From: Eric Snowberg <eric.snowberg@oracle.com>
To: keyrings@vger.kernel.org, linux-integrity@vger.kernel.org,
zohar@linux.ibm.com, dhowells@redhat.com, dwmw2@infradead.org,
herbert@gondor.apana.org.au, davem@davemloft.net,
jarkko@kernel.org, jmorris@namei.org, serge@hallyn.com
Cc: eric.snowberg@oracle.com, keescook@chromium.org,
gregkh@linuxfoundation.org, torvalds@linux-foundation.org,
scott.branden@broadcom.com, weiyongjun1@huawei.com,
nayna@linux.ibm.com, ebiggers@google.com, ardb@kernel.org,
nramas@linux.microsoft.com, lszubowi@redhat.com,
linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
linux-security-module@vger.kernel.org,
James.Bottomley@HansenPartnership.com, pjones@redhat.com,
glin@suse.com, konrad.wilk@oracle.com
Subject: [PATCH RFC 03/12] KEYS: CA link restriction
Date: Tue, 6 Jul 2021 22:43:54 -0400 [thread overview]
Message-ID: <20210707024403.1083977-4-eric.snowberg@oracle.com> (raw)
In-Reply-To: <20210707024403.1083977-1-eric.snowberg@oracle.com>
Restrict the addition of keys in a keyring based on the key to be
added being a CA (self-signed) or by being vouched for by a key in
either the built-in or the secondary trusted keyrings.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
certs/system_keyring.c | 18 ++++++++++
crypto/asymmetric_keys/restrict.c | 60 +++++++++++++++++++++++++++++++
include/crypto/public_key.h | 5 +++
include/keys/system_keyring.h | 14 ++++++++
4 files changed, 97 insertions(+)
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index f02bc5832684..b4c82276bba5 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -73,6 +73,24 @@ int restrict_link_by_builtin_and_secondary_trusted(
secondary_trusted_keys);
}
+/**
+ * restrict_link_by_secondary_trusted_or_ca - Restrict keyring
+ * addition by being a CA or vouched by the secondary keyrings.
+ *
+ * Restrict the addition of keys in a keyring based on the key-to-be-added
+ * being a CA (self signed) or by being vouched for by a key in either
+ * the built-in or the secondary system keyrings.
+ */
+int restrict_link_by_secondary_trusted_or_ca(
+ struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *restrict_key)
+{
+ return restrict_link_by_ca(dest_keyring, type, payload,
+ secondary_trusted_keys);
+}
+
/**
* Allocate a struct key_restriction for the "builtin and secondary trust"
* keyring. Only for use in system_trusted_keyring_init().
diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c
index 84cefe3b3585..75e4379226e8 100644
--- a/crypto/asymmetric_keys/restrict.c
+++ b/crypto/asymmetric_keys/restrict.c
@@ -108,6 +108,66 @@ int restrict_link_by_signature(struct key *dest_keyring,
return ret;
}
+/**
+ * restrict_link_by_ca - Restrict additions to a ring of public keys
+ * based on it being a CA
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @trusted: A key or ring of keys that can be used to vouch for the new cert.
+ *
+ * Check if the new certificate is a CA or if they key can be vouched for
+ * by keys already linked in the destination keyring or the trusted
+ * keyring. If one of those is the signing key or it is self signed, then
+ * mark the new certificate as being ok to link.
+ *
+ * Returns 0 if the new certificate was accepted, -ENOKEY if we could not find
+ * a matching parent certificate in the trusted list. -ENOPKG if the signature
+ * uses unsupported crypto, or some other error if there is a matching
+ * certificate but the signature check cannot be performed.
+ */
+int restrict_link_by_ca(struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *trust_keyring)
+{
+ const struct public_key_signature *sig;
+ const struct public_key *pkey;
+ struct key *key;
+ int ret;
+
+ if (type != &key_type_asymmetric)
+ return -EOPNOTSUPP;
+
+ sig = payload->data[asym_auth];
+ if (!sig)
+ return -ENOPKG;
+
+ if (!sig->auth_ids[0] && !sig->auth_ids[1])
+ return -ENOKEY;
+
+ pkey = payload->data[asym_crypto];
+ if (!pkey)
+ return -ENOPKG;
+
+ ret = public_key_verify_signature(pkey, sig);
+ if (!ret)
+ return 0;
+
+ if (!trust_keyring)
+ return -ENOKEY;
+
+ key = find_asymmetric_key(trust_keyring,
+ sig->auth_ids[0], sig->auth_ids[1],
+ false);
+ if (IS_ERR(key))
+ return -ENOKEY;
+
+ ret = verify_signature(key, sig);
+ key_put(key);
+ return ret;
+}
+
static bool match_either_id(const struct asymmetric_key_ids *pair,
const struct asymmetric_key_id *single)
{
diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h
index 47accec68cb0..545af1ea57de 100644
--- a/include/crypto/public_key.h
+++ b/include/crypto/public_key.h
@@ -71,6 +71,11 @@ extern int restrict_link_by_key_or_keyring_chain(struct key *trust_keyring,
const union key_payload *payload,
struct key *trusted);
+extern int restrict_link_by_ca(struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *trust_keyring);
+
extern int query_asymmetric_key(const struct kernel_pkey_params *,
struct kernel_pkey_query *);
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index f40837026d6d..43c76fba9481 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -34,10 +34,24 @@ extern int restrict_link_by_builtin_and_secondary_trusted(
const struct key_type *type,
const union key_payload *payload,
struct key *restriction_key);
+extern int restrict_link_by_secondary_trusted_or_ca(
+ struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *restrict_key);
extern __init int move_to_trusted_secondary_keyring(struct key *key,
struct key *from_keyring);
#else
#define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted
+static inline int restrict_link_by_secondary_trusted_or_ca(
+ struct key *dest_keyring,
+ const struct key_type *type,
+ const union key_payload *payload,
+ struct key *restrict_key)
+{
+ return -ENOKEY;
+}
+
static inline __init int move_to_trusted_secondary_keyring(struct key *key,
struct key *from_keyring)
{
--
2.18.4
next prev parent reply other threads:[~2021-07-07 2:45 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-07 2:43 [PATCH RFC 00/12] Enroll kernel keys thru MOK Eric Snowberg
2021-07-07 2:43 ` [PATCH RFC 01/12] KEYS: Add KEY_ALLOC_BYPASS_RESTRICTION option to key_move Eric Snowberg
2021-07-07 2:43 ` [PATCH RFC 02/12] KEYS: Allow unrestricted keys to be moved to the secondary keyring Eric Snowberg
2021-07-07 2:43 ` Eric Snowberg [this message]
2021-07-07 2:43 ` [PATCH RFC 04/12] integrity: add integrity_destroy_keyring Eric Snowberg
2021-07-07 2:43 ` [PATCH RFC 05/12] integrity: Introduce mok keyring Eric Snowberg
2021-07-07 19:31 ` Linus Torvalds
2021-07-07 21:26 ` Jarkko Sakkinen
2021-07-07 22:32 ` Eric Snowberg
2021-07-07 2:43 ` [PATCH RFC 06/12] integrity: Trust mok keys if MokListTrustedRT found Eric Snowberg
2021-07-07 2:43 ` [PATCH RFC 07/12] integrity: add add_to_mok_keyring Eric Snowberg
2021-07-07 2:43 ` [PATCH RFC 08/12] integrity: restrict INTEGRITY_KEYRING_MOK to restrict_link_by_secondary_trusted_or_ca Eric Snowberg
2021-07-07 2:44 ` [PATCH RFC 09/12] integrity: accessor function to get trust_moklist Eric Snowberg
2021-07-07 2:44 ` [PATCH RFC 10/12] integrity: add new keyring handler Eric Snowberg
2021-07-07 2:44 ` [PATCH RFC 11/12] integrity: move keys from the mok keyring into the secondary keyring Eric Snowberg
2021-07-07 2:44 ` [PATCH RFC 12/12] integrity: Suppress error message for keys added to the mok keyring Eric Snowberg
2021-07-07 6:46 ` [PATCH RFC 00/12] Enroll kernel keys thru MOK Christoph Hellwig
2021-07-07 16:23 ` Eric Snowberg
2021-07-07 16:28 ` Christoph Hellwig
2021-07-07 16:45 ` Eric Snowberg
2021-07-07 12:39 ` Mimi Zohar
2021-07-07 16:28 ` Eric Snowberg
2021-07-07 17:00 ` Mimi Zohar
2021-07-07 22:10 ` Eric Snowberg
2021-07-08 13:56 ` Mimi Zohar
2021-07-08 17:59 ` Eric Snowberg
2021-07-08 19:31 ` Mimi Zohar
2021-07-08 23:17 ` Eric Snowberg
2021-07-09 1:10 ` Mimi Zohar
2021-07-09 15:59 ` Nayna
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