Add SSLSessionTickets (on|off).

It controls the use of TLS session tickets
(RFC 5077). Default is unchanged (on).

Using session tickets without restarting
the web server with an appropriate frequency
(e.g. daily) compromises perfect forward
secrecy.

As long as we do not have a nice key management
there should be a way to deactivate session
tickets.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1650310 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/docs/manual/mod/mod_ssl.xml b/docs/manual/mod/mod_ssl.xml
index 33cc6d89cdd422bb7d4b7f761f9723c566a96ad2..d6dff12217493ae8ba1d922f9f476d3e81435e4b 100644 (file)
--- a/docs/manual/mod/mod_ssl.xml
+++ b/docs/manual/mod/mod_ssl.xml
@@ -2589,6 +2589,27 @@ CRIME attack).</p>
 </usage>
 </directivesynopsis>
 
+<directivesynopsis>
+<name>SSLSessionTickets</name>
+<description>Enable or disable use of TLS session tickets</description>
+<syntax>SSLSessionTickets on|off</syntax>
+<default>SSLCompression on</default>
+<contextlist><context>server config</context>
+<context>virtual host</context></contextlist>
+<compatibility>Available in httpd 2.4.11 and later, if using OpenSSL 0.9.8f
+or later.</compatibility>
+
+<usage>
+<p>This directive allows to enable or disable the use of TLS session tickets
+(RFC 5077).</p>
+<note type="warning">
+<p>TLS session tickets are enabled by default. Using them without restarting
+the web server with an appropriate frequency (e.g. daily) compromises perfect
+forward secrecy.</p>
+</note>
+</usage>
+</directivesynopsis>
+
 <directivesynopsis>
 <name>SSLOpenSSLConfCmd</name>
 <description>Configure OpenSSL parameters through its <em>SSL_CONF</em> API</description>

diff --git a/modules/ssl/mod_ssl.c b/modules/ssl/mod_ssl.c
index cae3f5d870ff45bc8d43ad6ffdffc08ca270b915..c4f9e90b19bf8b2fad20a99ba7de39fce560780d 100644 (file)
--- a/modules/ssl/mod_ssl.c
+++ b/modules/ssl/mod_ssl.c
@@ -148,6 +148,9 @@ static const command_rec ssl_config_cmds[] = {
     SSL_CMD_SRV(Compression, FLAG,
                 "Enable SSL level compression "
                 "(`on', `off')")
+    SSL_CMD_SRV(SessionTickets, FLAG,
+                "Enable or disable TLS session tickets"
+                "(`on', `off')")
     SSL_CMD_SRV(InsecureRenegotiation, FLAG,
                 "Enable support for insecure renegotiation")
     SSL_CMD_ALL(UserName, TAKE1,

diff --git a/modules/ssl/ssl_engine_config.c b/modules/ssl/ssl_engine_config.c
index 90260fde58d75b163e4690bf32713e3a1c685ef6..eed4e084c3c26eb245aceacd00b31da258bcf270 100644 (file)
--- a/modules/ssl/ssl_engine_config.c
+++ b/modules/ssl/ssl_engine_config.c
@@ -222,6 +222,7 @@ static SSLSrvConfigRec *ssl_config_server_new(apr_pool_t *p)
 #ifndef OPENSSL_NO_COMP
     sc->compression            = UNSET;
 #endif
+    sc->session_tickets        = UNSET;
 
     modssl_ctx_init_proxy(sc, p);
 
@@ -356,6 +357,7 @@ void *ssl_config_server_merge(apr_pool_t *p, void *basev, void *addv)
 #ifndef OPENSSL_NO_COMP
     cfgMergeBool(compression);
 #endif
+    cfgMergeBool(session_tickets);
 
     modssl_ctx_cfg_merge_proxy(p, base->proxy, add->proxy, mrg->proxy);
 
@@ -733,6 +735,17 @@ const char *ssl_cmd_SSLHonorCipherOrder(cmd_parms *cmd, void *dcfg, int flag)
 #endif
 }
 
+const char *ssl_cmd_SSLSessionTickets(cmd_parms *cmd, void *dcfg, int flag)
+{
+    SSLSrvConfigRec *sc = mySrvConfig(cmd->server);
+#ifndef SSL_OP_NO_TICKET
+    return "This version of OpenSSL does not support using "
+           "SSLSessionTickets.";
+#endif
+    sc->session_tickets = flag ? TRUE : FALSE;
+    return NULL;
+}
+
 const char *ssl_cmd_SSLInsecureRenegotiation(cmd_parms *cmd, void *dcfg, int flag)
 {
 #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION

diff --git a/modules/ssl/ssl_engine_init.c b/modules/ssl/ssl_engine_init.c
index c47cb7728982acfdbbc4e0b9048db1bedc5e262e..b44e01f1c27043db21958871cd634a5da0d7b751 100644 (file)
--- a/modules/ssl/ssl_engine_init.c
+++ b/modules/ssl/ssl_engine_init.c
@@ -574,6 +574,16 @@ static apr_status_t ssl_init_ctx_protocol(server_rec *s,
     }
 #endif
 
+#ifdef SSL_OP_NO_TICKET
+    /*
+     * Configure using RFC 5077 TLS session tickets
+     * for session resumption.
+     */
+    if (sc->session_tickets == FALSE) {
+        SSL_CTX_set_options(ctx, SSL_OP_NO_TICKET);
+    }
+#endif
+
 #ifdef SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
     if (sc->insecure_reneg == TRUE) {
         SSL_CTX_set_options(ctx, SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION);

diff --git a/modules/ssl/ssl_private.h b/modules/ssl/ssl_private.h
index 5fb5e7c6558f7556a7aa28bd1c1d6a7e1f5e2822..140b9c30991b5161e47d42108b061940842ca642 100644 (file)
--- a/modules/ssl/ssl_private.h
+++ b/modules/ssl/ssl_private.h
@@ -648,6 +648,7 @@ struct SSLSrvConfigRec {
 #ifndef OPENSSL_NO_COMP
     BOOL             compression;
 #endif
+    BOOL             session_tickets;
 };
 
 /**
@@ -702,6 +703,7 @@ const char  *ssl_cmd_SSLCARevocationFile(cmd_parms *, void *, const char *);
 const char  *ssl_cmd_SSLCARevocationCheck(cmd_parms *, void *, const char *);
 const char  *ssl_cmd_SSLHonorCipherOrder(cmd_parms *cmd, void *dcfg, int flag);
 const char  *ssl_cmd_SSLCompression(cmd_parms *, void *, int flag);
+const char  *ssl_cmd_SSLSessionTickets(cmd_parms *, void *, int flag);
 const char  *ssl_cmd_SSLVerifyClient(cmd_parms *, void *, const char *);
 const char  *ssl_cmd_SSLVerifyDepth(cmd_parms *, void *, const char *);
 const char  *ssl_cmd_SSLSessionCache(cmd_parms *, void *, const char *);