OSSP CVS Repository

Ticket 172: uuid changes behaviour under Linux when the ethernet device is'nt eth0

When uuid is run under Linux, and the ethernet device is not eth0, it silently falls back to using random multicast MAC addresses for v1 uuids. While v1 UUIDs may be conseidered insecure because they allow the generating machine to be identified, they are often useful for the same reason.

udev Linux distros link the MAC addresses with the device names, so that removable devices don't randomly change configuration, and fixed hardware doesn't depend on driver load order. This can result in a machine that has eth2, but not eth[01], for example.

This appears to affect programs that use the library as well, and not just the CLI, but that's where I discovered it so I'm reporting it as such.

Steps to reproduce: Set up a udev Linux distro (Ubuntu, Debian, etc.), then change the ethernet hardware, and run uuid.

Expected behaviour: uuid should use the new MAC address.

Actual behaviour: uuid does not identify the new ethernet address and silently used random multicast MAC addresses.

Workaround: Reconfigure udev to make the new device eth0.

Suggested fixes: 1. Discover device names, or iterate through potential ones. 2. Emit a warning if uuid expected to use a hardware address but couldn't. 3. Allow a MAC address to be specified. 4. Allow an ethernet device to be specified, either on the command line or through an environment variable.

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Properties:

Type:	new		Version:	1.6.2
Status:	new		Created:	2009-Apr-24 11:12
Severity:	4		Last Change:	2009-Apr-24 11:12
Priority:	4		Subsystem:	uuid
Assigned To:	rse		Derived From:
Creator:	anonymous