blob: 32fdb6045a6b1382908f4cc5d3f73f489bf03b8f [file] [log] [blame]
/*
* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
* 2001.
*/
/* ====================================================================
* Copyright (c) 1999-2004 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#include <stdio.h>
#include <string.h>
#include <openssl/digest.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include <openssl/thread.h>
#include <openssl/x509.h>
#include "../internal.h"
#include "internal.h"
#define V1_ROOT (EXFLAG_V1 | EXFLAG_SS)
#define ku_reject(x, usage) \
(((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
#define xku_reject(x, usage) \
(((x)->ex_flags & EXFLAG_XKUSAGE) && !((x)->ex_xkusage & (usage)))
#define ns_reject(x, usage) \
(((x)->ex_flags & EXFLAG_NSCERT) && !((x)->ex_nscert & (usage)))
static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
int ca);
static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
int ca);
static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
int ca);
static int purpose_smime(const X509 *x, int ca);
static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
int ca);
static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
int ca);
static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
int ca);
static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
int ca);
static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca);
static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca);
static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b);
static void xptable_free(X509_PURPOSE *p);
static X509_PURPOSE xstandard[] = {
{X509_PURPOSE_SSL_CLIENT, X509_TRUST_SSL_CLIENT, 0,
check_purpose_ssl_client, (char *)"SSL client", (char *)"sslclient", NULL},
{X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
check_purpose_ssl_server, (char *)"SSL server", (char *)"sslserver", NULL},
{X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
check_purpose_ns_ssl_server, (char *)"Netscape SSL server",
(char *)"nssslserver", NULL},
{X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
(char *)"S/MIME signing", (char *)"smimesign", NULL},
{X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
check_purpose_smime_encrypt, (char *)"S/MIME encryption",
(char *)"smimeencrypt", NULL},
{X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
(char *)"CRL signing", (char *)"crlsign", NULL},
{X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, (char *)"Any Purpose",
(char *)"any", NULL},
{X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
(char *)"OCSP helper", (char *)"ocsphelper", NULL},
{X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
check_purpose_timestamp_sign, (char *)"Time Stamp signing",
(char *)"timestampsign", NULL},
};
#define X509_PURPOSE_COUNT (sizeof(xstandard) / sizeof(X509_PURPOSE))
static STACK_OF(X509_PURPOSE) *xptable = NULL;
static int xp_cmp(const X509_PURPOSE *const *a, const X509_PURPOSE *const *b) {
return (*a)->purpose - (*b)->purpose;
}
// As much as I'd like to make X509_check_purpose use a "const" X509* I
// really can't because it does recalculate hashes and do other non-const
// things.
int X509_check_purpose(X509 *x, int id, int ca) {
int idx;
const X509_PURPOSE *pt;
if (!x509v3_cache_extensions(x)) {
return -1;
}
if (id == -1) {
return 1;
}
idx = X509_PURPOSE_get_by_id(id);
if (idx == -1) {
return -1;
}
pt = X509_PURPOSE_get0(idx);
return pt->check_purpose(pt, x, ca);
}
int X509_PURPOSE_set(int *p, int purpose) {
if (X509_PURPOSE_get_by_id(purpose) == -1) {
OPENSSL_PUT_ERROR(X509V3, X509V3_R_INVALID_PURPOSE);
return 0;
}
*p = purpose;
return 1;
}
int X509_PURPOSE_get_count(void) {
if (!xptable) {
return X509_PURPOSE_COUNT;
}
return sk_X509_PURPOSE_num(xptable) + X509_PURPOSE_COUNT;
}
X509_PURPOSE *X509_PURPOSE_get0(int idx) {
if (idx < 0) {
return NULL;
}
if (idx < (int)X509_PURPOSE_COUNT) {
return xstandard + idx;
}
return sk_X509_PURPOSE_value(xptable, idx - X509_PURPOSE_COUNT);
}
int X509_PURPOSE_get_by_sname(const char *sname) {
X509_PURPOSE *xptmp;
for (int i = 0; i < X509_PURPOSE_get_count(); i++) {
xptmp = X509_PURPOSE_get0(i);
if (!strcmp(xptmp->sname, sname)) {
return i;
}
}
return -1;
}
int X509_PURPOSE_get_by_id(int purpose) {
X509_PURPOSE tmp;
size_t idx;
if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX)) {
return purpose - X509_PURPOSE_MIN;
}
tmp.purpose = purpose;
if (!xptable) {
return -1;
}
if (!sk_X509_PURPOSE_find(xptable, &idx, &tmp)) {
return -1;
}
return idx + X509_PURPOSE_COUNT;
}
int X509_PURPOSE_add(int id, int trust, int flags,
int (*ck)(const X509_PURPOSE *, const X509 *, int),
const char *name, const char *sname, void *arg) {
X509_PURPOSE *ptmp;
char *name_dup, *sname_dup;
// This is set according to what we change: application can't set it
flags &= ~X509_PURPOSE_DYNAMIC;
// This will always be set for application modified trust entries
flags |= X509_PURPOSE_DYNAMIC_NAME;
// Get existing entry if any
int idx = X509_PURPOSE_get_by_id(id);
// Need a new entry
if (idx == -1) {
if (!(ptmp = OPENSSL_malloc(sizeof(X509_PURPOSE)))) {
return 0;
}
ptmp->flags = X509_PURPOSE_DYNAMIC;
} else {
ptmp = X509_PURPOSE_get0(idx);
}
// Duplicate the supplied names.
name_dup = OPENSSL_strdup(name);
sname_dup = OPENSSL_strdup(sname);
if (name_dup == NULL || sname_dup == NULL) {
if (name_dup != NULL) {
OPENSSL_free(name_dup);
}
if (sname_dup != NULL) {
OPENSSL_free(sname_dup);
}
if (idx == -1) {
OPENSSL_free(ptmp);
}
return 0;
}
// OPENSSL_free existing name if dynamic
if (ptmp->flags & X509_PURPOSE_DYNAMIC_NAME) {
OPENSSL_free(ptmp->name);
OPENSSL_free(ptmp->sname);
}
// dup supplied name
ptmp->name = name_dup;
ptmp->sname = sname_dup;
// Keep the dynamic flag of existing entry
ptmp->flags &= X509_PURPOSE_DYNAMIC;
// Set all other flags
ptmp->flags |= flags;
ptmp->purpose = id;
ptmp->trust = trust;
ptmp->check_purpose = ck;
ptmp->usr_data = arg;
// If its a new entry manage the dynamic table
if (idx == -1) {
// TODO(davidben): This should be locked. Alternatively, remove the dynamic
// registration mechanism entirely. The trouble is there no way to pass in
// the various parameters into an |X509_VERIFY_PARAM| directly. You can only
// register it in the global table and get an ID.
if (!xptable && !(xptable = sk_X509_PURPOSE_new(xp_cmp))) {
xptable_free(ptmp);
return 0;
}
if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
xptable_free(ptmp);
return 0;
}
sk_X509_PURPOSE_sort(xptable);
}
return 1;
}
static void xptable_free(X509_PURPOSE *p) {
if (!p) {
return;
}
if (p->flags & X509_PURPOSE_DYNAMIC) {
if (p->flags & X509_PURPOSE_DYNAMIC_NAME) {
OPENSSL_free(p->name);
OPENSSL_free(p->sname);
}
OPENSSL_free(p);
}
}
void X509_PURPOSE_cleanup(void) {
unsigned int i;
sk_X509_PURPOSE_pop_free(xptable, xptable_free);
for (i = 0; i < X509_PURPOSE_COUNT; i++) {
xptable_free(xstandard + i);
}
xptable = NULL;
}
int X509_PURPOSE_get_id(const X509_PURPOSE *xp) { return xp->purpose; }
char *X509_PURPOSE_get0_name(const X509_PURPOSE *xp) { return xp->name; }
char *X509_PURPOSE_get0_sname(const X509_PURPOSE *xp) { return xp->sname; }
int X509_PURPOSE_get_trust(const X509_PURPOSE *xp) { return xp->trust; }
static int nid_cmp(const void *void_a, const void *void_b) {
const int *a = void_a, *b = void_b;
return *a - *b;
}
int X509_supported_extension(const X509_EXTENSION *ex) {
// This table is a list of the NIDs of supported extensions: that is
// those which are used by the verify process. If an extension is
// critical and doesn't appear in this list then the verify process will
// normally reject the certificate. The list must be kept in numerical
// order because it will be searched using bsearch.
static const int supported_nids[] = {
NID_netscape_cert_type, // 71
NID_key_usage, // 83
NID_subject_alt_name, // 85
NID_basic_constraints, // 87
NID_certificate_policies, // 89
NID_ext_key_usage, // 126
NID_policy_constraints, // 401
NID_name_constraints, // 666
NID_policy_mappings, // 747
NID_inhibit_any_policy // 748
};
int ex_nid = OBJ_obj2nid(X509_EXTENSION_get_object(ex));
if (ex_nid == NID_undef) {
return 0;
}
if (bsearch(&ex_nid, supported_nids, sizeof(supported_nids) / sizeof(int),
sizeof(int), nid_cmp) != NULL) {
return 1;
}
return 0;
}
static int setup_dp(X509 *x, DIST_POINT *dp) {
if (!dp->distpoint || (dp->distpoint->type != 1)) {
return 1;
}
X509_NAME *iname = NULL;
for (size_t i = 0; i < sk_GENERAL_NAME_num(dp->CRLissuer); i++) {
GENERAL_NAME *gen = sk_GENERAL_NAME_value(dp->CRLissuer, i);
if (gen->type == GEN_DIRNAME) {
iname = gen->d.directoryName;
break;
}
}
if (!iname) {
iname = X509_get_issuer_name(x);
}
return DIST_POINT_set_dpname(dp->distpoint, iname);
}
static int setup_crldp(X509 *x) {
int j;
x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, &j, NULL);
if (x->crldp == NULL && j != -1) {
return 0;
}
for (size_t i = 0; i < sk_DIST_POINT_num(x->crldp); i++) {
if (!setup_dp(x, sk_DIST_POINT_value(x->crldp, i))) {
return 0;
}
}
return 1;
}
int x509v3_cache_extensions(X509 *x) {
BASIC_CONSTRAINTS *bs;
ASN1_BIT_STRING *usage;
ASN1_BIT_STRING *ns;
EXTENDED_KEY_USAGE *extusage;
size_t i;
int j;
CRYPTO_MUTEX_lock_read(&x->lock);
const int is_set = x->ex_flags & EXFLAG_SET;
CRYPTO_MUTEX_unlock_read(&x->lock);
if (is_set) {
return (x->ex_flags & EXFLAG_INVALID) == 0;
}
CRYPTO_MUTEX_lock_write(&x->lock);
if (x->ex_flags & EXFLAG_SET) {
CRYPTO_MUTEX_unlock_write(&x->lock);
return (x->ex_flags & EXFLAG_INVALID) == 0;
}
if (!X509_digest(x, EVP_sha256(), x->cert_hash, NULL)) {
x->ex_flags |= EXFLAG_INVALID;
}
// V1 should mean no extensions ...
if (X509_get_version(x) == X509_VERSION_1) {
x->ex_flags |= EXFLAG_V1;
}
// Handle basic constraints
if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &j, NULL))) {
if (bs->ca) {
x->ex_flags |= EXFLAG_CA;
}
if (bs->pathlen) {
if ((bs->pathlen->type == V_ASN1_NEG_INTEGER) || !bs->ca) {
x->ex_flags |= EXFLAG_INVALID;
x->ex_pathlen = 0;
} else {
// TODO(davidben): |ASN1_INTEGER_get| returns -1 on overflow,
// which currently acts as if the constraint isn't present. This
// works (an overflowing path length constraint may as well be
// infinity), but Chromium's verifier simply treats values above
// 255 as an error.
x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
}
} else {
x->ex_pathlen = -1;
}
BASIC_CONSTRAINTS_free(bs);
x->ex_flags |= EXFLAG_BCONS;
} else if (j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
// Handle key usage
if ((usage = X509_get_ext_d2i(x, NID_key_usage, &j, NULL))) {
if (usage->length > 0) {
x->ex_kusage = usage->data[0];
if (usage->length > 1) {
x->ex_kusage |= usage->data[1] << 8;
}
} else {
x->ex_kusage = 0;
}
x->ex_flags |= EXFLAG_KUSAGE;
ASN1_BIT_STRING_free(usage);
} else if (j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
x->ex_xkusage = 0;
if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &j, NULL))) {
x->ex_flags |= EXFLAG_XKUSAGE;
for (i = 0; i < sk_ASN1_OBJECT_num(extusage); i++) {
switch (OBJ_obj2nid(sk_ASN1_OBJECT_value(extusage, i))) {
case NID_server_auth:
x->ex_xkusage |= XKU_SSL_SERVER;
break;
case NID_client_auth:
x->ex_xkusage |= XKU_SSL_CLIENT;
break;
case NID_email_protect:
x->ex_xkusage |= XKU_SMIME;
break;
case NID_code_sign:
x->ex_xkusage |= XKU_CODE_SIGN;
break;
case NID_ms_sgc:
case NID_ns_sgc:
x->ex_xkusage |= XKU_SGC;
break;
case NID_OCSP_sign:
x->ex_xkusage |= XKU_OCSP_SIGN;
break;
case NID_time_stamp:
x->ex_xkusage |= XKU_TIMESTAMP;
break;
case NID_dvcs:
x->ex_xkusage |= XKU_DVCS;
break;
case NID_anyExtendedKeyUsage:
x->ex_xkusage |= XKU_ANYEKU;
break;
}
}
sk_ASN1_OBJECT_pop_free(extusage, ASN1_OBJECT_free);
} else if (j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &j, NULL))) {
if (ns->length > 0) {
x->ex_nscert = ns->data[0];
} else {
x->ex_nscert = 0;
}
x->ex_flags |= EXFLAG_NSCERT;
ASN1_BIT_STRING_free(ns);
} else if (j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &j, NULL);
if (x->skid == NULL && j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &j, NULL);
if (x->akid == NULL && j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
// Does subject name match issuer ?
if (!X509_NAME_cmp(X509_get_subject_name(x), X509_get_issuer_name(x))) {
x->ex_flags |= EXFLAG_SI;
// If SKID matches AKID also indicate self signed
if (X509_check_akid(x, x->akid) == X509_V_OK &&
!ku_reject(x, KU_KEY_CERT_SIGN)) {
x->ex_flags |= EXFLAG_SS;
}
}
x->altname = X509_get_ext_d2i(x, NID_subject_alt_name, &j, NULL);
if (x->altname == NULL && j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
x->nc = X509_get_ext_d2i(x, NID_name_constraints, &j, NULL);
if (x->nc == NULL && j != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
if (!setup_crldp(x)) {
x->ex_flags |= EXFLAG_INVALID;
}
for (j = 0; j < X509_get_ext_count(x); j++) {
const X509_EXTENSION *ex = X509_get_ext(x, j);
if (!X509_EXTENSION_get_critical(ex)) {
continue;
}
if (!X509_supported_extension(ex)) {
x->ex_flags |= EXFLAG_CRITICAL;
break;
}
}
x->ex_flags |= EXFLAG_SET;
CRYPTO_MUTEX_unlock_write(&x->lock);
return (x->ex_flags & EXFLAG_INVALID) == 0;
}
// check_ca returns one if |x| should be considered a CA certificate and zero
// otherwise.
static int check_ca(const X509 *x) {
// keyUsage if present should allow cert signing
if (ku_reject(x, KU_KEY_CERT_SIGN)) {
return 0;
}
// Version 1 certificates are considered CAs and don't have extensions.
if ((x->ex_flags & V1_ROOT) == V1_ROOT) {
return 1;
}
// Otherwise, it's only a CA if basicConstraints says so.
return ((x->ex_flags & EXFLAG_BCONS) && (x->ex_flags & EXFLAG_CA));
}
int X509_check_ca(X509 *x) {
if (!x509v3_cache_extensions(x)) {
return 0;
}
return check_ca(x);
}
static int check_purpose_ssl_client(const X509_PURPOSE *xp, const X509 *x,
int ca) {
if (xku_reject(x, XKU_SSL_CLIENT)) {
return 0;
}
if (ca) {
return check_ca(x);
}
// We need to do digital signatures or key agreement
if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_KEY_AGREEMENT)) {
return 0;
}
// nsCertType if present should allow SSL client use
if (ns_reject(x, NS_SSL_CLIENT)) {
return 0;
}
return 1;
}
// Key usage needed for TLS/SSL server: digital signature, encipherment or
// key agreement. The ssl code can check this more thoroughly for individual
// key types.
#define KU_TLS (KU_DIGITAL_SIGNATURE | KU_KEY_ENCIPHERMENT | KU_KEY_AGREEMENT)
static int check_purpose_ssl_server(const X509_PURPOSE *xp, const X509 *x,
int ca) {
if (xku_reject(x, XKU_SSL_SERVER)) {
return 0;
}
if (ca) {
return check_ca(x);
}
if (ns_reject(x, NS_SSL_SERVER)) {
return 0;
}
if (ku_reject(x, KU_TLS)) {
return 0;
}
return 1;
}
static int check_purpose_ns_ssl_server(const X509_PURPOSE *xp, const X509 *x,
int ca) {
int ret;
ret = check_purpose_ssl_server(xp, x, ca);
if (!ret || ca) {
return ret;
}
// We need to encipher or Netscape complains
if (ku_reject(x, KU_KEY_ENCIPHERMENT)) {
return 0;
}
return ret;
}
// purpose_smime returns one if |x| is a valid S/MIME leaf (|ca| is zero) or CA
// (|ca| is one) certificate, and zero otherwise.
static int purpose_smime(const X509 *x, int ca) {
if (xku_reject(x, XKU_SMIME)) {
return 0;
}
if (ca) {
// check nsCertType if present
if ((x->ex_flags & EXFLAG_NSCERT) && (x->ex_nscert & NS_SMIME_CA) == 0) {
return 0;
}
return check_ca(x);
}
if (x->ex_flags & EXFLAG_NSCERT) {
return (x->ex_nscert & NS_SMIME) == NS_SMIME;
}
return 1;
}
static int check_purpose_smime_sign(const X509_PURPOSE *xp, const X509 *x,
int ca) {
int ret;
ret = purpose_smime(x, ca);
if (!ret || ca) {
return ret;
}
if (ku_reject(x, KU_DIGITAL_SIGNATURE | KU_NON_REPUDIATION)) {
return 0;
}
return ret;
}
static int check_purpose_smime_encrypt(const X509_PURPOSE *xp, const X509 *x,
int ca) {
int ret;
ret = purpose_smime(x, ca);
if (!ret || ca) {
return ret;
}
if (ku_reject(x, KU_KEY_ENCIPHERMENT)) {
return 0;
}
return ret;
}
static int check_purpose_crl_sign(const X509_PURPOSE *xp, const X509 *x,
int ca) {
if (ca) {
return check_ca(x);
}
if (ku_reject(x, KU_CRL_SIGN)) {
return 0;
}
return 1;
}
// OCSP helper: this is *not* a full OCSP check. It just checks that each CA
// is valid. Additional checks must be made on the chain.
static int ocsp_helper(const X509_PURPOSE *xp, const X509 *x, int ca) {
if (ca) {
return check_ca(x);
}
// leaf certificate is checked in OCSP_verify()
return 1;
}
static int check_purpose_timestamp_sign(const X509_PURPOSE *xp, const X509 *x,
int ca) {
int i_ext;
// If ca is true we must return if this is a valid CA certificate.
if (ca) {
return check_ca(x);
}
// Check the optional key usage field:
// if Key Usage is present, it must be one of digitalSignature
// and/or nonRepudiation (other values are not consistent and shall
// be rejected).
if ((x->ex_flags & EXFLAG_KUSAGE) &&
((x->ex_kusage & ~(KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)) ||
!(x->ex_kusage & (KU_NON_REPUDIATION | KU_DIGITAL_SIGNATURE)))) {
return 0;
}
// Only time stamp key usage is permitted and it's required.
if (!(x->ex_flags & EXFLAG_XKUSAGE) || x->ex_xkusage != XKU_TIMESTAMP) {
return 0;
}
// Extended Key Usage MUST be critical
i_ext = X509_get_ext_by_NID((X509 *)x, NID_ext_key_usage, -1);
if (i_ext >= 0) {
const X509_EXTENSION *ext = X509_get_ext((X509 *)x, i_ext);
if (!X509_EXTENSION_get_critical(ext)) {
return 0;
}
}
return 1;
}
static int no_check(const X509_PURPOSE *xp, const X509 *x, int ca) { return 1; }
// Various checks to see if one certificate issued the second. This can be
// used to prune a set of possible issuer certificates which have been looked
// up using some simple method such as by subject name. These are: 1. Check
// issuer_name(subject) == subject_name(issuer) 2. If akid(subject) exists
// check it matches issuer 3. If key_usage(issuer) exists check it supports
// certificate signing returns 0 for OK, positive for reason for mismatch,
// reasons match codes for X509_verify_cert()
int X509_check_issued(X509 *issuer, X509 *subject) {
if (X509_NAME_cmp(X509_get_subject_name(issuer),
X509_get_issuer_name(subject))) {
return X509_V_ERR_SUBJECT_ISSUER_MISMATCH;
}
if (!x509v3_cache_extensions(issuer) || !x509v3_cache_extensions(subject)) {
return X509_V_ERR_UNSPECIFIED;
}
if (subject->akid) {
int ret = X509_check_akid(issuer, subject->akid);
if (ret != X509_V_OK) {
return ret;
}
}
if (ku_reject(issuer, KU_KEY_CERT_SIGN)) {
return X509_V_ERR_KEYUSAGE_NO_CERTSIGN;
}
return X509_V_OK;
}
int X509_check_akid(X509 *issuer, AUTHORITY_KEYID *akid) {
if (!akid) {
return X509_V_OK;
}
// Check key ids (if present)
if (akid->keyid && issuer->skid &&
ASN1_OCTET_STRING_cmp(akid->keyid, issuer->skid)) {
return X509_V_ERR_AKID_SKID_MISMATCH;
}
// Check serial number
if (akid->serial &&
ASN1_INTEGER_cmp(X509_get_serialNumber(issuer), akid->serial)) {
return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
}
// Check issuer name
if (akid->issuer) {
// Ugh, for some peculiar reason AKID includes SEQUENCE OF
// GeneralName. So look for a DirName. There may be more than one but
// we only take any notice of the first.
GENERAL_NAMES *gens;
GENERAL_NAME *gen;
X509_NAME *nm = NULL;
size_t i;
gens = akid->issuer;
for (i = 0; i < sk_GENERAL_NAME_num(gens); i++) {
gen = sk_GENERAL_NAME_value(gens, i);
if (gen->type == GEN_DIRNAME) {
nm = gen->d.dirn;
break;
}
}
if (nm && X509_NAME_cmp(nm, X509_get_issuer_name(issuer))) {
return X509_V_ERR_AKID_ISSUER_SERIAL_MISMATCH;
}
}
return X509_V_OK;
}
uint32_t X509_get_extension_flags(X509 *x) {
// Ignore the return value. On failure, |x->ex_flags| will include
// |EXFLAG_INVALID|.
x509v3_cache_extensions(x);
return x->ex_flags;
}
uint32_t X509_get_key_usage(X509 *x) {
if (!x509v3_cache_extensions(x)) {
return 0;
}
if (x->ex_flags & EXFLAG_KUSAGE) {
return x->ex_kusage;
}
return UINT32_MAX;
}
uint32_t X509_get_extended_key_usage(X509 *x) {
if (!x509v3_cache_extensions(x)) {
return 0;
}
if (x->ex_flags & EXFLAG_XKUSAGE) {
return x->ex_xkusage;
}
return UINT32_MAX;
}
const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x509) {
if (!x509v3_cache_extensions(x509)) {
return NULL;
}
return x509->skid;
}
const ASN1_OCTET_STRING *X509_get0_authority_key_id(X509 *x509) {
if (!x509v3_cache_extensions(x509)) {
return NULL;
}
return x509->akid != NULL ? x509->akid->keyid : NULL;
}
const GENERAL_NAMES *X509_get0_authority_issuer(X509 *x509) {
if (!x509v3_cache_extensions(x509)) {
return NULL;
}
return x509->akid != NULL ? x509->akid->issuer : NULL;
}
const ASN1_INTEGER *X509_get0_authority_serial(X509 *x509) {
if (!x509v3_cache_extensions(x509)) {
return NULL;
}
return x509->akid != NULL ? x509->akid->serial : NULL;
}
long X509_get_pathlen(X509 *x509) {
if (!x509v3_cache_extensions(x509) || (x509->ex_flags & EXFLAG_BCONS) == 0) {
return -1;
}
return x509->ex_pathlen;
}