Description
resource 
openssl_pkey_get_private ( mixed key [, string passphrase] )
     Returns a positive key resource identifier on success, or FALSE on error.
    
     openssl_get_privatekey() parses 
     key and prepares it for use by other functions.
     key can be one of the following:
     
- a string having the format
        file://path/to/file.pem. The named file must
        contain a PEM encoded certificate/private key (it may contain both).
        
- A PEM formatted private key. 
     The optional parameter passphrase must be used if
     the specified key is encrypted (protected by a passphrase).