path: root/certs/Kconfig
diff options
authorDavid Howells <>2017-04-03 16:07:24 +0100
committerDavid Howells <>2017-04-03 16:07:24 +0100
commit734114f8782f6c3398762f2353fe9101d87b6d06 (patch)
treee16e165dc33f7d1becfcb1f5d79c90e0e3c4e248 /certs/Kconfig
parentddb99e118e37f324a4be65a411bb60ae62795cf9 (diff)
KEYS: Add a system blacklist keyring
Add the following: (1) A new system keyring that is used to store information about blacklisted certificates and signatures. (2) A new key type (called 'blacklist') that is used to store a blacklisted hash in its description as a hex string. The key accepts no payload. (3) The ability to configure a list of blacklisted hashes into the kernel at build time. This is done by setting CONFIG_SYSTEM_BLACKLIST_HASH_LIST to the filename of a list of hashes that are in the form: "<hash>", "<hash>", ..., "<hash>" where each <hash> is a hex string representation of the hash and must include all necessary leading zeros to pad the hash to the right size. The above are enabled with CONFIG_SYSTEM_BLACKLIST_KEYRING. Once the kernel is booted, the blacklist keyring can be listed: root@andromeda ~]# keyctl show %:.blacklist Keyring 723359729 ---lswrv 0 0 keyring: .blacklist 676257228 ---lswrv 0 0 \_ blacklist: 123412341234c55c1dcc601ab8e172917706aa32fb5eaf826813547fdf02dd46 The blacklist cannot currently be modified by userspace, but it will be possible to load it, for example, from the UEFI blacklist database. A later commit will make it possible to load blacklisted asymmetric keys in here too. Signed-off-by: David Howells <>
Diffstat (limited to 'certs/Kconfig')
1 files changed, 18 insertions, 0 deletions
diff --git a/certs/Kconfig b/certs/Kconfig
index fc5955f..6ce51ed 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -64,4 +64,22 @@ config SECONDARY_TRUSTED_KEYRING
those keys are not blacklisted and are vouched for by a key built
into the kernel or already in the secondary trusted keyring.
+ bool "Provide system-wide ring of blacklisted keys"
+ depends on KEYS
+ help
+ Provide a system keyring to which blacklisted keys can be added.
+ Keys in the keyring are considered entirely untrusted. Keys in this
+ keyring are used by the module signature checking to reject loading
+ of modules signed with a blacklisted key.
+ string "Hashes to be preloaded into the system blacklist keyring"
+ help
+ If set, this option should be the filename of a list of hashes in the
+ form "<hash>", "<hash>", ... . This will be included into a C
+ wrapper to incorporate the list into the kernel. Each <hash> should
+ be a string of hex digits.
OpenPOWER on IntegriCloud