We hardcoded a list of known PKCS #9 attributes inside JDK so that getValue() method can always return the correct type for one (say, String for string, ObjectIdentifier for OID). However, this means when an unknown attribute is met, an exception is thrown. It's not easy to list all attributes inside there and sometimes it's not necessary to get the actual type of an attribute unless we really need to deal with it inside the JDK.
Date: 2013-04-23 16:55:28 +0000
provided test:test/sun/security/pkcs/pkcs9/UnknownAttribute.java have passed from b86 - b95 at all platform at 1.8
This was discovered when trying to solve JDK-8009636. A TSA server sends back a PKCS #9 structure with two unknown attributes.