in order to work around a bug in asn1c. When we keep the original
TBCD-STRING, the APER-encoded PLMNidentity always has an extra leading
length byte that the decoder doesn't expect.
When IMSI is a TBCD-STRING type, and TBCD-STRING is defined as OCTET
STRING, we end up encoding the IMSI the wrong way. I don't knwo why
that is, but changing it fixed the problem, as described below:
before this commit:
00 17 PeranentNAS-UE-ID
40 criticality ignore
0a (length)
00 presence = IMSI
08 BUG: why the additional length field?
46 23 91 34 70 77 80 f3 IMSI (643219430777083)
after this commit:
00 17 PeranentNAS-UE-ID
40 criticality ignore
09 (length)
50 presence = IMSI
46 23 91 34 70 77 80 f3 IMSI (643219430777083)
The definition of the above data types as per 3GPP specs results in a
SEQUENCE_OF() an anonymous structure, which is slightly inconvenient to
use. So let's split the SEQUENCE OF part and the actual definition of
the item in separate types.
If we avoid using Information Object Classes in the IE definitions
(which are only used for Extension Containers), then we can compile the
ASN.1 source using Lev Walkin's asn1c.
Harald Welte