Digi XBee 3 User Manual

API frames BLE Unlock API - 0x2C
Digi XBee® 3 Cellular LTE Cat 1 AT&T Smart Modem User Guide
261
BLE Unlock API - 0x2C
Description
The XBee Smart Modem uses this frame to authenticate a connection on the Bluetooth interface and
unlock the processing of ATcommand frames. This frame is used in conjunction with the Response
(0xAC) frame.
The unlock process is an implementation of the SRP (Secure Remote Password) algorithm using the
RFC5054 1024-bit group and the SHA-256 hash algorithm . The SRP identifying user name, commonly
referred to as I, is fixed to the value apiservice.
Upon completion, each side will have derived a shared session key which is used to communicate in an
encrypted fashion with the peer. Additionally, a Modem Status - 0x8A with the status code 0x32
(Bluetooth Connected) is sent through the UART (if AP=1 or 2). When an unlocked connection is
terminated, a Modem Status Frame with the status code 0x33 (Bluetooth Disconnected) is sent
through the UART.
The following implementations are known to work with the BLE SRP implementation:
n https://github.com/cncfanatics/SRP
You will need to modify the hashing algorithm to SHA256 and the values of N and g to use the
RFC5054 1024-bit group.
n https://github.com/cocagne/csrp
n https://github.com/cocagne/pysrp
Format
The following table provides the contents of the frame. For details on frame structure, see API frame
format.
Framedatafields Offset Description
Frame type 3 0x2C = Request
0xAC = Response

Digi XBee 3 Specifications

General

Brand	Digi
Model	XBee 3
Category	Modem
Language	English