For the "SSLStaplingReturnResponderErrors off" case, make sure to only

staple responses with certificate status "good". Also avoids including
inaccurate responses when the OCSP responder is not completely up
to date in terms of the CA-issued certificates (and provides interim
"unknown" or "extended revoked" [RFC 6960] status replies).

Log a certificate status other than "good" in stapling_check_response().

Propagate the "ok" status from stapling_check_response() back via both
stapling_renew_response() and get_and_check_cached_response() to the
callback code in stapling_cb(), enabling the decision whether to include
or skip the response.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1711728 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/CHANGES b/CHANGES
index 9b30522cc95d4edb85610dd6d8c8d97828996644..ad21b988786b83ae9fced7ee877023b5e18a47f8 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -1,6 +1,9 @@
                                                          -*- coding: utf-8 -*-
 Changes with Apache 2.5.0
 
+  *) mod_ssl: For the "SSLStaplingReturnResponderErrors off" case, make sure
+     to only staple responses with certificate status "good". [Kaspar Brand]
+
   *) core: Fix scoreboard crash (SIGBUS) on hardware requiring strict 64bit
      alignment (SPARC64, PPC64).  [Yann Ylavic]
 

diff --git a/docs/manual/mod/mod_ssl.xml b/docs/manual/mod/mod_ssl.xml
index 9b43b4e438016b2d706633c9d0a1558385b1fe0b..553197dc79b17be19053975aaaf8a57813c57ed6 100644 (file)
--- a/docs/manual/mod/mod_ssl.xml
+++ b/docs/manual/mod/mod_ssl.xml
@@ -2527,9 +2527,11 @@ used for controlling the timeout for invalid/unavailable responses.
 
 <usage>
 <p>When enabled, mod_ssl will pass responses from unsuccessful
-stapling related OCSP queries (such as status errors, expired responses etc.)
-on to the client. If set to <code>off</code>, no stapled responses
-for failed queries will be included in the TLS handshake.</p>
+stapling related OCSP queries (such as responses with an overall status
+other than "successful", responses with a certificate status other than
+"good", expired responses etc.) on to the client.
+If set to <code>off</code>, only responses indicating a certificate status
+of "good" will be included in the TLS handshake.</p>
 </usage>
 </directivesynopsis>
 

diff --git a/modules/ssl/ssl_util_stapling.c b/modules/ssl/ssl_util_stapling.c
index 7d9df5fdd41fdcd26d269d0a1fe3ec797098b09d..ce1f880485eb17a72bd5c7dde3cc23c837f4ad64 100644 (file)
--- a/modules/ssl/ssl_util_stapling.c
+++ b/modules/ssl/ssl_util_stapling.c
@@ -332,10 +332,12 @@ static int stapling_check_response(server_rec *s, modssl_ctx_t *mctx,
                                    certinfo *cinf, OCSP_RESPONSE *rsp,
                                    BOOL *pok)
 {
-    int status, reason;
+    int status = V_OCSP_CERTSTATUS_UNKNOWN;
+    int reason = OCSP_REVOKED_STATUS_NOSTATUS;
     OCSP_BASICRESP *bs = NULL;
     ASN1_GENERALIZEDTIME *rev, *thisupd, *nextupd;
     int response_status = OCSP_response_status(rsp);
+    int rv = SSL_TLSEXT_ERR_OK;
 
     if (pok)
         *pok = FALSE;
@@ -360,9 +362,11 @@ static int stapling_check_response(server_rec *s, modssl_ctx_t *mctx,
 
     if (!OCSP_resp_find_status(bs, cinf->cid, &status, &reason, &rev,
                                &thisupd, &nextupd)) {
-        /* If ID not present just pass back to client */
+        /* If ID not present pass back to client (if configured so) */
         ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01935)
                      "stapling_check_response: certificate ID not present in response!");
+        if (mctx->stapling_return_errors == FALSE)
+            rv = SSL_TLSEXT_ERR_NOACK;
     }
     else {
         if (OCSP_check_validity(thisupd, nextupd,
@@ -385,19 +389,45 @@ static int stapling_check_response(server_rec *s, modssl_ctx_t *mctx,
                              "stapling_check_response: cached response expired");
             }
 
-            OCSP_BASICRESP_free(bs);
-            return SSL_TLSEXT_ERR_NOACK;
+            rv = SSL_TLSEXT_ERR_NOACK;
+        }
+
+        if (status != V_OCSP_CERTSTATUS_GOOD) {
+            char snum[MAX_STRING_LEN] = { '\0' };
+            BIO *bio = BIO_new(BIO_s_mem());
+
+            if (bio) {
+                int n;
+                if ((i2a_ASN1_INTEGER(bio, cinf->cid->serialNumber) != -1) &&
+                    ((n = BIO_read(bio, snum, sizeof snum - 1)) > 0))
+                    snum[n] = '\0';
+                BIO_free(bio);
+            }
+
+            ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO()
+                         "stapling_check_response: response has certificate "
+                         "status %s (reason: %s) for serial number %s",
+                         OCSP_cert_status_str(status),
+                         (reason != OCSP_REVOKED_STATUS_NOSTATUS) ?
+                         OCSP_crl_reason_str(reason) : "n/a",
+                         snum[0] ? snum : "[n/a]");
+
+            if (mctx->stapling_return_errors == FALSE) {
+                if (pok)
+                    *pok = FALSE;
+                rv = SSL_TLSEXT_ERR_NOACK;
+            }
         }
     }
 
     OCSP_BASICRESP_free(bs);
 
-    return SSL_TLSEXT_ERR_OK;
+    return rv;
 }
 
 static BOOL stapling_renew_response(server_rec *s, modssl_ctx_t *mctx, SSL *ssl,
                                     certinfo *cinf, OCSP_RESPONSE **prsp,
-                                    apr_pool_t *pool)
+                                    BOOL *pok, apr_pool_t *pool)
 {
     conn_rec *conn      = (conn_rec *)SSL_get_app_data(ssl);
     apr_pool_t *vpool;
@@ -405,7 +435,6 @@ static BOOL stapling_renew_response(server_rec *s, modssl_ctx_t *mctx, SSL *ssl,
     OCSP_CERTID *id = NULL;
     STACK_OF(X509_EXTENSION) *exts;
     int i;
-    BOOL ok = FALSE;
     BOOL rv = TRUE;
     const char *ocspuri;
     apr_uri_t uri;
@@ -447,8 +476,7 @@ static BOOL stapling_renew_response(server_rec *s, modssl_ctx_t *mctx, SSL *ssl,
     /* Create a temporary pool to constrain memory use */
     apr_pool_create(&vpool, conn->pool);
 
-    ok = apr_uri_parse(vpool, ocspuri, &uri);
-    if (ok != APR_SUCCESS) {
+    if (apr_uri_parse(vpool, ocspuri, &uri) != APR_SUCCESS) {
         ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01939)
                      "stapling_renew_response: Error parsing uri %s",
                       ocspuri);
@@ -487,8 +515,8 @@ static BOOL stapling_renew_response(server_rec *s, modssl_ctx_t *mctx, SSL *ssl,
         if (response_status == OCSP_RESPONSE_STATUS_SUCCESSFUL) {
             ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01942)
                         "stapling_renew_response: query response received");
-            stapling_check_response(s, mctx, cinf, *prsp, &ok);
-            if (ok == FALSE) {
+            stapling_check_response(s, mctx, cinf, *prsp, pok);
+            if (*pok == FALSE) {
                 ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01943)
                              "stapling_renew_response: error in retrieved response!");
             }
@@ -497,9 +525,10 @@ static BOOL stapling_renew_response(server_rec *s, modssl_ctx_t *mctx, SSL *ssl,
             ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01944)
                          "stapling_renew_response: responder error %s",
                          OCSP_response_status_str(response_status));
+            *pok = FALSE;
         }
     }
-    if (stapling_cache_response(s, mctx, *prsp, cinf, ok, pool) == FALSE) {
+    if (stapling_cache_response(s, mctx, *prsp, cinf, *pok, pool) == FALSE) {
         ap_log_error(APLOG_MARK, APLOG_ERR, 0, s, APLOGNO(01945)
                      "stapling_renew_response: error caching response!");
     }
@@ -651,8 +680,8 @@ static int stapling_refresh_mutex_off(server_rec *s)
 }
 
 static int get_and_check_cached_response(server_rec *s, modssl_ctx_t *mctx,
-                                         OCSP_RESPONSE **rsp, certinfo *cinf, 
-                                         apr_pool_t *p)
+                                         OCSP_RESPONSE **rsp, BOOL *pok,
+                                         certinfo *cinf, apr_pool_t *p)
 {
     BOOL ok;
     int rv;
@@ -688,6 +717,7 @@ static int get_and_check_cached_response(server_rec *s, modssl_ctx_t *mctx,
             else if (!mctx->stapling_return_errors) {
                 OCSP_RESPONSE_free(*rsp);
                 *rsp = NULL;
+                *pok = FALSE;
                 return SSL_TLSEXT_ERR_NOACK;
             }
         }
@@ -712,6 +742,7 @@ static int stapling_cb(SSL *ssl, void *arg)
     certinfo *cinf = NULL;
     OCSP_RESPONSE *rsp = NULL;
     int rv;
+    BOOL ok = TRUE;
 
     if (sc->server->stapling_enabled != TRUE) {
         ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01950)
@@ -730,7 +761,7 @@ static int stapling_cb(SSL *ssl, void *arg)
     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01952)
                  "stapling_cb: retrieved cached certificate data");
 
-    rv = get_and_check_cached_response(s, mctx, &rsp, cinf, conn->pool);
+    rv = get_and_check_cached_response(s, mctx, &rsp, &ok, cinf, conn->pool);
     if (rv != 0) {
         return rv;
     }
@@ -742,7 +773,8 @@ static int stapling_cb(SSL *ssl, void *arg)
         /* Maybe another request refreshed the OCSP response while this
          * thread waited for the mutex.  Check again.
          */
-        rv = get_and_check_cached_response(s, mctx, &rsp, cinf, conn->pool);
+        rv = get_and_check_cached_response(s, mctx, &rsp, &ok, cinf,
+                                           conn->pool);
         if (rv != 0) {
             ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                          "stapling_cb: error checking for cached response "
@@ -760,7 +792,8 @@ static int stapling_cb(SSL *ssl, void *arg)
             ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s,
                          "stapling_cb: still must refresh cached response "
                          "after obtaining refresh mutex");
-            rv = stapling_renew_response(s, mctx, ssl, cinf, &rsp, conn->pool);
+            rv = stapling_renew_response(s, mctx, ssl, cinf, &rsp, &ok,
+                                         conn->pool);
             stapling_refresh_mutex_off(s);
 
             if (rv == TRUE) {
@@ -775,7 +808,7 @@ static int stapling_cb(SSL *ssl, void *arg)
         }
     }
 
-    if (rsp) {
+    if (rsp && ((ok == TRUE) || (mctx->stapling_return_errors == TRUE))) {
         ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01956)
                      "stapling_cb: setting response");
         if (!stapling_set_response(ssl, rsp))
@@ -783,7 +816,7 @@ static int stapling_cb(SSL *ssl, void *arg)
         return SSL_TLSEXT_ERR_OK;
     }
     ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, s, APLOGNO(01957)
-                 "stapling_cb: no response available");
+                 "stapling_cb: no suitable response available");
 
     return SSL_TLSEXT_ERR_NOACK;