/*
* Copyright (C) 2003-2014 Free Software Foundation, Inc.
* Copyright (C) 2013 Nikos Mavrogiannopoulos
* Copyright (C) 2014 Red Hat
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GnuTLS.
*
* The GnuTLS is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library 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
* Lesser 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/>
*
*/
/* All functions which relate to X.509 certificate verification stuff are
* included here
*/
#include "gnutls_int.h"
#include "errors.h"
#include <libtasn1.h>
#include <global.h>
#include <num.h> /* MAX */
#include <tls-sig.h>
#include <str.h>
#include <datum.h>
#include <pkcs11_int.h>
#include <x509_int.h>
#include <common.h>
#include <pk.h>
#include "supported_exts.h"
#include "profiles.h"
/* Checks if two certs have the same name and the same key. Return 1 on match.
* If @is_ca is zero then this function is identical to gnutls_x509_crt_equals()
*/
unsigned
_gnutls_check_if_same_key(gnutls_x509_crt_t cert1,
gnutls_x509_crt_t cert2,
unsigned is_ca)
{
int ret;
unsigned result;
if (is_ca == 0)
return gnutls_x509_crt_equals(cert1, cert2);
ret = _gnutls_is_same_dn(cert1, cert2);
if (ret == 0)
return 0;
if (cert1->raw_spki.size > 0 && (cert1->raw_spki.size == cert2->raw_spki.size) &&
(memcmp(cert1->raw_spki.data, cert2->raw_spki.data, cert1->raw_spki.size) == 0))
result = 1;
else
result = 0;
return result;
}
unsigned
_gnutls_check_if_same_key2(gnutls_x509_crt_t cert1,
gnutls_datum_t * cert2bin)
{
int ret;
gnutls_x509_crt_t cert2;
ret = gnutls_x509_crt_init(&cert2);
if (ret < 0)
return gnutls_assert_val(0);
ret = gnutls_x509_crt_import(cert2, cert2bin, GNUTLS_X509_FMT_DER);
if (ret < 0) {
gnutls_x509_crt_deinit(cert2);
return gnutls_assert_val(0);
}
ret = _gnutls_check_if_same_key(cert1, cert2, 1);
gnutls_x509_crt_deinit(cert2);
return ret;
}
/* checks whether there are present unknown/unsupported critical extensions.
*
* Returns true if they are present.
*/
static unsigned check_for_unknown_exts(gnutls_x509_crt_t cert)
{
unsigned i;
char oid[MAX_OID_SIZE];
size_t oid_size;
unsigned critical;
int ret;
for (i=0;;i++) {
oid_size = sizeof(oid);
oid[0] = 0;
critical = 0;
ret = gnutls_x509_crt_get_extension_info(cert, i, oid, &oid_size, &critical);
if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
return 0;
} else if (ret < 0) {
gnutls_assert();
/* could not decode? */
_gnutls_debug_log("Could not decode extension %d\n", i);
return 1;
}
if (critical == 0)
continue;
if (is_ext_oid_supported(oid, oid_size) == NULL) {
gnutls_assert();
_gnutls_debug_log("Unsupported critical extension: %s\n", oid);
return 1;
}
}
return 0;
}
/* Checks if the issuer of a certificate is a
* Certificate Authority, or if the certificate is the same
* as the issuer (and therefore it doesn't need to be a CA).
*
* Returns true or false, if the issuer is a CA,
* or not.
*/
static unsigned
check_if_ca(gnutls_x509_crt_t cert, gnutls_x509_crt_t issuer,
unsigned int *max_path, unsigned int flags)
{
gnutls_datum_t cert_signed_data = { NULL, 0 };
gnutls_datum_t issuer_signed_data = { NULL, 0 };
gnutls_datum_t cert_signature = { NULL, 0 };
gnutls_datum_t issuer_signature = { NULL, 0 };
int pathlen = -1, ret;
unsigned result;
unsigned int ca_status = 0;
/* Check if the issuer is the same with the
* certificate. This is added in order for trusted
* certificates to be able to verify themselves.
*/
ret =
_gnutls_x509_get_signed_data(issuer->cert, &issuer->der, "tbsCertificate",
&issuer_signed_data);
if (ret < 0) {
gnutls_assert();
goto fail;
}
ret =
_gnutls_x509_get_signed_data(cert->cert, &cert->der, "tbsCertificate",
&cert_signed_data);
if (ret < 0) {
gnutls_assert();
goto fail;
}
ret =
_gnutls_x509_get_signature(issuer->cert, "signature",
&issuer_signature);
if (ret < 0) {
gnutls_assert();
goto fail;
}
ret =
_gnutls_x509_get_signature(cert->cert, "signature",
&cert_signature);
if (ret < 0) {
gnutls_assert();
goto fail;
}
/* If the subject certificate is the same as the issuer
* return true.
*/
if (!(flags & GNUTLS_VERIFY_DO_NOT_ALLOW_SAME))
if (cert_signed_data.size == issuer_signed_data.size) {
if ((memcmp
(cert_signed_data.data,
issuer_signed_data.data,
cert_signed_data.size) == 0)
&& (cert_signature.size ==
issuer_signature.size)
&&
(memcmp
(cert_signature.data, issuer_signature.data,
cert_signature.size) == 0)) {
result = 1;
goto cleanup;
}
}
ret =
gnutls_x509_crt_get_basic_constraints(issuer, NULL, &ca_status,
&pathlen);
if (ret < 0) {
ca_status = 0;
pathlen = -1;
}
if (ca_status != 0 && pathlen != -1) {
if ((unsigned) pathlen < *max_path)
*max_path = pathlen;
}
if (ca_status != 0) {
result = 1;
goto cleanup;
}
/* Handle V1 CAs that do not have a basicConstraint, but accept
these certs only if the appropriate flags are set. */
else if ((ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) &&
((flags & GNUTLS_VERIFY_ALLOW_ANY_X509_V1_CA_CRT) ||
(!(flags & GNUTLS_VERIFY_DO_NOT_ALLOW_X509_V1_CA_CRT) &&
(gnutls_x509_crt_check_issuer(issuer, issuer) != 0)))) {
gnutls_assert();
result = 1;
goto cleanup;
} else {
gnutls_assert();
}
fail:
result = 0;
cleanup:
_gnutls_free_datum(&cert_signed_data);
_gnutls_free_datum(&issuer_signed_data);
_gnutls_free_datum(&cert_signature);
_gnutls_free_datum(&issuer_signature);
return result;
}
/* This function checks if cert's issuer is issuer.
* This does a straight (DER) compare of the issuer/subject DN fields in
* the given certificates, as well as check the authority key ID.
*
* Returns 1 if they match and (0) if they don't match.
*/
static unsigned is_issuer(gnutls_x509_crt_t cert, gnutls_x509_crt_t issuer)
{
uint8_t id1[MAX_KEY_ID_SIZE];
uint8_t id2[MAX_KEY_ID_SIZE];
size_t id1_size;
size_t id2_size;
int ret;
unsigned result;
if (_gnutls_x509_compare_raw_dn
(&cert->raw_issuer_dn, &issuer->raw_dn) != 0)
result = 1;
else
result = 0;
if (result != 0) {
/* check if the authority key identifier matches the subject key identifier
* of the issuer */
id1_size = sizeof(id1);
ret =
gnutls_x509_crt_get_authority_key_id(cert, id1,
&id1_size, NULL);
if (ret < 0) {
/* If there is no authority key identifier in the
* certificate, assume they match */
result = 1;
goto cleanup;
}
id2_size = sizeof(id2);
ret =
gnutls_x509_crt_get_subject_key_id(issuer, id2,
&id2_size, NULL);
if (ret < 0) {
/* If there is no subject key identifier in the
* issuer certificate, assume they match */
result = 1;
gnutls_assert();
goto cleanup;
}
if (id1_size == id2_size
&& memcmp(id1, id2, id1_size) == 0)
result = 1;
else
result = 0;
}
cleanup:
return result;
}
/* Check if the given certificate is the issuer of the CRL.
* Returns 1 on success and 0 otherwise.
*/
static unsigned is_crl_issuer(gnutls_x509_crl_t crl, gnutls_x509_crt_t issuer)
{
if (_gnutls_x509_compare_raw_dn
(&crl->raw_issuer_dn, &issuer->raw_dn) != 0)
return 1;
else
return 0;
}
/* Checks if the DN of two certificates is the same.
* Returns 1 if they match and (0) if they don't match. Otherwise
* a negative error code is returned to indicate error.
*/
unsigned _gnutls_is_same_dn(gnutls_x509_crt_t cert1, gnutls_x509_crt_t cert2)
{
if (_gnutls_x509_compare_raw_dn(&cert1->raw_dn, &cert2->raw_dn) !=
0)
return 1;
else
return 0;
}
/* Finds an issuer of the certificate. If multiple issuers
* are present, returns one that is activated and not expired.
*/
static inline gnutls_x509_crt_t
find_issuer(gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * trusted_cas, int tcas_size)
{
int i;
gnutls_x509_crt_t issuer = NULL;
/* this is serial search.
*/
for (i = 0; i < tcas_size; i++) {
if (is_issuer(cert, trusted_cas[i]) != 0) {
if (issuer == NULL) {
issuer = trusted_cas[i];
} else {
time_t now = gnutls_time(0);
if (now <
gnutls_x509_crt_get_expiration_time
(trusted_cas[i])
&& now >=
gnutls_x509_crt_get_activation_time
(trusted_cas[i])) {
issuer = trusted_cas[i];
}
}
}
}
return issuer;
}
static unsigned int check_time_status(gnutls_x509_crt_t crt, time_t now)
{
int status = 0;
time_t t;
t = gnutls_x509_crt_get_activation_time(crt);
if (t == (time_t) - 1 || now < t) {
status |= GNUTLS_CERT_NOT_ACTIVATED;
status |= GNUTLS_CERT_INVALID;
return status;
}
t = gnutls_x509_crt_get_expiration_time(crt);
if (t == (time_t) - 1 || now > t) {
status |= GNUTLS_CERT_EXPIRED;
status |= GNUTLS_CERT_INVALID;
return status;
}
return 0;
}
unsigned _gnutls_is_broken_sig_allowed(const gnutls_sign_entry_st *se, unsigned int flags)
{
gnutls_digest_algorithm_t hash;
/* we have a catch all */
if ((flags & GNUTLS_VERIFY_ALLOW_BROKEN) == GNUTLS_VERIFY_ALLOW_BROKEN)
return 1;
/* the first two are for backwards compatibility */
if ((se->id == GNUTLS_SIGN_RSA_MD2)
&& (flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD2))
return 1;
if ((se->id == GNUTLS_SIGN_RSA_MD5)
&& (flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD5))
return 1;
hash = se->hash;
if (hash == GNUTLS_DIG_SHA1 && (flags & GNUTLS_VERIFY_ALLOW_SIGN_WITH_SHA1))
return 1;
return 0;
}
#define CASE_SEC_PARAM(profile, level) \
case profile: \
sym_bits = gnutls_sec_param_to_symmetric_bits(level); \
hash = gnutls_sign_get_hash_algorithm(sigalg); \
entry = mac_to_entry(hash); \
if (hash <= 0 || entry == NULL) { \
_gnutls_cert_log("cert", crt); \
_gnutls_debug_log(#level": certificate's signature hash is unknown\n"); \
return gnutls_assert_val(0); \
} \
if (_gnutls_sign_get_hash_strength(sigalg) < sym_bits) { \
_gnutls_cert_log("cert", crt); \
_gnutls_debug_log(#level": certificate's signature hash strength is unacceptable (is %u bits, needed %u)\n", _gnutls_sign_get_hash_strength(sigalg), sym_bits); \
return gnutls_assert_val(0); \
} \
sp = gnutls_pk_bits_to_sec_param(pkalg, bits); \
if (sp < level) { \
_gnutls_cert_log("cert", crt); \
_gnutls_debug_log(#level": certificate's security level is unacceptable\n"); \
return gnutls_assert_val(0); \
} \
if (issuer) { \
sp = gnutls_pk_bits_to_sec_param(issuer_pkalg, issuer_bits); \
if (sp < level) { \
_gnutls_cert_log("issuer", issuer); \
_gnutls_debug_log(#level": certificate's issuer security level is unacceptable\n"); \
return gnutls_assert_val(0); \
} \
} \
break;
/* Checks whether the provided certificates are acceptable
* according to verification profile specified.
*
* @crt: a certificate
* @issuer: the certificates issuer (allowed to be NULL)
* @sigalg: the signature algorithm used
* @flags: the specified verification flags
*/
static unsigned is_level_acceptable(
gnutls_x509_crt_t crt, gnutls_x509_crt_t issuer,
gnutls_sign_algorithm_t sigalg, unsigned flags)
{
gnutls_certificate_verification_profiles_t profile = GNUTLS_VFLAGS_TO_PROFILE(flags);
const mac_entry_st *entry;
int issuer_pkalg = 0, pkalg, ret;
unsigned bits = 0, issuer_bits = 0, sym_bits = 0;
gnutls_pk_params_st params;
gnutls_sec_param_t sp;
int hash;
gnutls_certificate_verification_profiles_t min_profile;
min_profile = _gnutls_get_system_wide_verification_profile();
if (min_profile) {
if (profile < min_profile) {
gnutls_assert();
profile = min_profile;
}
}
if (profile == GNUTLS_PROFILE_UNKNOWN) {
return 1;
}
pkalg = gnutls_x509_crt_get_pk_algorithm(crt, &bits);
if (pkalg < 0)
return gnutls_assert_val(0);
if (issuer) {
issuer_pkalg = gnutls_x509_crt_get_pk_algorithm(issuer, &issuer_bits);
if (issuer_pkalg < 0)
return gnutls_assert_val(0);
}
switch (profile) {
CASE_SEC_PARAM(GNUTLS_PROFILE_VERY_WEAK, GNUTLS_SEC_PARAM_VERY_WEAK);
CASE_SEC_PARAM(GNUTLS_PROFILE_LOW, GNUTLS_SEC_PARAM_LOW);
CASE_SEC_PARAM(GNUTLS_PROFILE_LEGACY, GNUTLS_SEC_PARAM_LEGACY);
CASE_SEC_PARAM(GNUTLS_PROFILE_MEDIUM, GNUTLS_SEC_PARAM_MEDIUM);
CASE_SEC_PARAM(GNUTLS_PROFILE_HIGH, GNUTLS_SEC_PARAM_HIGH);
CASE_SEC_PARAM(GNUTLS_PROFILE_ULTRA, GNUTLS_SEC_PARAM_ULTRA);
CASE_SEC_PARAM(GNUTLS_PROFILE_FUTURE, GNUTLS_SEC_PARAM_FUTURE);
case GNUTLS_PROFILE_SUITEB128:
case GNUTLS_PROFILE_SUITEB192: {
unsigned curve, issuer_curve;
/* check suiteB params validity: rfc5759 */
if (gnutls_x509_crt_get_version(crt) != 3) {
_gnutls_debug_log("SUITEB: certificate uses an unacceptable version number\n");
return gnutls_assert_val(0);
}
if (sigalg != GNUTLS_SIGN_ECDSA_SHA256 && sigalg != GNUTLS_SIGN_ECDSA_SHA384) {
_gnutls_debug_log("SUITEB: certificate is not signed using ECDSA-SHA256 or ECDSA-SHA384\n");
return gnutls_assert_val(0);
}
if (pkalg != GNUTLS_PK_EC) {
_gnutls_debug_log("SUITEB: certificate does not contain ECC parameters\n");
return gnutls_assert_val(0);
}
if (issuer_pkalg != GNUTLS_PK_EC) {
_gnutls_debug_log("SUITEB: certificate's issuer does not have ECC parameters\n");
return gnutls_assert_val(0);
}
ret = _gnutls_x509_crt_get_mpis(crt, ¶ms);
if (ret < 0) {
_gnutls_debug_log("SUITEB: cannot read certificate params\n");
return gnutls_assert_val(0);
}
curve = params.curve;
gnutls_pk_params_release(¶ms);
if (curve != GNUTLS_ECC_CURVE_SECP256R1 &&
curve != GNUTLS_ECC_CURVE_SECP384R1) {
_gnutls_debug_log("SUITEB: certificate's ECC params do not contain SECP256R1 or SECP384R1\n");
return gnutls_assert_val(0);
}
if (profile == GNUTLS_PROFILE_SUITEB192) {
if (curve != GNUTLS_ECC_CURVE_SECP384R1) {
_gnutls_debug_log("SUITEB192: certificate does not use SECP384R1\n");
return gnutls_assert_val(0);
}
}
if (issuer != NULL) {
if (gnutls_x509_crt_get_version(issuer) != 3) {
_gnutls_debug_log("SUITEB: certificate's issuer uses an unacceptable version number\n");
return gnutls_assert_val(0);
}
ret = _gnutls_x509_crt_get_mpis(issuer, ¶ms);
if (ret < 0) {
_gnutls_debug_log("SUITEB: cannot read certificate params\n");
return gnutls_assert_val(0);
}
issuer_curve = params.curve;
gnutls_pk_params_release(¶ms);
if (issuer_curve != GNUTLS_ECC_CURVE_SECP256R1 &&
issuer_curve != GNUTLS_ECC_CURVE_SECP384R1) {
_gnutls_debug_log("SUITEB: certificate's issuer ECC params do not contain SECP256R1 or SECP384R1\n");
return gnutls_assert_val(0);
}
if (issuer_curve < curve) {
_gnutls_debug_log("SUITEB: certificate's issuer ECC params are weaker than the certificate's\n");
return gnutls_assert_val(0);
}
if (sigalg == GNUTLS_SIGN_ECDSA_SHA256 &&
issuer_curve == GNUTLS_ECC_CURVE_SECP384R1) {
_gnutls_debug_log("SUITEB: certificate is signed with ECDSA-SHA256 when using SECP384R1\n");
return gnutls_assert_val(0);
}
}
break;
case GNUTLS_PROFILE_UNKNOWN: /* already checked; avoid compiler warnings */
_gnutls_debug_log("An unknown profile (%d) was encountered\n", (int)profile);
}
}
return 1;
}
typedef struct verify_state_st {
time_t now;
unsigned int max_path;
gnutls_x509_name_constraints_t nc;
gnutls_x509_tlsfeatures_t tls_feat;
gnutls_verify_output_function *func;
} verify_state_st;
#define MARK_INVALID(x) { gnutls_assert(); \
out |= (x|GNUTLS_CERT_INVALID); \
result = 0; }
static int _gnutls_x509_verify_data(gnutls_sign_algorithm_t sign,
const gnutls_datum_t * data,
const gnutls_datum_t * signature,
gnutls_x509_crt_t cert,
gnutls_x509_crt_t issuer,
unsigned vflags);
/*
* Verifies the given certificate against a certificate list of
* trusted CAs.
*
* Returns only 0 or 1. If 1 it means that the certificate
* was successfully verified.
*
* 'flags': an OR of the gnutls_certificate_verify_flags enumeration.
*
* Output will hold some extra information about the verification
* procedure.
*/
static unsigned
verify_crt(gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * trusted_cas,
int tcas_size, unsigned int flags,
unsigned int *output,
verify_state_st *vparams,
unsigned end_cert)
{
gnutls_datum_t cert_signed_data = { NULL, 0 };
gnutls_datum_t cert_signature = { NULL, 0 };
gnutls_x509_crt_t issuer = NULL;
int issuer_version;
unsigned result = 1;
unsigned int out = 0, usage;
int sigalg, ret;
const gnutls_sign_entry_st *se;
if (output)
*output = 0;
if (vparams->max_path == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
/* bail immediately, to avoid inconistency */
goto cleanup;
}
vparams->max_path--;
if (tcas_size >= 1)
issuer = find_issuer(cert, trusted_cas, tcas_size);
ret =
_gnutls_x509_get_signed_data(cert->cert, &cert->der, "tbsCertificate",
&cert_signed_data);
if (ret < 0) {
MARK_INVALID(0);
cert_signed_data.data = NULL;
}
ret =
_gnutls_x509_get_signature(cert->cert, "signature",
&cert_signature);
if (ret < 0) {
MARK_INVALID(0);
cert_signature.data = NULL;
}
ret =
_gnutls_x509_get_signature_algorithm(cert->cert,
"signatureAlgorithm");
if (ret < 0) {
MARK_INVALID(0);
}
sigalg = ret;
se = _gnutls_sign_to_entry(sigalg);
/* issuer is not in trusted certificate
* authorities.
*/
if (issuer == NULL) {
MARK_INVALID(GNUTLS_CERT_SIGNER_NOT_FOUND);
} else {
if (vparams->nc != NULL) {
/* append the issuer's constraints */
ret = gnutls_x509_crt_get_name_constraints(issuer, vparams->nc,
GNUTLS_NAME_CONSTRAINTS_FLAG_APPEND, NULL);
if (ret < 0 && ret != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
/* only check name constraints in server certificates, not CAs */
if (end_cert != 0) {
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_DNSNAME, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_RFC822NAME, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_DN, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_URI, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
ret = gnutls_x509_name_constraints_check_crt(vparams->nc, GNUTLS_SAN_IPADDRESS, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto nc_done;
}
}
}
nc_done:
if (vparams->tls_feat != NULL) {
/* append the issuer's constraints */
ret = gnutls_x509_crt_get_tlsfeatures(issuer, vparams->tls_feat, GNUTLS_EXT_FLAG_APPEND, NULL);
if (ret < 0 && ret != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto feat_done;
}
ret = gnutls_x509_tlsfeatures_check_crt(vparams->tls_feat, cert);
if (ret == 0) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
goto feat_done;
}
}
feat_done:
issuer_version = gnutls_x509_crt_get_version(issuer);
if (issuer_version < 0) {
MARK_INVALID(0);
} else if (!(flags & GNUTLS_VERIFY_DISABLE_CA_SIGN) &&
((flags & GNUTLS_VERIFY_DO_NOT_ALLOW_X509_V1_CA_CRT)
|| issuer_version != 1)) {
if (check_if_ca(cert, issuer, &vparams->max_path, flags) != 1) {
MARK_INVALID(GNUTLS_CERT_SIGNER_NOT_CA);
}
ret =
gnutls_x509_crt_get_key_usage(issuer, &usage, NULL);
if (ret != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
if (ret < 0) {
MARK_INVALID(0);
} else if (!(usage & GNUTLS_KEY_KEY_CERT_SIGN)) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
}
}
}
if (sigalg < 0) {
MARK_INVALID(0);
} else if (cert_signed_data.data != NULL &&
cert_signature.data != NULL) {
ret =
_gnutls_x509_verify_data(sigalg,
&cert_signed_data,
&cert_signature,
cert,
issuer, flags);
if (ret == GNUTLS_E_PK_SIG_VERIFY_FAILED) {
MARK_INVALID(GNUTLS_CERT_SIGNATURE_FAILURE);
} else if (ret == GNUTLS_E_CONSTRAINT_ERROR) {
MARK_INVALID(GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE);
} else if (ret < 0) {
MARK_INVALID(0);
}
}
}
/* we always check the issuer for unsupported critical extensions */
if (issuer && check_for_unknown_exts(issuer) != 0) {
if (!(flags & GNUTLS_VERIFY_IGNORE_UNKNOWN_CRIT_EXTENSIONS)) {
MARK_INVALID(GNUTLS_CERT_UNKNOWN_CRIT_EXTENSIONS);
}
}
/* we only check the end-certificate for critical extensions; that
* way do not perform this check twice on the certificates when
* verifying a large list */
if (end_cert && check_for_unknown_exts(cert) != 0) {
if (!(flags & GNUTLS_VERIFY_IGNORE_UNKNOWN_CRIT_EXTENSIONS)) {
MARK_INVALID(GNUTLS_CERT_UNKNOWN_CRIT_EXTENSIONS);
}
}
if (sigalg >= 0 && se) {
if (is_level_acceptable(cert, issuer, sigalg, flags) == 0) {
MARK_INVALID(GNUTLS_CERT_INSECURE_ALGORITHM);
}
/* If the certificate is not self signed check if the algorithms
* used are secure. If the certificate is self signed it doesn't
* really matter.
*/
if (_gnutls_sign_is_secure2(se, GNUTLS_SIGN_FLAG_SECURE_FOR_CERTS) == 0 &&
_gnutls_is_broken_sig_allowed(se, flags) == 0 &&
is_issuer(cert, cert) == 0) {
MARK_INVALID(GNUTLS_CERT_INSECURE_ALGORITHM);
}
}
/* Check activation/expiration times
*/
if (!(flags & GNUTLS_VERIFY_DISABLE_TIME_CHECKS)) {
/* check the time of the issuer first */
if (issuer != NULL &&
!(flags & GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS)) {
out |= check_time_status(issuer, vparams->now);
if (out != 0) {
gnutls_assert();
result = 0;
}
}
out |= check_time_status(cert, vparams->now);
if (out != 0) {
gnutls_assert();
result = 0;
}
}
cleanup:
if (output)
*output |= out;
if (vparams->func) {
if (result == 0) {
out |= GNUTLS_CERT_INVALID;
}
vparams->func(cert, issuer, NULL, out);
}
_gnutls_free_datum(&cert_signed_data);
_gnutls_free_datum(&cert_signature);
return result;
}
/**
* gnutls_x509_crt_check_issuer:
* @cert: is the certificate to be checked
* @issuer: is the certificate of a possible issuer
*
* This function will check if the given certificate was issued by the
* given issuer. It checks the DN fields and the authority
* key identifier and subject key identifier fields match.
*
* If the same certificate is provided at the @cert and @issuer fields,
* it will check whether the certificate is self-signed.
*
* Returns: It will return true (1) if the given certificate is issued
* by the given issuer, and false (0) if not.
**/
unsigned
gnutls_x509_crt_check_issuer(gnutls_x509_crt_t cert,
gnutls_x509_crt_t issuer)
{
return is_issuer(cert, issuer);
}
static
unsigned check_ca_sanity(const gnutls_x509_crt_t issuer,
time_t now, unsigned int flags)
{
unsigned int status = 0;
unsigned sigalg;
int ret;
/* explicit time check for trusted CA that we remove from
* list. GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS
*/
if (!(flags & GNUTLS_VERIFY_DISABLE_TRUSTED_TIME_CHECKS) &&
!(flags & GNUTLS_VERIFY_DISABLE_TIME_CHECKS)) {
status |= check_time_status(issuer, now);
}
ret =
_gnutls_x509_get_signature_algorithm(issuer->cert, "signatureAlgorithm");
sigalg = ret;
/* we explicitly allow CAs which we do not support their self-algorithms
* to pass. */
if (ret >= 0 && !is_level_acceptable(issuer, NULL, sigalg, flags)) {
status |= GNUTLS_CERT_INSECURE_ALGORITHM|GNUTLS_CERT_INVALID;
}
return status;
}
/* Verify X.509 certificate chain.
*
* Note that the return value is an OR of GNUTLS_CERT_* elements.
*
* This function verifies a X.509 certificate list. The certificate
* list should lead to a trusted certificate in order to be trusted.
*/
unsigned int
_gnutls_verify_crt_status(const gnutls_x509_crt_t * certificate_list,
int clist_size,
const gnutls_x509_crt_t * trusted_cas,
int tcas_size,
unsigned int flags,
const char *purpose,
gnutls_verify_output_function func)
{
int i = 0, ret;
unsigned int status = 0, output;
time_t now = gnutls_time(0);
verify_state_st vparams;
if (clist_size > 1) {
/* Check if the last certificate in the path is self signed.
* In that case ignore it (a certificate is trusted only if it
* leads to a trusted party by us, not the server's).
*
* This prevents from verifying self signed certificates against
* themselves. This (although not bad) caused verification
* failures on some root self signed certificates that use the
* MD2 algorithm.
*/
if (gnutls_x509_crt_check_issuer
(certificate_list[clist_size - 1],
certificate_list[clist_size - 1]) != 0) {
clist_size--;
}
}
/* We want to shorten the chain by removing the cert that matches
* one of the certs we trust and all the certs after that i.e. if
* cert chain is A signed-by B signed-by C signed-by D (signed-by
* self-signed E but already removed above), and we trust B, remove
* B, C and D. */
if (!(flags & GNUTLS_VERIFY_DO_NOT_ALLOW_SAME))
i = 0; /* also replace the first one */
else
i = 1; /* do not replace the first one */
for (; i < clist_size; i++) {
int j;
for (j = 0; j < tcas_size; j++) {
/* we check for a certificate that may not be identical with the one
* sent by the client, but will have the same name and key. That is
* because it can happen that a CA certificate is upgraded from intermediate
* CA to self-signed CA at some point. */
if (_gnutls_check_if_same_key
(certificate_list[i], trusted_cas[j], i) != 0) {
status |= check_ca_sanity(trusted_cas[j], now, flags);
if (func)
func(certificate_list[i],
trusted_cas[j], NULL, status);
if (status != 0) {
return gnutls_assert_val(status);
}
clist_size = i;
break;
}
}
/* clist_size may have been changed which gets out of loop */
}
if (clist_size == 0) {
/* The certificate is already present in the trusted certificate list.
* Nothing to verify. */
return status;
}
memset(&vparams, 0, sizeof(vparams));
vparams.now = now;
vparams.max_path = MAX_VERIFY_DEPTH;
vparams.func = func;
ret = gnutls_x509_name_constraints_init(&vparams.nc);
if (ret < 0) {
gnutls_assert();
status |= GNUTLS_CERT_INVALID;
return status;
}
ret = gnutls_x509_tlsfeatures_init(&vparams.tls_feat);
if (ret < 0) {
gnutls_assert();
status |= GNUTLS_CERT_INVALID;
goto cleanup;
}
/* Verify the last certificate in the certificate path
* against the trusted CA certificate list.
*
* If no CAs are present returns CERT_INVALID. Thus works
* in self signed etc certificates.
*/
output = 0;
ret = verify_crt(certificate_list[clist_size - 1],
trusted_cas, tcas_size, flags,
&output,
&vparams,
clist_size==1?1:0);
if (ret != 1) {
/* if the last certificate in the certificate
* list is invalid, then the certificate is not
* trusted.
*/
gnutls_assert();
status |= output;
status |= GNUTLS_CERT_INVALID;
goto cleanup;
}
/* Verify the certificate path (chain)
*/
for (i = clist_size - 1; i > 0; i--) {
output = 0;
if (purpose != NULL) {
ret = _gnutls_check_key_purpose(certificate_list[i], purpose, 1);
if (ret != 1) {
gnutls_assert();
status |= GNUTLS_CERT_INVALID;
status |= GNUTLS_CERT_PURPOSE_MISMATCH;
if (func)
func(certificate_list[i-1],
certificate_list[i], NULL, status);
goto cleanup;
}
}
/* note that here we disable this V1 CA flag. So that no version 1
* certificates can exist in a supplied chain.
*/
if (!(flags & GNUTLS_VERIFY_ALLOW_ANY_X509_V1_CA_CRT)) {
flags |= GNUTLS_VERIFY_DO_NOT_ALLOW_X509_V1_CA_CRT;
}
if ((ret =
verify_crt(certificate_list[i - 1],
&certificate_list[i], 1,
flags, &output,
&vparams,
i==1?1:0)) != 1) {
gnutls_assert();
status |= output;
status |= GNUTLS_CERT_INVALID;
goto cleanup;
}
}
cleanup:
gnutls_x509_name_constraints_deinit(vparams.nc);
gnutls_x509_tlsfeatures_deinit(vparams.tls_feat);
return status;
}
#define PURPOSE_NSSGC "2.16.840.1.113730.4.1"
#define PURPOSE_VSGC "2.16.840.1.113733.1.8.1"
/* Returns true if the provided purpose is in accordance with the certificate.
*/
unsigned _gnutls_check_key_purpose(gnutls_x509_crt_t cert, const char *purpose, unsigned no_any)
{
char oid[MAX_OID_SIZE];
size_t oid_size;
int ret;
unsigned critical = 0;
unsigned check_obsolete_oids = 0;
unsigned i;
/* The check_obsolete_oids hack is because of certain very old CA certificates
* around which instead of having the GNUTLS_KP_TLS_WWW_SERVER have some old
* OIDs for that purpose. Assume these OIDs equal GNUTLS_KP_TLS_WWW_SERVER in
* CA certs */
if (strcmp(purpose, GNUTLS_KP_TLS_WWW_SERVER) == 0) {
unsigned ca_status;
ret =
gnutls_x509_crt_get_basic_constraints(cert, NULL, &ca_status,
NULL);
if (ret < 0)
ca_status = 0;
if (ca_status)
check_obsolete_oids = 1;
}
for (i=0;;i++) {
oid_size = sizeof(oid);
ret = gnutls_x509_crt_get_key_purpose_oid(cert, i, oid, &oid_size, &critical);
if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
if (i==0) {
/* no key purpose in certificate, assume ANY */
return 1;
} else {
gnutls_assert();
break;
}
} else if (ret < 0) {
gnutls_assert();
break;
}
if (check_obsolete_oids) {
if (strcmp(oid, PURPOSE_NSSGC) == 0) {
return 1;
} else if (strcmp(oid, PURPOSE_VSGC) == 0) {
return 1;
}
}
if (strcmp(oid, purpose) == 0 || (no_any == 0 && strcmp(oid, GNUTLS_KP_ANY) == 0)) {
return 1;
}
_gnutls_debug_log("looking for key purpose '%s', but have '%s'\n", purpose, oid);
}
return 0;
}
#ifdef ENABLE_PKCS11
/* Verify X.509 certificate chain using a PKCS #11 token.
*
* Note that the return value is an OR of GNUTLS_CERT_* elements.
*
* Unlike the non-PKCS#11 version, this function accepts a key purpose
* (from GNUTLS_KP_...). That is because in the p11-kit trust modules
* anchors are mixed and get assigned a purpose.
*
* This function verifies a X.509 certificate list. The certificate
* list should lead to a trusted certificate in order to be trusted.
*/
unsigned int
_gnutls_pkcs11_verify_crt_status(const char* url,
const gnutls_x509_crt_t * certificate_list,
unsigned clist_size,
const char *purpose,
unsigned int flags,
gnutls_verify_output_function func)
{
int ret;
unsigned int status = 0, i;
gnutls_x509_crt_t issuer = NULL;
gnutls_datum_t raw_issuer = {NULL, 0};
time_t now = gnutls_time(0);
if (clist_size > 1) {
/* Check if the last certificate in the path is self signed.
* In that case ignore it (a certificate is trusted only if it
* leads to a trusted party by us, not the server's).
*
* This prevents from verifying self signed certificates against
* themselves. This (although not bad) caused verification
* failures on some root self signed certificates that use the
* MD2 algorithm.
*/
if (gnutls_x509_crt_check_issuer
(certificate_list[clist_size - 1],
certificate_list[clist_size - 1]) != 0) {
clist_size--;
}
}
/* We want to shorten the chain by removing the cert that matches
* one of the certs we trust and all the certs after that i.e. if
* cert chain is A signed-by B signed-by C signed-by D (signed-by
* self-signed E but already removed above), and we trust B, remove
* B, C and D. */
if (!(flags & GNUTLS_VERIFY_DO_NOT_ALLOW_SAME))
i = 0; /* also replace the first one */
else
i = 1; /* do not replace the first one */
for (; i < clist_size; i++) {
unsigned vflags;
gnutls_x509_crt_t trusted_cert;
if (i == 0) /* in the end certificate do full comparison */
vflags = GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE|
GNUTLS_PKCS11_OBJ_FLAG_COMPARE|GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_TRUSTED;
else
vflags = GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE|
GNUTLS_PKCS11_OBJ_FLAG_COMPARE_KEY|GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_TRUSTED;
if (_gnutls_pkcs11_crt_is_known (url, certificate_list[i], vflags, &trusted_cert) != 0) {
status |= check_ca_sanity(trusted_cert, now, flags);
gnutls_x509_crt_deinit(trusted_cert);
if (func)
func(certificate_list[i],
certificate_list[i], NULL, status);
if (status != 0) {
return gnutls_assert_val(status);
}
clist_size = i;
break;
}
/* clist_size may have been changed which gets out of loop */
}
if (clist_size == 0) {
/* The certificate is already present in the trusted certificate list.
* Nothing to verify. */
return status;
}
/* check for blacklists */
for (i = 0; i < clist_size; i++) {
if (gnutls_pkcs11_crt_is_known (url, certificate_list[i],
GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE|
GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_DISTRUSTED) != 0) {
status |= GNUTLS_CERT_INVALID;
status |= GNUTLS_CERT_REVOKED;
if (func)
func(certificate_list[i], certificate_list[i], NULL, status);
goto cleanup;
}
}
/* check against issuer */
ret = gnutls_pkcs11_get_raw_issuer(url, certificate_list[clist_size - 1],
&raw_issuer, GNUTLS_X509_FMT_DER,
GNUTLS_PKCS11_OBJ_FLAG_OVERWRITE_TRUSTMOD_EXT|GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE);
if (ret < 0) {
gnutls_assert();
if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE && clist_size > 2) {
/* check if the last certificate in the chain is present
* in our trusted list, and if yes, verify against it. */
ret = gnutls_pkcs11_crt_is_known(url, certificate_list[clist_size - 1],
GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_TRUSTED|GNUTLS_PKCS11_OBJ_FLAG_COMPARE);
if (ret != 0) {
return _gnutls_verify_crt_status(certificate_list, clist_size,
&certificate_list[clist_size - 1], 1, flags,
purpose, func);
}
}
status |= GNUTLS_CERT_INVALID;
status |= GNUTLS_CERT_SIGNER_NOT_FOUND;
/* verify the certificate list against 0 trusted CAs in order
* to get, any additional flags from the certificate list (e.g.,
* insecure algorithms or expired */
status |= _gnutls_verify_crt_status(certificate_list, clist_size,
NULL, 0, flags, purpose, func);
goto cleanup;
}
ret = gnutls_x509_crt_init(&issuer);
if (ret < 0) {
gnutls_assert();
status |= GNUTLS_CERT_INVALID;
status |= GNUTLS_CERT_SIGNER_NOT_FOUND;
goto cleanup;
}
ret = gnutls_x509_crt_import(issuer, &raw_issuer, GNUTLS_X509_FMT_DER);
if (ret < 0) {
gnutls_assert();
status |= GNUTLS_CERT_INVALID;
status |= GNUTLS_CERT_SIGNER_NOT_FOUND;
goto cleanup;
}
/* check if the raw issuer is blacklisted (it can happen if
* the issuer is both in the trusted list and the blacklisted)
*/
if (gnutls_pkcs11_crt_is_known (url, issuer,
GNUTLS_PKCS11_OBJ_FLAG_PRESENT_IN_TRUSTED_MODULE|
GNUTLS_PKCS11_OBJ_FLAG_RETRIEVE_DISTRUSTED) != 0) {
status |= GNUTLS_CERT_INVALID;
status |= GNUTLS_CERT_SIGNER_NOT_FOUND; /* if the signer is revoked - it is as if it doesn't exist */
goto cleanup;
}
/* security modules that provide trust, bundle all certificates (of all purposes)
* together. In software that doesn't specify any purpose assume the default to
* be www-server. */
ret = _gnutls_check_key_purpose(issuer, purpose==NULL?GNUTLS_KP_TLS_WWW_SERVER:purpose, 0);
if (ret != 1) {
gnutls_assert();
status |= GNUTLS_CERT_INVALID;
status |= GNUTLS_CERT_SIGNER_NOT_FOUND;
goto cleanup;
}
status = _gnutls_verify_crt_status(certificate_list, clist_size,
&issuer, 1, flags, purpose, func);
cleanup:
gnutls_free(raw_issuer.data);
if (issuer != NULL)
gnutls_x509_crt_deinit(issuer);
return status;
}
#endif
static int
_gnutls_x509_validate_sign_params(gnutls_pk_algorithm_t pk_algorithm,
ASN1_TYPE cert,
const char *name,
gnutls_x509_spki_st *sig_params)
{
/* The signature parameter validation is only needed for RSA-PSS */
if (pk_algorithm == GNUTLS_PK_RSA_PSS) {
int result;
gnutls_x509_spki_st params;
result = _gnutls_x509_read_sign_params(cert, name, ¶ms);
if (result < 0) {
/* If parameters field is absent, no parameter
* validation is needed */
if (result != GNUTLS_E_ASN1_ELEMENT_NOT_FOUND &&
result != GNUTLS_E_ASN1_VALUE_NOT_FOUND) {
gnutls_assert();
return result;
}
} else {
/* Check if the underlying hash algorithms are same. */
if (sig_params->rsa_pss_dig != params.rsa_pss_dig) {
gnutls_assert();
return GNUTLS_E_CONSTRAINT_ERROR;
}
/* The salt length used to generate the
* signature must be equal to or larger than
* the one in the key parameter. */
if (sig_params->salt_size < params.salt_size) {
gnutls_assert();
return GNUTLS_E_CONSTRAINT_ERROR;
}
}
}
return 0;
}
/* verifies if the certificate is properly signed.
* returns GNUTLS_E_PK_VERIFY_SIG_FAILED on failure and 1 on success.
*
* 'data' is the signed data
* 'signature' is the signature!
*/
static int
_gnutls_x509_verify_data(gnutls_sign_algorithm_t sign,
const gnutls_datum_t * data,
const gnutls_datum_t * signature,
gnutls_x509_crt_t cert,
gnutls_x509_crt_t issuer,
unsigned vflags)
{
gnutls_pk_params_st params;
gnutls_pk_algorithm_t issuer_pk;
int ret;
gnutls_x509_spki_st sign_params;
const gnutls_sign_entry_st *se;
/* Read the MPI parameters from the issuer's certificate.
*/
ret = _gnutls_x509_crt_get_mpis(issuer, ¶ms);
if (ret < 0) {
gnutls_assert();
return ret;
}
issuer_pk = gnutls_x509_crt_get_pk_algorithm(issuer, NULL);
se = _gnutls_sign_to_entry(sign);
if (se == NULL)
return gnutls_assert_val(GNUTLS_E_UNSUPPORTED_SIGNATURE_ALGORITHM);
if (cert != NULL) {
ret = _gnutls_x509_read_sign_params(cert->cert,
"signatureAlgorithm",
&sign_params);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
ret = _gnutls_x509_validate_sign_params(issuer_pk,
issuer->cert,
"tbsCertificate."
"subjectPublicKeyInfo."
"algorithm",
&sign_params);
if (ret < 0) {
gnutls_assert();
goto cleanup;
}
} else {
memcpy(&sign_params, ¶ms.spki,
sizeof(gnutls_x509_spki_st));
sign_params.pk = se->pk;
if (sign_params.pk == GNUTLS_PK_RSA_PSS)
sign_params.rsa_pss_dig = se->hash;
}
ret = pubkey_verify_data(se, hash_to_entry(se->hash), data, signature, ¶ms,
&sign_params, vflags);
if (ret < 0) {
gnutls_assert();
}
cleanup:
/* release all allocated MPIs
*/
gnutls_pk_params_release(¶ms);
return ret;
}
/**
* gnutls_x509_crt_list_verify:
* @cert_list: is the certificate list to be verified
* @cert_list_length: holds the number of certificate in cert_list
* @CA_list: is the CA list which will be used in verification
* @CA_list_length: holds the number of CA certificate in CA_list
* @CRL_list: holds a list of CRLs.
* @CRL_list_length: the length of CRL list.
* @flags: Flags that may be used to change the verification algorithm. Use OR of the gnutls_certificate_verify_flags enumerations.
* @verify: will hold the certificate verification output.
*
*
* This function will try to verify the given certificate list and
* return its status. The details of the verification are the same
* as in gnutls_x509_trust_list_verify_crt2().
*
* You must check the peer's name in order to check if the verified
* certificate belongs to the actual peer.
*
* The certificate verification output will be put in @verify and will
* be one or more of the gnutls_certificate_status_t enumerated
* elements bitwise or'd. For a more detailed verification status use
* gnutls_x509_crt_verify() per list element.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
* negative error value.
**/
int
gnutls_x509_crt_list_verify(const gnutls_x509_crt_t * cert_list,
unsigned cert_list_length,
const gnutls_x509_crt_t * CA_list,
unsigned CA_list_length,
const gnutls_x509_crl_t * CRL_list,
unsigned CRL_list_length, unsigned int flags,
unsigned int *verify)
{
unsigned i;
int ret;
if (cert_list == NULL || cert_list_length == 0)
return GNUTLS_E_NO_CERTIFICATE_FOUND;
/* Verify certificate
*/
*verify =
_gnutls_verify_crt_status(cert_list, cert_list_length,
CA_list, CA_list_length,
flags, NULL, NULL);
/* Check for revoked certificates in the chain.
*/
for (i = 0; i < cert_list_length; i++) {
ret = gnutls_x509_crt_check_revocation(cert_list[i],
CRL_list,
CRL_list_length);
if (ret == 1) { /* revoked */
*verify |= GNUTLS_CERT_REVOKED;
*verify |= GNUTLS_CERT_INVALID;
}
}
return 0;
}
/**
* gnutls_x509_crt_verify:
* @cert: is the certificate to be verified
* @CA_list: is one certificate that is considered to be trusted one
* @CA_list_length: holds the number of CA certificate in CA_list
* @flags: Flags that may be used to change the verification algorithm. Use OR of the gnutls_certificate_verify_flags enumerations.
* @verify: will hold the certificate verification output.
*
* This function will try to verify the given certificate and return
* its status. Note that a verification error does not imply a negative
* return status. In that case the @verify status is set.
*
* The details of the verification are the same
* as in gnutls_x509_trust_list_verify_crt2().
*
* Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a
* negative error value.
**/
int
gnutls_x509_crt_verify(gnutls_x509_crt_t cert,
const gnutls_x509_crt_t * CA_list,
unsigned CA_list_length, unsigned int flags,
unsigned int *verify)
{
/* Verify certificate
*/
*verify =
_gnutls_verify_crt_status(&cert, 1,
CA_list, CA_list_length,
flags, NULL, NULL);
return 0;
}
/**
* gnutls_x509_crl_check_issuer:
* @crl: is the CRL to be checked
* @issuer: is the certificate of a possible issuer
*
* This function will check if the given CRL was issued by the given
* issuer certificate.
*
* Returns: true (1) if the given CRL was issued by the given issuer,
* and false (0) if not.
**/
unsigned
gnutls_x509_crl_check_issuer(gnutls_x509_crl_t crl,
gnutls_x509_crt_t issuer)
{
return is_crl_issuer(crl, issuer);
}
static inline gnutls_x509_crt_t
find_crl_issuer(gnutls_x509_crl_t crl,
const gnutls_x509_crt_t * trusted_cas, int tcas_size)
{
int i;
/* this is serial search.
*/
for (i = 0; i < tcas_size; i++) {
if (is_crl_issuer(crl, trusted_cas[i]) != 0)
return trusted_cas[i];
}
gnutls_assert();
return NULL;
}
/**
* gnutls_x509_crl_verify:
* @crl: is the crl to be verified
* @trusted_cas: is a certificate list that is considered to be trusted one
* @tcas_size: holds the number of CA certificates in CA_list
* @flags: Flags that may be used to change the verification algorithm. Use OR of the gnutls_certificate_verify_flags enumerations.
* @verify: will hold the crl verification output.
*
* This function will try to verify the given crl and return its verification status.
* See gnutls_x509_crt_list_verify() for a detailed description of
* return values. Note that since GnuTLS 3.1.4 this function includes
* the time checks.
*
* Note that value in @verify is set only when the return value of this
* function is success (i.e, failure to trust a CRL a certificate does not imply
* a negative return value).
*
* Before GnuTLS 3.5.7 this function would return zero or a positive
* number on success.
*
* Returns: On success, %GNUTLS_E_SUCCESS (0), otherwise a
* negative error value.
**/
int
gnutls_x509_crl_verify(gnutls_x509_crl_t crl,
const gnutls_x509_crt_t * trusted_cas,
unsigned tcas_size, unsigned int flags,
unsigned int *verify)
{
/* CRL is ignored for now */
gnutls_datum_t crl_signed_data = { NULL, 0 };
gnutls_datum_t crl_signature = { NULL, 0 };
gnutls_x509_crt_t issuer = NULL;
int result, sigalg;
time_t now = gnutls_time(0);
time_t nextu;
unsigned int usage;
if (verify)
*verify = 0;
if (tcas_size >= 1)
issuer = find_crl_issuer(crl, trusted_cas, tcas_size);
result =
_gnutls_x509_get_signed_data(crl->crl, &crl->der, "tbsCertList",
&crl_signed_data);
if (result < 0) {
gnutls_assert();
if (verify)
*verify |= GNUTLS_CERT_INVALID;
goto cleanup;
}
result =
_gnutls_x509_get_signature(crl->crl, "signature",
&crl_signature);
if (result < 0) {
gnutls_assert();
if (verify)
*verify |= GNUTLS_CERT_INVALID;
goto cleanup;
}
sigalg =
_gnutls_x509_get_signature_algorithm(crl->crl,
"signatureAlgorithm");
if (sigalg < 0) {
gnutls_assert();
if (verify)
*verify |= GNUTLS_CERT_INVALID;
goto cleanup;
}
/* issuer is not in trusted certificate
* authorities.
*/
if (issuer == NULL) {
gnutls_assert();
if (verify)
*verify |=
GNUTLS_CERT_SIGNER_NOT_FOUND |
GNUTLS_CERT_INVALID;
} else {
if (!(flags & GNUTLS_VERIFY_DISABLE_CA_SIGN)) {
if (gnutls_x509_crt_get_ca_status(issuer, NULL) != 1) {
gnutls_assert();
if (verify)
*verify |=
GNUTLS_CERT_SIGNER_NOT_CA |
GNUTLS_CERT_INVALID;
}
result =
gnutls_x509_crt_get_key_usage(issuer, &usage, NULL);
if (result != GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE) {
if (result < 0) {
gnutls_assert();
if (verify)
*verify |= GNUTLS_CERT_INVALID;
} else if (!(usage & GNUTLS_KEY_CRL_SIGN)) {
gnutls_assert();
if (verify)
*verify |=
GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE
| GNUTLS_CERT_INVALID;
}
}
}
result =
_gnutls_x509_verify_data(sigalg,
&crl_signed_data, &crl_signature,
NULL,
issuer, flags);
if (result == GNUTLS_E_PK_SIG_VERIFY_FAILED) {
gnutls_assert();
/* error. ignore it */
if (verify)
*verify |= GNUTLS_CERT_SIGNATURE_FAILURE;
result = 0;
} else if (result == GNUTLS_E_CONSTRAINT_ERROR) {
if (verify)
*verify |= GNUTLS_CERT_SIGNER_CONSTRAINTS_FAILURE;
result = 0;
} else if (result < 0) {
gnutls_assert();
if (verify)
*verify |= GNUTLS_CERT_INVALID;
goto cleanup;
} else if (result >= 0) {
result = 0; /* everything ok */
}
}
{
sigalg = gnutls_x509_crl_get_signature_algorithm(crl);
if (((sigalg == GNUTLS_SIGN_RSA_MD2) &&
!(flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD2)) ||
((sigalg == GNUTLS_SIGN_RSA_MD5) &&
!(flags & GNUTLS_VERIFY_ALLOW_SIGN_RSA_MD5))) {
if (verify)
*verify |= GNUTLS_CERT_INSECURE_ALGORITHM;
result = 0;
}
}
if (gnutls_x509_crl_get_this_update(crl) > now && verify)
*verify |= GNUTLS_CERT_REVOCATION_DATA_ISSUED_IN_FUTURE;
nextu = gnutls_x509_crl_get_next_update(crl);
if (nextu != -1 && nextu < now && verify)
*verify |= GNUTLS_CERT_REVOCATION_DATA_SUPERSEDED;
cleanup:
if (verify && *verify != 0)
*verify |= GNUTLS_CERT_INVALID;
_gnutls_free_datum(&crl_signed_data);
_gnutls_free_datum(&crl_signature);
return result;
}