int asymmetric_verify(struct key *keyring, 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;
struct key *key;
int ret = -ENOMEM;
if (siglen <= sizeof(*hdr))
return -EBADMSG;
siglen -= sizeof(*hdr);
if (siglen != __be16_to_cpu(hdr->sig_size))
return -EBADMSG;
if (hdr->hash_algo >= PKEY_HASH__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.pkey_hash_algo = hdr->hash_algo;
pks.digest = (u8 *)data;
pks.digest_size = datalen;
pks.nr_mpi = 1;
pks.rsa.s = mpi_read_raw_data(hdr->sig, siglen);
if (pks.rsa.s)
ret = verify_signature(key, &pks);
mpi_free(pks.rsa.s);
key_put(key);
pr_debug("%s() = %d\n", __func__, ret);
return ret;
}
/*
* Verify the signature on a module.
*/
int mod_verify_sig(const void *mod, unsigned long *_modlen)
{
struct public_key_signature *pks;
struct module_signature ms;
struct key *key;
const void *sig;
size_t modlen = *_modlen, sig_len;
int ret;
pr_devel("==>%s(,%zu)\n", __func__, modlen);
if (modlen <= sizeof(ms))
return -EBADMSG;
memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms));
modlen -= sizeof(ms);
sig_len = be32_to_cpu(ms.sig_len);
if (sig_len >= modlen)
return -EBADMSG;
modlen -= sig_len;
if ((size_t)ms.signer_len + ms.key_id_len >= modlen)
return -EBADMSG;
modlen -= (size_t)ms.signer_len + ms.key_id_len;
*_modlen = modlen;
sig = mod + modlen;
/* For the moment, only support RSA and X.509 identifiers */
if (ms.algo != PKEY_ALGO_RSA ||
ms.id_type != PKEY_ID_X509)
return -ENOPKG;
if (ms.hash >= PKEY_HASH__LAST ||
!pkey_hash_algo[ms.hash])
return -ENOPKG;
key = request_asymmetric_key(sig, ms.signer_len,
sig + ms.signer_len, ms.key_id_len);
if (IS_ERR(key))
return PTR_ERR(key);
pks = mod_make_digest(ms.hash, mod, modlen);
if (IS_ERR(pks)) {
ret = PTR_ERR(pks);
goto error_put_key;
}
ret = mod_extract_mpi_array(pks, sig + ms.signer_len + ms.key_id_len,
sig_len);
if (ret < 0)
goto error_free_pks;
ret = verify_signature(key, pks);
pr_devel("verify_signature() = %d\n", ret);
error_free_pks:
mpi_free(pks->rsa.s);
kfree(pks);
error_put_key:
key_put(key);
pr_devel("<==%s() = %d\n", __func__, ret);
return ret;
}
