[Sls-sea-dls] Fw: Question regarding the SDLS EP Standard
Daniel.Fischer at esa.int
Daniel.Fischer at esa.int
Tue Apr 11 10:32:12 UTC 2017
Dear Ed,
Sorry for not coming back to you earlier. I think we will discuss your
recommendation in the upcoming meetings.
In my opinion the scope of the impact of the new definitions of the
GVCIDR/S is not limited to SDLS or SDLS Extended Procedures and needs to
be discussed in a wider frame.
Cheers,
Daniel
Dr. Daniel Fischer
Head of the Engineering Support Section, OPS-GES
Ground Systems Engineering Department
Directorate of Operations
ESA - ESOC
Robert-Bosch-Str. 5, D-64392 Darmstadt, Germany
Tel. +49 6151 90 2718 | E-mail: Daniel.Fischer at esa.int
From: "Greenberg, Edward (312B)" <edward.greenberg at jpl.nasa.gov>
To: Moury Gilles <Gilles.Moury at cnes.fr>, "Daniel.Fischer at esa.int"
<Daniel.Fischer at esa.int>, "sls-sea-dls at mailman.ccsds.org"
<sls-sea-dls at mailman.ccsds.org>
Cc: "Kazz, Greg J (312B)" <greg.j.kazz at jpl.nasa.gov>
Date: 11/04/2017 01:36
Subject: RE: [Sls-sea-dls] Fw: Question regarding the SDLS EP
Standard
I never had a response to my recommendation. I made this recommendation
for compatibility with AOS, proximity 1 and USLP since these protocols can
be used in both directions thus the PVN is not a discriminator. TM and
TC have a 2 bit PVN and they are both ?00?.
From: Greenberg, Edward (312B)
Sent: Friday, March 31, 2017 2:24 PM
To: 'Moury Gilles'; Daniel.Fischer at esa.int; sls-sea-dls at mailman.ccsds.org
Subject: RE: [Sls-sea-dls] Fw: Question regarding the SDLS EP Standard
The SCID identifies the Spacecraft. The SOURCE/DESTINATION FLAG
identifies the sending side or the receiving side. Thus by including the
SOURCE/DESTINATION FLAG into the GVCID/GMAPID you determine the sending
side GVCID verses the receiving side GVCID. By simply modifying the term
GVCID to GVCIDS for the sending side and GVCIDR for the receiving side you
separate the VCs by directionality which is exactly what you want.
From: SLS-SEA-DLS [mailto:sls-sea-dls-bounces at mailman.ccsds.org] On Behalf
Of Moury Gilles
Sent: Friday, March 31, 2017 2:00 AM
To: Daniel.Fischer at esa.int; sls-sea-dls at mailman.ccsds.org
Subject: Re: [Sls-sea-dls] Fw: Question regarding the SDLS EP Standard
Dear all,
My response to David?s questions would be :
Q1 : values 0 and 65535 are reserved (for master keys I understand). Text
should be modified.
Q2 : EP baseline mode relies on SDLS baseline mode. SDLS baseline mode
uses AES-GCM. In that case, the SN is replaced by the IV which is 96 bits.
Therefore, the Set ARC procedure of the EP baseline mode is actually
setting the IV. I would recommend adding this clarification in the EP
baseline mode specification and changing the length of the ?New
anti-replay counter value? field from 64 to 96 bits for consistency with
SDLS baseline mode.
Q3 : My proposal would be the following:
· For the EP baseline mode, a format is specified for the
GVCID/GMAPID field of the Start SA PDU with the following sub-fields:
o TFVN (4 bits)
o SCID (16 bits)
o VCID (6 bits)
o MAPID (6bits)
· Since we have specified TFVN sub-field length as 4 bits, we have
2 spare bits there. We could use one of them to distinguish TC from TM :
?000? would code for TC TFVN and ?100? would code for TM TFVN, while ?001?
would code for AOS and ?010? for Prox-1 (which is not covered by SDLS by
the way).
Best regards,
Gilles
Gilles MOURY
CNES Toulouse
De : SLS-SEA-DLS [mailto:sls-sea-dls-bounces at mailman.ccsds.org] De la part
de Daniel.Fischer at esa.int
Envoyé : vendredi 31 mars 2017 08:57
À : sls-sea-dls at mailman.ccsds.org
Objet : [Sls-sea-dls] Fw: Question regarding the SDLS EP Standard
Dear all,
Could ask you to take a look at the questions that David sent a while
go...some of them need answers before a red book can be produced.
My take:
Q1 is a typo and will be corrected. --> No further discussion needed
Q2: This should be the case. What do the others think? Do we need to be
explicit there?
Q3: This is a critical one and we don't have an answer at the moment. I
remember we discussed this in the WG already but I am not sure we came to
a conclusion. This needs to be clarified in the standard. Any opinions?
Cheers,
Daniel.
Dr. Daniel Fischer
Head of the Engineering Support Section, OPS-GES
Ground Systems Engineering Department
Directorate of Operations
ESA - ESOC
Robert-Bosch-Str. 5, D-64392 Darmstadt, Germany
Tel. +49 6151 90 2718 | E-mail: Daniel.Fischer at esa.int
----- Forwarded by Daniel Fischer/esoc/ESA on 31/03/2017 08:51 -----
From: David.Koisser at esa.int
To: sls-sea-dls at mailman.ccsds.org
Cc: "John P. Lucas" <John.P.Lucas at ivv.nasa.gov>
Date: 01/03/2017 11:04
Subject: [Sls-sea-dls] Question regarding the SDLS EP Standard
Sent by: "SLS-SEA-DLS" <sls-sea-dls-bounces at mailman.ccsds.org>
Dear SDLS WG members,
John and I have completed setting up the interoperability testing
environment and now we are doing a few finishing touches. Whilst doing
this a few questions arose regarding the SDLS EP standard:
1. In Section E4.2.2 (in the baseline mode description of Key Activation)
and the following key procedures, it defines the Key ID fields to have a
length of 16 bits. And then states:
"Values 0-65535 shall not be used to reference session keys."
Which would be all possible Key IDs and leave none for any session keys.
Can you clarify?
2. While we are fairly sure it is implied: Does the M&C procedure Set ARC
set the IV instead of the SN parameter in the regarding cases (e.g.
AES-GCM)?
3. The standard is not addressing how to distinguish if a GVCID is
regarding the TM or TC channels for the Start SA procedure. An example to
clarify:
A mission wants a different SA assigned on VC 0 for the uplink (e.g.
authentication only) than the VC 0 for the downlink (e.g. authenticated
encryption). To be able to set this with the Start SA procedure, it needs
a way to distinguish between the TC and TM channel mapping to SPIs. As the
GVCID is defined as:
GVCID = TFVN + SCID + VCID
And the 2 bits long TFVN may have the following values: 01 -> AOS; 10 ->
Proximity-1; 00 -> TM- *or* TC-SDLP
The GVCID alone is not enough to distinguish between TC and TM and we are
currently using a custom data structure for unambiguously identifying the
channels in the Start SA procedure.
Best Regards,
David Koisser
This message and any attachments are intended for the use of the addressee
or addressees only.
The unauthorised disclosure, use, dissemination or copying (either in
whole or in part) of its
content is not permitted.
If you received this message in error, please notify the sender and delete
it from your system.
Emails can be altered and their integrity cannot be guaranteed by the
sender.
Please consider the environment before printing this email.
_______________________________________________
SLS-SEA-DLS mailing list
SLS-SEA-DLS at mailman.ccsds.org
https://mailman.ccsds.org/cgi-bin/mailman/listinfo/sls-sea-dls
Disclaimer
This message and any attachments are intended for the use of the addressee
or addressees only. The unauthorized disclosure, use, dissemination or
copying (either in whole or in part) of its content is not permitted. If
you received this message in error, please notify the sender and delete it
from your system. Emails can be altered and their integrity cannot be
guaranteed by the sender. Please consider the environment before printing
this email.
This message and any attachments are intended for the use of the addressee
or addressees only.
The unauthorised disclosure, use, dissemination or copying (either in
whole or in part) of its
content is not permitted.
If you received this message in error, please notify the sender and delete
it from your system.
Emails can be altered and their integrity cannot be guaranteed by the
sender.
Please consider the environment before printing this email.
Disclaimer
This message and any attachments are intended for the use of the addressee
or addressees only. The unauthorized disclosure, use, dissemination or
copying (either in whole or in part) of its content is not permitted. If
you received this message in error, please notify the sender and delete it
from your system. Emails can be altered and their integrity cannot be
guaranteed by the sender. Please consider the environment before printing
this email.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.ccsds.org/pipermail/sls-sea-dls/attachments/20170411/d66f173f/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/x-pkcs7-signature
Size: 11010 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://mailman.ccsds.org/pipermail/sls-sea-dls/attachments/20170411/d66f173f/attachment.bin>
More information about the SLS-SEA-DLS
mailing list