(PECL rnp >= 0.1.1)
rnp_key_export_autocrypt — Export minimal key for autocrypt feature (just 5 packets: key, uid, signature, encryption subkey, signature)
$ffi,$key_fp,$subkey_fp,$uid,$flags
ffikey_fpsubkey_fpuidflagsRNP_KEY_EXPORT_BASE64 is currently supported. Enabling
it would export base64-encoded key data instead of binary.
OpenPGP packets of exported key on success or false on failure.