Secured connection using keys that are more than 16 bytes hex

By adryan , 1 November, 2023
Forums
DLMSDirector

Hi!

I'm trying to connect to my meter to Gurux DLMS Director using secured connections. I have the system title and the keys but the keys are 24 bytes long not 16. So I couldn't enter my Auth Key and Block Cipher Key. and received error "Invalid authentication key" or "Invalid block cipher key".

Auth Key: 212DD693E9B4D075173266774F164CE9E3E1FC9FD5E00988
Block Cipher Key is same.

Is there anything I could try to connect to my meter?
Really need help for this.
Thank you.

Kurumi

2 years 7 months ago

Hi,

DLMS standard says that the Block cipher and authentication keys size is 16 bytes (AES-GCM-128) for Security Suite 0 and 1. Security Suite 2 (AES-GCM-256) uses 32 bytes long keys.

Check your keys or then your meter is not a DLMS meter.

BR,
Mikko

adryan

2 years 6 months ago

Hi!

Thanks for the answer. I contacted the person and told me that the key was encrypted. I got the decrypted one with 16bytes long. Everything works well now.

Kurumi

2 years 6 months ago

Hi,

Ciphering can be hard because there are so many different parameters. I'm glad that you can read your meter.

BR,
Mikko