[PATCH 2/3] integrity: Refactor asymmetric_verify for reusability

Stefan Berger
2026-04-05T23:12:49Z

Refactor asymmetric_verify for reusability. Have it call
asymmetric_verify_common with the signature verification key and the
public_key structure as parameters. sigv3 support for ML-DSA will need to
check the public key type first to decide how to do the signature
verification and therefore will have these parameters available for
calling asymmetric_verify_common.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
---
security/integrity/digsig_asymmetric.c | 42 +++++++++++++++++---------
1 file changed, 28 insertions(+), 14 deletions(-)

diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c
index 6e68ec3becbd..e29ed73f15cd 100644
--- a/security/integrity/digsig_asymmetric.c
+++ b/security/integrity/digsig_asymmetric.c
@@ -79,18 +79,15 @@ static struct key *request_asymmetric_key(struct key *keyring, uint32_t keyid)
return key;
}

-int asymmetric_verify(struct key *keyring, const char *sig,
- int siglen, const char *data, int datalen)
+static int asymmetric_verify_common(const struct key *key,
+ const struct public_key *pk,
+ const char *sig, int siglen,
+ const char *data, int datalen)
{
- struct public_key_signature pks;
struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
- const struct public_key *pk;
- struct key *key;
+ struct public_key_signature pks;
int ret;

- if (siglen <= sizeof(*hdr))
- return -EBADMSG;
-
siglen -= sizeof(*hdr);

if (siglen != be16_to_cpu(hdr->sig_size))
@@ -99,15 +96,10 @@ int asymmetric_verify(struct key *keyring, const char *sig,
if (hdr->hash_algo >= HASH_ALGO__LAST)
return -ENOPKG;

- key = request_asymmetric_key(keyring, be32_to_cpu(hdr->keyid));
- if (IS_ERR(key))
- return PTR_ERR(key);
-
memset(&pks, 0, sizeof(pks));

pks.hash_algo = hash_algo_name[hdr->hash_algo];

- pk = asymmetric_key_public_key(key);
pks.pkey_algo = pk->pkey_algo;
if (!strcmp(pk->pkey_algo, "rsa")) {
pks.encoding = "pkcs1";
@@ -127,11 +119,33 @@ int asymmetric_verify(struct key *keyring, const char *sig,
pks.s_size = siglen;
ret = verify_signature(key, &pks);
out:
- key_put(key);
pr_debug("%s() = %d\n", __func__, ret);
return ret;
}

+int asymmetric_verify(struct key *keyring, const char *sig,
+ int siglen, const char *data, int datalen)
+{
+ struct signature_v2_hdr *hdr = (struct signature_v2_hdr *)sig;
+ const struct public_key *pk;
+ struct key *key;
+ int ret;
+
+ if (siglen <= sizeof(*hdr))
+ return -EBADMSG;
+
+ key = request_asymmetric_key(keyring, be32_to_cpu(hdr->keyid));
+ if (IS_ERR(key))
+ return PTR_ERR(key);
+ pk = asymmetric_key_public_key(key);
+
+ ret = asymmetric_verify_common(key, pk, sig, siglen, data, datalen);
+
+ key_put(key);
+
+ return ret;
+}
+
/*
* calc_file_id_hash - calculate the hash of the ima_file_id struct data
* @type: xattr type [enum evm_ima_xattr_type]
--
2.53.0