Strange behavior with PIN validation

Felipe Castro

I'm using Bluetopia Release v1.5 R2 (4.0.1.10) SDK and SSPLEDemo as a template to develop my code and I'm facing a strange behavior with PIN validation flow.

At PINCodeResponse(&Params) function a verification like below is being done:

 ASSIGN_PIN_CODE(PINCode, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);

 BTPS_MemCopy(&PINCode, TempParam->Params[0].strParam, BTPS_StringLength(TempParam->Params[0].strParam));

 /* Populate the response structure.                         */
 GAP_Authentication_Information.GAP_Authentication_Type      = atPINCode;
 GAP_Authentication_Information.Authentication_Data_Length   = (Byte_t)(BTPS_StringLength(TempParam->Params[0].strParam));
 GAP_Authentication_Information.Authentication_Data.PIN_Code = PINCode;

 /* Submit the Authentication Response.                      */
 Result = GAP_Authentication_Response(BluetoothStackID, CurrentCBRemoteBD_ADDR, &GAP_Authentication_Information);

The problem is that even when I entered a wrong PIN GAP_Authentication_Response is returning 0.

Link is not created and device not paired when PIN is wrong but the strange think is GAP_Authentication_Response returning 0 all the time.

How can I solved this issue?

Thanks and regards,

Felipe Castro

over 10 years ago

Sundeep Javvaji over 10 years ago

TI__Mastermind 32615 points

Hi,

what is the the value of "TempParam->Params[0].strParam", this should be same as the pin you have entered on the other side (phone).

From what is see you are trying to do everything from the code, instead of terminal output. usually when we run it from the terminal this parameter will be read from the terminal, example "PINCodeResponse 0000", where "0000" is the pin.

Felipe Castro over 10 years ago in reply to Sundeep Javvaji

Prodigy 80 points

Hi Sundeep,

Yes, you are right. I'm doing everything at code.

TempParam->Params[0].strParam is receiving a hardcoded parameter, like suggested at SPPLEDemo application like below:

#define DEFAULT_PIN_CODE "1234"

...

Params.Params[0].strParam = DEFAULT_PIN_CODE;

Thanks and regards

Felipe Castro

Felipe Castro over 10 years ago in reply to Felipe Castro

Prodigy 80 points

Oh,

One thing, I was reading the documentation again and maybe it was my bad ...

At GAP_Authentication_Response it says:
Return Zero (0) if the remote authentication response was successfully submitted.

Is it supposed to return something different from 0 when authentication PIN does not match ?

The behavior I noticed is, the command was sent successfully and GAP_Authentication_Response return 0 and this is right according to API description. The PIN I entered is wrong, but link is not created and this is OK as well, maybe I need to check if PIN is right or not in other place.

If so, any clue how can I indentify if PIN validation was successfully or not ?

Thanks and regards,
Felipe Castro

Sundeep Javvaji over 10 years ago in reply to Felipe Castro

TI__Mastermind 32615 points

Hi,

Could you please try with "0000" instead of "1234", may be the android auto pairing mechanism is coming in between (which will use "0000" as the default pin)

Felipe Castro over 10 years ago in reply to Sundeep Javvaji

Prodigy 80 points

Hi,

Same result, DEFAULT_PIN_CODE set 0000

If I entered a wrong password, GAP_Authentication_Response returns 0

Thanks and regards,
Felipe Castro

Sundeep Javvaji over 10 years ago in reply to Felipe Castro

TI__Mastermind 32615 points

Hi,

That is strange, If the GAP_Authentication_Response has returned 0 (which mean success). are you receiving link key creation event, if so are you handling it.

Do you have any sniffer logs that you can share.

Felipe Castro over 10 years ago in reply to Sundeep Javvaji

Prodigy 80 points

You are write, this is strange.
But I'm not receiving link creation event call back.

Here is the log.
https://www.dropbox.com/s/fvoml3i80c3hk9n/btsnoop_hci.log?dl=0

Please let me know if you not able to access.

Thanks and regards
Felipe Castro

Sundeep Javvaji over 10 years ago in reply to Felipe Castro

TI__Mastermind 32615 points

Hi,

From the logs you have provided the Authentication Failed, could be because of incorrect PIN (the pin replay with the pin "1235" )

Felipe Castro over 10 years ago in reply to Sundeep Javvaji

Prodigy 80 points

Yes right,

I entered the wrong pin number but return from GAP_Authentication_Response was 0, as shown at first picture at this topic.
This is what is strange to me.

No Link is created but GAP_Authentication_Response is returning success.

Thanks and regards
Felipe Castro

Sundeep Javvaji over 10 years ago in reply to Felipe Castro

TI__Mastermind 32615 points

Hi,

Ok, now I understand what your issue is.

It is not strange to return 0 for GAP_Authentication_Response, as it is only a HCI command (HCI_PIN_Code_Request_Reply) and the the status is for the HCI command sent successfully.

and if you are initiating the pairing from CC256x, then you after entering a wrong pin from the remote device (phone) you will receive "atAuthenticationStatus" with failure reason.

Please see the Bluetooth specification for better understanding.

Felipe Castro over 10 years ago in reply to Sundeep Javvaji

Prodigy 80 points

Oh got it.

Thanks and regards

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Strange behavior with PIN validation