Secure access
Secured remote AT commands
Digi XBee® 3 802.15.4 RF Module User Guide
55
*Y = 0xAEE84E7A00B74DD2E19E257192EDE6B1D4ED993947DF2996CAE0D644C28E8307
Note
The salt and verifier will not always be the same even if the same password is used to generate
them.
2. Enforce secure access for Remote AT Commands by setting Bit 1 of the
SA
command:
SA
=
0x02
3. Write the configuration to flash using
WARNING!
Make sure that this step is completed. If your device resets for any reason and
*S and SA are not written to flash they will revert to defaults, rendering the node open to
insecure access.
4. From now on, any attempt to issue a
Remote AT Command Request frame - 0x17
to this device
will be rejected with a
0x0B
status unless a secure session is established first.
Remotely configure a node that has been secured
In the example above a node is secured against unauthorized remote configuration. In this instance,
the secured node acts as a Secure Session Server (remote). The sequence below describes how a
Secure Session Client (local) can authenticate and securely configure the server remotely.
Establish a secure session using the password that was set on the server node
1. Generate a
Secure Session Control frame - 0x2E
n
The destination address must match the 64-bit address (
SH
+
SL
) of the remote server.
n
Since you are logging in, leave the options field as
0x00
.
n
Set a five minute timeout, which should give sufficient time for ad hoc configuration. The units
are in tenths of a second, so
0x0BB8
gives you five minutes.
n
The options are set for a fixed duration, so after the five minutes expire, both the server and
client emit a modem status indicating the session ended.
n
Enter the original password used to generate the salt and verifier above.
2. Pass the type 0x2E Control frame into the serial interface of the local client:
n
For example, to log into a Secure Session server at address
0013A200 417B2162
for a five
minute duration using the password
pickle
, use the following frame:
7E 00 12 2E 00 13 A2 00 41 7B 21 62 00 0B B8 70 69 63 6B 6C 65 A2
3. Wait for a
Secure Session Response frame - 0xAE
to indicate the session establishment
succeeded or failed with the reason.
n
The address of the remote that is responding and the status is included in the response.
n
For example, the response to the request above is as follows:
7E 00 0B AE 00 00 13 A2 00 41 7B 21 62
00
5D. The 0
x00
status indicates success.
