Ciphered xDLMS PDU

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By Shaswat , 9 December, 2014

Good Day!

I just start working on DLMS protocol for my 3 phase energy meter. I want to know that how Ciphered xDLMS APDU's works. I don't understand how security header and encrypted parts works. What value should I assign into it.

I was also trying to understand using example provided into DLMS website, but get no success. I also tried to find out in excerpt Green book but still stuck in there.

Can you please give me some brief explanation how to take care of this with example?

Any new idea would be really appreciated...

Thanks in advance

Kurumi

11 years 6 months ago

Hi,

Just to make sure:

1. What programming language you want to use?

2. What High Level Authentication you want to use?

BR,

Mikko

Hi,

Currently, I am using C programming language. For the sake of simplicity, I want to use Lowest Level Authentication. I read the "Data Access Security" , "Data Transport Security" and "Ciphered xDLMS APDU" (Fig. 64 Green Book Ed. 7) section but still not understand how to encode the message , how to use security header bits and encrypted xDLMS APDU. What values to assign them.

Kurumi

11 years 5 months ago

Hi,

You must implement GMAC crypter. If you get source codes from C# you can get a clue how to start. DLMS/COSEM is quite complicated protocol. :-(

It's too hard to explain structure of APDU.
You can send me an email and we can talk more
if you want us to help you more in this case.

BR,

Mikko

pardeepk3264

6 years 6 months ago

I just start working on DLMS protocol for my 1-phase energy meter. I want to know that how Ciphered DLMS APDU's works.

Can you please give me some brief explanation in C Language, how to get or set METER RTC using Ciphering with 32 or 48 Association ?

Kurumi

6 years 6 months ago

Hi PARDEEP ,

Please, if you have a new question, create a new topic.

I believe that the best way to start is if you download GXDLMSDirector and play with that.
Try first without ciphering. It makes things easier.

If you want to use ciphering you need to set system title, authentication key, and block cipher key.
You find this information from "Secured connections" tab.
BR,
Mikko

pardeepk3264

6 years 5 months ago

BE 34 04 32 21
30 //length
30 //sc-ae
00 00 00 03 //ic inovation counter

00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 //apdu
93 E5 23 2C E1 54 85 A3 68 39 58 CE

17 : 25 : 30 METER-1 COSEM OUT DATA - CIPHERED
17 : 25 : 30 ====>Tx METER-1 60 63 A1 09 06 07 60 85 74 05 08 01 03 A6 0A 04 08 41 4D 45 30 30 30 30 30 8A 02 07 80 8B 07 60 85 74 05 08 02 01 AC 07
80 05 48 65 6C 6C 6F BE 34 04 32 21 30 30 00 00 00 03
92 F8 7C 7E 36 F0 5B 2A 8B BB BA 13 79 8C 15 EA AE 7C D0 D9 EE 02 7D F7 DD 63 A5 F4 38 6B 33
93 E5 23 2C E1 54 85 A3 68 39 58 CE

PLEASE HELP ME TO HOW CONVERT THE APDU DATA IN TO CIPHERTEXT{00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 //apdu} AND HOW CALCULATE A AUTHENTICATION TAG {93 E5 23 2C E1 54 85 A3 68 39 58 CE}