linux/crypto/asymmetric_keys/selftest.c
Joachim Vandersmissen 747ae81883 certs: Add ECDSA signature verification self-test
Commit c27b2d2012 ("crypto: testmgr - allow ecdsa-nist-p256 and -p384
in FIPS mode") enabled support for ECDSA in crypto/testmgr.c. The
PKCS#7 signature verification API builds upon the KCAPI primitives to
perform its high-level operations. Therefore, this change in testmgr.c
also allows ECDSA to be used by the PKCS#7 signature verification API
(in FIPS mode).

However, from a FIPS perspective, the PKCS#7 signature verification API
is a distinct "service" from the KCAPI primitives. This is because the
PKCS#7 API performs a "full" signature verification, which consists of
both hashing the data to be verified, and the public key operation.
On the other hand, the KCAPI primitive does not perform this hashing
step - it accepts pre-hashed data from the caller and only performs the
public key operation.

For this reason, the ECDSA self-tests in crypto/testmgr.c are not
sufficient to cover ECDSA signature verification offered by the PKCS#7
API. This is reflected by the self-test already present in this file
for RSA PKCS#1 v1.5 signature verification.

The solution is simply to add a second self-test here for ECDSA. P-256
with SHA-256 hashing was chosen as those parameters should remain
FIPS-approved for the foreseeable future, while keeping the performance
impact to a minimum. The ECDSA certificate and PKCS#7 signed data was
generated using OpenSSL. The input data is identical to the input data
for the existing RSA self-test.

Signed-off-by: Joachim Vandersmissen <git@jvdsn.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2024-05-14 05:01:04 +03:00

73 lines
1.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/* Self-testing for signature checking.
*
* Copyright (C) 2022 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#include <crypto/pkcs7.h>
#include <linux/cred.h>
#include <linux/kernel.h>
#include <linux/key.h>
#include <linux/module.h>
#include "selftest.h"
#include "x509_parser.h"
void fips_signature_selftest(const char *name,
const u8 *keys, size_t keys_len,
const u8 *data, size_t data_len,
const u8 *sig, size_t sig_len)
{
struct key *keyring;
int ret;
pr_notice("Running certificate verification %s selftest\n", name);
keyring = keyring_alloc(".certs_selftest",
GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, current_cred(),
(KEY_POS_ALL & ~KEY_POS_SETATTR) |
KEY_USR_VIEW | KEY_USR_READ |
KEY_USR_SEARCH,
KEY_ALLOC_NOT_IN_QUOTA,
NULL, NULL);
if (IS_ERR(keyring))
panic("Can't allocate certs %s selftest keyring: %ld\n", name, PTR_ERR(keyring));
ret = x509_load_certificate_list(keys, keys_len, keyring);
if (ret < 0)
panic("Can't allocate certs %s selftest keyring: %d\n", name, ret);
struct pkcs7_message *pkcs7;
pkcs7 = pkcs7_parse_message(sig, sig_len);
if (IS_ERR(pkcs7))
panic("Certs %s selftest: pkcs7_parse_message() = %d\n", name, ret);
pkcs7_supply_detached_data(pkcs7, data, data_len);
ret = pkcs7_verify(pkcs7, VERIFYING_MODULE_SIGNATURE);
if (ret < 0)
panic("Certs %s selftest: pkcs7_verify() = %d\n", name, ret);
ret = pkcs7_validate_trust(pkcs7, keyring);
if (ret < 0)
panic("Certs %s selftest: pkcs7_validate_trust() = %d\n", name, ret);
pkcs7_free_message(pkcs7);
key_put(keyring);
}
static int __init fips_signature_selftest_init(void)
{
fips_signature_selftest_rsa();
fips_signature_selftest_ecdsa();
return 0;
}
late_initcall(fips_signature_selftest_init);
MODULE_DESCRIPTION("X.509 self tests");
MODULE_AUTHOR("Red Hat, Inc.");
MODULE_LICENSE("GPL");