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+What:           security/evm
+Date:           March 2011
+Contact:        Mimi Zohar <zohar@us.ibm.com>
+Description:
+                EVM protects a file's security extended attributes(xattrs)
+                against integrity attacks. The initial method maintains an
+                HMAC-sha1 value across the extended attributes, storing the
+                value as the extended attribute 'security.evm'.
+
+                EVM depends on the Kernel Key Retention System to provide it
+                with a trusted/encrypted key for the HMAC-sha1 operation.
+                The key is loaded onto the root's keyring using keyctl.  Until
+                EVM receives notification that the key has been successfully
+                loaded onto the keyring (echo 1 > <securityfs>/evm), EVM
+                can not create or validate the 'security.evm' xattr, but
+                returns INTEGRITY_UNKNOWN.  Loading the key and signaling EVM
+                should be done as early as possible.  Normally this is done
+                in the initramfs, which has already been measured as part
+                of the trusted boot.  For more information on creating and
+                loading existing trusted/encrypted keys, refer to:
+                Documentation/keys-trusted-encrypted.txt.  (A sample dracut
+                patch, which loads the trusted/encrypted key and enables
+                EVM, is available from http://linux-ima.sourceforge.net/#EVM.)