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 <[email protected]> --- v3: - added kernel-doc - NULL pointer check on asymmetric_key_public_key return value --- security/integrity/digsig_asymmetric.c | 62 ++++++++++++++++++-------- 1 file changed, 43 insertions(+), 19 deletions(-) diff --git a/security/integrity/digsig_asymmetric.c b/security/integrity/digsig_asymmetric.c index ed171a627d18..a4eb73bba6d2 100644 --- a/security/integrity/digsig_asymmetric.c +++ b/security/integrity/digsig_asymmetric.c @@ -79,18 +79,25 @@ 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) +/** + * asymmetric_verify_common -- sigv2 and sigv3 common verify function + * @key: The key to use for signature verification; caller must free it + * @pk: The associated public key; must not be NULL + * @sig: The xattr signature + * @siglen: The length of the xattr signature; must be at least + * sizeof(struct signature_v2_hdr) + * @data: The data to verify the signature on + * @datalen: Length of @data + */ +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)) @@ -99,19 +106,9 @@ 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); - if (!pk) { - ret = -ENOKEY; - goto out; - } pks.pkey_algo = pk->pkey_algo; if (!strcmp(pk->pkey_algo, "rsa")) { pks.encoding = "pkcs1"; @@ -131,11 +128,38 @@ 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); + if (!pk) { + ret = -ENOKEY; + goto out; + } + + ret = asymmetric_verify_common(key, pk, sig, siglen, data, datalen); + +out: + 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
