[PATCH] certs: select PKCS7_MESSAGE_PARSER if needed

[PATCH] certs: select PKCS7_MESSAGE_PARSER if needed

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

When CONFIG_SYSTEM_BLACKLIST_KEYRING and CONFIG_INTEGRITY_PLATFORM_KEYRING
are both enabled, the system blacklist tries calling the
pkcs7_validate_trust() function, causing a link failure if the driver
that defines it is disabled or a loadable module:

ld.lld: error: undefined symbol: pkcs7_validate_trust
>>> referenced by blacklist.c
>>>               blacklist.o:(is_key_on_revocation_list) in archive certs/built-in.a

Add a Kconfig 'select' statement for this specific case that force-
enables the pkcs7 code as well.

Fixes: 30fdba3f40fd ("certs: Add EFI_CERT_X509_GUID support for dbx entries")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 certs/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/certs/Kconfig b/certs/Kconfig
index 379a6e198459..21192bb25c79 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -68,6 +68,7 @@ config SECONDARY_TRUSTED_KEYRING
 config SYSTEM_BLACKLIST_KEYRING
 	bool "Provide system-wide ring of blacklisted keys"
 	depends on KEYS
+	select PKCS7_MESSAGE_PARSER if INTEGRITY_PLATFORM_KEYRING
 	help
 	  Provide a system keyring to which blacklisted keys can be added.
 	  Keys in the keyring are considered entirely untrusted.  Keys in this
-- 
2.29.2

Re: [PATCH] certs: select PKCS7_MESSAGE_PARSER if needed

[David Howells]

Arnd Bergmann <arnd@kernel.org> wrote:

> +	select PKCS7_MESSAGE_PARSER if INTEGRITY_PLATFORM_KEYRING

I think a better way to do it is to add a separate config option for dealing
with revocation certs, which is part of what I suggested here:

	https://lore.kernel.org/keyrings/3731128.1614163916@warthog.procyon.org.uk/

David

Re: [PATCH] certs: select PKCS7_MESSAGE_PARSER if needed

[Arnd Bergmann]

On Thu, Feb 25, 2021 at 3:12 PM David Howells <dhowells@redhat.com> wrote:
>
> Arnd Bergmann <arnd@kernel.org> wrote:
>
> > +     select PKCS7_MESSAGE_PARSER if INTEGRITY_PLATFORM_KEYRING
>
> I think a better way to do it is to add a separate config option for dealing
> with revocation certs, which is part of what I suggested here:
>
>         https://lore.kernel.org/keyrings/3731128.1614163916@warthog.procyon.org.uk/

Ok, sounds good. Can this make it into v5.12 though, or do we need an
intermediate
fix to avoid the build failure?

        Arnd