Add vty 'encryption uea 0 1 2', defaults to 'encryption uea 0' to yield
previous behavior.
If any UEA above 0 is enabled, include the UEA key in the Iu Security
Mode Command.
I noticed that only the code bit in st_iu_security_cmd_on_enter()
affects the test. The same code in gsm48_gmm_authorize() seems to be
dead code? But applying the patch there as well just to be safe.
We cannot yet verify the chosen UEA to match a configured UEA level,
because the iu_client.c does not send us message details with the
RANAP_IU_EVENT_SECURITY_MODE_COMPLETE.
Also we cannot yet send the set of configured UEA to the hNodeB, since,
again, iu_client.c does not provide the proper API for it.
The proper solution here is to completely dissolve iu_client.c and do
all Iu handling in osmo-sgsn itself -- see OS#5487.
Related: SYS#5516
Related: I1a7c3b156830058c43f15f55883ea301d2d01d5f (osmo-ttcn3-hacks)
Change-Id: I27e8e0078c45426bf227bb44aac82a4875d18d0f
Neels Hofmeyr
3c7656a481