Hi all,
I have a BLE device that is unusually picky about the pairing requests
it receives. As far as I can tell, it will not pair if the MITM bit in
the authentication requirements is not set, or if the initiator key
distribution field is not set. It will not pair with BlueZ running under
kernel 3.10.17, where the pairing request looks like this:
< ACL Data TX: Handle 64 flags 0x00 dlen 11
SMP: Pairing Request (0x01) len 6
IO capability: KeyboardOnly (0x02)
OOB data: Authentication data not present (0x00)
Authentication requirement: Bonding, No MITM, Legacy, No
Keypresses (0x01)
Max encryption key size: 16
Initiator key distribution: <none> (0x00)
Responder key distribution: EncKey (0x01)
It will pair under kernel 4.4.11, where the pairing request looks like this:
< ACL Data TX: Handle 64 flags 0x00 dlen 11
SMP: Pairing Request (0x01) len 6
IO capability: KeyboardOnly (0x02)
OOB data: Authentication data not present (0x00)
Authentication requirement: Bonding - MITM (0x05)
Max encryption key size: 16
Initiator key distribution: EncKey IdKey Sign (0x07)
Responder key distribution: EncKey IdKey Sign (0x07)
I would like to make the older kernel's handling of pairing requests
match the newer one's. I'm having some success using newer Bluetooth
kernel modules from backports (3.15.9-1 appears to give the desired
behavior), but I don't know if this is a good long-term solution since
the target system is not using a mainline kernel. Is it possible to
change the authentication requirements and/or initiator key distribution
in user space?
Thanks,
Tom Harada
--
To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
