Messages in this thread | | | Subject | Re: [PATCH 00/14] EVM | From | Mimi Zohar <> | Date | Tue, 01 Jun 2010 15:28:56 -0400 |
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On Mon, 2010-05-31 at 15:08 +0500, Shaz wrote: > > EVM is based on EA while Aegis does not use EA as far as I can > > understand from the documentation available. Can we make EVM > > independent of EA? Even the MAC mechanism is very different then > > existing LSM based mechanisms. > > Have a look at the following: > > http://research.nokia.com/files/NRCTR2008010.pdf > http://research.nokia.com/files/NRCTR2008007.pdf > http://lwn.net/Articles/372937/
SELinux, Smack, Capabilities, and IMA all use extended attributes. The purpose of EVM is to detect offline tampering of these security extended attributes.
The IMA integrity appraisal extension extends IMA with local measurement appraisal. The extension stores and maintains the file integrity measurement as an extended attribute 'security.ima', which EVM can be configured to protect. Instead of storing the hash measurement as an extended attribute, the file hashes could be loaded in kernel memory, as long as the appraise policy is appropriately constrained.
Mimi
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