[HBASE-14554] Investigate the server side alternative to enable dynamic jar for security purpose

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Incomplete
• Assignee: Unassigned
• Reporter: Hua Xiang
• Created: 05/Oct/15 23:20
• Updated: 01/Jul/22 21:48
• Resolved: 01/Jul/22 21:48

Description

Per HBASE-14347, from mbertozzi "for 2.x we probably want to do some changes. the DynamicLoader seems to not be needed on the client side, so we should force that to "not enabled". but on the server side we probably want that still on, to allow user filters and so on. do we have any alternative to copy local instead of forcing that "not enable" with security reason as motivation? how one is supposed to use custom filters in a "secure" environment otherwise?"
"Esteban Gutierrez in theory we are already supposed to do the "remote" load. the problem is the code that copies those "remote" locally. I think that was done because it was the easy way to load the class form remote since you have the friendly API that loads the class by using addUrl() where url is expected to be something that java understand and hdfs is not.
Looking at the classLoader API there is a defineClass() that takes an array of bytes. In theory we can leverage that to open the hdfs stream (the jar we want to load) and add the class to our class loader and avoid the copy-to-local step. In that way we can get even rid of the tmp dir.
https://docs.oracle.com/javase/7/docs/api/java/security/SecureClassLoader.html#defineClass(java.lang.String,%20byte[],%20int,%20int,%20java.security.CodeSource)
I'll let huaxiang sun look into that, if it is something possible or not."

Issue Links

• relates to: HBASE-14347 Add a switch to DynamicClassLoader to disable it