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@bbockelm commented on this pull request.



> @@ -2229,9 +2246,18 @@ int XrdOfs::rename(const char             *old_name,  // In
 
 // Apply security, as needed
 //
-   AUTHORIZE2(client, einfo,
-              AOP_Rename, "renaming",    old_name, &old_Env,
-              AOP_Insert, "renaming to", new_name, &new_Env );
+   // Make a copy of the XrdSecEntity object xattrs as the authorization below may change it.
+   AUTHORIZE(client, &old_Env, AOP_Rename, "renaming", old_name, einfo);
+   if (client) client->eaAPI->Add("request.name", "", true);

Added a comment along these lines.

It's actually a fairly important thing to fix and points out that there's a small security issue with the existing `AUTHORIZE2` macro.

Basically, starting in XRootD 5, authorization checks now have side-effects, mutating the object if they succeed.  In my testing, I realized that the outcome of the `AOP_Rename` check added this extended attribute, giving the privilege to the `XrdSecEntity` that caused the `AOP_Insert` check to succeed where it would have otherwise failed.

That is, depending on the ordering of the `AUTHORIZE` checks, the client may-or-may-not have permissions to perform the rename -- an obviously silly setup.

Now, really cleaning this up would require a copy constructor for the `XrdSecEntity`.  That was a fairly big undertaking so I decided to take this smaller change - ensure the known extended attribute that might get mutated as a side-effect of the authorization check is reset to a harmless state.

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