Ubuntu SSL routines:tls_process_server_certificate:certificate verify failed

Issue

On CloudLinux Ubuntu servers, errors can appear when we attempt to add a template for WordPress from an archive.
The fopen function fails with the following errors:

PHP Warning: fopen(): SSL operation failed with code 1. OpenSSL Error messages:
error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed in /home/cltest/public_html/unzip2folder.php on line 53
PHP Warning: fopen(): Failed to enable crypto in /home/cltest/public_html/unzip2folder.php on line 53

The errors appear only when CageFS is enabled. With CageFS disabled, everything works as expected.

Environment

• Ubuntu
• CloudLinux
• CageFS

Solution

Add ca-certificates package to CageFS with these commands:

cagefsctl --addrpm ca-certificates
cagefsctl --force-update
cagefsctl -M

Cause

Incorrect permissions for the certificate files.

Useful links

• https://docs.cloudlinux.com/command-line_tools/#cagefs.