/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "ssl_private.h"
#ifndef OPENSSL_NO_OCSP
#include "apr_base64.h"
/* Return the responder URI specified in the given certificate, or
* NULL if none specified. */
static const char *extract_responder_uri(X509 *cert, apr_pool_t *pool)
{
STACK_OF(ACCESS_DESCRIPTION) *values;
char *result = NULL;
int j;
values = X509_get_ext_d2i(cert, NID_info_access, NULL, NULL);
if (!values) {
return NULL;
}
for (j = 0; j < sk_ACCESS_DESCRIPTION_num(values) && !result; j++) {
ACCESS_DESCRIPTION *value = sk_ACCESS_DESCRIPTION_value(values, j);
/* Name found in extension, and is a URI: */
if (OBJ_obj2nid(value->method) == NID_ad_OCSP
&& value->location->type == GEN_URI) {
result = apr_pstrdup(pool,
(char *)value->location->d.uniformResourceIdentifier->data);
}
}
AUTHORITY_INFO_ACCESS_free(values);
return result;
}
/* Return the responder URI object which should be used in the given
* configuration for the given certificate, or NULL if none can be
* determined. */
static apr_uri_t *determine_responder_uri(SSLSrvConfigRec *sc, X509 *cert,
conn_rec *c, apr_pool_t *p)
{
apr_uri_t *u = apr_palloc(p, sizeof *u);
const char *s;
apr_status_t rv;
/* Use default responder URL if forced by configuration, else use
* certificate-specified responder, falling back to default if
* necessary and possible. */
if (sc->server->ocsp_force_default == TRUE) {
s = sc->server->ocsp_responder;
}
else {
s = extract_responder_uri(cert, p);
if (s == NULL && sc->server->ocsp_responder) {
s = sc->server->ocsp_responder;
}
}
if (s == NULL) {
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(01918)
"no OCSP responder specified in certificate and "
"no default configured");
return NULL;
}
rv = apr_uri_parse(p, s, u);
if (rv || !u->hostname) {
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c, APLOGNO(01919)
"failed to parse OCSP responder URI '%s'", s);
return NULL;
}
if (strcasecmp(u->scheme, "http") != 0) {
ap_log_cerror(APLOG_MARK, APLOG_DEBUG, rv, c, APLOGNO(01920)
"cannot handle OCSP responder URI '%s'", s);
return NULL;
}
if (!u->port) {
u->port = apr_uri_port_of_scheme(u->scheme);
}
return u;
}
/* Create an OCSP request for the given certificate; returning the
* certificate ID in *certid and *issuer on success. Returns the
* request object on success, or NULL on error. */
static OCSP_REQUEST *create_request(X509_STORE_CTX *ctx, X509 *cert,
OCSP_CERTID **certid,
server_rec *s, apr_pool_t *p,
SSLSrvConfigRec *sc)
{
OCSP_REQUEST *req = OCSP_REQUEST_new();
*certid = OCSP_cert_to_id(NULL, cert, ctx->current_issuer);
if (!*certid || !OCSP_request_add0_id(req, *certid)) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01921)
"could not retrieve certificate id");
ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, s);
return NULL;
}
if (sc->server->ocsp_use_request_nonce != FALSE) {
OCSP_request_add1_nonce(req, 0, -1);
}
return req;
}
/* Verify the OCSP status of given certificate. Returns
* V_OCSP_CERTSTATUS_* result code. */
static int verify_ocsp_status(X509 *cert, X509_STORE_CTX *ctx, conn_rec *c,
SSLSrvConfigRec *sc, server_rec *s,
apr_pool_t *pool)
{
int rc = V_OCSP_CERTSTATUS_GOOD;
OCSP_RESPONSE *response = NULL;
OCSP_BASICRESP *basicResponse = NULL;
OCSP_REQUEST *request = NULL;
OCSP_CERTID *certID = NULL;
apr_uri_t *ruri;
ruri = determine_responder_uri(sc, cert, c, pool);
if (!ruri) {
return V_OCSP_CERTSTATUS_UNKNOWN;
}
request = create_request(ctx, cert, &certID, s, pool, sc);
if (request) {
apr_interval_time_t to = sc->server->ocsp_responder_timeout == UNSET ?
apr_time_from_sec(DEFAULT_OCSP_TIMEOUT) :
sc->server->ocsp_responder_timeout;
response = modssl_dispatch_ocsp_request(ruri, to, request, c, pool);
}
if (!request || !response) {
rc = V_OCSP_CERTSTATUS_UNKNOWN;
}
if (rc == V_OCSP_CERTSTATUS_GOOD) {
int r = OCSP_response_status(response);
if (r != OCSP_RESPONSE_STATUS_SUCCESSFUL) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01922)
"OCSP response not successful: %d", rc);
rc = V_OCSP_CERTSTATUS_UNKNOWN;
}
}
if (rc == V_OCSP_CERTSTATUS_GOOD) {
basicResponse = OCSP_response_get1_basic(response);
if (!basicResponse) {
ap_log_cerror(APLOG_MARK, APLOG_ERR, 0, c, APLOGNO(01923)
"could not retrieve OCSP basic response");
ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, s);
rc = V_OCSP_CERTSTATUS_UNKNOWN;
}
}
if (rc == V_OCSP_CERTSTATUS_GOOD &&
sc->server->ocsp_use_request_nonce != FALSE &&
OCSP_check_nonce(request, basicResponse) != 1) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01924)
"Bad OCSP responder answer (bad nonce)");
rc = V_OCSP_CERTSTATUS_UNKNOWN;
}
if (rc == V_OCSP_CERTSTATUS_GOOD) {
/* TODO: allow flags configuration. */
if (OCSP_basic_verify(basicResponse, NULL, ctx->ctx, 0) != 1) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01925)
"failed to verify the OCSP response");
ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, s);
rc = V_OCSP_CERTSTATUS_UNKNOWN;
}
}
if (rc == V_OCSP_CERTSTATUS_GOOD) {
int reason = -1, status;
ASN1_GENERALIZEDTIME *thisup = NULL, *nextup = NULL;
rc = OCSP_resp_find_status(basicResponse, certID, &status,
&reason, NULL, &thisup, &nextup);
if (rc != 1) {
ssl_log_cxerror(SSLLOG_MARK, APLOG_ERR, 0, c, cert, APLOGNO(02272)
"failed to retrieve OCSP response status");
ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, s);
rc = V_OCSP_CERTSTATUS_UNKNOWN;
}
else {
rc = status;
}
/* Check whether the response is inside the defined validity
* period; otherwise fail. */
if (rc != V_OCSP_CERTSTATUS_UNKNOWN) {
long resptime_skew = sc->server->ocsp_resptime_skew == UNSET ?
DEFAULT_OCSP_MAX_SKEW : sc->server->ocsp_resptime_skew;
/* oscp_resp_maxage can be passed verbatim - UNSET (-1) means
* that responses can be of any age as long as nextup is in the
* future. */
int vrc = OCSP_check_validity(thisup, nextup, resptime_skew,
sc->server->ocsp_resp_maxage);
if (vrc != 1) {
ssl_log_cxerror(SSLLOG_MARK, APLOG_ERR, 0, c, cert, APLOGNO(02273)
"OCSP response outside validity period");
ssl_log_ssl_error(SSLLOG_MARK, APLOG_ERR, s);
rc = V_OCSP_CERTSTATUS_UNKNOWN;
}
}
{
int level =
(status == V_OCSP_CERTSTATUS_GOOD) ? APLOG_INFO : APLOG_ERR;
const char *result =
status == V_OCSP_CERTSTATUS_GOOD ? "good" :
(status == V_OCSP_CERTSTATUS_REVOKED ? "revoked" : "unknown");
ssl_log_cxerror(SSLLOG_MARK, level, 0, c, cert,
"OCSP validation completed, "
"certificate status: %s (%d, %d)",
result, status, reason);
}
}
if (request) OCSP_REQUEST_free(request);
if (response) OCSP_RESPONSE_free(response);
if (basicResponse) OCSP_BASICRESP_free(basicResponse);
/* certID is freed when the request is freed */
return rc;
}
int modssl_verify_ocsp(X509_STORE_CTX *ctx, SSLSrvConfigRec *sc,
server_rec *s, conn_rec *c, apr_pool_t *pool)
{
X509 *cert = X509_STORE_CTX_get_current_cert(ctx);
apr_pool_t *vpool;
int rv;
if (!cert) {
/* starting with OpenSSL 1.0, X509_STORE_CTX_get_current_cert()
* may yield NULL. Return early, but leave the ctx error as is. */
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c,
"No cert available to check with OCSP");
return 1;
}
else if (cert->valid && X509_check_issued(cert,cert) == X509_V_OK) {
/* don't do OCSP checking for valid self-issued certs */
ap_log_cerror(APLOG_MARK, APLOG_TRACE2, 0, c,
"Skipping OCSP check for valid self-issued cert");
X509_STORE_CTX_set_error(ctx, X509_V_OK);
return 1;
}
/* Create a temporary pool to constrain memory use (the passed-in
* pool may be e.g. a connection pool). */
apr_pool_create(&vpool, pool);
rv = verify_ocsp_status(cert, ctx, c, sc, s, vpool);
apr_pool_destroy(vpool);
/* Propagate the verification status back to the passed-in
* context. */
switch (rv) {
case V_OCSP_CERTSTATUS_GOOD:
X509_STORE_CTX_set_error(ctx, X509_V_OK);
break;
case V_OCSP_CERTSTATUS_REVOKED:
X509_STORE_CTX_set_error(ctx, X509_V_ERR_CERT_REVOKED);
break;
case V_OCSP_CERTSTATUS_UNKNOWN:
/* correct error code for application errors? */
X509_STORE_CTX_set_error(ctx, X509_V_ERR_APPLICATION_VERIFICATION);
break;
}
return rv == V_OCSP_CERTSTATUS_GOOD;
}
#endif /* HAVE_OCSP */