Implement TLS ticket support in httpd. Off by default. Use

	tls ticket lifetime default
to turn it on with a 2h ticket lifetime.
Rekeying happens after a quarter of that time.
OK reky@ and bob@

6 files changed, 163 insertions, 12 deletions

diff --git a/usr.sbin/httpd/config.c b/usr.sbin/httpd/config.c
index f337a72d8e4..b8eee8c3505 100644
--- a/usr.sbin/httpd/config.c
+++ b/usr.sbin/httpd/config.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: config.c,v 1.50 2016/11/06 10:49:38 beck Exp $	*/
+/*	$OpenBSD: config.c,v 1.51 2017/03/25 17:25:34 claudio Exp $	*/
 
 /*
  * Copyright (c) 2011 - 2015 Reyk Floeter <reyk@openbsd.org>
@@ -146,6 +146,7 @@ config_getcfg(struct httpd *env, struct imsg *imsg)
 	memcpy(&cf, imsg->data, sizeof(cf));
 	env->sc_opts = cf.cf_opts;
 	env->sc_flags = cf.cf_flags;
+	memcpy(env->sc_tls_sid, cf.cf_tls_sid, sizeof(env->sc_tls_sid));
 
 	what = ps->ps_what[privsep_process];
 
@@ -239,6 +240,9 @@ config_setserver(struct httpd *env, struct server *srv)
 		srv->srv_s = -1;
 	}
 
+	explicit_bzero(&srv->srv_conf.tls_ticket_key,
+	    sizeof(srv->srv_conf.tls_ticket_key));
+
 	return (0);
 }
 
diff --git a/usr.sbin/httpd/httpd.c b/usr.sbin/httpd/httpd.c
index 6daccdf52ad..879845a6650 100644
--- a/usr.sbin/httpd/httpd.c
+++ b/usr.sbin/httpd/httpd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: httpd.c,v 1.64 2017/01/23 04:25:05 deraadt Exp $	*/
+/*	$OpenBSD: httpd.c,v 1.65 2017/03/25 17:25:34 claudio Exp $	*/
 
 /*
  * Copyright (c) 2014 Reyk Floeter <reyk@openbsd.org>
@@ -57,6 +57,8 @@ int		 parent_dispatch_server(int, struct privsep_proc *,
 		    struct imsg *);
 int		 parent_dispatch_logger(int, struct privsep_proc *,
 		    struct imsg *);
+void		 parent_tls_ticket_rekey_start(struct server *);
+void		 parent_tls_ticket_rekey(int, short, void *);
 
 struct httpd			*httpd_env;
 
@@ -252,6 +254,9 @@ main(int argc, char *argv[])
 		exit(0);
 	}
 
+	/* initialize the TLS session id to a random key for all procs */
+	arc4random_buf(env->sc_tls_sid, sizeof(env->sc_tls_sid));
+
 	if (parent_configure(env) == -1)
 		fatalx("configuration failed");
 
@@ -287,6 +292,10 @@ parent_configure(struct httpd *env)
 	TAILQ_FOREACH(srv, env->sc_servers, srv_entry) {
 		if (srv->srv_conf.flags & SRVFLAG_LOCATION)
 			continue;
+		/* start the rekey of the tls ticket keys */
+		if (srv->srv_conf.flags & SRVFLAG_TLS &&
+		    srv->srv_conf.tls_ticket_lifetime)
+			parent_tls_ticket_rekey_start(srv);
 		if (config_setserver(env, srv) == -1)
 			fatal("send server");
 	}
@@ -306,6 +315,7 @@ parent_configure(struct httpd *env)
 			continue;
 		cf.cf_opts = env->sc_opts;
 		cf.cf_flags = env->sc_flags;
+		memcpy(cf.cf_tls_sid, env->sc_tls_sid, sizeof(cf.cf_tls_sid));
 
 		proc_compose(env->sc_ps, id, IMSG_CFG_DONE, &cf, sizeof(cf));
 	}
@@ -451,6 +461,38 @@ parent_dispatch_logger(int fd, struct privsep_proc *p, struct imsg *imsg)
 	return (0);
 }
 
+void
+parent_tls_ticket_rekey_start(struct server *srv)
+{
+	struct timeval		 tv;
+
+	server_generate_ticket_key(&srv->srv_conf);
+
+	evtimer_set(&srv->srv_evt, parent_tls_ticket_rekey, srv);
+	timerclear(&tv);
+	tv.tv_sec = srv->srv_conf.tls_ticket_lifetime / 4;
+	evtimer_add(&srv->srv_evt, &tv);
+}
+
+void
+parent_tls_ticket_rekey(int fd, short events, void *arg)
+{
+	struct server		*srv = arg;
+	struct timeval		 tv;
+
+	server_generate_ticket_key(&srv->srv_conf);
+	proc_compose_imsg(httpd_env->sc_ps, PROC_SERVER, -1,
+	    IMSG_TLSTICKET_REKEY, -1, -1, &srv->srv_conf.tls_ticket_key,
+	    sizeof(srv->srv_conf.tls_ticket_key));
+	explicit_bzero(&srv->srv_conf.tls_ticket_key,
+	    sizeof(srv->srv_conf.tls_ticket_key));
+
+	evtimer_set(&srv->srv_evt, parent_tls_ticket_rekey, srv);
+	timerclear(&tv);
+	tv.tv_sec = srv->srv_conf.tls_ticket_lifetime / 4;
+	evtimer_add(&srv->srv_evt, &tv);
+}
+
 /*
  * Utility functions
  */
diff --git a/usr.sbin/httpd/httpd.conf.5 b/usr.sbin/httpd/httpd.conf.5
index 05735332386..548bc7ed027 100644
--- a/usr.sbin/httpd/httpd.conf.5
+++ b/usr.sbin/httpd/httpd.conf.5
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: httpd.conf.5,v 1.80 2017/03/16 10:18:11 florian Exp $
+.\"	$OpenBSD: httpd.conf.5,v 1.81 2017/03/25 17:25:34 claudio Exp $
 .\"
 .\" Copyright (c) 2014, 2015 Reyk Floeter <reyk@openbsd.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: March 16 2017 $
+.Dd $Mdocdate: March 25 2017 $
 .Dt HTTPD.CONF 5
 .Os
 .Sh NAME
@@ -564,6 +564,13 @@ will be used (secure protocols; TLSv1.2-only).
 Refer to the
 .Xr tls_config_parse_protocols 3
 function for other valid protocol string values.
+.It Ic ticket Ic lifetime Ar seconds
+Enable TLS session tickets with a
+.Ar seconds
+session lifetime.
+It is possible to set
+.Ar seconds
+to default to use the httpd default timeout of 2 hours.
 .El
 .El
 .Sh TYPES
diff --git a/usr.sbin/httpd/httpd.h b/usr.sbin/httpd/httpd.h
index 7e527c105c3..6cf2412bf44 100644
--- a/usr.sbin/httpd/httpd.h
+++ b/usr.sbin/httpd/httpd.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: httpd.h,v 1.130 2017/02/07 12:27:42 reyk Exp $	*/
+/*	$OpenBSD: httpd.h,v 1.131 2017/03/25 17:25:34 claudio Exp $	*/
 
 /*
  * Copyright (c) 2006 - 2015 Reyk Floeter <reyk@openbsd.org>
@@ -76,6 +76,9 @@
 #define SERVER_MIN_PREFETCHED	32
 #define SERVER_HSTS_DEFAULT_AGE	31536000
 #define SERVER_MAX_RANGES	4
+#define SERVER_DEF_TLS_LIFETIME	(2 * 3600)
+#define SERVER_MIN_TLS_LIFETIME	(60)
+#define SERVER_MAX_TLS_LIFETIME	(24 * 3600)
 
 #define MEDIATYPE_NAMEMAX	128	/* file name extension */
 #define MEDIATYPE_TYPEMAX	64	/* length of type/subtype */
@@ -109,6 +112,7 @@ enum httpchunk {
 struct ctl_flags {
 	uint8_t		 cf_opts;
 	uint32_t	 cf_flags;
+	uint8_t		 cf_tls_sid[TLS_MAX_SESSION_ID_LENGTH];
 };
 
 enum key_type {
@@ -219,7 +223,8 @@ enum imsg_type {
 	IMSG_CFG_DONE,
 	IMSG_LOG_ACCESS,
 	IMSG_LOG_ERROR,
-	IMSG_LOG_OPEN
+	IMSG_LOG_OPEN,
+	IMSG_TLSTICKET_REKEY
 };
 
 enum privsep_procid {
@@ -444,6 +449,12 @@ struct auth {
 };
 TAILQ_HEAD(serverauth, auth);
 
+struct server_tls_ticket {
+	uint32_t	tt_id;
+	uint32_t 	tt_keyrev;
+	unsigned char	tt_key[TLS_TICKET_KEY_SIZE];
+};
+
 struct server_config {
 	uint32_t		 id;
 	uint32_t		 parent_id;
@@ -477,6 +488,8 @@ struct server_config {
 	uint8_t			*tls_ocsp_staple;
 	size_t			 tls_ocsp_staple_len;
 	char			*tls_ocsp_staple_file;
+	struct server_tls_ticket tls_ticket_key;
+	int			 tls_ticket_lifetime;
 
 	uint32_t		 flags;
 	int			 strip;
@@ -540,6 +553,8 @@ struct httpd {
 	char			*sc_chroot;
 	char			*sc_logdir;
 
+	uint8_t			 sc_tls_sid[TLS_MAX_SESSION_ID_LENGTH];
+
 	struct serverlist	*sc_servers;
 	struct mediatypes	*sc_mediatypes;
 	struct media_type	 sc_default_type;
@@ -573,6 +588,7 @@ void	 server(struct privsep *, struct privsep_proc *);
 int	 server_tls_cmp(struct server *, struct server *, int);
 int	 server_tls_load_keypair(struct server *);
 int	 server_tls_load_ocsp(struct server *);
+void	 server_generate_ticket_key(struct server_config *);
 int	 server_privinit(struct server *);
 void	 server_purge(struct server *);
 void	 serverconfig_free(struct server_config *);
diff --git a/usr.sbin/httpd/parse.y b/usr.sbin/httpd/parse.y
index f53cfff67bf..41964765f0f 100644
--- a/usr.sbin/httpd/parse.y
+++ b/usr.sbin/httpd/parse.y
@@ -1,4 +1,4 @@
-/*	$OpenBSD: parse.y,v 1.89 2017/02/07 12:27:42 reyk Exp $	*/
+/*	$OpenBSD: parse.y,v 1.90 2017/03/25 17:25:34 claudio Exp $	*/
 
 /*
  * Copyright (c) 2007 - 2015 Reyk Floeter <reyk@openbsd.org>
@@ -130,10 +130,10 @@ typedef struct {
 %}
 
 %token	ACCESS ALIAS AUTO BACKLOG BODY BUFFER CERTIFICATE CHROOT CIPHERS COMMON
-%token	COMBINED CONNECTION DHE DIRECTORY ECDHE ERR FCGI INDEX IP KEY LISTEN
-%token	LOCATION LOG LOGDIR MATCH MAXIMUM NO NODELAY OCSP ON PORT PREFORK
-%token	PROTOCOLS REQUESTS ROOT SACK SERVER SOCKET STRIP STYLE SYSLOG TCP TIMEOUT
-%token	TLS TYPE TYPES HSTS MAXAGE SUBDOMAINS DEFAULT PRELOAD REQUEST
+%token	COMBINED CONNECTION DHE DIRECTORY ECDHE ERR FCGI INDEX IP KEY LIFETIME
+%token	LISTEN LOCATION LOG LOGDIR MATCH MAXIMUM NO NODELAY OCSP ON PORT PREFORK
+%token	PROTOCOLS REQUESTS ROOT SACK SERVER SOCKET STRIP STYLE SYSLOG TCP TICKET
+%token	TIMEOUT TLS TYPE TYPES HSTS MAXAGE SUBDOMAINS DEFAULT PRELOAD REQUEST
 %token	ERROR INCLUDE AUTHENTICATE WITH BLOCK DROP RETURN PASS
 %token	<v.string>	STRING
 %token  <v.number>	NUMBER
@@ -766,6 +766,23 @@ tlsopts		: CERTIFICATE STRING		{
 			}
 			free($2);
 		}
+		| TICKET LIFETIME DEFAULT	{
+			srv_conf->tls_ticket_lifetime = SERVER_DEF_TLS_LIFETIME;
+		}
+		| TICKET LIFETIME NUMBER	{
+			if ($3 != 0 && $3 < SERVER_MIN_TLS_LIFETIME) {
+				yyerror("ticket lifetime too small");
+				YYERROR;
+			}
+			if ($3 > SERVER_MAX_TLS_LIFETIME) {
+				yyerror("ticket lifetime too large");
+				YYERROR;
+			}
+			srv_conf->tls_ticket_lifetime = $3;
+		}
+		| NO TICKET			{
+			srv_conf->tls_ticket_lifetime = 0;
+		}
 		;
 
 root		: ROOT rootflags
@@ -1218,6 +1235,7 @@ lookup(char *s)
 		{ "index",		INDEX },
 		{ "ip",			IP },
 		{ "key",		KEY },
+		{ "lifetime",		LIFETIME },
 		{ "listen",		LISTEN },
 		{ "location",		LOCATION },
 		{ "log",		LOG },
@@ -1246,6 +1264,7 @@ lookup(char *s)
 		{ "subdomains",		SUBDOMAINS },
 		{ "syslog",		SYSLOG },
 		{ "tcp",		TCP },
+		{ "ticket",		TICKET },
 		{ "timeout",		TIMEOUT },
 		{ "tls",		TLS },
 		{ "type",		TYPE },
diff --git a/usr.sbin/httpd/server.c b/usr.sbin/httpd/server.c
index a00378bf9de..9ff532d7746 100644
--- a/usr.sbin/httpd/server.c
+++ b/usr.sbin/httpd/server.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: server.c,v 1.107 2017/02/07 12:27:42 reyk Exp $	*/
+/*	$OpenBSD: server.c,v 1.108 2017/03/25 17:25:34 claudio Exp $	*/
 
 /*
  * Copyright (c) 2006 - 2015 Reyk Floeter <reyk@openbsd.org>
@@ -58,6 +58,7 @@ int		 server_socket(struct sockaddr_storage *, in_port_t,
 		    struct server_config *, int, int);
 int		 server_socket_listen(struct sockaddr_storage *, in_port_t,
 		    struct server_config *);
+struct server	*server_byid(uint32_t);
 
 int		 server_tls_init(struct server *);
 void		 server_tls_readcb(int, short, void *);
@@ -135,6 +136,8 @@ server_tls_cmp(struct server *s1, struct server *s2, int match_keypair)
 
 	if (sc1->tls_protocols != sc2->tls_protocols)
 		return (-1);
+	if (sc1->tls_ticket_lifetime != sc2->tls_ticket_lifetime)
+		return (-1);
 	if (strcmp(sc1->tls_ciphers, sc2->tls_ciphers) != 0)
 		return (-1);
 	if (strcmp(sc1->tls_dhe_params, sc2->tls_dhe_params) != 0)
@@ -266,6 +269,31 @@ server_tls_init(struct server *srv)
 		}
 	}
 
+	/* set common session ID among all processes */
+	if (tls_config_set_session_id(srv->srv_tls_config,
+	    httpd_env->sc_tls_sid, sizeof(httpd_env->sc_tls_sid)) == -1) {
+		log_warnx("%s: could not set the TLS session ID: %s",
+		    __func__, tls_config_error(srv->srv_tls_config));
+		return (-1);
+	}
+
+	/* ticket support */
+	if (srv->srv_conf.tls_ticket_lifetime) {
+		if (tls_config_set_session_lifetime(srv->srv_tls_config,
+		    srv->srv_conf.tls_ticket_lifetime) == -1) {
+			log_warnx("%s: could not set the TLS session lifetime: "
+			    "%s", __func__,
+			    tls_config_error(srv->srv_tls_config));
+			return (-1);
+		}
+		tls_config_add_ticket_key(srv->srv_tls_config,
+		    srv->srv_conf.tls_ticket_key.tt_keyrev,
+		    srv->srv_conf.tls_ticket_key.tt_key,
+		    sizeof(srv->srv_conf.tls_ticket_key.tt_key));
+		explicit_bzero(&srv->srv_conf.tls_ticket_key,
+		    sizeof(srv->srv_conf.tls_ticket_key));
+	}
+
 	if (tls_configure(srv->srv_tls_ctx, srv->srv_tls_config) != 0) {
 		log_warnx("%s: failed to configure tls - %s", __func__,
 		    tls_error(srv->srv_tls_ctx));
@@ -287,6 +315,16 @@ server_tls_init(struct server *srv)
 }
 
 void
+server_generate_ticket_key(struct server_config *srv_conf)
+{
+	struct server_tls_ticket *key = &srv_conf->tls_ticket_key;
+
+	key->tt_id = srv_conf->id;
+	key->tt_keyrev = arc4random();
+	arc4random_buf(key->tt_key, sizeof(key->tt_key));
+}
+
+void
 server_init(struct privsep *ps, struct privsep_proc *p, void *arg)
 {
 	server_http();
@@ -438,6 +476,18 @@ serverconfig_byid(uint32_t id)
 	return (NULL);
 }
 
+struct server *
+server_byid(uint32_t id)
+{
+	struct server	*srv;
+
+	TAILQ_FOREACH(srv, httpd_env->sc_servers, srv_entry) {
+		if (srv->srv_conf.id == id)
+			return (srv);
+	}
+	return (NULL);
+}
+
 int
 server_foreach(int (*srv_cb)(struct server *,
     struct server_config *, void *), void *arg)
@@ -1226,6 +1276,9 @@ server_close(struct client *clt, const char *msg)
 int
 server_dispatch_parent(int fd, struct privsep_proc *p, struct imsg *imsg)
 {
+	struct server			*srv;
+	struct server_tls_ticket	 key;
+
 	switch (imsg->hdr.type) {
 	case IMSG_CFG_MEDIA:
 		config_getmedia(httpd_env, imsg);
@@ -1248,6 +1301,16 @@ server_dispatch_parent(int fd, struct privsep_proc *p, struct imsg *imsg)
 	case IMSG_CTL_RESET:
 		config_getreset(httpd_env, imsg);
 		break;
+	case IMSG_TLSTICKET_REKEY:
+		IMSG_SIZE_CHECK(imsg, (&key));
+		memcpy(&key, imsg->data, sizeof(key));
+		/* apply to the right server */
+		srv = server_byid(key.tt_id);
+		if (srv) {
+			tls_config_add_ticket_key(srv->srv_tls_config,
+			    key.tt_keyrev, key.tt_key, sizeof(key.tt_key));
+		}
+		break;
 	default:
 		return (-1);
 	}