Create a new certificate authority with the given options.

Create a new certificate, either self-signed (if ca is nil) or signed by the certificate authority with the given options.

Import certificate from byte stream.

Set certificate expiry.

Set host or IP address restrictions.

Set private key type.

Set Serial number.

Set X509 name.

Create a new serial number for the certificate, or nil if there was an error.

Cert represents a certificate with a private key which can be used for signing other certificates.