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authorAnton Vorontsov <cbouatmailru@gmail.com>2012-01-04 00:09:35 -0500
committerAnton Vorontsov <cbouatmailru@gmail.com>2012-01-04 00:09:35 -0500
commit251f39fe42dae863bd24e30864e6b66076ba076d (patch)
treec804944bc17f3836d19cc8b5bc611dd1fb0ea915 /Documentation/ABI/testing/evm
parent9b8872273af6983b246252a6508fa7cf34c69d6e (diff)
parent35b4c01e29bdd9632dabf9784ed3486333f00427 (diff)
Merge branch 'power-supply-scope' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen
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1What: security/evm
2Date: March 2011
3Contact: Mimi Zohar <zohar@us.ibm.com>
4Description:
5 EVM protects a file's security extended attributes(xattrs)
6 against integrity attacks. The initial method maintains an
7 HMAC-sha1 value across the extended attributes, storing the
8 value as the extended attribute 'security.evm'.
9
10 EVM depends on the Kernel Key Retention System to provide it
11 with a trusted/encrypted key for the HMAC-sha1 operation.
12 The key is loaded onto the root's keyring using keyctl. Until
13 EVM receives notification that the key has been successfully
14 loaded onto the keyring (echo 1 > <securityfs>/evm), EVM
15 can not create or validate the 'security.evm' xattr, but
16 returns INTEGRITY_UNKNOWN. Loading the key and signaling EVM
17 should be done as early as possible. Normally this is done
18 in the initramfs, which has already been measured as part
19 of the trusted boot. For more information on creating and
20 loading existing trusted/encrypted keys, refer to:
21 Documentation/keys-trusted-encrypted.txt. (A sample dracut
22 patch, which loads the trusted/encrypted key and enables
23 EVM, is available from http://linux-ima.sourceforge.net/#EVM.)