From 734114f8782f6c3398762f2353fe9101d87b6d06 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 3 Apr 2017 16:07:24 +0100 Subject: 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: "", "", ..., "" where each 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 --- certs/Kconfig | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'certs/Kconfig') 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. +config SYSTEM_BLACKLIST_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. + +config SYSTEM_BLACKLIST_HASH_LIST + string "Hashes to be preloaded into the system blacklist keyring" + depends on SYSTEM_BLACKLIST_KEYRING + help + If set, this option should be the filename of a list of hashes in the + form "", "", ... . This will be included into a C + wrapper to incorporate the list into the kernel. Each should + be a string of hex digits. + endmenu -- cgit v1.1