On Mon, Mar 20, 2023 at 04:35:33PM -0400, Mimi Zohar wrote:

On Mon, 2023-03-20 at 20:28 +0200, Jarkko Sakkinen wrote:

quoted

On Mon, Mar 20, 2023 at 05:35:05PM +0000, Eric Snowberg wrote:

quoted

quoted

On Mar 11, 2023, at 3:10 PM, Jarkko Sakkinen [off-list ref] wrote:

On Thu, Mar 02, 2023 at 11:46:51AM -0500, Eric Snowberg wrote:

quoted

Add a new link restriction.  Restrict the addition of keys in a keyring
based on the key to be added being a CA.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
---
crypto/asymmetric_keys/restrict.c | 38 +++++++++++++++++++++++++++++++
include/crypto/public_key.h       | 15 ++++++++++++
2 files changed, 53 insertions(+)

diff --git a/crypto/asymmetric_keys/restrict.c b/crypto/asymmetric_keys/restrict.c
index 6b1ac5f5896a..48457c6f33f9 100644
--- a/crypto/asymmetric_keys/restrict.c
+++ b/crypto/asymmetric_keys/restrict.c

@@ -108,6 +108,44 @@ int restrict_link_by_signature(struct key *dest_keyring,

	return ret;
}

+/**
+ * restrict_link_by_ca - Restrict additions to a ring of CA keys
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @trust_keyring: Unused.
+ *
+ * Check if the new certificate is a CA. If it is a CA, then mark the new
+ * certificate as being ok to link.
+ *
+ * Returns 0 if the new certificate was accepted, -ENOKEY if the
+ * certificate is not a CA. -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 *pkey;
+
+	if (type != &key_type_asymmetric)
+		return -EOPNOTSUPP;
+
+	pkey = payload->data[asym_crypto];
+	if (!pkey)
+		return -ENOPKG;
+	if (!test_bit(KEY_EFLAG_CA, &pkey->key_eflags))
+		return -ENOKEY;
+	if (!test_bit(KEY_EFLAG_KEYCERTSIGN, &pkey->key_eflags))
+		return -ENOKEY;
+	if (test_bit(KEY_EFLAG_DIGITALSIG, &pkey->key_eflags))
+		return -ENOKEY;

nit: would be more readable, if conditions were separated by
empty lines.

Ok, I will make this change in the next round.  Thanks.

Cool! Mimi have you tested these patches with IMA applied?

Yes, it's working as expected.

OK, I will pick these.

BR, Jarkko