i have a problem with my OfficeJet Pro 8710 All-in-One, but i believe the problem is exactly the same with all similar HP printers.
I want to use a LetsEncrypt certificate to secure the Embedded Web Server on my printer via HTTPS.
The Certificate Signing Request (CSR) i can generate on the printer directly uses 3 as exponent.
LetsEncrypt enforces the exponent to be odd and greater than 65536, so i can't use this CSR.
Therefore i generated a RSA key and a CSR on my computer and got a certificate from LetsEncrypt.
Now i try to install this cert and private key on my printer.
The printer only accepts PKCS#12 file format.
I'm failing to get the printer use my LetsEncrypt certificate and also include the LetsEncrypt Intermediate Cert in the certificate chain. It uses the correct certificate, but doesn't include the intermediate cert in the chain, so my browser can't build the chain up to the LetsEncrypt Root Cert and fails on validiating the connection.
Is there something i do wrong or an alternative to what i did above?
Does anyone have a working setup with LetsEncrypt certificates?