Convert .cer to .crt certificates for Apache/mod_ssl using OpenSSL

Assume you have a CER is an DER encoded X.509 certificate in binary form, and you want to have a PEM-encoded X.509 Certificate file for Apache.

The following command may help:

 

Apache/mod_ssl request PEM-encoded X.509 Certificate file

Reference: http://www.modssl.org/docs/2.8/ssl_reference.html#ToC10