| Q: |
What is this all about anyway? |
| A: |
As part of an overall goal for
assessing risks to Bluetooth devices,
we're interested in the common MAC address prefixes that vendors
allocate to devices. When a vendor registers and obtains a
MAC prefix
or organizationally unique identifier, they can use it for anything
they like. We're interested in the actual prefixes that are
being
allocated by vendors in common (and uncommon) Blueetooth devices. |
| Q: |
What are the characteristics of
Bluetooth Device Addresses?
|
| A: |
A Bluetooth Device Address
(BD_ADDR) is a globally unique value assigned to each Bluetooth adapter
by the manufacturer. The BD_ADDR information is made up of
three components:
- LAP: The Lower Address Part of the BD_ADDR is the
portion of the MAC address that is allocated by the vendor to devices.
The LAP makes up 24-bits of the BD_ADDR. The LAP is
used for uniquely identifying a Bluetooth device as part of the Access
Code and synchronization word information that precedes the Bluetooth
baseband header for every transmitted frame.
- UAP: The Upper Address Part of the BD_ADDR is 8-bits
of the device MAC address, representing a portion of the 24-bit prefix
that is allocated to vendors by the IEEE (OUI). The UAP is
used for seeding various algorithms used in the Bluetooth
specification, including the generation of the Header Error Correct
(HEC) field used to identify accidentally corrupted Bluetooth packets
in transit.
- NAP: The Non-significant Address Part makes up the
remaining 16 bits of the BD_ADDR information, and the remaining 16 bits
of the OUI. The NAP value is not used for any significant
purposes for Bluetooth networking, other than that it is present in
Frequency Hopping Synchronization frames.
The format of the BD_ADDR information is shown below. Note
that this diagram represents the BD_ADDR information in "Bluetooth
Order", with the least-significant bit at the left-most position.
More information
about Bluetooth networking is available in the Bluetooth Special
Interest Group (SIG) specification documentation at http://www.bluetooth.org. |
| Q: |
Why is this information interesting? |
| A: |
The LAP information is allocated
uniquely for each Bluetooth device, but the UAP and NAP are part of the
Organizationally Unique Identifier (OUI). We're interested in
collecting UAP and NAP information to determine what OUI's are being
used by vendors for BD_ADDR values. With this information, we
can correlate manufacturer information to a specific device, and
accelerate Bluetooth device discovery. |
| Q: |
Why should I share this information
with you? |
| A: |
We are independent researchers
without commercial funding or alterior motives. We're simply
interested in evaluating how vendors are using NAP and UAP information.
Since we can only get so far by assessing the devices that we
own specifically, we're asking for your help in this effort.
If we are able to identify any particularly useful analysis
mechanisms from the information we obtain through this community
effort, we will share our results openly and publicly to make
meaningful improvements to the wireless security and networking
industries. |
| Q: |
Who is behind this effort? |
A:
|
- Joshua Wright (jwright@hasborg.com)
|
| Q: |
Why isn't my entry listed in "The List" yet? |
| A: |
For purposes of data validation, we only list entries that have matching OUI's submitted by more than one host. |
| Q: |
What's with the Smurf? |
|
It's a light take on the Smurf's
episode where one Smurf becomes infected with a communicable disease,
and turns purple. When purple, the Smurf seeks out to infect
other Smurfs (by biting them on the butt) and yells out "GNAP, GNAP" in
a torrets-like fashion. It's juvenile, I know. |