Extract public key from certificate and prepare it for use.
Returns a positive key resource identifier on success, or False
pkey_get_public extracts the public key from certificate
and prepares it for use by other functions. certificate
can be one of the following:
an X.509 certificate resource
a string having the format file://path/to/file.pem.
The named file must contain a PEM encoded certificate/private key (it may
A PEM formatted private key.