SecBSD
/
src
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
src/lib/libcrypto/x509/x509_purp.c

945 lines
24 KiB
C
Raw Blame History

/* $OpenBSD: x509_purp.c,v 1.35 2024/01/07 16:22:46 tb Exp $ */
/* 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/opensslconf.h>
#include <openssl/err.h>
#include <openssl/x509v3.h>
#include <openssl/x509_vfy.h>
#include "x509_internal.h"
#include "x509_local.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_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 X509_PURPOSE xstandard[] = {
{
.purpose = X509_PURPOSE_SSL_CLIENT,
.trust = X509_TRUST_SSL_CLIENT,
.check_purpose = check_purpose_ssl_client,
.name = "SSL client",
.sname = "sslclient",
},
{
.purpose = X509_PURPOSE_SSL_SERVER,
.trust = X509_TRUST_SSL_SERVER,
.check_purpose = check_purpose_ssl_server,
.name = "SSL server",
.sname = "sslserver",
},
{
.purpose = X509_PURPOSE_NS_SSL_SERVER,
.trust = X509_TRUST_SSL_SERVER,
.check_purpose = check_purpose_ns_ssl_server,
.name = "Netscape SSL server",
.sname = "nssslserver",
},
{
.purpose = X509_PURPOSE_SMIME_SIGN,
.trust = X509_TRUST_EMAIL,
.check_purpose = check_purpose_smime_sign,
.name = "S/MIME signing",
.sname = "smimesign",
},
{
.purpose = X509_PURPOSE_SMIME_ENCRYPT,
.trust = X509_TRUST_EMAIL,
.check_purpose = check_purpose_smime_encrypt,
.name = "S/MIME encryption",
.sname = "smimeencrypt",
},
{
.purpose = X509_PURPOSE_CRL_SIGN,
.trust = X509_TRUST_COMPAT,
.check_purpose = check_purpose_crl_sign,
.name = "CRL signing",
.sname = "crlsign",
},
{
.purpose = X509_PURPOSE_ANY,
.trust = X509_TRUST_DEFAULT,
.check_purpose = no_check,
.name = "Any Purpose",
.sname = "any",
},
{
.purpose = X509_PURPOSE_OCSP_HELPER,
.trust = X509_TRUST_COMPAT,
.check_purpose = ocsp_helper,
.name = "OCSP helper",
.sname = "ocsphelper",
},
{
.purpose = X509_PURPOSE_TIMESTAMP_SIGN,
.trust = X509_TRUST_TSA,
.check_purpose = check_purpose_timestamp_sign,
.name = "Time Stamp signing",
.sname = "timestampsign",
},
};
#define X509_PURPOSE_COUNT (sizeof(xstandard) / sizeof(xstandard[0]))
/* 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);
}
LCRYPTO_ALIAS(X509_check_purpose);
int
X509_PURPOSE_set(int *p, int purpose)
{
if (X509_PURPOSE_get_by_id(purpose) == -1) {
X509V3error(X509V3_R_INVALID_PURPOSE);
return 0;
}
*p = purpose;
return 1;
}
LCRYPTO_ALIAS(X509_PURPOSE_set);
int
X509_PURPOSE_get_count(void)
{
return X509_PURPOSE_COUNT;
}
LCRYPTO_ALIAS(X509_PURPOSE_get_count);
X509_PURPOSE *
X509_PURPOSE_get0(int idx)
{
if (idx < 0 || (size_t)idx >= X509_PURPOSE_COUNT)
return NULL;
return &xstandard[idx];
}
LCRYPTO_ALIAS(X509_PURPOSE_get0);
int
X509_PURPOSE_get_by_sname(const 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))
return i;
}
return -1;
}
LCRYPTO_ALIAS(X509_PURPOSE_get_by_sname);
int
X509_PURPOSE_get_by_id(int purpose)
{
/*
* Ensure the purpose identifier is between MIN and MAX inclusive.
* If so, translate it to an index into the xstandard[] table.
*/
if (purpose < X509_PURPOSE_MIN || purpose > X509_PURPOSE_MAX)
return -1;
return purpose - X509_PURPOSE_MIN;
}
LCRYPTO_ALIAS(X509_PURPOSE_get_by_id);
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)
{
X509error(ERR_R_DISABLED);
return 0;
}
LCRYPTO_ALIAS(X509_PURPOSE_add);
void
X509_PURPOSE_cleanup(void)
{
}
LCRYPTO_ALIAS(X509_PURPOSE_cleanup);
int
X509_PURPOSE_get_id(const X509_PURPOSE *xp)
{
return xp->purpose;
}
LCRYPTO_ALIAS(X509_PURPOSE_get_id);
char *
X509_PURPOSE_get0_name(const X509_PURPOSE *xp)
{
return xp->name;
}
LCRYPTO_ALIAS(X509_PURPOSE_get0_name);
char *
X509_PURPOSE_get0_sname(const X509_PURPOSE *xp)
{
return xp->sname;
}
LCRYPTO_ALIAS(X509_PURPOSE_get0_sname);
int
X509_PURPOSE_get_trust(const X509_PURPOSE *xp)
{
return xp->trust;
}
LCRYPTO_ALIAS(X509_PURPOSE_get_trust);
/*
* List of NIDs of extensions supported by the verifier. If an extension
* is critical and doesn't appear in this list, then the certificate will
* normally be rejected.
*/
int
X509_supported_extension(X509_EXTENSION *ext)
{
switch (OBJ_obj2nid(X509_EXTENSION_get_object(ext))) {
case NID_basic_constraints:
case NID_certificate_policies:
case NID_ext_key_usage:
case NID_inhibit_any_policy:
case NID_key_usage:
case NID_name_constraints:
case NID_netscape_cert_type:
case NID_policy_constraints:
case NID_policy_mappings:
#ifndef OPENSSL_NO_RFC3779
case NID_sbgp_ipAddrBlock:
case NID_sbgp_autonomousSysNum:
#endif
case NID_subject_alt_name:
return 1;
default:
return 0;
}
}
LCRYPTO_ALIAS(X509_supported_extension);
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, &i, NULL);
if (x->crldp == NULL && i != -1) {
x->ex_flags |= EXFLAG_INVALID;
return;
}
for (i = 0; i < sk_DIST_POINT_num(x->crldp); i++)
setup_dp(x, sk_DIST_POINT_value(x->crldp, i));
}
static int
x509_extension_oid_cmp(const X509_EXTENSION *const *a,
const X509_EXTENSION *const *b)
{
return OBJ_cmp((*a)->object, (*b)->object);
}
static int
x509_extension_oids_are_unique(X509 *x509)
{
STACK_OF(X509_EXTENSION) *exts = NULL;
const X509_EXTENSION *prev_ext, *curr_ext;
int i;
int ret = 0;
if (X509_get_ext_count(x509) <= 1)
goto done;
if ((exts = sk_X509_EXTENSION_dup(x509->cert_info->extensions)) == NULL)
goto err;
(void)sk_X509_EXTENSION_set_cmp_func(exts, x509_extension_oid_cmp);
sk_X509_EXTENSION_sort(exts);
prev_ext = sk_X509_EXTENSION_value(exts, 0);
for (i = 1; i < sk_X509_EXTENSION_num(exts); i++) {
curr_ext = sk_X509_EXTENSION_value(exts, i);
if (x509_extension_oid_cmp(&prev_ext, &curr_ext) == 0)
goto err;
prev_ext = curr_ext;
}
done:
ret = 1;
err:
sk_X509_EXTENSION_free(exts);
return ret;
}
static void
x509v3_cache_extensions_internal(X509 *x)
{
BASIC_CONSTRAINTS *bs;
ASN1_BIT_STRING *usage;
ASN1_BIT_STRING *ns;
EXTENDED_KEY_USAGE *extusage;
X509_EXTENSION *ex;
long version;
int i;
if (x->ex_flags & EXFLAG_SET)
return;
if (!X509_digest(x, X509_CERT_HASH_EVP, x->hash, NULL))
x->ex_flags |= EXFLAG_INVALID;
version = X509_get_version(x);
if (version < 0 || version > 2)
x->ex_flags |= EXFLAG_INVALID;
if (version == 0) {
x->ex_flags |= EXFLAG_V1;
/* UIDs may only appear in v2 or v3 certs */
if (x->cert_info->issuerUID != NULL ||
x->cert_info->subjectUID != NULL)
x->ex_flags |= EXFLAG_INVALID;
}
if (version != 2 && X509_get_ext_count(x) != 0)
x->ex_flags |= EXFLAG_INVALID;
/* Handle basic constraints */
if ((bs = X509_get_ext_d2i(x, NID_basic_constraints, &i, 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;
} else if (i != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
/* Handle key usage */
if ((usage = X509_get_ext_d2i(x, NID_key_usage, &i, 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 (i != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
x->ex_xkusage = 0;
if ((extusage = X509_get_ext_d2i(x, NID_ext_key_usage, &i, 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 (i != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
if ((ns = X509_get_ext_d2i(x, NID_netscape_cert_type, &i, 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 (i != -1) {
x->ex_flags |= EXFLAG_INVALID;
}
x->skid = X509_get_ext_d2i(x, NID_subject_key_identifier, &i, NULL);
if (x->skid == NULL && i != -1)
x->ex_flags |= EXFLAG_INVALID;
x->akid = X509_get_ext_d2i(x, NID_authority_key_identifier, &i, NULL);
if (x->akid == NULL && i != -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, &i, NULL);
if (x->altname == NULL && i != -1)
x->ex_flags |= EXFLAG_INVALID;
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, &i, NULL);
if (x->rfc3779_addr == NULL && i != -1)
x->ex_flags |= EXFLAG_INVALID;
if (!X509v3_addr_is_canonical(x->rfc3779_addr))
x->ex_flags |= EXFLAG_INVALID;
x->rfc3779_asid = X509_get_ext_d2i(x, NID_sbgp_autonomousSysNum, &i, NULL);
if (x->rfc3779_asid == NULL && i != -1)
x->ex_flags |= EXFLAG_INVALID;
if (!X509v3_asid_is_canonical(x->rfc3779_asid))
x->ex_flags |= EXFLAG_INVALID;
#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;
}
}
if (!x509_extension_oids_are_unique(x))
x->ex_flags |= EXFLAG_INVALID;
if (!x509_verify_cert_info_populate(x))
x->ex_flags |= EXFLAG_INVALID;
x->ex_flags |= EXFLAG_SET;
}
int
x509v3_cache_extensions(X509 *x)
{
if ((x->ex_flags & EXFLAG_SET) == 0) {
CRYPTO_w_lock(CRYPTO_LOCK_X509);
x509v3_cache_extensions_internal(x);
CRYPTO_w_unlock(CRYPTO_LOCK_X509);
}
return (x->ex_flags & EXFLAG_INVALID) == 0;
}
/* 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)
{
x509v3_cache_extensions(x);
return check_ca(x);
}
LCRYPTO_ALIAS(X509_check_ca);
/* 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 with it */
if (ku_reject(x, KU_DIGITAL_SIGNATURE))
return 0;
/* nsCertType if present should allow SSL client use */
if (ns_reject(x, NS_SSL_CLIENT))
return 0;
return 1;
}
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;
/* Now as for keyUsage: we'll at least need to sign OR encipher */
if (ku_reject(x, KU_DIGITAL_SIGNATURE|KU_KEY_ENCIPHERMENT))
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;
if (!x509v3_cache_extensions(issuer))
return X509_V_ERR_UNSPECIFIED;
if (!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;
}
LCRYPTO_ALIAS(X509_check_issued);
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;
}
LCRYPTO_ALIAS(X509_check_akid);
uint32_t
X509_get_extension_flags(X509 *x)
{
/* Call for side-effect of computing hash and caching extensions */
if (X509_check_purpose(x, -1, -1) != 1)
return EXFLAG_INVALID;
return x->ex_flags;
}
LCRYPTO_ALIAS(X509_get_extension_flags);
uint32_t
X509_get_key_usage(X509 *x)
{
/* Call for side-effect of computing hash and caching extensions */
if (X509_check_purpose(x, -1, -1) != 1)
return 0;
if (x->ex_flags & EXFLAG_KUSAGE)
return x->ex_kusage;
return UINT32_MAX;
}
LCRYPTO_ALIAS(X509_get_key_usage);
uint32_t
X509_get_extended_key_usage(X509 *x)
{
/* Call for side-effect of computing hash and caching extensions */
if (X509_check_purpose(x, -1, -1) != 1)
return 0;
if (x->ex_flags & EXFLAG_XKUSAGE)
return x->ex_xkusage;
return UINT32_MAX;
}
LCRYPTO_ALIAS(X509_get_extended_key_usage);
Reference in New Issue View Git Blame Copy Permalink