From: Eric Snowberg <eric.snowberg@oracle.com>
To: jarkko@kernel.org, zohar@linux.ibm.com, dhowells@redhat.com,
dwmw2@infradead.org
Cc: mic@linux.microsoft.com, eric.snowberg@oracle.com,
kanth.ghatraju@oracle.com, konrad.wilk@oracle.com,
linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] certs: Restrict blacklist updates to the secondary trusted keyring
Date: Fri, 8 Sep 2023 17:34:28 -0400 [thread overview]
Message-ID: <20230908213428.731513-1-eric.snowberg@oracle.com> (raw)
Currently root can dynamically update the blacklist keyring if the hash
being added is signed and vouched for by the builtin trusted keyring.
Currently keys in the secondary trusted keyring can not be used.
Keys within the secondary trusted keyring carry the same capabilities as
the builtin trusted keyring. Relax the current restriction for updating
the .blacklist keyring and allow the secondary to also be referenced as
a trust source. Since the machine keyring is linked to the secondary
trusted keyring, any key within it may also be used.
An example use case for this is IMA appraisal. Now that IMA both
references the blacklist keyring and allows the machine owner to add
custom IMA CA certs via the machine keyring, this adds the additional
capability for the machine owner to also do revocations on a running
system.
IMA appraisal usage example to add a revocation for /usr/foo:
sha256sum /bin/foo | awk '{printf "bin:" $1}' > hash.txt
openssl smime -sign -in hash.txt -inkey machine-private-key.pem \
-signer machine-certificate.pem -noattr -binary -outform DER \
-out hash.p7s
keyctl padd blacklist "$(< hash.txt)" %:.blacklist < hash.p7s
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
certs/Kconfig | 2 +-
certs/blacklist.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/certs/Kconfig b/certs/Kconfig
index 1f109b070877..23dc87c52aff 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -134,7 +134,7 @@ config SYSTEM_BLACKLIST_AUTH_UPDATE
depends on SYSTEM_DATA_VERIFICATION
help
If set, provide the ability to load new blacklist keys at run time if
- they are signed and vouched by a certificate from the builtin trusted
+ they are signed and vouched by a certificate from the secondary trusted
keyring. The PKCS#7 signature of the description is set in the key
payload. Blacklist keys cannot be removed.
diff --git a/certs/blacklist.c b/certs/blacklist.c
index 675dd7a8f07a..0b346048ae2d 100644
--- a/certs/blacklist.c
+++ b/certs/blacklist.c
@@ -102,12 +102,12 @@ static int blacklist_key_instantiate(struct key *key,
#ifdef CONFIG_SYSTEM_BLACKLIST_AUTH_UPDATE
/*
- * Verifies the description's PKCS#7 signature against the builtin
+ * Verifies the description's PKCS#7 signature against the secondary
* trusted keyring.
*/
err = verify_pkcs7_signature(key->description,
strlen(key->description), prep->data, prep->datalen,
- NULL, VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL);
+ VERIFY_USE_SECONDARY_KEYRING, VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL);
if (err)
return err;
#else
--
2.39.3
next reply other threads:[~2023-09-08 21:57 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-08 21:34 Eric Snowberg [this message]
2023-09-11 13:29 ` [PATCH] certs: Restrict blacklist updates to the secondary trusted keyring Mimi Zohar
2023-09-11 16:51 ` Mickaël Salaün
2023-09-11 22:17 ` Eric Snowberg
2023-09-11 23:08 ` Mimi Zohar
2023-09-12 2:00 ` Eric Snowberg
2023-09-12 11:54 ` Mimi Zohar
2023-09-12 17:11 ` Eric Snowberg
2023-09-12 22:47 ` Mimi Zohar
2023-09-13 2:40 ` Eric Snowberg
2023-09-13 10:21 ` Mickaël Salaün
2023-09-13 22:29 ` Eric Snowberg
2023-09-14 8:34 ` Mickaël Salaün
2023-10-05 10:32 ` RFC: New LSM to control usage of x509 certificates Mickaël Salaün
2023-10-05 14:05 ` Paul Moore
2023-10-17 13:39 ` Mimi Zohar
2023-10-17 15:45 ` Paul Moore
2023-10-17 17:08 ` Mimi Zohar
2023-10-17 17:29 ` Paul Moore
2023-10-17 17:58 ` Mimi Zohar
2023-10-17 18:51 ` Paul Moore
2023-10-17 19:34 ` Eric Snowberg
2023-10-18 14:14 ` Mickaël Salaün
2023-10-18 23:12 ` Eric Snowberg
2023-10-19 9:12 ` Mickaël Salaün
2023-10-19 23:08 ` Eric Snowberg
2023-10-20 15:05 ` Mickaël Salaün
2023-10-20 15:26 ` Roberto Sassu
2023-10-20 15:53 ` Eric Snowberg
2023-09-11 22:04 ` [PATCH] certs: Restrict blacklist updates to the secondary trusted keyring Jarkko Sakkinen
2023-09-11 22:23 ` Eric Snowberg
2023-09-11 22:01 ` Jarkko Sakkinen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230908213428.731513-1-eric.snowberg@oracle.com \
--to=eric.snowberg@oracle.com \
--cc=dhowells@redhat.com \
--cc=dwmw2@infradead.org \
--cc=jarkko@kernel.org \
--cc=kanth.ghatraju@oracle.com \
--cc=keyrings@vger.kernel.org \
--cc=konrad.wilk@oracle.com \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mic@linux.microsoft.com \
--cc=zohar@linux.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.