Issue DKIM public key longer than 255 chars

[Ingesi]

Server operating system version

Ubuntu 22.04.3 LTS

Plesk version and microupdate number

18.0.57 Update #5

Hi all

I've migrated a domain from a server (Ubuntu 22.04.3 LTS) with Plesk Obsidian 18.0.57 to a new server (Ubuntu 22.04.3 LTS) with the same version of Plesk Obsidian 18.0.57
On the old server plesk was creating DKIM keys with default length (2048); the DKIM public key was long about 200 chars and all it was working good
On the new server with the same key length (2048) the generated record with the public key is long about 400 chars; when I try to copy the key on the DNS zone editor provided by the domain name maintainer the key is truncated at 255 chars, and this is normal because DNS records should be shorter then 255 chars
I tried to modify the DKIM key length in the panel.ini to 1024, then I've disabled andre-enabled DKIM for the domain to generate new keys, but the public keys was always longer than 255 chars
How can I have plesk generating shorter keys as in the old server?
If you need more details please let me know
Kind regards
Alessandro Barisone

 

[Peter Debik]

2048 bit keys cannot be stored in a single DNS record. Instead a second record must be used. Have you checked whether a second record exists in your DNS?

 

[Ingesi]

The control panel of the maintainer (OVH) allows to paste keys longer than 255 chars; but when I do a nslookup I got the entire key with a space after the 255 char. If you want to check, try nslookup -q=txt default._domainkey.ingesi.it
I opened a ticket and they replied that domain records should be shorter than 255 chars and they can't handle an out of standard record
How can I split correctly they key in two different records?
Anyway, I'm 100% sure that on the previous server I'm using 2048 bit keys and the keys are shorter than 255 chars
If you want you can do nslookup -q=txt default._domainkey.ingesi.it server7.ingesi.it , Bind on Plesk replies with a key shorter, while in panel.ini the key length is set to the defaut value
Thank you
Kind regards
Alessandro Barisone

 

[Kaspar]

You can use this tool to help you split DKIM DNS record in to multiple records.

 

[Peter Debik]

Anyway, I'm 100% sure that on the previous server I'm using 2048 bit keys and the keys are shorter than 255 chars

The 2048 bit keys may never have been active. For example if you only changed the configuration but did not recreate keys, the existing keys would not have been changed.