HP LaserJet M337dw - Certificate Management Issues

Issue

When attempting to upload a certificate authority (CA) certificate, or export the printer's certificate, the printer's embedded web interface may repeatedly prompt for administrator authentication. Entering the correct username and password does not resolve the issue, and the authentication prompt continues to reappear, preventing certificate management tasks from being completed.

Cause

This behaviour can occur when an administrator password is configured on the printer. The web interface may fail to properly authenticate certificate-related operations, resulting in an endless authentication prompt loop.

Resolution

  1. Access the printer's web interface.
  2. Temporarily remove the administrator password from the printer.
  3. Perform the required certificate operation.
  4. Reapply the administrator password once the certificate task has been completed.

Certificate Requirements

If the CA certificate is provided as a DER-encoded .crt file, it must be converted to a Base64-encoded PEM format before it can be imported.

Example OpenSSL command:

openssl x509 -inform DER -in certificate.crt -out certificate.pem

Printer Certificates

Use an RSA 4096-bit encryption key for the printer's certificate. ECDSA 384-bit certificates are not supported and may fail to import.