How to pair and bond with a static passkey?

RE: How to pair and bond with a static passkey?

Edvin — Thu, 12 Sep 2024 21:12:44 GMT

Ok, thank you for showing me. This could actually be unrelated to the security part. Do you know what connection interval that is being used? A sniffer trace using nRF Connect for Bluetooth LE would reveal this, and probably also reveal what takes so long. I suspect it is a long connection interval being used. I didn't see that you specify it anywhere, so it could be the phone that is selecting a long connection interval. It is possible for your peripheral to request a shorter connection interval, so that is something we could try. For a guide, you can follow the Nordic Developer Academy, and the Bluetooth Low Energy Fundamentals course. Particularly Lesson 3, exercise 2, steps 1-6 is relevant for this. It will also tell you the connection interval without using a sniffer, based on the connection callbacks from your application.

Best regards,

Edvin

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Tue, 10 Sep 2024 00:31:09 GMT

It is slow as case 1 that you say,just like that as follow:

devzone.nordicsemi.com/.../SVID_5F00_20240910_5F00_082715_5F00_1.mp4

There no the same 5 second delay when I test cgms in my HW.

RE: How to pair and bond with a static passkey?

Edvin — Mon, 09 Sep 2024 09:48:57 GMT

Do you mean that it is slow:

1: after you have entered the code and press "confirm"

2: It takes a long time before the popup with the passkey appears?

In my test, using the ncs\nrf\samples\bluetooth\peripheral_cgms on an nRF52832 DK the time after pressing confirm was almost instantly. Can you please try this sample on both a DK and your custom hardware? You don't need to worry about setting the static passkey, as this shouldn't affect the time it takes roughly one second before I can see it in the log, but the logging has some delay.

Can you see if you see the same 5 second delay in that application on a) a DK and b) your HW?

Best regards,

Edvin

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Mon, 09 Sep 2024 00:26:49 GMT

When I using my phone to connect with my board , The pop-up is quick appeared.

The waiting happen at the time that I entry passkey and confirm.

The display of phone is pairing and the process will keep about five seconds.

But it finished immediately when I use the application in nRF SDK.

The board using to test is designed by myself that refer to official design.

RE: How to pair and bond with a static passkey?

Edvin — Fri, 06 Sep 2024 12:49:37 GMT

What do you mean by slow? How long does it take?

It looks like it happens almost instantly when I run it.

What HW are you running on? The nRF52832 DK?

Best regards,

Edvin

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Thu, 05 Sep 2024 05:03:54 GMT

devzone.nordicsemi.com/.../1202.rar

This is the project file.It is semi-finished.

Now I seem realize the pairing and bonding with passkey successfully.But the time of this process seem a little bit long,at least longer than it in nrf SDK.If there have some methods to let it quicker?

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Wed, 04 Sep 2024 00:52:51 GMT

Hi Edvin,

I checked the code of cgms.But it use the security_change to trigger the process of pairing.

I want to arrive those function that using hid service and appearance to realize the board can be connected in my phone settings->bluetooth.And find a way to realize when my board be connected,the phone need to input the passkey otherwise it will be refused and disconnected.

But the cgms sample use security_change that mean only have data change can trigger the pairing?

It is unsuitable to my application.If there have other sample can I refer to?

RE: How to pair and bond with a static passkey?

Edvin — Tue, 03 Sep 2024 12:39:44 GMT

We don't have any samples using a static/fixed passkey (because of the false security it gives).

You can check out the ncs\nrf\samples\bluetooth\peripheral_cgms, which uses a non-static passkey.

I was able to make this use a static passkey by adding CONFIG_BT_FIXED_PASSKEY=y in the prj.conf, and adding this snippet after settings_load(); (after bt_enable())

    err = bt_passkey_set(123456);
    printk("bt_passkey_set returned %d\n", err);

Best regards,

Edvin

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Tue, 03 Sep 2024 01:57:38 GMT

The location of bt_passkey_set() as above.The application run normally before pairing.And I debugged to check the return value of bt_passkey_set() and the num is zero that mean set success.

I think the issue due to conn_auth_callbacks.I'm not familiar with it.So I just copy it from hid_mouse.And the passkey_confirm is high priority, so i'm failed to use passkey.

If there have some samples use passkey to pairing?

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Mon, 02 Sep 2024 00:50:05 GMT

int main(void) int主要(空白) int主要(空白) int主要(空白) int主要(空白) int主要(空白) int主要(空白)

{

int err; int犯错; int犯错; int犯错; int犯错; int犯错; int犯错;

uint32_t blink_status = 0;

struct dm_init_param init_param; struct dm_init_param;struct dm_init_param;struct dm_init_param;struct dm_init_param;struct dm_init_param;struct dm_init_param;

printk("1202 Start\n"); printk(“1202年开始\ n”); printk(“1202年开始\ n”); printk(“1202年开始\ n”); printk(“1202年开始\ n”); printk(“1202年开始\ n”); printk(“1202年开始\ n”);

if (!device_is_ready(uart)) 如果(! device_is_ready (uart))如果(! device_is_ready (uart))如果(! device_is_ready (uart))如果(! device_is_ready (uart))如果(! device_is_ready (uart))如果(! device_is_ready (uart))

{

printk("UART device not ready\r\n"); printk("UART设备未就绪\r\n");printk("UART设备未就绪\r\n");printk("UART设备未就绪\r\n");printk("UART设备未就绪\r\n");printk("UART设备未就绪\r\n");printk("UART设备未就绪\r\n");

return 1 ; 返回1; 返回1; 返回1; 返回1; 返回1; 返回1;

}

int main(void)
{
	int err;
	uint32_t blink_status = 0;
	struct dm_init_param init_param;

	printk("1202 Start\n");

	if (!device_is_ready(uart))
	{
		printk("UART device not ready\r\n");
		return 1 ;
	}
	
	err = uart_callback_set(uart,uart_cb,NULL);
	if (err)
	{
		return err;
	}

	err = dk_leds_init();
	if (err) {
		printk("LEDs init failed (err %d)\n", err);
		return 0;
	}

	err = bt_passkey_set(pairing_passkey);
	if(err){
		printk("passkey set failed(err %d)\n",err);
		return 0;
	}

	err = bt_conn_auth_cb_register(&conn_auth_callbacks);
	if (err) {
		printk("Failed to register authorization callbacks.\n");
		return 0;
	}

	err = bt_conn_auth_info_cb_register(&conn_auth_info_callbacks);
	if (err) {
		printk("Failed to register authorization info callbacks.\n");
		return 0;
	}

	err = peer_init();
	if (err) {
		printk("Peer init failed (err %d)\n", err);
		return 0;
	}

	init_param.cb = &dm_cb;

	err = dm_init(&init_param);
	if (err) {
		printk("Distance measurement init failed (err %d)\n", err);
		return 0;
	}

	hid_init();

	err = bt_enable(NULL);
	if (err) {
		printk("Bluetooth init failed (err %d)\n", err);
		return 0;
	}

	k_work_init(&pairing_work, pairing_process);

	if (IS_ENABLED(CONFIG_SETTINGS)) {
		settings_load();
	}

	namecat();
	
	err = bt_set_name(name);
	if (err)
	{
		printk("Name set failed (err %d)\n",err);
		return 0;
	}
	

	err = bt_sync_init();
	if (err) {
		printk("Synchronisation init failed (err %d)\n", err);
		return 0;
	}

	for (;;) {
		dk_set_led(RUN_STATUS_LED, (++blink_status) % 2);
		k_sleep(K_MSEC(RUN_LED_BLINK_INTERVAL));
	}
}

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Sun, 01 Sep 2024 13:42:35 GMT

Yes,Icall bt_passkey_set() at the main function but I didn't care what has been returned.Maybe the error happened here?but it seem work normally

RE: How to pair and bond with a static passkey?

Edvin — Fri, 30 Aug 2024 12:24:17 GMT

So you want to input the key on the phone, right?

Where do you currently call bt_passkey_set()? And what does it return?

Best regards,

Edvin

RE: How to pair and bond with a static passkey?

Chaoyue Ying — Fri, 30 Aug 2024 09:15:58 GMT

Hi,

I already set CONFIG_BT_FIXED_PASSKEY=y and use bt_passkey_set() to set the static passkey.

But I think the relevant code that I used is misfit to the way that use the passkey.

I imitate the hid_mouse that use bt_conn_auth_cb_register() and bt_conn_auth_info_cb_register() to replace the peer_manager in nRF SDK17.

I think it is the issue that even CONFIG_BT_FIXED_PASSKEY=y and bt_passkey_set() be used,the pairing show in my phone still display a 8 length passkey and confirm 、cancal button rather than a input box just like this:

And that's what I want to achieve:

RE: How to pair and bond with a static passkey?

Edvin — Fri, 30 Aug 2024 08:55:38 GMT

Hello,

Please see this API:
https://docs.nordicsemi.com/bundle/ncs-2.7.99-cs1/page/zephyr/connectivity/bluetooth/api/connection_mgmt.html#c.bt_passkey_set

As you can see from the description, you need to set CONFIG_BT_FIXED_PASSKEY=y for this API to work.

Also note that using a fixed/static passkey doesn't really provide any real security. It is possible to brute force relatively easily, and it is also possible to sniff/capture and crack it later. Adding LESC on top of a static passkey will increase the security though, since the sniffer can't pick up the Diffie Hellman keys (used in LESC).

But that being said, the security risk of a BLE mouse is relatively low. Even though someone would be able to listen in, the value of the data from a mouse is relatively low, which is why it usually doesn't use a (non-static) passkey in the first place.

A fixed passkey does however make it easier for the user to know that they connect to the correct device, since a normal user would see that they are able to use e.g. a 6-digit key printed on a sticker somewhere.

Best regards,

Edvin