Master emulator pairing, passkey and bonding issue

[Ben]

Hi  Sir/ Miss:

I use master emulator to develop software testing device that dll version is 2.1.13.14.

It's developed on using C#.

And, I use nrf51 dongle (PCA10031) to develop software.

I have two questions about pairing, entering passkey and bonding with peripheral device.

Q1.

When I connect that device don't require to enter passkey, I can get the data on device information service and battery service.

But, I can't get any data on requiring passkey device. The API display " ATT error insufficient authentication " message.

I check the master emulator document of pairing, passkey and bonding in security sections.

It has some topic about these sections.

I can't find how to enter passkey and send to device?

It only mentions that "public int Passkey { set;}". That, I can set value for passkey.

But, I don't understand how to send it to device? Is there having API function for user in MasterEmulator.dll?

Or, should I use "SendData" function to send passkey?

Q2.

I don't understand the SOP of pairing, passkey and bonding.

In my current thoughts, the SOP might be connect -> pairing (STK) -> send passkey -> bonding (LTK).

If it's wrong, please correct me.

Thank you.

[Jørgen Holmefjord]

Hi,

Q1: Are you writing a Peripheral or Central application? Which example are you basing your application on? The passkey is normally generated and displayed on the Peripheral side (display, terminal, etc.) and then entered on the Central. Please have a look at the Message Sequence Charts in softdevice documentation: 

• Peripheral Security Procedures
• Central Security Procedures

Q2: I would recommend that you read the 4 blog posts on Bluetooth SIG that described Pairing.

[Jørgen Holmefjord]

You should be able to set the IoCapabilities in SecurityParameters Class and pass this as argument to MasterEmulator.Bond Method.

[Ben]

I try to create below function.

        void OnSecurityRequest(object sender, SecurityRequestEventArgs arguments)
        {
            SecurityRequestEventArgs securityRequestEventArgs = new SecurityRequestEventArgs(true, true);
            securityParameters.IoCapabilities = IoCapabilitiesEnum.DisplayOnly;
            securityParameters.MaximumEncryptionKeySize = 16;
            securityParameters.OobAvailability = OobAvailibilityEnum.OobNotAvailable;

        }

        void OnPasskeyRequest(object sender, PasskeyRequestEventArgs eventArgs)
        {
            
            passkeyRequestEventArgs.Passkey = 123456;
        }

And, these functions add in RegisterEventHandlers()

But, I can't check whether the setup is working?

Or, are these setting wrong?

Thank you.

[Jørgen Holmefjord]

It is correct that you should set the passkey in the OnPasskeyRequest event, when it is being requested. I see you have set iocapabilities to displayonly. This should be set to keyboardonly or keyboarddisplay in order to get a passkey request.

[Ben]

I've set iocapability to keyboardonly or keyboarddisplay.

When I want to get DIS, it still displays ATT error insufficient authentication.

I think it should be got event to notify me to enter passkey.

May I ask whether is it having this event?

Thank you.

[Jørgen Holmefjord]

Some more details and clarifications from the developers:

It is always the Central that has to initiate pairing, i.e, call Bond() in master emulator. The Central can either initiate pairing on own initiative, or wait for Peripheral to send a Security Request. Either way Bond() must be called. SecurityParameters that is sent in SequrityRequestEvent is information about the Peripheral's parameters. The Central's parameters must be set in the Bond()-call. If no parameters are set in then Bond()-call, default SecurityParameters will be used.