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/*
* Copyright (C) 2017 Red Hat, Inc.
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GnuTLS.
*
* GnuTLS is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* GnuTLS is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <gnutls/gnutls.h>
#include <gnutls/x509.h>
#include <gnutls/abstract.h>
#include <assert.h>
#include "utils.h"
/* This tests the key conversion from basic RSA to RSA-PSS.
*/
static void tls_log_func(int level, const char *str)
{
fprintf(stderr, "<%d>| %s", level, str);
}
const gnutls_datum_t raw_data = {
(void *) "hello there",
11
};
static void inv_sign_check(unsigned sigalgo,
gnutls_privkey_t privkey, int exp_error)
{
int ret;
gnutls_datum_t signature;
ret = gnutls_privkey_sign_data2(privkey, sigalgo, 0,
&raw_data, &signature);
if (ret != exp_error)
fail("gnutls_privkey_sign_data succeeded with %s and %s: %s\n", gnutls_pk_get_name(gnutls_privkey_get_pk_algorithm(privkey, NULL)),
gnutls_sign_get_name(sigalgo), gnutls_strerror(ret));
if (ret == 0)
gnutls_free(signature.data);
}
static void inv_encryption_check(gnutls_pk_algorithm_t algorithm,
gnutls_privkey_t privkey, int exp_error)
{
int ret;
gnutls_datum_t ct;
gnutls_pubkey_t pubkey;
assert(gnutls_pubkey_init(&pubkey) >= 0);
ret = gnutls_pubkey_import_privkey(pubkey, privkey, 0, 0);
if (ret < 0)
fail("gnutls_pubkey_import_privkey\n");
ret = gnutls_pubkey_encrypt_data(pubkey, 0, &raw_data, &ct);
if (ret != exp_error)
fail("gnutls_pubkey_encrypt_data succeeded with %s: %s\n", gnutls_pk_get_name(algorithm),
gnutls_strerror(ret));
gnutls_pubkey_deinit(pubkey);
}
static void sign_verify_data(unsigned sigalgo, gnutls_privkey_t privkey,
unsigned int sign_flags, unsigned int verify_flags,
int sign_exp_error, int verify_exp_error)
{
int ret;
gnutls_datum_t signature = { NULL, 0 };
ret = gnutls_privkey_sign_data2(privkey, sigalgo, sign_flags,
&raw_data, &signature);
if (ret != sign_exp_error)
fail("gnutls_x509_privkey_sign_data returned unexpected error: %s\n",
gnutls_strerror(ret));
if (ret < 0) {
success("skipping verification as signing is expected to fail\n");
} else {
gnutls_pubkey_t pubkey;
/* verify data */
assert(gnutls_pubkey_init(&pubkey) >= 0);
ret = gnutls_pubkey_import_privkey(pubkey, privkey, 0, 0);
if (ret < 0)
fail("gnutls_pubkey_import_privkey\n");
ret = gnutls_pubkey_verify_data2(pubkey, sigalgo,
verify_flags, &raw_data, &signature);
if (ret != verify_exp_error)
fail("gnutls_pubkey_verify_data2 returned unexpected error: %s\n",
gnutls_strerror(ret));
gnutls_pubkey_deinit(pubkey);
}
gnutls_free(signature.data);
}
static void
prepare_keys(gnutls_privkey_t *pkey_rsa_pss, gnutls_privkey_t *pkey_rsa,
gnutls_digest_algorithm_t dig, size_t salt_size)
{
gnutls_privkey_t pkey;
gnutls_x509_privkey_t tkey;
int ret;
gnutls_x509_spki_t spki;
gnutls_datum_t tmp;
assert(gnutls_x509_spki_init(&spki)>=0);
assert(gnutls_privkey_init(&pkey) >=0);
gnutls_x509_spki_set_rsa_pss_params(spki, dig, salt_size);
ret =
gnutls_privkey_generate(pkey, GNUTLS_PK_RSA, 2048, 0);
if (ret < 0) {
fail("gnutls_privkey_generate: %s\n", gnutls_strerror(ret));
}
assert(gnutls_privkey_set_spki(pkey, spki, 0)>=0);
assert(gnutls_privkey_export_x509(pkey, &tkey) >=0);
gnutls_x509_spki_deinit(spki);
gnutls_x509_privkey_export2_pkcs8(tkey, GNUTLS_X509_FMT_PEM, NULL, 0, &tmp);
/* import RSA-PSS version of key */
assert(gnutls_privkey_init(pkey_rsa_pss) >=0);
assert(gnutls_privkey_import_x509_raw(*pkey_rsa_pss, &tmp, GNUTLS_X509_FMT_PEM, NULL, 0) >= 0);
gnutls_free(tmp.data);
/* import RSA version of key */
gnutls_x509_privkey_export2(tkey, GNUTLS_X509_FMT_PEM, &tmp);
assert(gnutls_privkey_init(pkey_rsa) >=0);
assert(gnutls_privkey_import_x509_raw(*pkey_rsa, &tmp, GNUTLS_X509_FMT_PEM, NULL, 0) >= 0);
gnutls_x509_privkey_deinit(tkey);
gnutls_free(tmp.data);
gnutls_privkey_deinit(pkey);
}
void doit(void)
{
gnutls_privkey_t pkey_rsa_pss;
gnutls_privkey_t pkey_rsa;
gnutls_x509_spki_t spki;
int ret;
ret = global_init();
if (ret < 0)
fail("global_init: %d\n", ret);
gnutls_global_set_log_function(tls_log_func);
if (debug)
gnutls_global_set_log_level(4711);
prepare_keys(&pkey_rsa_pss, &pkey_rsa, GNUTLS_DIG_SHA256, 32);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss, 0, 0, 0, 0);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa, 0, 0, 0, 0);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa, 0, 0, 0, 0);
if (debug)
success("success signing with RSA-PSS-SHA256\n");
/* check whether the RSA-PSS key restrictions are being followed */
inv_encryption_check(GNUTLS_PK_RSA_PSS, pkey_rsa_pss, GNUTLS_E_INVALID_REQUEST);
inv_sign_check(GNUTLS_SIGN_RSA_SHA512, pkey_rsa_pss, GNUTLS_E_CONSTRAINT_ERROR);
inv_sign_check(GNUTLS_SIGN_RSA_SHA256, pkey_rsa_pss, GNUTLS_E_CONSTRAINT_ERROR);
inv_sign_check(GNUTLS_SIGN_RSA_PSS_SHA384, pkey_rsa_pss, GNUTLS_E_CONSTRAINT_ERROR);
inv_sign_check(GNUTLS_SIGN_RSA_PSS_SHA512, pkey_rsa_pss, GNUTLS_E_CONSTRAINT_ERROR);
inv_sign_check(GNUTLS_SIGN_RSA_PSS_RSAE_SHA384, pkey_rsa_pss, GNUTLS_E_CONSTRAINT_ERROR);
inv_sign_check(GNUTLS_SIGN_RSA_PSS_RSAE_SHA512, pkey_rsa_pss, GNUTLS_E_CONSTRAINT_ERROR);
/* check whether the RSA key is not being restricted */
inv_sign_check(GNUTLS_SIGN_RSA_SHA512, pkey_rsa, 0);
inv_sign_check(GNUTLS_SIGN_RSA_SHA256, pkey_rsa, 0);
inv_sign_check(GNUTLS_SIGN_RSA_PSS_RSAE_SHA384, pkey_rsa, 0);
inv_sign_check(GNUTLS_SIGN_RSA_PSS_RSAE_SHA512, pkey_rsa, 0);
/* an RSA key can also generate "pure" for TLS RSA-PSS signatures
* as they are essentially the same thing, and we cannot always
* know whether a key is RSA-PSS only, or not (e.g., in PKCS#11
* keys). */
inv_sign_check(GNUTLS_SIGN_RSA_PSS_SHA384, pkey_rsa, 0);
inv_sign_check(GNUTLS_SIGN_RSA_PSS_SHA512, pkey_rsa, 0);
gnutls_privkey_deinit(pkey_rsa_pss);
gnutls_privkey_deinit(pkey_rsa);
/* Use the mismatched salt length with the digest length */
prepare_keys(&pkey_rsa_pss, &pkey_rsa, GNUTLS_DIG_SHA256, 48);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa_pss,
0, 0, 0, 0);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss,
GNUTLS_PRIVKEY_FLAG_RSA_PSS_FIXED_SALT_LENGTH,
0,
GNUTLS_E_CONSTRAINT_ERROR,
0);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_SHA256, pkey_rsa_pss,
0,
GNUTLS_VERIFY_RSA_PSS_FIXED_SALT_LENGTH,
0,
GNUTLS_E_PK_SIG_VERIFY_FAILED);
assert(gnutls_x509_spki_init(&spki)>=0);
gnutls_x509_spki_set_rsa_pss_params(spki, GNUTLS_DIG_SHA256, 48);
assert(gnutls_privkey_set_spki(pkey_rsa, spki, 0)>=0);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa, 0, 0, 0, 0);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa,
GNUTLS_PRIVKEY_FLAG_RSA_PSS_FIXED_SALT_LENGTH,
0,
GNUTLS_E_CONSTRAINT_ERROR,
0);
sign_verify_data(GNUTLS_SIGN_RSA_PSS_RSAE_SHA256, pkey_rsa,
0,
GNUTLS_VERIFY_RSA_PSS_FIXED_SALT_LENGTH,
0,
GNUTLS_E_PK_SIG_VERIFY_FAILED);
gnutls_privkey_deinit(pkey_rsa_pss);
gnutls_privkey_deinit(pkey_rsa);
gnutls_x509_spki_deinit(spki);
gnutls_global_deinit();
}
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