The certificate to download the issuer certificate for, can be a PEM encoded string, X509Certificate object, pkijs.Certificate or the raw certificate as Buffer or ArrayBuffer
Optional
timeout: numberOptional timeout in milliseconds for the request. Default is 6000ms
A pkijs.Certificate object of the issuer certificate
Function to download and parse the certificate of the issuer of a certificate This function is used internally to download the issuer certificate if it is not provided in the config Its exported for convenience if you want to download the issuer certificate manually for some reason