Subject: Re: exporting -ro nfs
To: Bill Studenmund <>
From: Jason Thorpe <>
List: tech-security
Date: 01/29/2007 15:38:28
On Jan 29, 2007, at 9:47 AM, Bill Studenmund wrote:

> The idea would be to 1) add some sort of long-term key that is  
> passed in
> with each export. Something that is stable across boots. 2) add  
> space in
> the file handle to indicate which export point a file handle came  
> from,
> and 3) add some sort of authentication so that we can tell if it's  
> likely
> the file handle has not been tampered with. The thought is to do  
> something
> so that it's harder to forge file handles.

I've long thought that our "file system ID" in NFS file handles ought  
to be a UUID, but even better, you could expand that to "export point  
ID" and have something like:

	128-bit UUID
	64-bit persistent object ID

For UFS, that persistent object ID could be:

	inode number
	generation number

So, if you have enough room in the NFS file handle, it would be quite  
easy to do this.

-- thorpej