(PHP 4 = 4.2.0)
Returns a positive key resource identifier on success,
or FALSE on error.
openssl_get_publickey() extracts the
public key from certificate
and prepares it for use by other functions. certificate 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.