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openssl/crypto/x509v3/v3_purp.c
Dr. Stephen Henson f51e5ed6b4 Fix self signed handling. 
Don't mark a certificate as self signed if keyUsage is present and
certificate signing not asserted.

PR#3979

Reviewed-by: Matt Caswell <matt@openssl.org>
2015-10-15 15:36:58 +01:00

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/* v3_purp.c */
/*
* 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 "internal/cryptlib.h"
#include "internal/numbers.h"
#include <openssl/x509v3.h>
#include <openssl/x509_vfy.h>
#include "internal/x509_int.h"
static void x509v3_cache_extensions(X509 *x);
static int check_ssl_ca(const X509 *x);
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, "SSL client", "sslclient", NULL},
{X509_PURPOSE_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
check_purpose_ssl_server, "SSL server", "sslserver", NULL},
{X509_PURPOSE_NS_SSL_SERVER, X509_TRUST_SSL_SERVER, 0,
check_purpose_ns_ssl_server, "Netscape SSL server", "nssslserver", NULL},
{X509_PURPOSE_SMIME_SIGN, X509_TRUST_EMAIL, 0, check_purpose_smime_sign,
"S/MIME signing", "smimesign", NULL},
{X509_PURPOSE_SMIME_ENCRYPT, X509_TRUST_EMAIL, 0,
check_purpose_smime_encrypt, "S/MIME encryption", "smimeencrypt", NULL},
{X509_PURPOSE_CRL_SIGN, X509_TRUST_COMPAT, 0, check_purpose_crl_sign,
"CRL signing", "crlsign", NULL},
{X509_PURPOSE_ANY, X509_TRUST_DEFAULT, 0, no_check, "Any Purpose", "any",
NULL},
{X509_PURPOSE_OCSP_HELPER, X509_TRUST_COMPAT, 0, ocsp_helper,
"OCSP helper", "ocsphelper", NULL},
{X509_PURPOSE_TIMESTAMP_SIGN, X509_TRUST_TSA, 0,
check_purpose_timestamp_sign, "Time Stamp signing", "timestampsign",
NULL},
};
#define X509_PURPOSE_COUNT OSSL_NELEM(xstandard)
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 (!(x->ex_flags & EXFLAG_SET)) {
CRYPTO_w_lock(CRYPTO_LOCK_X509);
x509v3_cache_extensions(x);
CRYPTO_w_unlock(CRYPTO_LOCK_X509);
}
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) {
X509V3err(X509V3_F_X509_PURPOSE_SET, 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(char *sname)
{
int i;
X509_PURPOSE *xptmp;
for (i = 0; i < X509_PURPOSE_get_count(); i++) {
xptmp = X509_PURPOSE_get0(i);
if (strcmp(xptmp->sname, sname) == 0)
return i;
}
return -1;
}
int X509_PURPOSE_get_by_id(int purpose)
{
X509_PURPOSE tmp;
int idx;
if ((purpose >= X509_PURPOSE_MIN) && (purpose <= X509_PURPOSE_MAX))
return purpose - X509_PURPOSE_MIN;
tmp.purpose = purpose;
if (!xptable)
return -1;
idx = sk_X509_PURPOSE_find(xptable, &tmp);
if (idx == -1)
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),
char *name, char *sname, void *arg)
{
int idx;
X509_PURPOSE *ptmp;
/*
* 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 */
idx = X509_PURPOSE_get_by_id(id);
/* Need a new entry */
if (idx == -1) {
if ((ptmp = OPENSSL_malloc(sizeof(*ptmp))) == NULL) {
X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
return 0;
}
ptmp->flags = X509_PURPOSE_DYNAMIC;
} else
ptmp = X509_PURPOSE_get0(idx);
/* 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 = BUF_strdup(name);
ptmp->sname = BUF_strdup(sname);
if (!ptmp->name || !ptmp->sname) {
X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
return 0;
}
/* 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) {
if (xptable == NULL
&& (xptable = sk_X509_PURPOSE_new(xp_cmp)) == NULL) {
X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
return 0;
}
if (!sk_X509_PURPOSE_push(xptable, ptmp)) {
X509V3err(X509V3_F_X509_PURPOSE_ADD, ERR_R_MALLOC_FAILURE);
return 0;
}
}
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(X509_PURPOSE *xp)
{
return xp->purpose;
}
char *X509_PURPOSE_get0_name(X509_PURPOSE *xp)
{
return xp->name;
}
char *X509_PURPOSE_get0_sname(X509_PURPOSE *xp)
{
return xp->sname;
}
int X509_PURPOSE_get_trust(X509_PURPOSE *xp)
{
return xp->trust;
}
static int nid_cmp(const int *a, const int *b)
{
return *a - *b;
}
DECLARE_OBJ_BSEARCH_CMP_FN(int, int, nid);
IMPLEMENT_OBJ_BSEARCH_CMP_FN(int, int, nid);
int X509_supported_extension(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 */
#ifndef OPENSSL_NO_RFC3779
NID_sbgp_ipAddrBlock, /* 290 */
NID_sbgp_autonomousSysNum, /* 291 */
#endif
NID_policy_constraints, /* 401 */
NID_proxyCertInfo, /* 663 */
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 (OBJ_bsearch_nid(&ex_nid, supported_nids, OSSL_NELEM(supported_nids)))
return 1;
return 0;
}
static void setup_dp(X509 *x, DIST_POINT *dp)
{
X509_NAME *iname = NULL;
int i;
if (dp->reasons) {
if (dp->reasons->length > 0)
dp->dp_reasons = dp->reasons->data[0];
if (dp->reasons->length > 1)
dp->dp_reasons |= (dp->reasons->data[1] << 8);
dp->dp_reasons &= CRLDP_ALL_REASONS;
} else
dp->dp_reasons = CRLDP_ALL_REASONS;
if (!dp->distpoint || (dp->distpoint->type != 1))
return;
for (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);
DIST_POINT_set_dpname(dp->distpoint, iname);
}
static void setup_crldp(X509 *x)
{
int i;
x->crldp = X509_get_ext_d2i(x, NID_crl_distribution_points, NULL, NULL);
for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
}
#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 void x509v3_cache_extensions(X509 *x)
{
BASIC_CONSTRAINTS *bs;
PROXY_CERT_INFO_EXTENSION *pci;
ASN1_BIT_STRING *usage;
ASN1_BIT_STRING *ns;
EXTENDED_KEY_USAGE *extusage;
X509_EXTENSION *ex;
int i;
if (x->ex_flags & EXFLAG_SET)
return;
X509_digest(x, EVP_sha1(), x->sha1_hash, NULL);
/* V1 should mean no extensions ... */
if (!X509_get_version(x))
x->ex_flags |= EXFLAG_V1;
/* Handle basic constraints */
if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, NULL, 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
x->ex_pathlen = ASN1_INTEGER_get(bs->pathlen);
} else
x->ex_pathlen = -1;
BASIC_CONSTRAINTS_free(bs);
x->ex_flags |= EXFLAG_BCONS;
}
/* Handle proxy certificates */
if ((pci = X509_get_ext_d2i(x, NID_proxyCertInfo, NULL, NULL))) {
if (x->ex_flags & EXFLAG_CA
|| X509_get_ext_by_NID(x, NID_subject_alt_name, -1) >= 0
|| X509_get_ext_by_NID(x, NID_issuer_alt_name, -1) >= 0) {
x->ex_flags |= EXFLAG_INVALID;
}
if (pci->pcPathLengthConstraint) {
x->ex_pcpathlen = ASN1_INTEGER_get(pci->pcPathLengthConstraint);
} else
x->ex_pcpathlen = -1;
PROXY_CERT_INFO_EXTENSION_free(pci);
x->ex_flags |= EXFLAG_PROXY;
}
/* Handle key usage */
if ((usage = X509_get_ext_d2i(x, NID_key_usage, NULL, 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);
}
x->ex_xkusage = 0;
if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, NULL, 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);
}
if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, NULL, 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);
}
x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, NULL, NULL);
x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, NULL, NULL);
/* 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, NULL, NULL);
x->nc = X509_get_ext_d2i(x, NID_name_constraints, &i, NULL);
if (!x->nc && (i != -1))
x->ex_flags |= EXFLAG_INVALID;
setup_crldp(x);
#ifndef OPENSSL_NO_RFC3779
x->rfc3779_addr = X509_get_ext_d2i(x, NID_sbgp_ipAddrBlock, NULL, NULL);
x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum,
NULL, NULL);
#endif
for (i = 0; i < X509_get_ext_count(x); i++) {
ex = X509_get_ext(x, i);
if (OBJ_obj2nid(X509_EXTENSION_get_object(ex))
== NID_freshest_crl)
x->ex_flags |= EXFLAG_FRESHEST;
if (!X509_EXTENSION_get_critical(ex))
continue;
if (!X509_supported_extension(ex)) {
x->ex_flags |= EXFLAG_CRITICAL;
break;
}
}
x->ex_flags |= EXFLAG_SET;
}
/*-
* CA checks common to all purposes
* return codes:
* 0 not a CA
* 1 is a CA
* 2 basicConstraints absent so "maybe" a CA
* 3 basicConstraints absent but self signed V1.
* 4 basicConstraints absent but keyUsage present and keyCertSign asserted.
*/
static int check_ca(const X509 *x)
{
/* keyUsage if present should allow cert signing */
if (ku_reject(x, KU_KEY_CERT_SIGN))
return 0;
if (x->ex_flags & EXFLAG_BCONS) {
if (x->ex_flags & EXFLAG_CA)
return 1;
/* If basicConstraints says not a CA then say so */
else
return 0;
} else {
/* we support V1 roots for... uh, I don't really know why. */
if ((x->ex_flags & V1_ROOT) == V1_ROOT)
return 3;
/*
* If key usage present it must have certSign so tolerate it
*/
else if (x->ex_flags & EXFLAG_KUSAGE)
return 4;
/* Older certificates could have Netscape-specific CA types */
else if (x->ex_flags & EXFLAG_NSCERT && x->ex_nscert & NS_ANY_CA)
return 5;
/* can this still be regarded a CA certificate? I doubt it */
return 0;
}
}
int X509_check_ca(X509 *x)
{
if (!(x->ex_flags & EXFLAG_SET)) {
CRYPTO_w_lock(CRYPTO_LOCK_X509);
x509v3_cache_extensions(x);
CRYPTO_w_unlock(CRYPTO_LOCK_X509);
}
return check_ca(x);
}
/* Check SSL CA: common checks for SSL client and server */
static int check_ssl_ca(const X509 *x)
{
int ca_ret;
ca_ret = check_ca(x);
if (!ca_ret)
return 0;
/* check nsCertType if present */
if (ca_ret != 5 || x->ex_nscert & NS_SSL_CA)
return ca_ret;
else
return 0;
}
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_ssl_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 | XKU_SGC))
return 0;
if (ca)
return check_ssl_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;
}
/* common S/MIME checks */
static int purpose_smime(const X509 *x, int ca)
{
if (xku_reject(x, XKU_SMIME))
return 0;
if (ca) {
int ca_ret;
ca_ret = check_ca(x);
if (!ca_ret)
return 0;
/* check nsCertType if present */
if (ca_ret != 5 || x->ex_nscert & NS_SMIME_CA)
return ca_ret;
else
return 0;
}
if (x->ex_flags & EXFLAG_NSCERT) {
if (x->ex_nscert & NS_SMIME)
return 1;
/* Workaround for some buggy certificates */
if (x->ex_nscert & NS_SSL_CLIENT)
return 2;
return 0;
}
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) {
int ca_ret;
if ((ca_ret = check_ca(x)) != 2)
return ca_ret;
else
return 0;
}
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)
{
/*
* Must be a valid CA. Should we really support the "I don't know" value
* (2)?
*/
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) {
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;
x509v3_cache_extensions(issuer);
x509v3_cache_extensions(subject);
if (subject->akid) {
int ret = X509_check_akid(issuer, subject->akid);
if (ret != X509_V_OK)
return ret;
}
if (subject->ex_flags & EXFLAG_PROXY) {
if (ku_reject(issuer, KU_DIGITAL_SIGNATURE))
return X509_V_ERR_KEYUSAGE_NO_DIGITAL_SIGNATURE;
} else 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;
int 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)
{
X509_check_purpose(x, -1, -1);
return x->ex_flags;
}
uint32_t X509_get_key_usage(X509 *x)
{
X509_check_purpose(x, -1, -1);
if (x->ex_flags & EXFLAG_KUSAGE)
return x->ex_kusage;
return UINT32_MAX;
}
uint32_t X509_get_extended_key_usage(X509 *x)
{
X509_check_purpose(x, -1, -1);
if (x->ex_flags & EXFLAG_XKUSAGE)
return x->ex_xkusage;
return UINT32_MAX;
}
const ASN1_OCTET_STRING *X509_get0_subject_key_id(X509 *x)
{
X509_check_purpose(x, -1, -1);
return x->skid;
}
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