[HP-Binding] No Connection SSL Error?

Add-ons Bindings
1

Hi,

just tried the HP Printer Binding. Have got two printers, the newer one is a Color Laserjet M553.

I created the thing file, interesting: I had to add some additional routes in the firewall.

After that, instead of coming online, the Thing gives error:

javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

But no errors in log.

2

I assume this is because of a self signed certificate of the printer.
One other example of the same problem is in this thread: HP printer M554 binding error (handshake failure from javax.net.ssl) .
Was solved there by using a different binding ( snmp ).

3

Thank you. I found that post, but this raises the question about the hp binding…

I don’t believe there are much openHAB users creating official certificates for their printer instead using default (hp comes directly with self signed certificates)

4

Did you try to turn off the SSL flag?

5

Didn’t found it in documentation. Will look for it later.

6

it looks like this option was available in earlier versions but not in OH3/OH4 versions.

7

Hm, then there is no solution?

8

As long as it is related to the certificate you can try to import it into the openhab java keystore or ‘relax’ the security on OH application level by adding a java option - from security point of view this isn’t a good idea.

9

Import to the keystone sounds good. Will google how to do on Ubuntu. Thanks for the hint

10

Well, I exported the cer-File from Administration area of the printer, after that imported it to /var/lib/openhab/etc/keystore with

 keytool -importcert -file /ExportedCertificate_2_22_2024.cer -keystore keystore -alias "HP"

But printer still shows error:

javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

EDIT: After restart openhab sometimes I got:

javax.net.ssl.SSLHandshakeException: No subject alternative names present
11

I think I previously used the wrong buzz word.
Instead of keystore I should have written java trust store or java cert store.
This one is stored in a lib directory in your java installation.

E.g.
/opt/jdk/zulu11.50.19-ca-jdk11.0.12-linux_aarch32hf/lib/security/cacerts or
/usr/lib/jvm/java-11-openjdk-amd64/lib/security/cacerts

12

Those are linked to / etc/ssl/certs/java where I added the certificates too. :confused:

Still

javax.net.ssl.SSLHandshakeException: No subject alternative names present

13

Which name of the printer ( just hostname or FQDN ? )is stored in the certificate and which name ( hostname, FQDN, IP ) do you use in the binding ?
Does it work if you use the same name ?

14

Not until yet! But can try. Will it be important to to give same alias in keystore?

Name is HP-LJ-M553.OWNDOMAIN.de in Printer.
IP is local one 10.10.10.112
Certificate is created for HP-LJ-M553.OWNDOMAIN.de

Tried with Name (label) in openhab of HP-LJ-M553.OWNDOMAIN.de

Still same issue

Tried reimported with different aliases and also mit SAN=HP-LJ-M553.OWNDOMAIN.de

No success