	sl_bt_sm_passkey_confirm (uint8_t connection, uint8_t confirm)
sl_status_t	sl_bt_sm_bonding_confirm (uint8_t connection, uint8_t confirm)
sl_status_t	sl_bt_sm_list_all_bondings ()
sl_status_t	sl_bt_sm_delete_bonding (uint8_t bonding)
sl_status_t	sl_bt_sm_delete_bondings ()

Detailed Description#

Security Manager.

The commands in this class manage Bluetooth security, including commands for starting and stopping encryption and commands for management of all bonding operations.

Use the following procedure to bond with a remote device:

Use the command sl_bt_sm_configure to configure security requirements and I/O capabilities of this device.
Use the command sl_bt_sm_set_bondable_mode to set this device into bondable mode.
Use the command sl_bt_connection_open to open a connection to the remote device.
After the connection is open, use command sl_bt_sm_increase_security to encrypt the connection. This will also start the bonding process.

Use the following procedure to respond to the bonding initiated by a remote device:

Use the command sl_bt_sm_configure to configure security requirements and I/O capabilities of this device.
Use the command sl_bt_sm_set_bondable_mode to set this device into bondable mode.
Use the command sl_bt_advertiser_start to set this device into advertising and connectable mode.
Open a connection to this device from the remote device.
After the connection is open, start the bonding process on the remote device.

If MITM is required, the application needs to display or ask the user to enter a passkey during the process. See events sl_bt_evt_sm_passkey_display and sl_bt_evt_sm_passkey_request for more information.

Enumeration Type Documentation#

sl_bt_sm_io_capability_t#

enum sl_bt_sm_io_capability_t

SMP I/O Capabilities.


Enumerator
sl_bt_sm_io_capability_displayonly	(0x0) Display Only
sl_bt_sm_io_capability_displayyesno	(0x1) Display with Yes/No-buttons
sl_bt_sm_io_capability_keyboardonly	(0x2) Keyboard Only
sl_bt_sm_io_capability_noinputnooutput	(0x3) No Input and No Output
sl_bt_sm_io_capability_keyboarddisplay	(0x4) Display with Keyboard

Function Documentation#

sl_bt_sm_configure()#



sl_status_t sl_bt_sm_configure	(	uint8_t	`flags,`
		uint8_t	`io_capabilities`
	)

Configure security requirements and I/O capabilities of the system.

Parameters



[in]	`flags`	Security requirement bitmask. Bit 0: 0: Allow bonding without MITM protection 1: Bonding requires MITM protection Bit 1: 0: Allow encryption without bonding 1: Encryption requires bonding. Note that this setting will also enable bonding. Bit 2: 0: Allow bonding with legacy pairing 1: Secure connections only Bit 3: 0: Bonding request does not need to be confirmed 1: Bonding requests need to be confirmed. Received bonding requests are notified by sl_bt_evt_sm_confirm_bonding Bit 4: 0: Allow all connections 1: Allow connections only from bonded devices Bit 5 to 7: Reserved Default value: 0x00
[in]	`io_capabilities`	Enum sl_bt_sm_io_capability_t. I/O Capabilities. The default I/O Capability used by the stack is No Input and No Output. Values: sl_bt_sm_io_capability_displayonly (0x0): Display Only sl_bt_sm_io_capability_displayyesno (0x1): Display with Yes/No-buttons sl_bt_sm_io_capability_keyboardonly (0x2): Keyboard Only sl_bt_sm_io_capability_noinputnooutput (0x3): No Input and No Output sl_bt_sm_io_capability_keyboarddisplay (0x4): Display with Keyboard

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_set_minimum_key_size()#

sl_status_t sl_bt_sm_set_minimum_key_size ( uint8_t minimum_key_size )

Set the minimum allowed key size used for bonding. The default value is 16 bytes.

Parameters



[in]	`minimum_key_size`	Minimum allowed key size for bonding. Range: 7 to 16

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_set_debug_mode()#

sl_status_t sl_bt_sm_set_debug_mode ( )

Set Security Manager in debug mode. In this mode, the secure connections bonding uses known debug keys, so that the encrypted packet can be opened by Bluetooth protocol analyzer. To disable the debug mode, restart the device.

Bondings made in debug mode are unsecure.

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_add_to_whitelist()#



sl_status_t sl_bt_sm_add_to_whitelist	(	bd_addr	`address,`
		uint8_t	`address_type`
	)

Add device to whitelist, which can be enabled with sl_bt_gap_enable_whitelisting.

Parameters



[in]	`address`	Address of the device added to whitelist
[in]	`address_type`	Enum sl_bt_gap_address_type_t. Address type of the device added to whitelist. Values: sl_bt_gap_public_address (0x0): Public device address sl_bt_gap_static_address (0x1): Static device address sl_bt_gap_random_resolvable_address (0x2): Private resolvable random address sl_bt_gap_random_nonresolvable_address (0x3): Private non-resolvable random address

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_store_bonding_configuration()#



sl_status_t sl_bt_sm_store_bonding_configuration	(	uint8_t	`max_bonding_count,`
		uint8_t	`policy_flags`
	)

Set the maximum allowed bonding count and bonding policy. The maximum number of bondings that can be supported depends on how much user data is stored in the NVM and the NVM size. When bond policy value 1 or 2 is selected, the stack will automatically write the new bond, as per the policy, only if the maximum allowed bonding count has been reached. If the stack can't write a new bond for any other reason (e.g., NVM is full), an error will be thrown through the bonding_failed event indicating why the bonding was not written. The application has to manually release space from the NVM (e.g., by deleting one of the existing bonds or application data) so that a new bond can be saved. The default value is 13.

Parameters



[in]	`max_bonding_count`	Maximum allowed bonding count. Range: 1 to 32
[in]	`policy_flags`	Bonding policy. Values: 0: If database is full, new bonding attempts will fail 1: New bonding will overwrite the oldest existing bonding 2: New bonding will overwrite the bonding that was used the longest time ago Default: 0

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_set_bondable_mode()#

sl_status_t sl_bt_sm_set_bondable_mode ( uint8_t bondable )

Set whether the device should accept new bondings. By default, the device does not accept new bondings.

Parameters



[in]	`bondable`	Bondable mode. Values: 0: New bondings not accepted 1: Bondings allowed Default value: 0

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_set_passkey()#

sl_status_t sl_bt_sm_set_passkey ( int32_t passkey )

Enter a fixed passkey, which will be used in the sl_bt_evt_sm_passkey_display event.

Parameters



[in]	`passkey`	Passkey. Valid range: 0-999999. Set -1 to disable and start using random passkeys.

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_set_oob_data()#



sl_status_t sl_bt_sm_set_oob_data	(	size_t	`oob_data_len,`
		const uint8_t *	`oob_data`
	)

Set OOB data (out-of-band encryption data) for legacy pairing for a device. OOB data may be, for example, a PIN code exchanged over an alternate path, such as NFC. The device will not allow any other bonding if OOB data is set. OOB data can't be set simultaneously with secure connections OOB data.

Parameters



[in]	`oob_data_len`	Array length
[in]	`oob_data`	OOB data. To set OOB data, send a 16-byte array. Values are in little endian format. To clear OOB data, send a zero-length array.

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_use_sc_oob()#



sl_status_t sl_bt_sm_use_sc_oob	(	uint8_t	`enable,`
		size_t	`max_oob_data_size,`
		size_t *	`oob_data_len,`
		uint8_t *	`oob_data`
	)

Enable the use of OOB data (out-of-band encryption data) for a device for secure connections pairing. Enabling will generate new OOB data and confirm values, which can be sent to the remote device. After enabling the secure connections OOB data, the remote devices OOB data can be set with sl_bt_sm_set_sc_remote_oob_data. Calling this function will erase any set remote device OOB data and confirm values. The device will not allow any other bonding if OOB data is set. The secure connections OOB data cannot be enabled simultaneously with legacy pairing OOB data.

Parameters



[in]	`enable`	Enable OOB with secure connections pairing. Values: 0: disable 1: enable
[in]	`max_oob_data_size`	Size of output buffer passed in `oob_data`
[out]	`oob_data_len`	On return, set to the length of output data written to `oob_data`
[out]	`oob_data`	OOB data. 32-byte array. The first 16-bytes contain randomly-generated OOB data and the last 16-bytes confirm value. Values are in little endian format.

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_set_sc_remote_oob_data()#



sl_status_t sl_bt_sm_set_sc_remote_oob_data	(	size_t	`oob_data_len,`
		const uint8_t *	`oob_data`
	)

Set OOB data and confirm values (out-of-band encryption) received from the remote device for secure connections pairing. OOB data must be enabled with sl_bt_sm_use_sc_oob before setting the remote device OOB data.

Parameters



[in]	`oob_data_len`	Array length
[in]	`oob_data`	Remote device OOB data and confirm values. To set OOB data, send a 32-byte array. First 16-bytes is OOB data and last 16-bytes the confirm value. Values are in little endian format. To clear OOB data, send a zero-length array.

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_increase_security()#

sl_status_t sl_bt_sm_increase_security ( uint8_t connection )

Enhance the security of a connection to current security requirements. On an unencrypted connection, it will encrypt the connection and will also perform bonding if requested by both devices. On an encrypted connection, it will cause the connection to be re-encrypted.

Parameters



[in]	`connection`	Connection handle

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

sl_bt_evt_connection_parameters - Triggered after increasing security has been completed successfully and indicates the latest security mode of the connection.
sl_bt_evt_sm_bonded - Triggered if pairing or bonding was performed in this operation and the result is successful.
sl_bt_evt_sm_bonding_failed - Triggered if pairing or bonding was performed in this operation and the result has failed.

sl_bt_sm_enter_passkey()#



sl_status_t sl_bt_sm_enter_passkey	(	uint8_t	`connection,`
		int32_t	`passkey`
	)

Enter a passkey after receiving a passkey request event.

Parameters



[in]	`connection`	Connection handle
[in]	`passkey`	Passkey. Valid range: 0-999999. Set -1 to cancel pairing.

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_passkey_confirm()#



sl_status_t sl_bt_sm_passkey_confirm	(	uint8_t	`connection,`
		uint8_t	`confirm`
	)

Accept or reject the reported passkey confirm value.

Parameters



[in]	`connection`	Connection handle
[in]	`confirm`	Acceptance. Values: 0: Reject 1: Accept confirm value

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_bonding_confirm()#



sl_status_t sl_bt_sm_bonding_confirm	(	uint8_t	`connection,`
		uint8_t	`confirm`
	)

Accept or reject the bonding request.

Parameters



[in]	`connection`	Connection handle
[in]	`confirm`	Acceptance. Values: 0: Reject 1: Accept confirm value

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_list_all_bondings()#

sl_status_t sl_bt_sm_list_all_bondings ( )

List all bondings stored in the bonding database. Bondings are reported by the sl_bt_evt_sm_list_bonding_entry event for each bonding and the report is ended with sl_bt_evt_sm_list_all_bondings_complete event. Use only for debugging purposes because reading from the persistent store is relatively slow.

Returns

SL_STATUS_OK if successful. Error code otherwise.

Events

sl_bt_sm_delete_bonding()#

| sl_status_t sl_bt_sm_delete_bonding ( uint8_t bonding )

Delete specified bonding information or whitelist from the persistent store.

Parameters



[in]	`bonding`	Bonding handle

Returns

SL_STATUS_OK if successful. Error code otherwise.

sl_bt_sm_delete_bondings()#

| sl_status_t sl_bt_sm_delete_bondings ( )

Delete all bonding information and whitelist from the persistent store. This will also delete device local identity resolving key (IRK).

Returns

SL_STATUS_OK if successful. Error code otherwise.