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Bug #3842

inter-BSC Handover doesn't work with Ciphering enabled

Added by neels about 2 years ago. Updated almost 2 years ago.

Status:
Resolved
Priority:
High
Assignee:
Category:
-
Target version:
-
Start date:
03/15/2019
Due date:
% Done:

100%

Spec Reference:

Description

Decoding of the BSSMAP Handover Request from the MSC omits the Chosen Encryption Algorithm,
which is crucial for establishing the new lchan with identical encryption as the old lchan.

For intra-BSC handover, the previous encryption is copied from the old lchan, which of course is not available during inter-BSC handover.
Hence the lchan activation info needs to include an explicit encryption information,
and we must not rely on the presence of the previous lchan to copy encryption information from.

Associated revisions

Revision 58cf1b1f (diff)
Added by Neels Hofmeyr about 2 years ago

lchan activation: add explicit encryption info to activation

For intra-BSC handover, the previous encryption is copied from the old lchan,
which of course is not available during inter-BSC handover. Hence the lchan
activation info needs to include an explicit encryption information, and we
must not rely on the presence of the previous lchan to copy encryption
information from.

Add struct lchan_activate_info.encr to allow passing encryption info through
lchan_activate() without requiring a previous struct gsm_lchan to be present.

Instead of copying from the old lchan, always copy encryption info to
lchan_activate_info, and during activation, just before sending the Channel
Activation, copy the lchan_activate_info.encr to the new lchan.

This prepares for upcoming I5b269f50bd2092516bfdf87746196983d3ac49d1 which
obtains the encryption information from an intra-BSC-incoming Handover Request
message.

Related: OS#3842
Related: I5b269f50bd2092516bfdf87746196983d3ac49d1
Change-Id: Ib3d259a5711add65ab7298bfa3977855a17a1642

History

#1 Updated by neels almost 2 years ago

  • Status changed from In Progress to Resolved
  • % Done changed from 0 to 100

fixed since
commit c15f6cd640bef63d8d52eaf4a187645ca95d0765
"Handover Request: also parse Chosen Algorithm IE, pass to lchan activation"
Change-Id: I5b269f50bd2092516bfdf87746196983d3ac49d1

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