(PECL rnp >= 0.1.1)
rnp_supported_features — Get supported features in JSON format
$type
): string|falseGet the JSON formatted string containing array of supported rnp feature values (algorithms, curves, etc) by type.
type
See RNP_FEATURE_* constants for supported values.
String containing JSON formatted array of supported algorithms, curves, etc 或者在失败时返回 false
.