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x509_vfy.c
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x509_vfy.c
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/*
* Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <limits.h>
#include "crypto/ctype.h"
#include "internal/cryptlib.h"
#include <openssl/crypto.h>
#include <openssl/buffer.h>
#include <openssl/evp.h>
#include <openssl/asn1.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/objects.h>
#include "internal/dane.h"
#include "crypto/x509.h"
#include "x509_local.h"
/* CRL score values */
/* No unhandled critical extensions */
#define CRL_SCORE_NOCRITICAL 0x100
/* certificate is within CRL scope */
#define CRL_SCORE_SCOPE 0x080
/* CRL times valid */
#define CRL_SCORE_TIME 0x040
/* Issuer name matches certificate */
#define CRL_SCORE_ISSUER_NAME 0x020
/* If this score or above CRL is probably valid */
#define CRL_SCORE_VALID (CRL_SCORE_NOCRITICAL|CRL_SCORE_TIME|CRL_SCORE_SCOPE)
/* CRL issuer is certificate issuer */
#define CRL_SCORE_ISSUER_CERT 0x018
/* CRL issuer is on certificate path */
#define CRL_SCORE_SAME_PATH 0x008
/* CRL issuer matches CRL AKID */
#define CRL_SCORE_AKID 0x004
/* Have a delta CRL with valid times */
#define CRL_SCORE_TIME_DELTA 0x002
static int build_chain(X509_STORE_CTX *ctx);
static int verify_chain(X509_STORE_CTX *ctx);
static int dane_verify(X509_STORE_CTX *ctx);
static int null_callback(int ok, X509_STORE_CTX *e);
static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer);
static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x);
static int check_chain_extensions(X509_STORE_CTX *ctx);
static int check_name_constraints(X509_STORE_CTX *ctx);
static int check_id(X509_STORE_CTX *ctx);
static int check_trust(X509_STORE_CTX *ctx, int num_untrusted);
static int check_revocation(X509_STORE_CTX *ctx);
static int check_cert(X509_STORE_CTX *ctx);
static int check_policy(X509_STORE_CTX *ctx);
static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x);
static int check_dane_issuer(X509_STORE_CTX *ctx, int depth);
static int check_key_level(X509_STORE_CTX *ctx, X509 *cert);
static int check_sig_level(X509_STORE_CTX *ctx, X509 *cert);
static int check_curve(X509 *cert);
static int get_crl_score(X509_STORE_CTX *ctx, X509 **pissuer,
unsigned int *preasons, X509_CRL *crl, X509 *x);
static int get_crl_delta(X509_STORE_CTX *ctx,
X509_CRL **pcrl, X509_CRL **pdcrl, X509 *x);
static void get_delta_sk(X509_STORE_CTX *ctx, X509_CRL **dcrl,
int *pcrl_score, X509_CRL *base,
STACK_OF(X509_CRL) *crls);
static void crl_akid_check(X509_STORE_CTX *ctx, X509_CRL *crl, X509 **pissuer,
int *pcrl_score);
static int crl_crldp_check(X509 *x, X509_CRL *crl, int crl_score,
unsigned int *preasons);
static int check_crl_path(X509_STORE_CTX *ctx, X509 *x);
static int check_crl_chain(X509_STORE_CTX *ctx,
STACK_OF(X509) *cert_path,
STACK_OF(X509) *crl_path);
static int internal_verify(X509_STORE_CTX *ctx);
static int null_callback(int ok, X509_STORE_CTX *e)
{
return ok;
}
/*
* Return 1 if given cert is considered self-signed, 0 if not or on error.
* This does not verify self-signedness but relies on x509v3_cache_extensions()
* matching issuer and subject names (i.e., the cert being self-issued) and any
* present authority key identifier matching the subject key identifier, etc.
*/
static int cert_self_signed(X509 *x)
{
if (X509_check_purpose(x, -1, 0) != 1)
return 0;
if (x->ex_flags & EXFLAG_SS)
return 1;
else
return 0;
}
/* Given a certificate try and find an exact match in the store */
static X509 *lookup_cert_match(X509_STORE_CTX *ctx, X509 *x)
{
STACK_OF(X509) *certs;
X509 *xtmp = NULL;
int i;
/* Lookup all certs with matching subject name */
certs = ctx->lookup_certs(ctx, X509_get_subject_name(x));
if (certs == NULL)
return NULL;
/* Look for exact match */
for (i = 0; i < sk_X509_num(certs); i++) {
xtmp = sk_X509_value(certs, i);
if (!X509_cmp(xtmp, x))
break;
xtmp = NULL;
}
if (xtmp != NULL && !X509_up_ref(xtmp))
xtmp = NULL;
sk_X509_pop_free(certs, X509_free);
return xtmp;
}
/*-
* Inform the verify callback of an error.
* If B<x> is not NULL it is the error cert, otherwise use the chain cert at
* B<depth>.
* If B<err> is not X509_V_OK, that's the error value, otherwise leave
* unchanged (presumably set by the caller).
*
* Returns 0 to abort verification with an error, non-zero to continue.
*/
static int verify_cb_cert(X509_STORE_CTX *ctx, X509 *x, int depth, int err)
{
ctx->error_depth = depth;
ctx->current_cert = (x != NULL) ? x : sk_X509_value(ctx->chain, depth);
if (err != X509_V_OK)
ctx->error = err;
return ctx->verify_cb(0, ctx);
}
/*-
* Inform the verify callback of an error, CRL-specific variant. Here, the
* error depth and certificate are already set, we just specify the error
* number.
*
* Returns 0 to abort verification with an error, non-zero to continue.
*/
static int verify_cb_crl(X509_STORE_CTX *ctx, int err)
{
ctx->error = err;
return ctx->verify_cb(0, ctx);
}
static int check_auth_level(X509_STORE_CTX *ctx)
{
int i;
int num = sk_X509_num(ctx->chain);
if (ctx->param->auth_level <= 0)
return 1;
for (i = 0; i < num; ++i) {
X509 *cert = sk_X509_value(ctx->chain, i);
/*
* We've already checked the security of the leaf key, so here we only
* check the security of issuer keys.
*/
if (i > 0 && !check_key_level(ctx, cert) &&
verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_KEY_TOO_SMALL) == 0)
return 0;
/*
* We also check the signature algorithm security of all certificates
* except those of the trust anchor at index num-1.
*/
if (i < num - 1 && !check_sig_level(ctx, cert) &&
verify_cb_cert(ctx, cert, i, X509_V_ERR_CA_MD_TOO_WEAK) == 0)
return 0;
}
return 1;
}
static int verify_chain(X509_STORE_CTX *ctx)
{
int err;
int ok;
/*
* Before either returning with an error, or continuing with CRL checks,
* instantiate chain public key parameters.
*/
if ((ok = build_chain(ctx)) == 0 ||
(ok = check_chain_extensions(ctx)) == 0 ||
(ok = check_auth_level(ctx)) == 0 ||
(ok = check_id(ctx)) == 0 || 1)
X509_get_pubkey_parameters(NULL, ctx->chain);
if (ok == 0 || (ok = ctx->check_revocation(ctx)) == 0)
return ok;
err = X509_chain_check_suiteb(&ctx->error_depth, NULL, ctx->chain,
ctx->param->flags);
if (err != X509_V_OK) {
if ((ok = verify_cb_cert(ctx, NULL, ctx->error_depth, err)) == 0)
return ok;
}
/* Verify chain signatures and expiration times */
ok = (ctx->verify != NULL) ? ctx->verify(ctx) : internal_verify(ctx);
if (!ok)
return ok;
if ((ok = check_name_constraints(ctx)) == 0)
return ok;
#ifndef OPENSSL_NO_RFC3779
/* RFC 3779 path validation, now that CRL check has been done */
if ((ok = X509v3_asid_validate_path(ctx)) == 0)
return ok;
if ((ok = X509v3_addr_validate_path(ctx)) == 0)
return ok;
#endif
/* If we get this far evaluate policies */
if (ctx->param->flags & X509_V_FLAG_POLICY_CHECK)
ok = ctx->check_policy(ctx);
return ok;
}
int X509_verify_cert(X509_STORE_CTX *ctx)
{
SSL_DANE *dane = ctx->dane;
int ret;
if (ctx->cert == NULL) {
X509err(X509_F_X509_VERIFY_CERT, X509_R_NO_CERT_SET_FOR_US_TO_VERIFY);
ctx->error = X509_V_ERR_INVALID_CALL;
return -1;
}
if (ctx->chain != NULL) {
/*
* This X509_STORE_CTX has already been used to verify a cert. We
* cannot do another one.
*/
X509err(X509_F_X509_VERIFY_CERT, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
ctx->error = X509_V_ERR_INVALID_CALL;
return -1;
}
if (!X509_up_ref(ctx->cert)) {
X509err(X509_F_X509_VERIFY_CERT, ERR_R_INTERNAL_ERROR);
ctx->error = X509_V_ERR_UNSPECIFIED;
return -1;
}
/*
* first we make sure the chain we are going to build is present and that
* the first entry is in place
*/
if ((ctx->chain = sk_X509_new_null()) == NULL
|| !sk_X509_push(ctx->chain, ctx->cert)) {
X509_free(ctx->cert);
X509err(X509_F_X509_VERIFY_CERT, ERR_R_MALLOC_FAILURE);
ctx->error = X509_V_ERR_OUT_OF_MEM;
return -1;
}
ctx->num_untrusted = 1;
/* If the peer's public key is too weak, we can stop early. */
if (!check_key_level(ctx, ctx->cert) &&
!verify_cb_cert(ctx, ctx->cert, 0, X509_V_ERR_EE_KEY_TOO_SMALL))
return 0;
if (DANETLS_ENABLED(dane))
ret = dane_verify(ctx);
else
ret = verify_chain(ctx);
/*
* Safety-net. If we are returning an error, we must also set ctx->error,
* so that the chain is not considered verified should the error be ignored
* (e.g. TLS with SSL_VERIFY_NONE).
*/
if (ret <= 0 && ctx->error == X509_V_OK)
ctx->error = X509_V_ERR_UNSPECIFIED;
return ret;
}
static int sk_X509_contains(STACK_OF(X509) *sk, X509 *cert)
{
int i, n = sk_X509_num(sk);
for (i = 0; i < n; i++)
if (X509_cmp(sk_X509_value(sk, i), cert) == 0)
return 1;
return 0;
}
/*
* Find in given STACK_OF(X509) sk an issuer cert of given cert x.
* The issuer must not yet be in ctx->chain, where the exceptional case
* that x is self-issued and ctx->chain has just one element is allowed.
* Prefer the first one that is not expired, else take the last expired one.
*/
static X509 *find_issuer(X509_STORE_CTX *ctx, STACK_OF(X509) *sk, X509 *x)
{
int i;
X509 *issuer, *rv = NULL;
for (i = 0; i < sk_X509_num(sk); i++) {
issuer = sk_X509_value(sk, i);
if (ctx->check_issued(ctx, x, issuer)
&& (((x->ex_flags & EXFLAG_SI) != 0 && sk_X509_num(ctx->chain) == 1)
|| !sk_X509_contains(ctx->chain, issuer))) {
rv = issuer;
if (x509_check_cert_time(ctx, rv, -1))
break;
}
}
return rv;
}
/* Check that the given certificate 'x' is issued by the certificate 'issuer' */
static int check_issued(X509_STORE_CTX *ctx, X509 *x, X509 *issuer)
{
return x509_likely_issued(issuer, x) == X509_V_OK;
}
/* Alternative lookup method: look from a STACK stored in other_ctx */
static int get_issuer_sk(X509 **issuer, X509_STORE_CTX *ctx, X509 *x)
{
*issuer = find_issuer(ctx, ctx->other_ctx, x);
if (*issuer == NULL || !X509_up_ref(*issuer))
goto err;
return 1;
err:
*issuer = NULL;
return 0;
}
static STACK_OF(X509) *lookup_certs_sk(X509_STORE_CTX *ctx, X509_NAME *nm)
{
STACK_OF(X509) *sk = NULL;
X509 *x;
int i;
for (i = 0; i < sk_X509_num(ctx->other_ctx); i++) {
x = sk_X509_value(ctx->other_ctx, i);
if (X509_NAME_cmp(nm, X509_get_subject_name(x)) == 0) {
if (!X509_up_ref(x)) {
sk_X509_pop_free(sk, X509_free);
X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_INTERNAL_ERROR);
ctx->error = X509_V_ERR_UNSPECIFIED;
return NULL;
}
if (sk == NULL)
sk = sk_X509_new_null();
if (sk == NULL || !sk_X509_push(sk, x)) {
X509_free(x);
sk_X509_pop_free(sk, X509_free);
X509err(X509_F_LOOKUP_CERTS_SK, ERR_R_MALLOC_FAILURE);
ctx->error = X509_V_ERR_OUT_OF_MEM;
return NULL;
}
}
}
return sk;
}
/*
* Check EE or CA certificate purpose. For trusted certificates explicit local
* auxiliary trust can be used to override EKU-restrictions.
*/
static int check_purpose(X509_STORE_CTX *ctx, X509 *x, int purpose, int depth,
int must_be_ca)
{
int tr_ok = X509_TRUST_UNTRUSTED;
/*
* For trusted certificates we want to see whether any auxiliary trust
* settings trump the purpose constraints.
*
* This is complicated by the fact that the trust ordinals in
* ctx->param->trust are entirely independent of the purpose ordinals in
* ctx->param->purpose!
*
* What connects them is their mutual initialization via calls from
* X509_STORE_CTX_set_default() into X509_VERIFY_PARAM_lookup() which sets
* related values of both param->trust and param->purpose. It is however
* typically possible to infer associated trust values from a purpose value
* via the X509_PURPOSE API.
*
* Therefore, we can only check for trust overrides when the purpose we're
* checking is the same as ctx->param->purpose and ctx->param->trust is
* also set.
*/
if (depth >= ctx->num_untrusted && purpose == ctx->param->purpose)
tr_ok = X509_check_trust(x, ctx->param->trust, X509_TRUST_NO_SS_COMPAT);
switch (tr_ok) {
case X509_TRUST_TRUSTED:
return 1;
case X509_TRUST_REJECTED:
break;
default:
switch (X509_check_purpose(x, purpose, must_be_ca > 0)) {
case 1:
return 1;
case 0:
break;
default:
if ((ctx->param->flags & X509_V_FLAG_X509_STRICT) == 0)
return 1;
}
break;
}
return verify_cb_cert(ctx, x, depth, X509_V_ERR_INVALID_PURPOSE);
}
/*
* Check a certificate chains extensions for consistency with the supplied
* purpose
*/
static int check_chain_extensions(X509_STORE_CTX *ctx)
{
int i, must_be_ca, plen = 0;
X509 *x;
int proxy_path_length = 0;
int purpose;
int allow_proxy_certs;
int num = sk_X509_num(ctx->chain);
/*-
* must_be_ca can have 1 of 3 values:
* -1: we accept both CA and non-CA certificates, to allow direct
* use of self-signed certificates (which are marked as CA).
* 0: we only accept non-CA certificates. This is currently not
* used, but the possibility is present for future extensions.
* 1: we only accept CA certificates. This is currently used for
* all certificates in the chain except the leaf certificate.
*/
must_be_ca = -1;
/* CRL path validation */
if (ctx->parent) {
allow_proxy_certs = 0;
purpose = X509_PURPOSE_CRL_SIGN;
} else {
allow_proxy_certs =
! !(ctx->param->flags & X509_V_FLAG_ALLOW_PROXY_CERTS);
purpose = ctx->param->purpose;
}
for (i = 0; i < num; i++) {
int ret;
x = sk_X509_value(ctx->chain, i);
if (!(ctx->param->flags & X509_V_FLAG_IGNORE_CRITICAL)
&& (x->ex_flags & EXFLAG_CRITICAL)) {
if (!verify_cb_cert(ctx, x, i,
X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION))
return 0;
}
if (!allow_proxy_certs && (x->ex_flags & EXFLAG_PROXY)) {
if (!verify_cb_cert(ctx, x, i,
X509_V_ERR_PROXY_CERTIFICATES_NOT_ALLOWED))
return 0;
}
ret = X509_check_ca(x);
switch (must_be_ca) {
case -1:
if ((ctx->param->flags & X509_V_FLAG_X509_STRICT)
&& (ret != 1) && (ret != 0)) {
ret = 0;
ctx->error = X509_V_ERR_INVALID_CA;
} else
ret = 1;
break;
case 0:
if (ret != 0) {
ret = 0;
ctx->error = X509_V_ERR_INVALID_NON_CA;
} else
ret = 1;
break;
default:
/* X509_V_FLAG_X509_STRICT is implicit for intermediate CAs */
if ((ret == 0)
|| ((i + 1 < num || ctx->param->flags & X509_V_FLAG_X509_STRICT)
&& (ret != 1))) {
ret = 0;
ctx->error = X509_V_ERR_INVALID_CA;
} else
ret = 1;
break;
}
if (ret > 0
&& (ctx->param->flags & X509_V_FLAG_X509_STRICT) && num > 1) {
/* Check for presence of explicit elliptic curve parameters */
ret = check_curve(x);
if (ret < 0) {
ctx->error = X509_V_ERR_UNSPECIFIED;
ret = 0;
} else if (ret == 0) {
ctx->error = X509_V_ERR_EC_KEY_EXPLICIT_PARAMS;
}
}
if (ret > 0
&& (x->ex_flags & EXFLAG_CA) == 0
&& x->ex_pathlen != -1
&& (ctx->param->flags & X509_V_FLAG_X509_STRICT)) {
ctx->error = X509_V_ERR_INVALID_EXTENSION;
ret = 0;
}
if (ret == 0 && !verify_cb_cert(ctx, x, i, X509_V_OK))
return 0;
/* check_purpose() makes the callback as needed */
if (purpose > 0 && !check_purpose(ctx, x, purpose, i, must_be_ca))
return 0;
/* Check pathlen */
if ((i > 1) && (x->ex_pathlen != -1)
&& (plen > (x->ex_pathlen + proxy_path_length))) {
if (!verify_cb_cert(ctx, x, i, X509_V_ERR_PATH_LENGTH_EXCEEDED))
return 0;
}
/* Increment path length if not a self issued intermediate CA */
if (i > 0 && (x->ex_flags & EXFLAG_SI) == 0)
plen++;
/*
* If this certificate is a proxy certificate, the next certificate
* must be another proxy certificate or a EE certificate. If not,
* the next certificate must be a CA certificate.
*/
if (x->ex_flags & EXFLAG_PROXY) {
/*
* RFC3820, 4.1.3 (b)(1) stipulates that if pCPathLengthConstraint
* is less than max_path_length, the former should be copied to
* the latter, and 4.1.4 (a) stipulates that max_path_length
* should be verified to be larger than zero and decrement it.
*
* Because we're checking the certs in the reverse order, we start
* with verifying that proxy_path_length isn't larger than pcPLC,
* and copy the latter to the former if it is, and finally,
* increment proxy_path_length.
*/
if (x->ex_pcpathlen != -1) {
if (proxy_path_length > x->ex_pcpathlen) {
if (!verify_cb_cert(ctx, x, i,
X509_V_ERR_PROXY_PATH_LENGTH_EXCEEDED))
return 0;
}
proxy_path_length = x->ex_pcpathlen;
}
proxy_path_length++;
must_be_ca = 0;
} else
must_be_ca = 1;
}
return 1;
}
static int has_san_id(X509 *x, int gtype)
{
int i;
int ret = 0;
GENERAL_NAMES *gs = X509_get_ext_d2i(x, NID_subject_alt_name, NULL, NULL);
if (gs == NULL)
return 0;
for (i = 0; i < sk_GENERAL_NAME_num(gs); i++) {
GENERAL_NAME *g = sk_GENERAL_NAME_value(gs, i);
if (g->type == gtype) {
ret = 1;
break;
}
}
GENERAL_NAMES_free(gs);
return ret;
}
static int check_name_constraints(X509_STORE_CTX *ctx)
{
int i;
/* Check name constraints for all certificates */
for (i = sk_X509_num(ctx->chain) - 1; i >= 0; i--) {
X509 *x = sk_X509_value(ctx->chain, i);
int j;
/* Ignore self issued certs unless last in chain */
if (i && (x->ex_flags & EXFLAG_SI))
continue;
/*
* Proxy certificates policy has an extra constraint, where the
* certificate subject MUST be the issuer with a single CN entry
* added.
* (RFC 3820: 3.4, 4.1.3 (a)(4))
*/
if (x->ex_flags & EXFLAG_PROXY) {
X509_NAME *tmpsubject = X509_get_subject_name(x);
X509_NAME *tmpissuer = X509_get_issuer_name(x);
X509_NAME_ENTRY *tmpentry = NULL;
int last_object_nid = 0;
int err = X509_V_OK;
int last_object_loc = X509_NAME_entry_count(tmpsubject) - 1;
/* Check that there are at least two RDNs */
if (last_object_loc < 1) {
err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
goto proxy_name_done;
}
/*
* Check that there is exactly one more RDN in subject as
* there is in issuer.
*/
if (X509_NAME_entry_count(tmpsubject)
!= X509_NAME_entry_count(tmpissuer) + 1) {
err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
goto proxy_name_done;
}
/*
* Check that the last subject component isn't part of a
* multivalued RDN
*/
if (X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
last_object_loc))
== X509_NAME_ENTRY_set(X509_NAME_get_entry(tmpsubject,
last_object_loc - 1))) {
err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
goto proxy_name_done;
}
/*
* Check that the last subject RDN is a commonName, and that
* all the previous RDNs match the issuer exactly
*/
tmpsubject = X509_NAME_dup(tmpsubject);
if (tmpsubject == NULL) {
X509err(X509_F_CHECK_NAME_CONSTRAINTS, ERR_R_MALLOC_FAILURE);
ctx->error = X509_V_ERR_OUT_OF_MEM;
return 0;
}
tmpentry =
X509_NAME_delete_entry(tmpsubject, last_object_loc);
last_object_nid =
OBJ_obj2nid(X509_NAME_ENTRY_get_object(tmpentry));
if (last_object_nid != NID_commonName
|| X509_NAME_cmp(tmpsubject, tmpissuer) != 0) {
err = X509_V_ERR_PROXY_SUBJECT_NAME_VIOLATION;
}
X509_NAME_ENTRY_free(tmpentry);
X509_NAME_free(tmpsubject);
proxy_name_done:
if (err != X509_V_OK
&& !verify_cb_cert(ctx, x, i, err))
return 0;
}
/*
* Check against constraints for all certificates higher in chain
* including trust anchor. Trust anchor not strictly speaking needed
* but if it includes constraints it is to be assumed it expects them
* to be obeyed.
*/
for (j = sk_X509_num(ctx->chain) - 1; j > i; j--) {
NAME_CONSTRAINTS *nc = sk_X509_value(ctx->chain, j)->nc;
if (nc) {
int rv = NAME_CONSTRAINTS_check(x, nc);
/* If EE certificate check commonName too */
if (rv == X509_V_OK && i == 0
&& (ctx->param->hostflags
& X509_CHECK_FLAG_NEVER_CHECK_SUBJECT) == 0
&& ((ctx->param->hostflags
& X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT) != 0
|| !has_san_id(x, GEN_DNS)))
rv = NAME_CONSTRAINTS_check_CN(x, nc);
switch (rv) {
case X509_V_OK:
break;
case X509_V_ERR_OUT_OF_MEM:
return 0;
default:
if (!verify_cb_cert(ctx, x, i, rv))
return 0;
break;
}
}
}
}
return 1;
}
static int check_id_error(X509_STORE_CTX *ctx, int errcode)
{
return verify_cb_cert(ctx, ctx->cert, 0, errcode);
}
static int check_hosts(X509 *x, X509_VERIFY_PARAM *vpm)
{
int i;
int n = sk_OPENSSL_STRING_num(vpm->hosts);
char *name;
if (vpm->peername != NULL) {
OPENSSL_free(vpm->peername);
vpm->peername = NULL;
}
for (i = 0; i < n; ++i) {
name = sk_OPENSSL_STRING_value(vpm->hosts, i);
if (X509_check_host(x, name, 0, vpm->hostflags, &vpm->peername) > 0)
return 1;
}
return n == 0;
}
static int check_id(X509_STORE_CTX *ctx)
{
X509_VERIFY_PARAM *vpm = ctx->param;
X509 *x = ctx->cert;
if (vpm->hosts && check_hosts(x, vpm) <= 0) {
if (!check_id_error(ctx, X509_V_ERR_HOSTNAME_MISMATCH))
return 0;
}
if (vpm->email && X509_check_email(x, vpm->email, vpm->emaillen, 0) <= 0) {
if (!check_id_error(ctx, X509_V_ERR_EMAIL_MISMATCH))
return 0;
}
if (vpm->ip && X509_check_ip(x, vpm->ip, vpm->iplen, 0) <= 0) {
if (!check_id_error(ctx, X509_V_ERR_IP_ADDRESS_MISMATCH))
return 0;
}
return 1;
}
static int check_trust(X509_STORE_CTX *ctx, int num_untrusted)
{
int i;
X509 *x = NULL;
X509 *mx;
SSL_DANE *dane = ctx->dane;
int num = sk_X509_num(ctx->chain);
int trust;
/*
* Check for a DANE issuer at depth 1 or greater, if it is a DANE-TA(2)
* match, we're done, otherwise we'll merely record the match depth.
*/
if (DANETLS_HAS_TA(dane) && num_untrusted > 0 && num_untrusted < num) {
switch (trust = check_dane_issuer(ctx, num_untrusted)) {
case X509_TRUST_TRUSTED:
case X509_TRUST_REJECTED:
return trust;
}
}
/*
* Check trusted certificates in chain at depth num_untrusted and up.
* Note, that depths 0..num_untrusted-1 may also contain trusted
* certificates, but the caller is expected to have already checked those,
* and wants to incrementally check just any added since.
*/
for (i = num_untrusted; i < num; i++) {
x = sk_X509_value(ctx->chain, i);
trust = X509_check_trust(x, ctx->param->trust, 0);
/* If explicitly trusted return trusted */
if (trust == X509_TRUST_TRUSTED)
goto trusted;
if (trust == X509_TRUST_REJECTED)
goto rejected;
}
/*
* If we are looking at a trusted certificate, and accept partial chains,
* the chain is PKIX trusted.
*/
if (num_untrusted < num) {
if (ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN)
goto trusted;
return X509_TRUST_UNTRUSTED;
}
if (num_untrusted == num && ctx->param->flags & X509_V_FLAG_PARTIAL_CHAIN) {
/*
* Last-resort call with no new trusted certificates, check the leaf
* for a direct trust store match.
*/
i = 0;
x = sk_X509_value(ctx->chain, i);
mx = lookup_cert_match(ctx, x);
if (!mx)
return X509_TRUST_UNTRUSTED;
/*
* Check explicit auxiliary trust/reject settings. If none are set,
* we'll accept X509_TRUST_UNTRUSTED when not self-signed.
*/
trust = X509_check_trust(mx, ctx->param->trust, 0);
if (trust == X509_TRUST_REJECTED) {
X509_free(mx);
goto rejected;
}
/* Replace leaf with trusted match */
(void) sk_X509_set(ctx->chain, 0, mx);
X509_free(x);
ctx->num_untrusted = 0;
goto trusted;
}
/*
* If no trusted certs in chain at all return untrusted and allow
* standard (no issuer cert) etc errors to be indicated.
*/
return X509_TRUST_UNTRUSTED;
rejected:
if (!verify_cb_cert(ctx, x, i, X509_V_ERR_CERT_REJECTED))
return X509_TRUST_REJECTED;
return X509_TRUST_UNTRUSTED;
trusted:
if (!DANETLS_ENABLED(dane))
return X509_TRUST_TRUSTED;
if (dane->pdpth < 0)
dane->pdpth = num_untrusted;
/* With DANE, PKIX alone is not trusted until we have both */
if (dane->mdpth >= 0)
return X509_TRUST_TRUSTED;
return X509_TRUST_UNTRUSTED;
}
static int check_revocation(X509_STORE_CTX *ctx)
{
int i = 0, last = 0, ok = 0;
if (!(ctx->param->flags & X509_V_FLAG_CRL_CHECK))
return 1;
if (ctx->param->flags & X509_V_FLAG_CRL_CHECK_ALL)
last = sk_X509_num(ctx->chain) - 1;
else {
/* If checking CRL paths this isn't the EE certificate */
if (ctx->parent)
return 1;
last = 0;
}
for (i = 0; i <= last; i++) {
ctx->error_depth = i;
ok = check_cert(ctx);
if (!ok)
return ok;
}
return 1;
}
static int check_cert(X509_STORE_CTX *ctx)
{
X509_CRL *crl = NULL, *dcrl = NULL;
int ok = 0;
int cnum = ctx->error_depth;
X509 *x = sk_X509_value(ctx->chain, cnum);
ctx->current_cert = x;
ctx->current_issuer = NULL;
ctx->current_crl_score = 0;
ctx->current_reasons = 0;
if (x->ex_flags & EXFLAG_PROXY)
return 1;
while (ctx->current_reasons != CRLDP_ALL_REASONS) {
unsigned int last_reasons = ctx->current_reasons;
/* Try to retrieve relevant CRL */
if (ctx->get_crl)
ok = ctx->get_crl(ctx, &crl, x);
else
ok = get_crl_delta(ctx, &crl, &dcrl, x);
/*
* If error looking up CRL, nothing we can do except notify callback
*/
if (!ok) {
ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
goto done;
}
ctx->current_crl = crl;
ok = ctx->check_crl(ctx, crl);
if (!ok)
goto done;
if (dcrl) {
ok = ctx->check_crl(ctx, dcrl);
if (!ok)
goto done;
ok = ctx->cert_crl(ctx, dcrl, x);
if (!ok)
goto done;
} else
ok = 1;
/* Don't look in full CRL if delta reason is removefromCRL */
if (ok != 2) {
ok = ctx->cert_crl(ctx, crl, x);
if (!ok)
goto done;
}
X509_CRL_free(crl);
X509_CRL_free(dcrl);
crl = NULL;
dcrl = NULL;
/*
* If reasons not updated we won't get anywhere by another iteration,
* so exit loop.
*/
if (last_reasons == ctx->current_reasons) {
ok = verify_cb_crl(ctx, X509_V_ERR_UNABLE_TO_GET_CRL);
goto done;
}
}
done:
X509_CRL_free(crl);
X509_CRL_free(dcrl);
ctx->current_crl = NULL;
return ok;
}
/* Check CRL times against values in X509_STORE_CTX */
static int check_crl_time(X509_STORE_CTX *ctx, X509_CRL *crl, int notify)
{
time_t *ptime;
int i;
if (ctx->param->flags & X509_V_FLAG_USE_CHECK_TIME)
ptime = &ctx->param->check_time;
else if (ctx->param->flags & X509_V_FLAG_NO_CHECK_TIME)
return 1;
else
ptime = NULL;
if (notify)
ctx->current_crl = crl;
i = X509_cmp_time(X509_CRL_get0_lastUpdate(crl), ptime);
if (i == 0) {
if (!notify)
return 0;
if (!verify_cb_crl(ctx, X509_V_ERR_ERROR_IN_CRL_LAST_UPDATE_FIELD))
return 0;
}
if (i > 0) {
if (!notify)
return 0;
if (!verify_cb_crl(ctx, X509_V_ERR_CRL_NOT_YET_VALID))
return 0;
}
if (X509_CRL_get0_nextUpdate(crl)) {