S332 SoftDevice v0.9.1
When the application detects that the pairing should not be performed, for example an insufficient IO combination, it can use sd_ble_gap_sec_params_reply() to send SMP Pairing failed to the peer.
When the stack handles the response from the application it will also validate the passkey (SMP_STC_PASSKEY_ENTRY_FAILED). If any error is detected it will be reported when sd_ble_gap_sec_params_reply() is called.
