The certificate is not RFC 5280 compliant.

[Theitdude]

We are trying to add a certificate to out printer so that I can be connected to our radius server. When we go import the certificate. We get "The certificate is not RFC 5280 compliant."  It is LaserJet Pro MFP m428 fdw.  New to this whole certificate thing any steps would be helpful. The printer is on the lasted Firmware and has now been restored to factory setting in case there was setting set somewhere. Any help would be great.  Thanks

[Anderson_CR]

Good Afternoon,

Hope you are well, please try the following, access the Embedded web server, then please go to Network tab > security > certificates > use the import button under Certificate Authority (CA) Certificate.

As well, please click on Management Protocol and make sure if the SSL / TLS version that are checked matched with the one supported in your server.

If further assistance is required, please contact HP Support. 

Regards, 

[DATAndrews]

I had the same error message on the same printer. The solution was to include the chain of certificates in the PEM file. You'll need to find out who signed the certificate you want to install, then get the certificate from that signer, and then put them both in the same file, in order of authority:

-----BEGIN CERTIFICATE-----

... data from signer of certificate below ...

-----END CERTIFICATE-----

-----BEGIN CERTIFICATE-----

... certificate that you really wanted to install ...

-----END CERTIFICATE-----

It worked for me, and I hope it does for you. I have no idea what to do if the cert you're trying to install is self-signed.