From: William A. Rowe Jr <wrowe@apache.org>
Date: Thu, 27 Jun 2013 17:24:58 +0000 (+0000)
Subject: mod_ssl/proxy: enable the SNI extension for backend TLS connections
X-Git-Tag: 2.2.25~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6e886db17b3fcaae9077b1620294769feca4aeb9;p=thirdparty%2Fapache%2Fhttpd.git

mod_ssl/proxy: enable the SNI extension for backend TLS connections

Backports: r1175416
Submitted by: kbrand
Reviewed by: wrowe, rjung, trawick


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@1497466 13f79535-47bb-0310-9956-ffa450edef68
---

diff --git a/CHANGES b/CHANGES
index 91f544ba7ce..c7b2c6c4b16 100644
--- a/CHANGES
+++ b/CHANGES
@@ -17,12 +17,12 @@ Changes with Apache 2.2.25
   *) mod_setenvif: Log error on substitution overflow.
      [Stefan Fritsch]
 
+  *) mod_ssl/proxy: enable the SNI extension for backend TLS connections
+     [Kaspar Brand]
+
   *) mod_ssl: Quiet FIPS mode weak keys disabled and FIPS not selected emits
      in the error log to debug level.  [William Rowe]
 
-  *) htdigest: Fix buffer overflow when reading digest password file
-     with very long lines. PR 54893. [Rainer Jung]
-
   *) mod_ssl: Catch missing, mismatched or encrypted client cert/key pairs
      with SSLProxyMachineCertificateFile/Path directives. PR 52212, PR 54698.
      [Keith Burdis <keith burdis.org>, Joe Orton, Kaspar Brand]
@@ -31,6 +31,9 @@ Changes with Apache 2.2.25
      admin to configure an IO timeout as an error in the balancer.
      [Daniel Ruggeri]
 
+  *) htdigest: Fix buffer overflow when reading digest password file
+     with very long lines. PR 54893. [Rainer Jung]
+
   *) mod_dav: Sending a MERGE request against a URI handled by mod_dav_svn with
      the source href (sent as part of the request body as XML) pointing to a
      URI that is not configured for DAV will trigger a segfault. [Ben Reser
diff --git a/STATUS b/STATUS
index 320464742d6..716833afb08 100644
--- a/STATUS
+++ b/STATUS
@@ -96,11 +96,6 @@ RELEASE SHOWSTOPPERS:
 PATCHES ACCEPTED TO BACKPORT FROM TRUNK:
   [ start all new proposals below, under PATCHES PROPOSED. ]
   
-  * mod_ssl/proxy: enable the SNI extension for backend TLS connections
-    [Kaspar Brand]
-    2.2.x patch: http://people.apache.org/~rjung/patches/r1175416-2.0-v2.patch
-    +1: wrowe, rjung, trawick
-
    * mod_proxy_http: Use the same hostname for SNI as for the HTTP request when
      forwarding to SSL backends.
      PR: 53134
diff --git a/modules/ssl/ssl_engine_io.c b/modules/ssl/ssl_engine_io.c
index 7bba787e588..13131900fb6 100644
--- a/modules/ssl/ssl_engine_io.c
+++ b/modules/ssl/ssl_engine_io.c
@@ -1063,9 +1063,39 @@ static int ssl_io_filter_connect(ssl_filter_ctx_t *filter_ctx)
 
     server = sslconn->server;
     if (sslconn->is_proxy) {
-        const char *hostname_note;
-
+#ifndef OPENSSL_NO_TLSEXT
+        apr_ipsubnet_t *ip;
+#endif
+        const char *hostname_note = apr_table_get(c->notes,
+                                                  "proxy-request-hostname");
         sc = mySrvConfig(server);
+
+#ifndef OPENSSL_NO_TLSEXT
+        /*
+         * Enable SNI for backend requests. Make sure we don't do it for
+         * pure SSLv2 or SSLv3 connections, and also prevent IP addresses
+         * from being included in the SNI extension. (OpenSSL would simply
+         * pass them on, but RFC 6066 is quite clear on this: "Literal
+         * IPv4 and IPv6 addresses are not permitted".)
+         */
+        if (hostname_note &&
+            sc->proxy->protocol != SSL_PROTOCOL_SSLV2 &&
+            sc->proxy->protocol != SSL_PROTOCOL_SSLV3 &&
+            apr_ipsubnet_create(&ip, hostname_note, NULL,
+                                c->pool) != APR_SUCCESS) {
+            if (SSL_set_tlsext_host_name(filter_ctx->pssl, hostname_note)) {
+                ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c,
+                              "SNI extension for SSL Proxy request set to '%s'",
+                              hostname_note);
+            } else {
+                ap_log_cerror(APLOG_MARK, APLOG_WARNING, 0, c,
+                              "Failed to set SNI extension for SSL Proxy "
+                              "request to '%s'", hostname_note);
+                ssl_log_ssl_error(APLOG_MARK, APLOG_WARNING, server);
+            }
+	}
+#endif
+
         if ((n = SSL_connect(filter_ctx->pssl)) <= 0) {
             ap_log_cerror(APLOG_MARK, APLOG_INFO, 0, c,
                           "SSL Proxy connect failed");
@@ -1096,8 +1126,7 @@ static int ssl_io_filter_connect(ssl_filter_ctx_t *filter_ctx)
             X509_free(cert);
         }
         if ((sc->proxy_ssl_check_peer_cn == SSL_ENABLED_TRUE)
-            && ((hostname_note =
-                 apr_table_get(c->notes, "proxy-request-hostname")) != NULL)) {
+            && hostname_note) {
             const char *hostname;
 
             hostname = ssl_var_lookup(NULL, server, c, NULL,