gnupg: Dirmngr CACHECERT

 
 3.6.5 Put a certificate into the internal cache
 -----------------------------------------------
 
 Put a certificate into the internal cache.  This command might be useful
 if a client knows in advance certificates required for a test and wants
 to make sure they get added to the internal cache.  It is also helpful
 for debugging.  To get the actual certificate, this command immediately
 inquires it using
 
        S: INQUIRE TARGETCERT
        C: D <DER encoded certificate>
        C: END
 
    Thus the caller is expected to return the certificate for the request
 as a binary blob.
 
 The return code is 0 for success; i.e.  the certificate has not been
 successfully cached or one of the usual error codes from libgpg-error.