(PHP 4 >= 4.2.0, PHP 5)openssl_csr_sign -- Sign a CSR with another certificate (or itself) and generate a certificate
openssl_csr_sign() generates an x509 certificate resource from the csr previously generated by openssl_csr_new(), but it can also be the path to a PEM encoded CSR when specified as file://path/to/csr or an exported string generated by openssl_csr_export(). The generated certificate will be signed by cacert. If cacert is NULL, the generated certificate will be a self-signed certificate. priv_key is the private key that corresponds to cacert. days specifies the length of time for which the generated certificate will be valid, in days. You can finetune the CSR signing by configargs. See openssl_csr_new() for more information about configargs. Since PHP 4.3.3 you can specify the serial number of issued certificate by serial. In earlier versions, it was always 0.
Returns an x509 certificate resource on success, FALSE on failure.
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.
Example 1. openssl_csr_sign() example - signing a CSR (how to implement your own CA)