ANCS resets after deleting bond on dev board

Question

Hi, 
 I have a problem that the ANCS keeps resetting my board, so I was able to reproduce the problem on the PCA 10028 dev board. 
 Conditions: 
 
 iOS 8.x or 9.x 
 No app needed on iOS. This is on settings->bluetooth 
 SD 110 
 ANCS nordic implementation as is on SDK 9.0 
 Check on serial port. 
 
 The steps to reproduce the problem are: 
 
 Bond iOS device to ANCS. Leave it connected. 
 Reset dev board with button 2 pressed, to erase all bonds 
 Watch on the serial term how ANCS keeps resetting. 
 
 What I have been able to see on the sniff is that when iOS tries to connect after the board resets, ANCS rejects the ENC request due to the bond not existing (it was erased)
After that when the timeout on the ANCS to check if the line is already encrypted asks for Bonding, now it is the turn of iOS to reject the request. 
 After that ANCS does not responds anymore. It has not reset yet and the connection is still active, but all retries from iOS for Rcvd By Type Request are just acknowledged but not answered. 
 I am attaching a wireshark file with this.
 Bonds erased.pcapng 
and a print of the serial terminal... Screen Shot 2015-12-03 at 3.59.50 PM.png 
 HELP!!!

Anders Strand · Accepted Answer

Hi. 
 When the phone has bonding data and the device doesn't, it is not really any easy way out. The phone will try to encrypt the link with the existing encryption keys, and the peripheral device must deny these attempts because it does not have the keys. The only solution to this is to delete the device from the phone bluetooth settings. 
 You mentioned this potentially being an issue when using DFU. You have the option to keep bond data when doing DFU, so this should not be a problem. 
 About the board resetting or freezing when an error occurs:
This is how the default error handler reacts on errors. It resets by default, and freezes (while(1)), when DEBUG is defined. 
 From the documentation of app_error_handler: 
 
 @warning This handler is an example
only and does not fit a final product.
You need to analyze * how
your product is supposed to react in
case of error. 
 
 It is up to the developer to decide how the application should react to different errors. 
 The return code 0x88 comes from 
 event_result = p_ble_evt->evt.gap_evt.params.auth_status.auth_status;
 
 The status is BLE_GAP_SEC_STATUS_UNSPECIFIED. This status describes that the authorization failed with an unspecified reason. (As we can see on event 1415 in the sniffer log).