[srslte-users] srsLTE Encryption

[David Rupprecht]

Hi Melvin,

against my initial assumption, I just noticed that there is decryption /
encryption functionality included within the MME. For testing purpose
you can include the decryption function "srslte::security_128_eea1" in
https://github.com/srsLTE/srsLTE/blob/master/srsepc/src/mme/s1ap_nas_transport.cc#L266
and call the  liblte_mme_parse_msg_header((LIBLTE_BYTE_MSG_STRUCT *)
nas_msg, &pd, &msg_type) function again.

I'm busy this week, but I can help you with including the
decrpytion/encryption function at the weekend.

Best regards,
David

On 12.11.18 04:37, #LIM HENG LI MELVIN# wrote:
> Hi David,
> 
> 
> I think I might have found the problem. I was comparing the ue's
> nas.pcap, the enb's enb.pcap, and the msg_type variable in
> s1ap_nas_transport.cc.
> 
> It seems that "msg_type" is still encrypted when processed
> here: https://github.com/srsLTE/srsLTE/blob/master/srsepc/src/mme/s1ap_nas_transport.cc#L201
> 
> <https://github.com/srsLTE/srsLTE/blob/master/srsepc/src/mme/s1ap_nas_transport.cc#L201>
> 	
> srsLTE/srsLTE
> <https://github.com/srsLTE/srsLTE/blob/master/srsepc/src/mme/s1ap_nas_transport.cc#L201>
> github.com
> Open source SDR LTE software suite . Contribute to srsLTE/srsLTE
> development by creating an account on GitHub.
> 
> Hence, when the program reaches the if-else statements below, the epc
> doesn't handle msg_type correctly because it is still encrypted.
> 
> Do you know who should I contact for this fix?
> 
> Thanks.
> 
> 
> Regards,
> Melvin.
> 
> 
> ------------------------------------------------------------------------
> *From:* David Rupprecht <david.rupprecht at rub.de>
> *Sent:* Friday, November 9, 2018 5:05:12 PM
> *To:* #LIM HENG LI MELVIN#
> *Subject:* Re: [srslte-users] srsLTE Encryption
>  
> Hi Melvin,
> 
> for enabling PDCP encryption you can change the line:
> 
> https://github.com/srsLTE/srsLTE/blob/master/srsenb/src/upper/rrc.cc#L1142
> 
> for enabling NAS encryption you can change the line:
> 
> https://github.com/srsLTE/srsLTE/blob/master/srsepc/src/mme/s1ap_nas_transport.cc#L1611
> 
> and
> 
> https://github.com/srsLTE/srsLTE/blob/master/srsepc/src/mme/s1ap_nas_transport.cc#L1642
> 
> I did not tried it myself. Please let me know if it worked.
> 
> Best regards,
> David
> 
> On 09.11.18 01:15, #LIM HENG LI MELVIN# wrote:
>> Hello Everyone,
>> 
>> 
>> I am trying to use encryption, i.e. EEA1 or EEA2, for over the air
>> communications between a srsUE and a srseNB+srsEPC. However, I can't
>> seem to get it working correctly. EEA0 is always the default choice.
>> 
>> 
>> Is enabling encryption just a simple configuration (maybe in some config
>> files) or does the aforementioned srsLTE setup not support encryption
>> inherently and requires some programming efforts to get it working?
>> 
>> 
>> Thanks.
>> 
>> 
>> Regards,
>> Melvin.
>> 
>> 
>> **Disclaimer** The sender of this email does not represent Nanyang
>> Technological University and this email does not express the views or
>> opinions of the University.
>> 
>> _______________________________________________
>> srslte-users mailing list
>> srslte-users at lists.softwareradiosystems.com
>> http://www.softwareradiosystems.com/mailman/listinfo/srslte-users
>> 
> 
> -- 
> M.Sc. David Rupprecht
> 
> Ruhr-University Bochum
> Research Group Information Security
> Universitätsstraße 150
> ID 2/130
> 44780 Bochum / Germany
> 
> Phone: +49 234 / 32 - 23508
> Web: www.infsec.rub.de <http://www.infsec.rub.de>
> **Disclaimer** The sender of this email does not represent Nanyang
> Technological University and this email does not express the views or
> opinions of the University.

-- 
M.Sc. David Rupprecht

Ruhr-University Bochum
Research Group Information Security
Universitätsstraße 150
ID 2/130
44780 Bochum / Germany

Phone: +49 234 / 32 - 23508
Web: www.infsec.rub.de