@@ -2757,6 +2757,18 @@ client\-connect), then

 every module and script must return success (0) in order for

 the connection to be authenticated.

 .\"*********************************************************

+.TP

+.B \-\-keying-material-exporter label len

+Save Exported Keying Material [RFC5705] of len bytes (must be

+between 16 and 4095 bytes) using label in environment

+(exported_keying_material) for use by plugins in

+OPENVPN_PLUGIN_TLS_FINAL callback.

+

+Note that exporter labels have the potential to collide with existing PRF

+labels. In order to prevent this, labels MUST begin with "EXPORTER".

+

+This option requires OpenSSL 1.0.1 or newer.

+.\"*********************************************************

 .SS Server Mode

 Starting with OpenVPN 2.0, a multi-client TCP/UDP server mode

 is supported, and can be enabled with the

@@ -2279,6 +2279,22 @@ do_init_crypto_tls (struct context *c, const unsigned int flags)

   to.comp_options = options->comp;

 #endif

+#if defined(ENABLE_CRYPTO_OPENSSL) && OPENSSL_VERSION_NUMBER >= 0x10001000

+  if (options->keying_material_exporter_label)

+    {

+      to.ekm_size = options->keying_material_exporter_length;

+      if (to.ekm_size < 16 || to.ekm_size > 4095)

+          to.ekm_size = 0;

+

+      to.ekm_label = options->keying_material_exporter_label;

+      to.ekm_label_size = strlen(to.ekm_label);

+    }

+  else

+    {

+      to.ekm_size = 0;

+    }

+#endif

+

   /* TLS handshake authentication (--tls-auth) */

   if (options->tls_auth_file)

     {

@@ -611,6 +611,10 @@ static const char usage_message[] =

   "--x509-track x  : Save peer X509 attribute x in environment for use by\n"

   "                  plugins and management interface.\n"

 #endif

+#if defined(ENABLE_CRYPTO_OPENSSL) && OPENSSL_VERSION_NUMBER >= 0x10001000

+  "--keying-material-exporter label len : Save Exported Keying Material (RFC5705)\n"

+  "                  of len bytes (min. 16 bytes) using label in environment for use by plugins.\n"

+#endif

   "--remote-cert-ku v ... : Require that the peer certificate was signed with\n"

   "                  explicit key usage, you can specify more than one value.\n"

   "                  value should be given in hex format.\n"

@@ -7066,6 +7070,29 @@ add_option (struct options *options,

       options->use_peer_id = true;

       options->peer_id = atoi(p[1]);

     }

+#if defined(ENABLE_CRYPTO_OPENSSL) && OPENSSL_VERSION_NUMBER >= 0x10001000

+  else if (streq (p[0], "keying-material-exporter") && p[1] && p[2])

+    {

+      int ekm_length = positive_atoi (p[2]);

+

+      VERIFY_PERMISSION (OPT_P_GENERAL);

+

+      if (strncmp(p[1], "EXPORTER", 8))

+        {

+          msg (msglevel, "Keying material exporter label must begin with "

+                         "\"EXPORTER\"");

+          goto err;

+        }

+      if (ekm_length < 16 || ekm_length > 4095)

+        {

+          msg (msglevel, "Invalid keying material exporter length");

+          goto err;

+        }

+

+      options->keying_material_exporter_label = p[1];

+      options->keying_material_exporter_length = ekm_length;

+    }

+#endif

   else

     {

       int i;

@@ -591,6 +591,12 @@ struct options

   bool use_peer_id;

   uint32_t peer_id;

+

+#if defined(ENABLE_CRYPTO_OPENSSL) && OPENSSL_VERSION_NUMBER >= 0x10001000

+  /* Keying Material Exporters [RFC 5705] */

+  const char *keying_material_exporter_label;

+  int keying_material_exporter_length;

+#endif

 };

 #define streq(x, y) (!strcmp((x), (y)))

@@ -2160,8 +2160,12 @@ key_method_2_read (struct buffer *buf, struct tls_multi *multi, struct tls_sessi

    */

   if (ks->authenticated && plugin_defined (session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL))

     {

+      key_state_export_keying_material(&ks->ks_ssl, session);

+

       if (plugin_call (session->opt->plugins, OPENVPN_PLUGIN_TLS_FINAL, NULL, NULL, session->opt->es) != OPENVPN_PLUGIN_FUNC_SUCCESS)

 	ks->authenticated = false;

+

+      setenv_del (session->opt->es, "exported_keying_material");

     }

   /*

@@ -334,6 +334,19 @@ void key_state_ssl_init(struct key_state_ssl *ks_ssl,

  */

 void key_state_ssl_free(struct key_state_ssl *ks_ssl);

+/**

+ * Keying Material Exporters [RFC 5705] allows additional keying material to be

+ * derived from existing TLS channel. This exported keying material can then be

+ * used for a variety of purposes.

+ *

+ * @param ks_ssl       The SSL channel's state info

+ * @param session      The session associated with the given key_state

+ */

+

+void

+key_state_export_keying_material(struct key_state_ssl *ks_ssl,

+    struct tls_session *session) __attribute__((nonnull));

+

 /**************************************************************************/

 /** @addtogroup control_tls

  *  @{ */

@@ -317,6 +317,11 @@ struct tls_options

   /* --gremlin bits */

   int gremlin;

+

+  /* Keying Material Exporter [RFC 5705] parameters */

+  const char *ekm_label;

+  size_t ekm_label_size;

+  size_t ekm_size;

 };

 /** @addtogroup control_processor

@@ -133,6 +133,39 @@ bool tls_ctx_initialised(struct tls_root_ctx *ctx)

   return NULL != ctx->ctx;

 }

+void

+key_state_export_keying_material(struct key_state_ssl *ssl,

+                                 struct tls_session *session)

+{

+  if (session->opt->ekm_size > 0)

+    {

+#if (OPENSSL_VERSION_NUMBER >= 0x10001000)

+      unsigned int size = session->opt->ekm_size;

+      unsigned char ekm[size];

+

+      if (SSL_export_keying_material(ssl->ssl, ekm, sizeof(ekm),

+          session->opt->ekm_label, session->opt->ekm_label_size, NULL, 0, 0))

+       {

+         struct gc_arena gc = gc_new();

+         unsigned int len = (size * 2) + 2;

+

+         const char *key = format_hex_ex (ekm, size, len, 0, NULL, &gc);

+         setenv_str (session->opt->es, "exported_keying_material", key);

+

+         dmsg(D_TLS_DEBUG_MED, "%s: exported keying material: %s",

+              __func__, key);

+

+         gc_free(&gc);

+       }

+      else

+       {

+         msg (M_WARN, "WARNING: Export keying material failed!");

+         setenv_del (session->opt->es, "exported_keying_material");

+       }

+#endif

+    }

+}

+

 /*

  * Print debugging information on SSL/TLS session negotiation.

  */

@@ -149,6 +149,12 @@ tls_ctx_initialised(struct tls_root_ctx *ctx)

 }

 void

+key_state_export_keying_material(struct key_state_ssl *ssl,

+                                 struct tls_session *session)

+{

+}

+

+void

 tls_ctx_set_options (struct tls_root_ctx *ctx, unsigned int ssl_flags)

 {

 }