GSUP transmits AUTS for UMTS authentication procedures, and OAP uses the same
procedures to authenticate. osmo-gen-vec is a utility program that passes AUTS
to our osmo_auth_gen_vec_auts() API.
According to 3GPP 33.102 6.3.3, AUTS = SQN^AK || MAC-S, which are 6 || 8 == 14
bytes. This is confirmed by 24.008 9.2.3a where the TLV has 16 bytes, TL = 2
and AUTS being the V = 14.
It is not harmful for milenage_gen_vec_auts() to pass two more AUTS bytes. But
writing 16 bytes to a GSUP struct is a potential problem when passing in a 14
byte long AUTS buffer to the GSUP API, which then reads past the AUTS buffer.
The API implies the length, so far to be 16, so passing in a 14 byte buffer to
GSUP would require copying to a larger buffer first.
Fix this by using a length of 14 for AUTS everywhere instead.
This constitues an ABI breakage, we may handle it as a "fix before an official
release", otherwise we need a version bump.
The OAP protocol document has also been updated, needs an update in the
osmo-gsm-manuals as well.
Change-Id: If25b173d9ec57ea4c504d860954912b7d82af455
In the process, also:
* Change the license from AGPLv3 to GPLv2-or-later;
* correct spelling of 'sysmocom' to lowercase;
* add '2016' to the copyright;
* rename to osmo_*;
* add API docs;
* add logging category DLOAP: define id and add to internal_cat;
* redirect all oap.c logging to DLOAP.
A unit test will follow in a subsequent patch, since it needs a minor tweak for
decoding of boolean values.
The related openbsc change-id is I2f06aaa6eb54eafa860cfed8e72e41d82ff1c4cf.
Tweaked-by: Neels Hofmeyr
Change-Id: If5099e60681a215e798b6675f21813f26769c253
Neels Hofmeyr
Harald Welte