[DERBY-6521] Improve error handling when restricting file permissions

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.11.1.1
• Fix Version/s: 10.11.1.1
• Component/s: Services
• Assignee: Knut Anders Hatlen
• Reporter: Knut Anders Hatlen
• Created: 20/Mar/14 08:36
• Updated: 13/Sep/14 00:46
• Resolved: 23/Apr/14 13:00

Description

In DERBY-6503 there was some discussion about changing how errors are handled when Derby fails to restrict the file permissions.

There seemed to be consensus that Derby should raise an exception if the user had explicitly requested (by setting derby.storage.useDefaultFilePermissions=false) that it should try to restrict file permissions. Currently, it only raises an error on non-posix file systems that support access control lists.

In the case were the user has not explicitly requested restriction of file permissions, two options have been suggested:

1) Raise an exception

2) Don't raise an exception, possibly print a warning in derby.log

Option 1 is the more secure one, since it forces the user to make a decision on how to handle a possible security problem (either by addressing the underlying cause of the failure, so that permissions can be successfully restricted by Derby, or by disabling the file restriction functionality).

Option 2 is the more backward compatible one, since it gracefully falls back to the pre-10.10/pre-Java 7 behaviour if it cannot restrict the file permissions.

Issue Links

• relates to: DERBY-6503 Starting network server on a network drive fails with JDK 7 on Windows
• relates to: DERBY-6410 ClassCastException when launching derby from windows subst drive
• relates to: DERBY-1981 copy routines in the FileUtil.java just return false on IO Exception. This leads to backup not reprting the real error in some cases.
• relates to: DERBY-5363 Tighten permissions of DB files to owner with >= JDK7