resource openssl_csr_sign ( mixed $csr , mixed $cacert , mixed $priv_key , int $days [, array $configargs [, int $serial = 0 ]] )
openssl_csr_sign() generates an x509 certificate resource from the given CSR. Note: You need to have a valid openssl.cnf installed for this function to operate correctly. See the notes under the installation section for more information.
Returns an x509 certificate resource on success, FALSE on failure.