v1.18

Initial addition of systemd socket based activiation

COPYING

@@ -0,0 +1,339 @@
+                    GNU GENERAL PUBLIC LICENSE
+                       Version 2, June 1991
+
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+
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+  Ty Coon, President of Vice
+
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+library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.

ChangeLog

@@ -1,3 +1,45 @@
+v1.18:	29MAR2016
+	Added USELIBPCRE to make use of regex engine
+	optional.
+
+	Added support for RFC4366 SNI and RFC7301 ALPN
+	(Travis Burtrum)
+
+	Changed connection log to include the name of the probe that
+	triggered.
+
+	Changed configuration file format: 'probe' field is
+	no longer required, 'name' field can now contain
+	'tls' or 'regex', with corresponding options (see
+	example.cfg)
+	Added 'log_level' option to each protocol, which
+	allows to turn off generation of log at each
+	connection.
+	Added 'keepalive' option.
+
+v1.17: 	09MAR2015
+	Support RFC5952-style IPv6 addresses, e.g. [::]:443.
+
+	Transparant proxy support for FreeBSD.
+	(Ruben van Staveren)
+
+	Using -F with no argument will try
+	/etc/sslh/sslh.cfg and then /etc/sslh.cfg as
+	configuration files. (argument to -F can no longer
+	be separated from the option by a space, e.g. must
+	be -Ffoo.cfg)
+
+	Call setgroups() before setgid() (fixes potential
+	privilege escalation).
+	(Lars Vogdt)
+
+	Use portable way of getting modified time for OSX
+	support.
+	(Aaron Madlon-Kay)
+
+	Example configuration for fail2ban.
+	(Every Mouw)
+
 v1.16:	11FEB2014
 	Probes made more resilient, to incoming data
 	containing NULLs. Also made them behave properly

Makefile

@@ -1,11 +1,16 @@
 # Configuration
 
 VERSION=$(shell ./genver.sh -r)
+ENABLE_REGEX=1  # Enable regex probes
 USELIBCONFIG=1	# Use libconfig? (necessary to use configuration files)
-USELIBWRAP=	# Use libwrap?
+USELIBPCRE=	# Use libpcre? (needed for regex on musl)
+USELIBWRAP?=	# Use libwrap?
 USELIBCAP=	# Use libcap?
+USESYSTEMD=     # Make use of systemd socket activation
 COV_TEST= 	# Perform test coverage?
-PREFIX=/usr/local
+PREFIX?=/usr
+BINDIR?=$(PREFIX)/sbin
+MANDIR?=$(PREFIX)/share/man/man8
 
 MAN=sslh.8.gz	# man page name
 
@@ -20,13 +25,22 @@ CC ?= gcc
 CFLAGS ?=-Wall -g $(CFLAGS_COV)
 
 LIBS=
-OBJS=common.o sslh-main.o probe.o
+OBJS=common.o sslh-main.o probe.o tls.o
 
 ifneq ($(strip $(USELIBWRAP)),)
 	LIBS:=$(LIBS) -lwrap
 	CPPFLAGS+=-DLIBWRAP
 endif
 
+ifneq ($(strip $(ENABLE_REGEX)),)
+	CPPFLAGS+=-DENABLE_REGEX
+endif
+
+ifneq ($(strip $(USELIBPCRE)),)
+	CPPFLAGS+=-DLIBPCRE
+	LIBS:=$(LIBS) -lpcre
+endif
+
 ifneq ($(strip $(USELIBCONFIG)),)
 	LIBS:=$(LIBS) -lconfig
 	CPPFLAGS+=-DLIBCONFIG
@@ -37,6 +51,12 @@ ifneq ($(strip $(USELIBCAP)),)
 	CPPFLAGS+=-DLIBCAP
 endif
 
+ifneq ($(strip $(USESYSTEMD)),)
+        LIBS:=$(LIBS) -lsystemd
+        CPPFLAGS+=-DSYSTEMD
+endif
+
+
 all: sslh $(MAN) echosrv
 
 .c.o: *.h
@@ -55,8 +75,11 @@ sslh-select: version.h $(OBJS) sslh-select.o Makefile common.h
 	$(CC) $(CFLAGS) $(LDFLAGS) -o sslh-select sslh-select.o $(OBJS) $(LIBS)
 	#strip sslh-select
 
+systemd-sslh-generator: systemd-sslh-generator.o
+	$(CC) $(CFLAGS) $(LDFLAGS) -o systemd-sslh-generator systemd-sslh-generator.o -lconfig
+
 echosrv: $(OBJS) echosrv.o
-	$(CC) $(CFLAGS) $(LDFLAGS) -o echosrv echosrv.o probe.o common.o $(LIBS)
+	$(CC) $(CFLAGS) $(LDFLAGS) -o echosrv echosrv.o probe.o common.o tls.o $(LIBS)
 
 $(MAN): sslh.pod Makefile
 	pod2man --section=8 --release=$(VERSION) --center=" " sslh.pod | gzip -9 - > $(MAN)
@@ -68,25 +91,26 @@ release:
 
 # generic install: install binary and man page
 install: sslh $(MAN)
-	install -pD sslh-fork $(DESTDIR)$(PREFIX)/sbin/sslh
-	install -pD -m 0644 $(MAN) $(DESTDIR)$(PREFIX)/share/man/man8/$(MAN)
+	mkdir -p $(DESTDIR)/$(BINDIR)
+	mkdir -p $(DESTDIR)/$(MANDIR)
+	install -p sslh-fork $(DESTDIR)/$(BINDIR)/sslh
+	install -p -m 0644 $(MAN) $(DESTDIR)/$(MANDIR)/$(MAN)
 
 # "extended" install for Debian: install startup script
 install-debian: install sslh $(MAN)
 	sed -e "s+^PREFIX=+PREFIX=$(PREFIX)+" scripts/etc.init.d.sslh > /etc/init.d/sslh
 	chmod 755 /etc/init.d/sslh
-	cp scripts/etc.default.sslh /etc/default/sslh
 	update-rc.d sslh defaults
 
 uninstall:
-	rm -f $(DESTDIR)$(PREFIX)/sbin/sslh $(DESTDIR)$(PREFIX)/share/man/man8/$(MAN) $(DESTDIR)/etc/init.d/sslh $(DESTDIR)/etc/default/sslh
+	rm -f $(DESTDIR)$(BINDIR)/sslh $(DESTDIR)$(MANDIR)/$(MAN) $(DESTDIR)/etc/init.d/sslh $(DESTDIR)/etc/default/sslh
 	update-rc.d sslh remove
 
 distclean: clean
 	rm -f tags cscope.*
 
 clean:
-	rm -f sslh-fork sslh-select echosrv version.h $(MAN) *.o *.gcov *.gcno *.gcda *.png *.html *.css *.info
+	rm -f sslh-fork sslh-select echosrv version.h $(MAN) systemd-sslh-generator *.o *.gcov *.gcno *.gcda *.png *.html *.css *.info
 
 tags:
 	ctags --globals -T *.[ch]
@@ -97,4 +121,3 @@ cscope:
 
 test:
 	./t
-

README.md

@@ -59,6 +59,8 @@ of the Makefile:
   file. You will need `libconfig` headers to compile
   (`libconfig8-dev` in Debian).
 
+*  `USESYSTEMD` compiles support for using systemd socket activation.
+   You will need `systemd` headers to compile (`systemd-devel` in Fedora).
 
 Binaries
 --------
@@ -93,7 +95,8 @@ Installation
 
 		make
 		cp sslh-fork /usr/local/sbin/sslh
-		cp scripts/etc.default.sslh /etc/default/sslh
+		cp basic.cfg /etc/sslh.cfg
+                vi /etc/sslh.cfg
 
 * For Debian:
 
@@ -101,7 +104,7 @@ Installation
 	
 * For CentOS:
 
-		cp scripts/etc.rc.d.init.d.sslh /etc/rc.d/init.d/sslh
+		cp scripts/etc.rc.d.init.d.sslh.centos /etc/rc.d/init.d/sslh
 
 
 You might need to create links in /etc/rc<x>.d so that the server
@@ -113,14 +116,12 @@ start automatically at boot-up, e.g. under Debian:
 Configuration
 =============
 
-You can edit settings in /etc/default/sslh:
-
-	LISTEN=ifname:443
-	SSH=localhost:22
-	SSL=localhost:443
+If you use the scripts provided, sslh will get its
+configuration from /etc/sslh.cfg. Please refer to
+example.cfg for an overview of all the settings.
 
 A good scheme is to use the external name of the machine in
-`$LISTEN`, and bind `httpd` to `localhost:443` (instead of all
+`listen`, and bind `httpd` to `localhost:443` (instead of all
 binding to all interfaces): that way, HTTPS connections
 coming from inside your network don't need to go through
 `sslh`, and `sslh` is only there as a frontal for connections
@@ -151,7 +152,8 @@ To support OpenVPN connexions reliably, it is necessary to
 increase `sslh`'s timeout to 5 seconds.
 
 Instead of using OpenVPN's port sharing, it is more reliable
-to use `sslh`'s `-o` option to get `sslh` to do the port sharing.
+to use `sslh`'s `--openvpn` option to get `sslh` to do the
+port sharing.
 
 Using proxytunnel with sslh
 ---------------------------
@@ -216,13 +218,15 @@ transparent proxying, just don't use it (or use the libcap method).
 Transparent proxy support
 -------------------------
 
-On Linux (only?) you can use the `--transparent` option to
-request transparent proying. This means services behind `sslh`
+On Linux and FreeBSD you can use the `--transparent` option to
+request transparent proxying. This means services behind `sslh`
 (Apache, `sshd` and so on) will see the external IP and ports
 as if the external world connected directly to them. This
 simplifies IP-based access control (or makes it possible at
 all).
 
+Linux:
+
 `sslh` needs extended rights to perform this: you'll need to
 give it `CAP_NET_ADMIN` capabilities (see appropriate chapter)
 or run it as root (but don't do that).
@@ -240,6 +244,58 @@ this scheme -- let me know if you manage that:
 	# ip rule add fwmark 0x1 lookup 100
 	# ip route add local 0.0.0.0/0 dev lo table 100
 
+Tranparent proxying with IPv6 is similarly set up as follows:
+
+        # ip6tables -t mangle -N SSLH
+        # ip6tables -t mangle -A  OUTPUT --protocol tcp --out-interface eth0 --sport 22 --jump SSLH
+        # ip6tables -t mangle -A OUTPUT --protocol tcp --out-interface eth0 --sport 4443 --jump SSLH
+        # ip6tables -t mangle -A SSLH --jump MARK --set-mark 0x1
+        # ip6tables -t mangle -A SSLH --jump ACCEPT
+        # ip -6 rule add fwmark 0x1 lookup 100
+        # ip -6 route add local ::/0 dev lo table 100
+
+Note that these rules will prevent from connecting directly
+to ssh on the port 22, as packets coming out of sshd will be
+tagged. If you need to retain direct access to ssh on port
+22 as well as through sslh, you can make sshd listen to
+22 AND another port (e.g. 2222), and change the above rules
+accordingly.
+
+FreeBSD:
+
+Given you have no firewall defined yet, you can use the following configuration
+to have ipfw properly redirect traffic back to sslh
+
+	/etc/rc.conf
+	firewall_enable="YES"
+	firewall_type="open"
+	firewall_logif="YES"
+	firewall_coscripts="/etc/ipfw/sslh.rules"
+
+
+/etc/ipfw/sslh.rules
+
+	#! /bin/sh
+
+	# ssl
+	ipfw add 20000 fwd 192.0.2.1,443 log tcp from 192.0.2.1 8443 to any out
+	ipfw add 20010 fwd 2001:db8::1,443 log tcp from 2001:db8::1 8443 to any out
+
+	# ssh
+	ipfw add 20100 fwd 192.0.2.1,443 log tcp from 192.0.2.1 8022 to any out
+	ipfw add 20110 fwd 2001:db8::1,443 log tcp from 2001:db8::1 8022 to any out
+
+	# xmpp
+	ipfw add 20200 fwd 192.0.2.1,443 log tcp from 192.0.2.1 5222 to any out
+	ipfw add 20210 fwd 2001:db8::1,443 log tcp from 2001:db8::1 5222 to any out
+
+	# openvpn (running on other internal system)
+	ipfw add 20300 fwd 192.0.2.1,443 log tcp from 198.51.100.7 1194 to any out
+	ipfw add 20310 fwd 2001:db8::1,443 log tcp from 2001:db8:1::7 1194 to any out
+
+General notes:
+
+
 This will only work if `sslh` does not use any loopback
 addresses (no `127.0.0.1` or `localhost`), you'll need to use
 explicit IP addresses (or names):
@@ -249,6 +305,120 @@ explicit IP addresses (or names):
 This will not work:
 
 	sslh --listen 192.168.0.1:443 --ssh 127.0.0.1:22 --ssl 127.0.0.1:4443
+    
+Transparent proxying means the target server sees the real
+origin address, so it means if the client connects using
+IPv6, the server must also support IPv6. It is easy to
+support both IPv4 and IPv6 by configuring the server
+accordingly, and setting `sslh` to connect to a name that
+resolves to both IPv4 and IPv6, e.g.:
+
+        sslh --transparent --listen <extaddr>:443 --ssh insideaddr:22
+
+        /etc/hosts:
+        192.168.0.1  insideaddr
+        201::::2     insideaddr
+
+Upon incoming IPv6 connection, `sslh` will first try to
+connect to the IPv4 address (which will fail), then connect
+to the IPv6 address.
+
+Systemd Socket Activation
+-------------------------
+If compiled with `USESYSTEMD` then it is possible to activate 
+the service on demand and avoid running any code as root.
+
+In this mode any listen configuration options are ignored and 
+the sockets are passed by systemd to the service.
+
+Example socket unit:
+
+	[Unit]
+	Before=sslh.service
+	
+	[Socket]
+	ListenStream=1.2.3.4:443
+	ListenStream=5.6.7.8:444
+	ListenStream=9.10.11.12:445
+	FreeBind=true
+
+	[Install]
+	WantedBy=sockets.target
+
+Example service unit:
+
+	[Unit]
+	PartOf=sslh.socket
+	
+	[Service]
+	ExecStart=/usr/sbin/sslh -v -f --ssh 127.0.0.1:22 --ssl 127.0.0.1:443
+	KillMode=process
+	CapabilityBoundingSet=CAP_NET_BIND_SERVICE CAP_NET_ADMIN CAP_SETGID CAP_SETUID
+	PrivateTmp=true
+	PrivateDevices=true
+	ProtectSystem=full
+	ProtectHome=true
+	User=sslh
+
+
+With this setup only the socket needs to be enabled. The sslh service 
+will be started on demand and does not need to run as root to bind the 
+sockets as systemd has already bound and passed them over. If the sslh
+service is started on its own without the sockets being passed by systemd
+then it will look to use those defined on the command line or config
+file as usual. Any number of ListenStreams can be defined in the socket
+file and systemd will pass them all over to sslh to use as usual.
+
+To avoid inconsistency between starting via socket and starting directly
+via the service Requires=sslh.socket can be added to the service unit to
+mandate the use of the socket configuration.
+
+Rather than overwriting the entire socket file drop in values can be placed
+in /etc/systemd/system/sslh.socket.d/<name>.conf with additional ListenStream
+values that will be merged.
+
+In addition to the above with manual .socket file configuration there is an
+optional systemd generator which can be compiled - systemd-sslh-generator 
+
+This parses the /etc/sslh.cfg (or /etc/sslh/sslh.cfg file if that exists 
+instead) configuration file and dynamically generates a socket file to use.
+
+This will also merge with any sslh.socket.d drop in configuration but will be 
+overriden by a /etc/systemd/system/sslh.socket file.
+
+To use the generator place it in /usr/lib/systemd/system-generators and then
+call systemctl daemon-reload after any changes to /etc/sslh.cfg to generate 
+the new dynamic socket unit.
+
+Transparent proxying means the target server sees the real
+origin address, so it means if the client connects using
+IPv6, the server must also support IPv6. It is easy to
+support both IPv4 and IPv6 by configuring the server
+accordingly, and setting `sslh` to connect to a name that
+resolves to both IPv4 and IPv6, e.g.:
+
+        sslh --transparent --listen <extaddr>:443 --ssh insideaddr:22
+
+        /etc/hosts:
+        192.168.0.1  insideaddr
+        201::::2     insideaddr
+
+Upon incoming IPv6 connection, `sslh` will first try to
+connect to the IPv4 address (which will fail), then connect
+to the IPv6 address.
+
+
+Fail2ban
+--------
+
+If using transparent proxying, just use the standard ssh
+rules. If you can't or don't want to use transparent
+proxying, you can set `fail2ban` rules to block repeated ssh
+connections from a same IP address (obviously this depends
+on the site, there might be legimite reasons you would get
+many connections to ssh from the same IP address...)
+
+See example files in scripts/fail2ban.
 
 Comments? Questions?
 ====================

basic.cfg

@@ -19,11 +19,11 @@ listen:
 
 protocols:
 (
-     { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; probe: "builtin"; },
-     { name: "openvpn"; host: "localhost"; port: "1194"; probe: "builtin"; },
-     { name: "xmpp"; host: "localhost"; port: "5222"; probe: "builtin"; },
-     { name: "http"; host: "localhost"; port: "80"; probe: "builtin"; },
-     { name: "ssl"; host: "localhost"; port: "443"; probe: "builtin"; },
-     { name: "anyprot"; host: "localhost"; port: "443"; probe: "builtin"; }
+     { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; },
+     { name: "openvpn"; host: "localhost"; port: "1194"; },
+     { name: "xmpp"; host: "localhost"; port: "5222"; },
+     { name: "http"; host: "localhost"; port: "80"; },
+     { name: "ssl"; host: "localhost"; port: "443"; log_level: 0; },
+     { name: "anyprot"; host: "localhost"; port: "443"; }
 );
 

common.c

@@ -6,17 +6,24 @@
 
 #define _GNU_SOURCE
 #include <stdarg.h>
+#include <grp.h>
 
 #include "common.h"
 #include "probe.h"
 
-/* Added to make the code compilable under CYGWIN 
+/* Added to make the code compilable under CYGWIN
  * */
 #ifndef SA_NOCLDWAIT
 #define SA_NOCLDWAIT 0
 #endif
 
-/* 
+/* Make use of systemd socket activation
+ * */
+#ifdef SYSTEMD
+#include <systemd/sd-daemon.h>
+#endif
+
+/*
  * Settings that depend on the command line.  They're set in main(), but also
  * used in other places in common.c, and it'd be heavy-handed to pass it all as
  * parameters
@@ -43,14 +50,35 @@ void check_res_dumpdie(int res, struct addrinfo *addr, char* syscall)
     char buf[NI_MAXHOST];
 
     if (res == -1) {
-        fprintf(stderr, "%s:%s: %s\n", 
-                sprintaddr(buf, sizeof(buf), addr), 
-                syscall, 
+        fprintf(stderr, "%s:%s: %s\n",
+                sprintaddr(buf, sizeof(buf), addr),
+                syscall,
                 strerror(errno));
         exit(1);
     }
 }
 
+int get_fd_sockets(int *sockfd[])
+{
+    int sd = 0;
+
+#ifdef SYSTEMD
+    sd = sd_listen_fds(0);
+    if (sd < 0) {
+      fprintf(stderr, "sd_listen_fds(): %s\n", strerror(-sd));
+      exit(1);
+    }
+    if (sd > 0) {
+      *sockfd = malloc(sd * sizeof(*sockfd[0]));
+      for (int i = 0; i < sd; i++) {
+        (*sockfd)[i] = SD_LISTEN_FDS_START + i;
+      }
+    }
+#endif
+
+    return sd;
+}
+
 /* Starts listening sockets on specified addresses.
  * IN: addr[], num_addr
  * OUT: *sockfd[]  pointer to newly-allocated array of file descriptors
@@ -63,6 +91,13 @@ int start_listen_sockets(int *sockfd[], struct addrinfo *addr_list)
    struct addrinfo *addr;
    int i, res, one;
    int num_addr = 0;
+   int sd_socks = 0;
+
+   sd_socks = get_fd_sockets(sockfd);
+
+   if (sd_socks > 0) {
+       return sd_socks;
+   }
 
    for (addr = addr_list; addr; addr = addr->ai_next)
        num_addr++;
@@ -86,6 +121,12 @@ int start_listen_sockets(int *sockfd[], struct addrinfo *addr_list)
        res = setsockopt((*sockfd)[i], SOL_SOCKET, SO_REUSEADDR, (char*)&one, sizeof(one));
        check_res_dumpdie(res, addr, "setsockopt(SO_REUSEADDR)");
 
+       if (addr->ai_flags & SO_KEEPALIVE) {
+           res = setsockopt((*sockfd)[i], SOL_SOCKET, SO_KEEPALIVE, (char*)&one, sizeof(one));
+           check_res_dumpdie(res, addr, "setsockopt(SO_KEEPALIVE)");
+           printf("set up keepalive\n");
+       }
+
        if (IP_FREEBIND) {
            res = setsockopt((*sockfd)[i], IPPROTO_IP, IP_FREEBIND, (char*)&one, sizeof(one));
            check_res_dumpdie(res, addr, "setsockopt(IP_FREEBIND)");
@@ -119,8 +160,20 @@ int bind_peer(int fd, int fd_from)
      * got here */
     res = getpeername(fd_from, from.ai_addr, &from.ai_addrlen);
     CHECK_RES_RETURN(res, "getpeername");
+#ifndef IP_BINDANY /* use IP_TRANSPARENT */
     res = setsockopt(fd, IPPROTO_IP, IP_TRANSPARENT, &trans, sizeof(trans));
     CHECK_RES_DIE(res, "setsockopt");
+#else
+    if (from.ai_addr->sa_family==AF_INET) { /* IPv4 */
+        res = setsockopt(fd, IPPROTO_IP, IP_BINDANY, &trans, sizeof(trans));
+        CHECK_RES_RETURN(res, "setsockopt IP_BINDANY");
+#ifdef IPV6_BINDANY
+    } else { /* IPv6 */
+        res = setsockopt(fd, IPPROTO_IPV6, IPV6_BINDANY, &trans, sizeof(trans));
+        CHECK_RES_RETURN(res, "setsockopt IPV6_BINDANY");
+#endif /* IPV6_BINDANY */
+    }
+#endif /* IP_TRANSPARENT / IP_BINDANY */
     res = bind(fd, from.ai_addr, from.ai_addrlen);
     CHECK_RES_RETURN(res, "bind");
 
@@ -128,20 +181,33 @@ int bind_peer(int fd, int fd_from)
 }
 
 /* Connect to first address that works and returns a file descriptor, or -1 if
- * none work. 
+ * none work.
  * If transparent proxying is on, use fd_from peer address on external address
  * of new file descriptor. */
 int connect_addr(struct connection *cnx, int fd_from)
 {
-    struct addrinfo *a;
+    struct addrinfo *a, from;
+    struct sockaddr_storage ss;
     char buf[NI_MAXHOST];
-    int fd, res;
+    int fd, res, one;
+
+    memset(&from, 0, sizeof(from));
+    from.ai_addr = (struct sockaddr*)&ss;
+    from.ai_addrlen = sizeof(ss);
+
+    res = getpeername(fd_from, from.ai_addr, &from.ai_addrlen);
+    CHECK_RES_RETURN(res, "getpeername");
 
     for (a = cnx->proto->saddr; a; a = a->ai_next) {
-        if (verbose) 
-            fprintf(stderr, "connecting to %s family %d len %d\n", 
+        /* When transparent, make sure both connections use the same address family */
+        if (transparent && a->ai_family != from.ai_addr->sa_family)
+            continue;
+        if (verbose)
+            fprintf(stderr, "connecting to %s family %d len %d\n",
                     sprintaddr(buf, sizeof(buf), a),
                     a->ai_addr->sa_family, a->ai_addrlen);
+
+        /* XXX Needs to match ai_family from fd_from when being transparent! */
         fd = socket(a->ai_family, SOCK_STREAM, 0);
         if (fd == -1) {
             log_message(LOG_ERR, "forward to %s failed:socket: %s\n",
@@ -153,9 +219,16 @@ int connect_addr(struct connection *cnx, int fd_from)
             }
             res = connect(fd, a->ai_addr, a->ai_addrlen);
             if (res == -1) {
-                log_message(LOG_ERR, "forward to %s failed:connect: %s\n", 
+                log_message(LOG_ERR, "forward to %s failed:connect: %s\n",
                             cnx->proto->description, strerror(errno));
+                close(fd);
             } else {
+                if (cnx->proto->keepalive) {
+                    one = 1;
+                    res = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (char*)&one, sizeof(one));
+                    CHECK_RES_RETURN(res, "setsockopt(SO_KEEPALIVE)");
+                    printf("set up keepalive\n");
+                }
                 return fd;
             }
         }
@@ -164,10 +237,10 @@ int connect_addr(struct connection *cnx, int fd_from)
 }
 
 /* Store some data to write to the queue later */
-int defer_write(struct queue *q, void* data, int data_size) 
+int defer_write(struct queue *q, void* data, int data_size)
 {
     char *p;
-    if (verbose) 
+    if (verbose)
         fprintf(stderr, "**** writing deferred on fd %d\n", q->fd);
 
     p = realloc(q->begin_deferred_data, q->deferred_data_size + data_size);
@@ -231,7 +304,7 @@ void dump_connection(struct connection *cnx)
 }
 
 
-/* 
+/*
  * moves data from one fd to other
  *
  * returns number of bytes copied if success
@@ -299,16 +372,16 @@ char* sprintaddr(char* buf, size_t size, struct addrinfo *a)
    int res;
 
    res = getnameinfo(a->ai_addr, a->ai_addrlen,
-               host, sizeof(host), 
-               serv, sizeof(serv), 
+               host, sizeof(host),
+               serv, sizeof(serv),
                numeric ? NI_NUMERICHOST | NI_NUMERICSERV : 0 );
 
    if (res) {
        log_message(LOG_ERR, "sprintaddr:getnameinfo: %s\n", gai_strerror(res));
        /* Name resolution failed: do it numerically instead */
        res = getnameinfo(a->ai_addr, a->ai_addrlen,
-                         host, sizeof(host), 
-                         serv, sizeof(serv), 
+                         host, sizeof(host),
+                         serv, sizeof(serv),
                          NI_NUMERICHOST | NI_NUMERICSERV);
        /* should not fail but... */
        if (res) {
@@ -323,7 +396,7 @@ char* sprintaddr(char* buf, size_t size, struct addrinfo *a)
    return buf;
 }
 
-/* Turns a hostname and port (or service) into a list of struct addrinfo 
+/* Turns a hostname and port (or service) into a list of struct addrinfo
  * returns 0 on success, -1 otherwise and logs error
  **/
 int resolve_split_name(struct addrinfo **out, const char* host, const char* serv)
@@ -347,21 +420,31 @@ fullname: input string -- it gets clobbered
 */
 void resolve_name(struct addrinfo **out, char* fullname)
 {
-   char *serv, *host;
+   char *serv, *host, *end;
    int res;
 
+   /* Find port */
    char *sep = strrchr(fullname, ':');
-
-   if (!sep) /* No separator: parameter is just a port */
-   {
+   if (!sep) { /* No separator: parameter is just a port */
       fprintf(stderr, "%s: names must be fully specified as hostname:port\n", fullname);
       exit(1);
    }
-
-   host = fullname;
    serv = sep+1;
    *sep = 0;
 
+   host = fullname;
+
+   /* If it is a RFC-Compliant IPv6 address ("[1234::12]:443"), remove brackets
+    * around IP address */
+   if (host[0] == '[') {
+       end = strrchr(host, ']');
+       if (!end) {
+           fprintf(stderr, "%s: no closing bracket in IPv6 address?\n", host);
+       }
+       host++; /* skip first bracket */
+       *end = 0; /* remove last bracket */
+   }
+
    res = resolve_split_name(out, host, serv);
    if (res) {
       fprintf(stderr, "%s `%s'\n", gai_strerror(res), fullname);
@@ -394,11 +477,14 @@ void log_connection(struct connection *cnx)
         local[MAX_NAMELENGTH], target[MAX_NAMELENGTH];
     int res;
 
+    if (cnx->proto->log_level < 1)
+        return;
+
     addr.ai_addr = (struct sockaddr*)&ss;
     addr.ai_addrlen = sizeof(ss);
 
     res = getpeername(cnx->q[0].fd, addr.ai_addr, &addr.ai_addrlen);
-    if (res == -1) return; /* Can happen if connection drops before we get here. 
+    if (res == -1) return; /* Can happen if connection drops before we get here.
                                In that case, don't log anything (there is no connection) */
     sprintaddr(peer, sizeof(peer), &addr);
 
@@ -417,7 +503,8 @@ void log_connection(struct connection *cnx)
     if (res == -1) return;
     sprintaddr(local, sizeof(local), &addr);
 
-    log_message(LOG_INFO, "connection from %s to %s forwarded from %s to %s\n",
+    log_message(LOG_INFO, "%s:connection from %s to %s forwarded from %s to %s\n",
+                cnx->proto->description,
                 peer,
                 service,
                 local,
@@ -434,16 +521,19 @@ void log_connection(struct connection *cnx)
 int check_access_rights(int in_socket, const char* service)
 {
 #ifdef LIBWRAP
-    struct sockaddr peeraddr;
-    socklen_t size = sizeof(peeraddr);
+    union {
+        struct sockaddr saddr;
+        struct sockaddr_storage ss;
+    } peer;
+    socklen_t size = sizeof(peer);
     char addr_str[NI_MAXHOST], host[NI_MAXHOST];
     int res;
 
-    res = getpeername(in_socket, &peeraddr, &size);
+    res = getpeername(in_socket, &peer.saddr, &size);
     CHECK_RES_RETURN(res, "getpeername");
 
     /* extract peer address */
-    res = getnameinfo(&peeraddr, size, addr_str, sizeof(addr_str), NULL, 0, NI_NUMERICHOST);
+    res = getnameinfo(&peer.saddr, size, addr_str, sizeof(addr_str), NULL, 0, NI_NUMERICHOST);
     if (res) {
         if (verbose)
             fprintf(stderr, "getnameinfo(NI_NUMERICHOST):%s\n", gai_strerror(res));
@@ -452,7 +542,7 @@ int check_access_rights(int in_socket, const char* service)
     /* extract peer name */
     strcpy(host, STRING_UNKNOWN);
     if (!numeric) {
-        res = getnameinfo(&peeraddr, size, host, sizeof(host), NULL, 0, NI_NAMEREQD);
+        res = getnameinfo(&peer.saddr, size, host, sizeof(host), NULL, 0, NI_NAMEREQD);
         if (res) {
             if (verbose)
                 fprintf(stderr, "getnameinfo(NI_NAMEREQD):%s\n", gai_strerror(res));
@@ -497,7 +587,7 @@ void setup_signals(void)
 
 }
 
-/* Open syslog connection with appropriate banner; 
+/* Open syslog connection with appropriate banner;
  * banner is made up of basename(bin_name)+"[pid]" */
 void setup_syslog(const char* bin_name) {
     char *name1, *name2;
@@ -507,7 +597,7 @@ void setup_syslog(const char* bin_name) {
     res = asprintf(&name2, "%s[%d]", basename(name1), getpid());
     CHECK_RES_DIE(res, "asprintf");
     openlog(name2, LOG_CONS, LOG_AUTH);
-    free(name1); 
+    free(name1);
     /* Don't free name2, as openlog(3) uses it (at least in glibc) */
 
     log_message(LOG_INFO, "%s %s started\n", server_type, VERSION);
@@ -577,6 +667,13 @@ void drop_privileges(const char* user_name)
 
     set_keepcaps(1);
 
+    /* remove extraneous groups in case we belong to several extra groups that
+     * may have unwanted rights. If non-root when calling setgroups(), it
+     * fails, which is fine because... we have no unwanted rights
+     * (see POS36-C for security context)
+     * */
+    setgroups(0, NULL);
+
     res = setgid(pw->pw_gid);
     CHECK_RES_DIE(res, "setgid");
     res = setuid(pw->pw_uid);

common.h

@@ -1,5 +1,5 @@
-#ifndef __COMMON_H_
-#define __COMMON_H_
+#ifndef COMMON_H
+#define COMMON_H
 
 /* FD_SETSIZE is 64 on Cygwin, which is really low. Just redefining it is
  * enough for the macros to adapt (http://support.microsoft.com/kb/111855)

example.cfg

@@ -14,39 +14,78 @@ pidfile: "/var/run/sslh.pid";
 
 
 # List of interfaces on which we should listen
+# Options:
 listen:
 (
     { host: "thelonious"; port: "443"; },
-    { host: "thelonious"; port: "8080"; }
+    { host: "thelonious"; port: "8080"; keepalive: true; }
 );
 
 # List of protocols
 #
 # Each protocol entry consists of:
-#   name: name of the protocol
+#   name: name of the probe. These are listed on the command
+#   line (ssh -?), plus 'regex' and 'timeout'.
+
 #   service: (optional) libwrap service name (see hosts_access(5))
-#   host: host name to connect that protocol
-#   port: port number to connect that protocol
-#   probe: "builtin" or a list of regular expressions
-#          (can be left out, e.g. to use with on-timeout)
+#   host, port: where to connect when this probe succeeds
+#   log_level:  0 to turn off logging
+#               1 to log each incoming connection
+#   keepalive:  Should TCP keepalive be on or off for that
+#               connection (default is off)
+#
+#  Probe-specific options:
+#       tls:
+#               sni_hostnames:  list of FQDN for that target
+#               alpn_protocols: list of ALPN protocols for that target, see:
+#               https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtml#alpn-protocol-ids
+#
+#               if both sni_hostnames AND alpn_protocols are specified, both must match
+#               if neither are set, it is just checked whether this is the TLS protocol or not
+#       regex:
+#               regex_patterns: list of patterns to match for
+#               that target.
 #   
 # sslh will try each probe in order they are declared, and
 # connect to the first that matches.
-
+#
+# You can specify several of 'regex' and 'tls'.
+ 
 protocols:
 (
-     { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; probe: "builtin"; },
-     { name: "openvpn"; host: "localhost"; port: "1194"; probe: [ "^\x00[\x0D-\xFF]$", "^\x00[\x0D-\xFF]\x38" ]; },
-     { name: "xmpp"; host: "localhost"; port: "5222"; probe: [ "jabber" ]; },
-     { name: "http"; host: "localhost"; port: "80"; probe: "builtin"; },
-     { name: "ssl"; host: "localhost"; port: "443"; probe: [ "" ]; },
+     { name: "ssh"; service: "ssh"; host: "localhost"; port: "22"; keepalive: true; },
+     { name: "http"; host: "localhost"; port: "80"; },
+
+# match BOTH ALPN/SNI
+     { name: "tls"; host: "localhost"; port: "5223"; alpn_protocols: [ "xmpp-client" ]; sni_hostnames: [ "im.somethingelse.net" ]; log_level: 0;},
+
+# just match ALPN
+     { name: "tls"; host: "localhost"; port: "443"; alpn_protocols: [ "h2", "http/1.1", "spdy/1", "spdy/2", "spdy/3" ]; log_level: 0; },
+     { name: "tls"; host: "localhost"; port: "xmpp-client"; alpn_protocols: [ "xmpp-client" ];  log_level: 0;},
+
+# just match SNI
+     { name: "tls"; host: "localhost"; port: "993"; sni_hostnames: [ "mail.rutschle.net", "mail.englishintoulouse.com" ]; log_level: 0; },
+     { name: "tls"; host: "localhost"; port: "xmpp-client"; sni_hostnames: [ "im.rutschle.net", "im.englishintoulouse.com" ];  log_level: 0;},
+
+# catch anything else TLS
+     { name: "tls"; host: "localhost"; port: "443"; },
+
+# OpenVPN
+     { name: "regex"; host: "localhost"; port: "1194"; regex_patterns: [ "^\x00[\x0D-\xFF]$", "^\x00[\x0D-\xFF]\x38" ]; },
+# Jabber
+     { name: "regex"; host: "localhost"; port: "5222"; regex_patterns: [ "jabber" ]; },
+
+# Catch-all
+     { name: "regex"; host: "localhost"; port: "443"; regex_patterns: [ "" ]; },
+
+# Where to connect in case of timeout (defaults to ssh)
      { name: "timeout"; service: "daytime"; host: "localhost"; port: "daytime"; }
 );
 
 # Optionally, specify to which protocol to connect in case
 # of timeout (defaults to "ssh").
-# You can timeout to any arbitrary address by setting a
-# protocol with no probe, as is the case with this example.
+# You can timeout to any arbitrary address by setting an
+# entry in 'protocols' named "timeout".
 # This enables you to set a tcpd service name for this
 # protocol too.
 on-timeout: "timeout";

genver.sh

@@ -1,4 +1,4 @@
-#! /bin/bash
+#! /bin/sh
 
 if [ ${#} -eq 1 ] && [ "x$1" = "x-r" ]; then
 	# release text only
@@ -10,10 +10,19 @@ fi
 if ! `(git status | grep -q "On branch") 2> /dev/null`; then
         # If we don't have git, we can't work out what
         # version this is. It must have been downloaded as a
-        # zip file. Github creates the zip file with all
-        # files dated from the last change: use the
-        # Makefile's modification time as a release number
-	release=zip-`stat -c "%y" Makefile | sed 's/ .*//'`
+        # zip file. 
+        
+        # If downloaded from the release page, the directory
+        # has the version number.
+        release=`pwd | sed s/.*sslh-// | grep "[[:digit:]]"`
+        
+        if [ "x$release" = "x" ]; then
+            # If downloaded from the head, Github creates the
+            # zip file with all files dated from the last
+            # change: use the Makefile's modification time as a
+            # release number
+            release=head-`perl -MPOSIX -e 'print strftime "%Y-%m-%d",localtime((stat "Makefile")[9])'`
+        fi
 fi
 
 if head=`git rev-parse --verify HEAD 2>/dev/null`; then
@@ -31,8 +40,8 @@ fi
 
 
 if [ $QUIET -ne 1 ]; then
-	printf "#ifndef _VERSION_H_ \n"
-	printf "#define _VERSION_H_ \n\n"
+	printf "#ifndef VERSION_H \n"
+	printf "#define VERSION_H \n\n"
 	printf "#define VERSION \"$release\"\n"
 	printf "#endif\n"
 else

probe.c

@@ -1,7 +1,7 @@
 /*
 # probe.c: Code for probing protocols
 #
-# Copyright (C) 2007-2012  Yves Rutschle
+# Copyright (C) 2007-2015  Yves Rutschle
 # 
 # This program is free software; you can redistribute it
 # and/or modify it under the terms of the GNU General Public
@@ -21,7 +21,13 @@
 
 #define _GNU_SOURCE
 #include <stdio.h>
+#ifdef ENABLE_REGEX
+#ifdef LIBPCRE
+#include <pcreposix.h>
+#else
 #include <regex.h>
+#endif
+#endif
 #include <ctype.h>
 #include "probe.h"
 
@@ -33,20 +39,22 @@ static int is_tinc_protocol(const char *p, int len, struct proto*);
 static int is_xmpp_protocol(const char *p, int len, struct proto*);
 static int is_http_protocol(const char *p, int len, struct proto*);
 static int is_tls_protocol(const char *p, int len, struct proto*);
+static int is_adb_protocol(const char *p, int len, struct proto*);
 static int is_true(const char *p, int len, struct proto* proto) { return 1; }
 
 /* Table of protocols that have a built-in probe
  */
 static struct proto builtins[] = {
-    /* description   service  saddr   probe  */
-    { "ssh",         "sshd",   NULL,   is_ssh_protocol},
-    { "openvpn",     NULL,     NULL,   is_openvpn_protocol },
-    { "tinc",        NULL,     NULL,   is_tinc_protocol },
-    { "xmpp",        NULL,     NULL,   is_xmpp_protocol },
-    { "http",        NULL,     NULL,   is_http_protocol },
-    { "ssl",         NULL,     NULL,   is_tls_protocol },
-    { "tls",         NULL,     NULL,   is_tls_protocol },
-    { "anyprot",     NULL,     NULL,   is_true }
+    /* description   service  saddr  log_level  keepalive  probe  */
+    { "ssh",         "sshd",   NULL,  1,        0,         is_ssh_protocol},
+    { "openvpn",     NULL,     NULL,  1,        0,         is_openvpn_protocol },
+    { "tinc",        NULL,     NULL,  1,        0,         is_tinc_protocol },
+    { "xmpp",        NULL,     NULL,  1,        0,         is_xmpp_protocol },
+    { "http",        NULL,     NULL,  1,        0,         is_http_protocol },
+    { "ssl",         NULL,     NULL,  1,        0,         is_tls_protocol },
+    { "tls",         NULL,     NULL,  1,        0,         is_tls_protocol },
+    { "adb",         NULL,     NULL,  1,        0,         is_adb_protocol },
+    { "anyprot",     NULL,     NULL,  1,        0,         is_true }
 };
 
 static struct proto *protocols;
@@ -153,7 +161,8 @@ static int is_openvpn_protocol (const char*p,int len, struct proto *proto)
 }
 
 /* Is the buffer the beginning of a tinc connections?
- * (protocol is undocumented, but starts with "0 " in 1.0.15)
+ * Protocol is documented here: http://www.tinc-vpn.org/documentation/tinc.pdf
+ * First connection starts with "0 " in 1.0.15)
  * */
 static int is_tinc_protocol( const char *p, int len, struct proto *proto)
 {
@@ -169,7 +178,10 @@ static int is_tinc_protocol( const char *p, int len, struct proto *proto)
  * */
 static int is_xmpp_protocol( const char *p, int len, struct proto *proto)
 {
-    if (len < 6)
+    /* sometimes the word 'jabber' shows up late in the initial string,
+       sometimes after a newline. this makes sure we snarf the entire preamble
+       and detect it. (fixed for adium/pidgin) */
+    if (len < 50)
         return PROBE_AGAIN;
 
     return memmem(p, len, "jabber", 6) ? 1 : 0;
@@ -209,6 +221,19 @@ static int is_http_protocol(const char *p, int len, struct proto *proto)
     return PROBE_NEXT;
 }
 
+static int is_sni_alpn_protocol(const char *p, int len, struct proto *proto)
+{
+    int valid_tls;
+
+    valid_tls = parse_tls_header(proto->data, p, len);
+
+    if(valid_tls < 0)
+        return -1 == valid_tls ? PROBE_AGAIN : PROBE_NEXT;
+
+    /* There *was* a valid match */
+    return PROBE_MATCH;
+}
+
 static int is_tls_protocol(const char *p, int len, struct proto *proto)
 {
     if (len < 3)
@@ -221,15 +246,37 @@ static int is_tls_protocol(const char *p, int len, struct proto *proto)
     return p[0] == 0x16 && p[1] == 0x03 && ( p[2] >= 0 && p[2] <= 0x03);
 }
 
+static int is_adb_protocol(const char *p, int len, struct proto *proto)
+{
+    if (len < 30)
+        return PROBE_AGAIN;
+
+    /* The initial ADB host->device packet has a command type of CNXN, and a
+     * data payload starting with "host:".  Note that current versions of the
+     * client hardcode "host::" (with empty serialno and banner fields) but
+     * other clients may populate those fields.
+     *
+     * We aren't checking amessage.data_length, under the assumption that
+     * a packet >= 30 bytes long will have "something" in the payload field.
+     */
+    return !memcmp(&p[0], "CNXN", 4) && !memcmp(&p[24], "host:", 5);
+}
+
 static int regex_probe(const char *p, int len, struct proto *proto)
 {
+#ifdef ENABLE_REGEX
     regex_t **probe = proto->data;
     regmatch_t pos = { 0, len };
 
     for (; *probe && regexec(*probe, p, 0, &pos, REG_STARTEND); probe++)
         /* try them all */;
 
-    return (probe != NULL);
+    return (*probe != NULL);
+#else
+    /* Should never happen as we check when loading config file */
+    fprintf(stderr, "FATAL: regex probe called but not built in\n");
+    exit(5);
+#endif
 }
 
 /* 
@@ -305,6 +352,15 @@ T_PROBE* get_probe(const char* description) {
     if (!strcmp(description, "regex"))
         return regex_probe;
 
+    /* Special case of "sni/alpn" probe for same reason as above*/
+    if (!strcmp(description, "sni_alpn"))
+        return is_sni_alpn_protocol;
+
+    /* Special case of "timeout" is allowed as a probe name in the
+     * configuration file even though it's not really a probe */
+    if (!strcmp(description, "timeout"))
+        return is_true;
+
     return NULL;
 }
 

probe.h

@@ -1,9 +1,10 @@
 /* API for probe.c */
 
-#ifndef __PROBE_H_
-#define __PROBE_H_
+#ifndef PROBE_H
+#define PROBE_H
 
 #include "common.h"
+#include "tls.h"
 
 typedef enum {
     PROBE_NEXT,  /* Enough data, probe failed -- it's some other protocol */
@@ -19,11 +20,16 @@ struct proto {
     const char* description;  /* a string that says what it is (for logging and command-line parsing) */
     const char* service;      /* service name to do libwrap checks */
     struct addrinfo *saddr; /* list of addresses to try and switch that protocol */
+    int log_level;  /* 0: No logging of connection
+                     * 1: Log incoming connection
+                     */
+    int keepalive; /* 0: No keepalive ; 1: Set Keepalive for this connection */
 
     /* function to probe that protocol; parameters are buffer and length
      * containing the data to probe, and a pointer to the protocol structure */
     T_PROBE* probe;
-    void* data;     /* opaque pointer ; used to pass list of regex to regex probe */
+    /* opaque pointer ; used to pass list of regex to regex probe, or TLSProtocol struct to sni/alpn probe */
+    void* data;
     struct proto *next; /* pointer to next protocol in list, NULL if last */
 };
 

scripts/etc.default.sslh

@@ -1,5 +0,0 @@
-LISTEN=ifname:443
-SSH=localhost:22
-SSL=localhost:443
-USER=nobody
-PID=/var/run/sslh.pid

scripts/etc.init.d.sslh

@@ -27,7 +27,7 @@ DAEMON=$PREFIX/sbin/sslh
 start()
 {
         echo "Start services: sslh"
-        $DAEMON --user ${USER} --pidfile ${PID} --listen ${LISTEN} --ssh ${SSH} --ssl ${SSL}
+        $DAEMON -F/etc/sslh.cfg
         logger -t ${tag} -p ${facility} -i 'Started sslh'
 }
 

scripts/fail2ban/jail.conf

@@ -0,0 +1,9 @@
+# Add the following to your fail2ban jail.conf
+# In Debian you'd append it to /etc/fail2ban/jail.local
+
+[sslh-ssh]
+enabled = true
+filter = sslh-ssh
+action = iptables-multiport[name=sslh,port="443"]
+logpath = /var/log/messages
+maxretry = 5

scripts/fail2ban/sslh-ssh.conf

@@ -0,0 +1,25 @@
+# Add the following to you fail2ban configuration file
+# In Debian it'd go in /etc/fail2ban/filter.d/sslh-ssh.conf
+
+
+# Fail2Ban filter for sslh demultiplexed ssh
+#
+# Doesn't (and cannot) detect auth errors,
+# but many connection attempts from the same
+# origin is reason enough to block.
+#
+# Verion: 2014-03-28
+
+[INCLUDES]
+
+# no includes
+
+[Definition]
+
+failregex = ^.+ sslh\[.+\]: connection from <HOST>:.+ to .+ forwarded
+from .+ to .+:ssh\s*$
+
+ignoreregex =
+
+# Author: Evert Mouw <post@evert.net>
+

sslh-main.c

@@ -2,7 +2,7 @@
 # main: processing of config file, command line options and start the main
 # loop.
 #
-# Copyright (C) 2007-2012  Yves Rutschle
+# Copyright (C) 2007-2016  Yves Rutschle
 # 
 # This program is free software; you can redistribute it
 # and/or modify it under the terms of the GNU General Public
@@ -25,7 +25,13 @@
 #ifdef LIBCONFIG
 #include <libconfig.h>
 #endif
+#ifdef ENABLE_REGEX
+#ifdef LIBPCRE
+#include <pcreposix.h>
+#else
 #include <regex.h>
+#endif
+#endif
 
 #include "common.h"
 #include "probe.h"
@@ -33,7 +39,7 @@
 const char* USAGE_STRING =
 "sslh " VERSION "\n" \
 "usage:\n" \
-"\tsslh  [-v] [-i] [-V] [-f] [-n] [-F <file>]\n"
+"\tsslh  [-v] [-i] [-V] [-f] [-n] [--transparent] [-F <file>]\n"
 "\t[-t <timeout>] [-P <pidfile>] -u <username> -p <add> [-p <addr> ...] \n" \
 "%s\n\n" /* Dynamically built list of builtin protocols */  \
 "\t[--on-timeout <addr>]\n" \
@@ -41,12 +47,13 @@ const char* USAGE_STRING =
 "-V: version\n" \
 "-f: foreground\n" \
 "-n: numeric output\n" \
+"-u: specify under which user to run\n" \
+"--transparent: behave as a transparent proxy\n" \
 "-F: use configuration file\n" \
 "--on-timeout: connect to specified address upon timeout (default: ssh address)\n" \
 "-t: seconds to wait before connecting to --on-timeout address.\n" \
 "-p: address and port to listen on.\n    Can be used several times to bind to several addresses.\n" \
 "--[ssh,ssl,...]: where to connect connections from corresponding protocol.\n" \
-"-F: specify a configuration file\n" \
 "-P: PID file.\n" \
 "-i: Run as a inetd service.\n" \
 "";
@@ -62,7 +69,7 @@ static struct option const_options[] = {
     { "numeric",    no_argument,            &numeric,       1 },
     { "verbose",    no_argument,            &verbose,       1 },
     { "user",       required_argument,      0,              'u' },
-    { "config",     required_argument,      0,              'F' },
+    { "config",     optional_argument,      0,              'F' },
     { "pidfile",    required_argument,      0,              'P' },
     { "timeout",    required_argument,      0,              't' },
     { "on-timeout", required_argument,      0,              OPT_ONTIMEOUT },
@@ -71,7 +78,7 @@ static struct option const_options[] = {
 };
 static struct option* all_options;
 static struct proto* builtins;
-static const char *optstr = "vt:T:p:VP:F:";
+static const char *optstr = "vt:T:p:VP:F::";
 
 
 
@@ -116,16 +123,21 @@ static void printsettings(void)
     
     for (p = get_first_protocol(); p; p = p->next) {
         fprintf(stderr,
-                "%s addr: %s. libwrap service: %s family %d %d\n", 
+                "%s addr: %s. libwrap service: %s log_level: %d family %d %d [%s]\n", 
                 p->description, 
                 sprintaddr(buf, sizeof(buf), p->saddr), 
                 p->service,
+                p->log_level,
                 p->saddr->ai_family,
-                p->saddr->ai_addr->sa_family);
+                p->saddr->ai_addr->sa_family,
+                p->keepalive ? "keepalive" : "");
     }
     fprintf(stderr, "listening on:\n");
     for (a = addr_listen; a; a = a->ai_next) {
-        fprintf(stderr, "\t%s\n", sprintaddr(buf, sizeof(buf), a));
+        fprintf(stderr, 
+                "\t%s\t[%s]\n", 
+                sprintaddr(buf, sizeof(buf), a), 
+                a->ai_flags & SO_KEEPALIVE ? "keepalive" : "");
     }
     fprintf(stderr, "timeout: %d\non-timeout: %s\n", probing_timeout,
             timeout_protocol()->description);
@@ -139,7 +151,7 @@ static void printsettings(void)
 static int config_listen(config_t *config, struct addrinfo **listen) 
 {
     config_setting_t *setting, *addr;
-    int len, i;
+    int len, i, keepalive;
     const char *hostname, *port;
 
     setting = config_lookup(config, "listen");
@@ -155,12 +167,20 @@ static int config_listen(config_t *config, struct addrinfo **listen)
                 return -1;
             }
 
+            keepalive = 0;
+            config_setting_lookup_bool(addr, "keepalive", &keepalive);
+
             resolve_split_name(listen, hostname, port);
 
             /* getaddrinfo returned a list of addresses corresponding to the
              * specification; move the pointer to the end of that list before
-             * processing the next specification */
-            for (; *listen; listen = &((*listen)->ai_next));
+             * processing the next specification, while setting flags for
+             * start_listen_sockets() through ai_flags (which is not meant for
+             * that, but is only used as hint in getaddrinfo, so it's OK) */
+            for (; *listen; listen = &((*listen)->ai_next)) {
+                if (keepalive)
+                    (*listen)->ai_flags = SO_KEEPALIVE;
+            }
         }
     }
 
@@ -173,6 +193,7 @@ static int config_listen(config_t *config, struct addrinfo **listen)
 #ifdef LIBCONFIG
 static void setup_regex_probe(struct proto *p, config_setting_t* probes)
 {
+#ifdef ENABLE_REGEX
     int num_probes, errsize, i, res;
     char *err;
     const char * expr;
@@ -200,6 +221,55 @@ static void setup_regex_probe(struct proto *p, config_setting_t* probes)
             exit(1);
         }
     }
+#else
+    fprintf(stderr, "line %d: regex probe specified but not compiled in\n", config_setting_source_line(probes));
+    exit(5);
+#endif
+}
+#endif
+
+#ifdef LIBCONFIG
+static void setup_sni_alpn_list(struct proto *p, config_setting_t* config_items, const char* name, int alpn)
+{
+    int num_probes, i, max_server_name_len, server_name_len;
+    const char * config_item;
+    char** sni_hostname_list;
+
+    if(!config_items || !config_setting_is_array(config_items)) {
+        fprintf(stderr, "%s: no %s specified\n", p->description, name);
+        return;
+    }
+    num_probes = config_setting_length(config_items);
+    if (!num_probes) {
+        fprintf(stderr, "%s: no %s specified\n", p->description, name);
+        return;
+    }
+
+    max_server_name_len = 0;
+    for (i = 0; i < num_probes; i++) {
+        server_name_len = strlen(config_setting_get_string_elem(config_items, i));
+        if(server_name_len > max_server_name_len)
+            max_server_name_len = server_name_len;
+    }
+
+    sni_hostname_list = calloc(num_probes + 1, ++max_server_name_len);
+
+    for (i = 0; i < num_probes; i++) {
+        config_item = config_setting_get_string_elem(config_items, i);
+        sni_hostname_list[i] = malloc(max_server_name_len);
+        strcpy (sni_hostname_list[i], config_item);
+        if(verbose) fprintf(stderr, "%s: %s[%d]: %s\n", p->description, name, i, sni_hostname_list[i]);
+    }
+
+    p->data = (void*)tls_data_set_list(p->data, alpn, sni_hostname_list);
+}
+
+static void setup_sni_alpn(struct proto *p, config_setting_t* sni_hostnames, config_setting_t* alpn_protocols)
+{
+    p->data = (void*)new_tls_data();
+    p->probe = get_probe("sni_alpn");
+    setup_sni_alpn_list(p, sni_hostnames, "sni_hostnames", 0);
+    setup_sni_alpn_list(p, alpn_protocols, "alpn_protocols", 1);
 }
 #endif
 
@@ -209,7 +279,7 @@ static void setup_regex_probe(struct proto *p, config_setting_t* probes)
 #ifdef LIBCONFIG
 static int config_protocols(config_t *config, struct proto **prots)
 {
-    config_setting_t *setting, *prot, *probes;
+    config_setting_t *setting, *prot, *patterns, *sni_hostnames, *alpn_protocols;
     const char *hostname, *port, *name;
     int i, num_prots;
     struct proto *p, *prev = NULL;
@@ -230,33 +300,38 @@ static int config_protocols(config_t *config, struct proto **prots)
                 )) {
                 p->description = name;
                 config_setting_lookup_string(prot, "service", &(p->service));
+                config_setting_lookup_bool(prot, "keepalive", &p->keepalive);
+
+                if (config_setting_lookup_int(prot, "log_level", &p->log_level) == CONFIG_FALSE) {
+                    p->log_level = 1;
+                }
 
                 resolve_split_name(&(p->saddr), hostname, port);
 
+                p->probe = get_probe(name);
+                if (!p->probe || !strcmp(name, "sni_alpn")) {
+                    fprintf(stderr, "line %d: %s: probe unknown\n", config_setting_source_line(prot), name);
+                    exit(1);
+                }
 
-                probes = config_setting_get_member(prot, "probe");
-                if (probes) {
-                    if (config_setting_is_array(probes)) {
-                        /* If 'probe' is an array, setup a regex probe using the
-                         * array of strings as pattern */
-
-                        setup_regex_probe(p, probes);
-
-                    } else {
-                        /* if 'probe' is 'builtin', set the probe to the
-                         * appropriate builtin protocol */
-                        if (!strcmp(config_setting_get_string(probes), "builtin")) {
-                            p->probe = get_probe(name);
-                            if (!p->probe) {
-                                fprintf(stderr, "%s: no builtin probe for this protocol\n", name);
-                                exit(1);
-                            }
-                        } else {
-                            fprintf(stderr, "%s: illegal probe name\n", name);
-                            exit(1);
-                        }
+                /* Probe-specific options: regex patterns */
+                if (!strcmp(name, "regex")) {
+                    patterns = config_setting_get_member(prot, "regex_patterns");
+                    if (patterns && config_setting_is_array(patterns)) {
+                        setup_regex_probe(p, patterns);
                     }
                 }
+
+                /* Probe-specific options: SNI/ALPN */
+                if (!strcmp(name, "tls")) {
+                    sni_hostnames = config_setting_get_member(prot, "sni_hostnames");
+                    alpn_protocols = config_setting_get_member(prot, "alpn_protocols");
+
+                    if((sni_hostnames && config_setting_is_array(sni_hostnames)) || (alpn_protocols && config_setting_is_array(alpn_protocols))) {
+                        setup_sni_alpn(p, sni_hostnames, alpn_protocols);
+                    }
+                }
+
             }
         }
     }
@@ -269,6 +344,7 @@ static int config_protocols(config_t *config, struct proto **prots)
  * in: *filename
  * out: *listen, a newly-allocated linked list of listen addrinfo
  *      *prots, a newly-allocated linked list of protocols
+ *      1 on error, 0 on success
  */
 #ifdef LIBCONFIG
 static int config_parse(char *filename, struct addrinfo **listen, struct proto **prots)
@@ -279,11 +355,20 @@ static int config_parse(char *filename, struct addrinfo **listen, struct proto *
 
     config_init(&config);
     if (config_read_file(&config, filename) == CONFIG_FALSE) {
-        fprintf(stderr, "%s:%d:%s\n", 
+        /* If it's a parse error then there will be a line number for the failure
+         * an I/O error (such as non-existent file) will have the error line as 0
+         */
+        if (config_error_line(&config) != 0) {
+            fprintf(stderr, "%s:%d:%s\n", 
                     filename,
                     config_error_line(&config),
                     config_error_text(&config));
-        exit(1);
+            exit(1);
+        }
+        fprintf(stderr, "%s:%s\n", 
+                filename,
+                config_error_text(&config));
+        return 1;
     }
 
     config_lookup_bool(&config, "verbose", &verbose);
@@ -359,10 +444,22 @@ static void cmdline_config(int argc, char* argv[], struct proto** prots)
     optind = 1;
     opterr = 0; /* we're missing protocol options at this stage so don't output errors */
     while ((c = getopt_long_only(argc, argv, optstr, all_options, NULL)) != -1) {
+        if (c == 'v') {
+            verbose++;
+        }
         if (c == 'F') {
             config_filename = optarg;
-            /* find the end of the listen list */
-            res = config_parse(config_filename, &addr_listen, prots);
+            if (config_filename) {
+                res = config_parse(config_filename, &addr_listen, prots);
+            } else {
+                /* No configuration file specified -- try default file locations */
+                res = config_parse("/etc/sslh/sslh.cfg", &addr_listen, prots);
+                if (!res && verbose) fprintf(stderr, "Using /etc/sslh/sslh.cfg\n");
+                if (res) {
+                    res = config_parse("/etc/sslh.cfg", &addr_listen, prots);
+                    if (!res && verbose) fprintf(stderr, "Using /etc/sslh.cfg\n");
+                }
+            }
             if (res)
                 exit(4);
             break;
@@ -467,10 +564,13 @@ next_arg:
 
     set_protocol_list(prots);
 
+/* If compiling with systemd socket support no need to require listen address */
+#ifndef SYSTEMD
     if (!addr_listen && !inetd) {
         fprintf(stderr, "No listening address specified; use at least one -p option\n");
         exit(1);
     }
+#endif
 
     /* Did command-line override foreground setting? */
     if (background)
@@ -507,6 +607,13 @@ int main(int argc, char *argv[])
 
    num_addr_listen = start_listen_sockets(&listen_sockets, addr_listen);
 
+#ifdef SYSTEMD
+   if (num_addr_listen < 1) {
+     fprintf(stderr, "No listening sockets found, restart sockets or specify addresses in config\n");
+     exit(1);
+    }
+#endif
+
    if (!foreground) {
        if (fork() > 0) exit(0); /* Detach */
 

sslh.pod

@@ -6,7 +6,7 @@
 
 =head1 SYNOPSIS
 
-sslh [B<-F> I<config file>] [ B<-t> I<num> ] [B<-p> I<listening address> [B<-p> I<listening address> ...] [B<--ssl> I<target address for SSL>] [B<--ssh> I<target address for SSH>] [B<--openvpn> I<target address for OpenVPN>] [B<--http> I<target address for HTTP>] [B<--anyprot> I<default target address>] [B<--on-timeout> I<protocol name>] [B<-u> I<username>] [B<-P> I<pidfile>] [-v] [-i] [-V] [-f] [-n]
+sslh [B<-F> I<config file>] [ B<-t> I<num> ] [B<--transparent>] [B<-p> I<listening address> [B<-p> I<listening address> ...] [B<--ssl> I<target address for SSL>] [B<--ssh> I<target address for SSH>] [B<--openvpn> I<target address for OpenVPN>] [B<--http> I<target address for HTTP>] [B<--anyprot> I<default target address>] [B<--on-timeout> I<protocol name>] [B<-u> I<username>] [B<-P> I<pidfile>] [-v] [-i] [-V] [-f] [-n]
 
 =head1 DESCRIPTION
 
@@ -51,14 +51,10 @@ and the list of protocols).
 
 The configuration file makes it possible to specify
 protocols using regular expressions: a list of regular
-expressions is given as the I<probe> parameter, and if the
+expressions is given as the I<regex_patterns> parameter, and if the
 first packet received from the client matches any of these
 expressions, B<sslh> connects to that protocol.
 
-Alternatively, the I<probe> parameter can be set to
-"builtin", to use the compiled probes which are much faster
-than regular expressions.
-
 =head2 Probing protocols
 
 When receiving an incoming connection, B<sslh> will read the
@@ -72,10 +68,22 @@ If no data is sent by the client, B<sslh> will eventually
 time out and connect to the protocol specified with
 B<--on-timeout>, or I<ssh> if none is specified.
 
+=head2 Logging
+
+As a security/authorization program, B<sslh> logs to the
+LOG_AUTH facility, with priority LOG_INFO for normal
+connections and LOG_ERR for failures.
+
 =head1 OPTIONS
 
 =over 4
 
+=item B<-F> I<filename>, B<--config> I<filename>
+
+Uses I<filename> has configuration file. If other
+command-line options are specified, they will override the
+configuration file's settings.
+
 =item B<-t> I<num>, B<--timeout> I<num>
 
 Timeout before forwarding the connection to the timeout
@@ -86,6 +94,13 @@ protocol (which should usually be SSH). Default is 2s.
 Name of the protocol to connect to after the timeout period
 is over. Default is 'ssh'.
 
+=item B<--transparent>
+
+Makes B<sslh> behave as a transparent proxy, i.e. the
+receiving service sees the original client's IP address.
+This works on Linux only and involves B<iptables> settings.
+Refer to the README for more information.
+
 =item B<-p> I<listening address>, B<--listen> I<listening address>
 
 Interface and port on which to listen, e.g. I<foobar:443>,

systemd-sslh-generator.c

@@ -0,0 +1,153 @@
+#include <libconfig.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
+
+static char* resolve_listen(const char *hostname, const char *port) {
+
+/* Need room in the strcat for \0 and :
+ * the format in the socket unit file is hostname:port */
+    char *conn = (char*)malloc(strlen(hostname)+strlen(port)+2);
+    strcpy(conn, hostname);
+    strcat(conn, ":");
+    strcat(conn, port);
+
+    return conn;
+
+}
+
+
+static int get_listen_from_conf(const char *filename, char **listen) {
+
+  config_t config;
+  config_setting_t *setting, *addr;
+  const char *hostname, *port;
+  int len = 0;
+
+/* look up the listen stanzas in the config file so these
+ * can be used in the socket file generated */
+
+  config_init(&config);
+  if (config_read_file(&config, filename) == CONFIG_FALSE) {
+  /* we don't care if file is missing, skip it */
+       if (config_error_line(&config) != 0) {
+       fprintf(stderr, "%s:%d:%s\n",
+                filename,
+                config_error_line(&config),
+                config_error_text(&config));
+        return -1;
+        }
+  } else {
+   setting = config_lookup(&config, "listen");
+    if (setting) {
+      len = config_setting_length(setting);
+      for (int i = 0; i < len; i++) {
+        addr = config_setting_get_elem(setting, i);
+        if (! (config_setting_lookup_string(addr, "host", &hostname) &&
+               config_setting_lookup_string(addr, "port", &port))) {
+          fprintf(stderr,
+            "line %d:Incomplete specification (hostname and port required)\n",
+            config_setting_source_line(addr));
+            return -1;
+         } else {
+
+        listen[i] = malloc(strlen(resolve_listen(hostname, port)));
+        strcpy(listen[i], resolve_listen(hostname, port));
+        }
+      }
+    }
+  }
+
+  return len;
+
+}
+
+static int write_socket_unit(FILE *socket, char **listen, int num_addr, const char *source) {
+
+   fprintf(socket,
+        "# Automatically generated by systemd-sslh-generator\n\n"
+        "[Unit]\n"
+        "Before=sslh.service\n"
+        "SourcePath=%s\n"
+        "Documentation=man:sslh(8) man:systemd-sslh-generator(8)\n\n"
+        "[Socket]\n"
+        "FreeBind=true\n",
+        source);
+
+        for (int i = 0; i < num_addr; i++) {
+            fprintf(socket, "ListenStream=%s\n", listen[i]);
+        }
+
+return 0;
+}
+
+static int gen_sslh_config(char *runtime_unit_dir) {
+
+  char *sslh_conf;
+  int num_addr;
+  FILE *config;
+  char **listen;
+  FILE *runtime_conf_fd = stdout;
+  const char *unit_file;
+
+/* There are two default locations so check both with first given preference */
+  sslh_conf = "/etc/sslh.cfg";
+
+  config = fopen(sslh_conf, "r");
+  if (config  == NULL) {
+    sslh_conf="/etc/sslh/sslh.cfg";
+     config = fopen(sslh_conf, "r");
+    if (config == NULL) {
+      return -1;
+    }
+  }
+
+  fclose(config);
+
+
+  num_addr = get_listen_from_conf(sslh_conf, listen);
+  if (num_addr < 0)
+    return -1;
+
+/* If this is run by systemd directly write to the location told to
+ * otherwise write to standard out so that it's trivial to check what
+ * will be written */
+   if (runtime_unit_dir != "") {
+   unit_file = "/sslh.socket";
+   size_t uf_len = strlen(unit_file);
+   size_t runtime_len = strlen(runtime_unit_dir) + uf_len + 1;
+   char *runtime_conf = malloc(runtime_len);
+       strcpy(runtime_conf, runtime_unit_dir);
+       strcat(runtime_conf, unit_file);
+       runtime_conf_fd = fopen(runtime_conf, "w");
+   }
+
+
+ return write_socket_unit(runtime_conf_fd, listen, num_addr, sslh_conf);
+
+}
+
+int main(int argc, char *argv[]){
+
+        int r = 0;
+        int k;
+        char *runtime_unit_dest = "";
+
+        if (argc > 1 && (argc != 4) ) {
+                printf("This program takes three or no arguments.\n");
+                return -1;
+        }
+
+        if (argc  > 1)
+            runtime_unit_dest = argv[1];
+
+        k = gen_sslh_config(runtime_unit_dest);
+        if (k < 0)
+          r = k;
+
+       return r < 0 ? -1 : 0;
+
+}
+
+

t

@@ -295,21 +295,6 @@ if ($RB_OPEN_PID_FILE) {
     is($code, 3, "Exit status if can't open PID file");
 }
 
-# Robustness: Can't bind address
-if ($RB_BIND_ADDRESS) {
-    print "***Test: Can't bind address\n";
-    my $sslh_pid;
-    if (!($sslh_pid = fork)) {
-        my $user = (getpwuid $<)[0]; # Run under current username
-        exec "./sslh-select -v -f -u $user --listen 74.125.39.106:9000 --ssh $ssh_address --ssl $ssl_address -P $pidfile";
-    }
-    warn "spawned $sslh_pid\n";
-    waitpid $sslh_pid, 0;
-    my $code = $? >> 8;
-    warn "exited with $code\n";
-    is($code, 1, "Exit status if can't bind address");
-}
-
 # Robustness: Can't resolve address
 if ($RB_RESOLVE_ADDRESS) {
     print "***Test: Can't resolve address\n";

tls.c

@@ -0,0 +1,327 @@
+/*
+ * Copyright (c) 2011 and 2012, Dustin Lundquist <dustin@null-ptr.net>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+/*
+ * This is a minimal TLS implementation intended only to parse the server name
+ * extension.  This was created based primarily on Wireshark dissection of a
+ * TLS handshake and RFC4366.
+ */
+#include <stdio.h>
+#include <stdlib.h> /* malloc() */
+#include "tls.h"
+
+#define TLS_HEADER_LEN 5
+#define TLS_HANDSHAKE_CONTENT_TYPE 0x16
+#define TLS_HANDSHAKE_TYPE_CLIENT_HELLO 0x01
+
+#ifndef MIN
+#define MIN(X, Y) ((X) < (Y) ? (X) : (Y))
+#endif
+
+
+struct TLSProtocol {
+    int use_alpn;
+    char** sni_hostname_list;
+    char** alpn_protocol_list;
+};
+
+static int parse_extensions(const struct TLSProtocol *, const char *, size_t);
+static int parse_server_name_extension(const struct TLSProtocol *, const char *, size_t);
+static int parse_alpn_extension(const struct TLSProtocol *, const char *, size_t);
+static int has_match(char**, const char*, size_t);
+
+/* Parse a TLS packet for the Server Name Indication and ALPN extension in the client
+ * hello handshake, returning a status code
+ *
+ * Returns:
+ *  >=0  - length of the hostname and updates *hostname
+ *         caller is responsible for freeing *hostname
+ *  -1   - Incomplete request
+ *  -2   - No Host header included in this request
+ *  -3   - Invalid hostname pointer
+ *  < -4 - Invalid TLS client hello
+ */
+int
+parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t data_len) {
+    char tls_content_type;
+    char tls_version_major;
+    char tls_version_minor;
+    size_t pos = TLS_HEADER_LEN;
+    size_t len;
+
+    /* Check that our TCP payload is at least large enough for a TLS header */
+    if (data_len < TLS_HEADER_LEN)
+        return -1;
+
+    tls_content_type = data[0];
+    if (tls_content_type != TLS_HANDSHAKE_CONTENT_TYPE) {
+        if (verbose) fprintf(stderr, "Request did not begin with TLS handshake.\n");
+        return -5;
+    }
+
+    tls_version_major = data[1];
+    tls_version_minor = data[2];
+    if (tls_version_major < 3) {
+        if (verbose) fprintf(stderr, "Received SSL %d.%d handshake which cannot be parsed.\n",
+              tls_version_major, tls_version_minor);
+
+        return -2;
+    }
+
+    /* TLS record length */
+    len = ((unsigned char)data[3] << 8) +
+          (unsigned char)data[4] + TLS_HEADER_LEN;
+    data_len = MIN(data_len, len);
+
+    /* Check we received entire TLS record length */
+    if (data_len < len)
+        return -1;
+
+    /*
+     * Handshake
+     */
+    if (pos + 1 > data_len) {
+        return -5;
+    }
+    if (data[pos] != TLS_HANDSHAKE_TYPE_CLIENT_HELLO) {
+        if (verbose) fprintf(stderr, "Not a client hello\n");
+
+        return -5;
+    }
+
+    /* Skip past fixed length records:
+       1	Handshake Type
+       3	Length
+       2	Version (again)
+       32	Random
+       to	Session ID Length
+     */
+    pos += 38;
+
+    /* Session ID */
+    if (pos + 1 > data_len)
+        return -5;
+    len = (unsigned char)data[pos];
+    pos += 1 + len;
+
+    /* Cipher Suites */
+    if (pos + 2 > data_len)
+        return -5;
+    len = ((unsigned char)data[pos] << 8) + (unsigned char)data[pos + 1];
+    pos += 2 + len;
+
+    /* Compression Methods */
+    if (pos + 1 > data_len)
+        return -5;
+    len = (unsigned char)data[pos];
+    pos += 1 + len;
+
+    if (pos == data_len && tls_version_major == 3 && tls_version_minor == 0) {
+        if (verbose) fprintf(stderr, "Received SSL 3.0 handshake without extensions\n");
+        return -2;
+    }
+
+    /* Extensions */
+    if (pos + 2 > data_len)
+        return -5;
+    len = ((unsigned char)data[pos] << 8) + (unsigned char)data[pos + 1];
+    pos += 2;
+
+    if (pos + len > data_len)
+        return -5;
+    return parse_extensions(tls_data, data + pos, len);
+}
+
+static int
+parse_extensions(const struct TLSProtocol *tls_data, const char *data, size_t data_len) {
+    size_t pos = 0;
+    size_t len;
+    int last_matched = 0;
+
+    if (tls_data == NULL)
+        return -3;
+
+    /* Parse each 4 bytes for the extension header */
+    while (pos + 4 <= data_len) {
+        /* Extension Length */
+        len = ((unsigned char) data[pos + 2] << 8) +
+              (unsigned char) data[pos + 3];
+
+        if (pos + 4 + len > data_len)
+            return -5;
+
+        size_t extension_type = ((unsigned char) data[pos] << 8) +
+                                (unsigned char) data[pos + 1];
+
+
+        /* Check if it's a server name extension */
+        /* There can be only one extension of each type, so we break
+           our state and move pos to beginning of the extension here */
+        if (tls_data->use_alpn == 2) {
+            /* we want BOTH alpn and sni to match */
+            if (extension_type == 0x00) { /* Server Name */
+                if (parse_server_name_extension(tls_data, data + pos + 4, len)) {
+                    /* SNI matched */
+                    if(last_matched) {
+                        /* this is only true if ALPN matched, so return true */
+                        return last_matched;
+                    } else {
+                        /* otherwise store that SNI matched */
+                        last_matched = 1;
+                    }
+                } else {
+                    // both can't match
+                    return -2;
+                }
+            } else if (extension_type == 0x10) { /* ALPN */
+                if (parse_alpn_extension(tls_data, data + pos + 4, len)) {
+                    /* ALPN matched */
+                    if(last_matched) {
+                        /* this is only true if SNI matched, so return true */
+                        return last_matched;
+                    } else {
+                        /* otherwise store that ALPN matched */
+                        last_matched = 1;
+                    }
+                } else {
+                    // both can't match
+                    return -2;
+                }
+            }
+
+        } else if (extension_type == 0x00 && tls_data->use_alpn == 0) { /* Server Name */
+            return parse_server_name_extension(tls_data, data + pos + 4, len);
+        } else if (extension_type == 0x10 && tls_data->use_alpn == 1) { /* ALPN */
+            return parse_alpn_extension(tls_data, data + pos + 4, len);
+        }
+
+        pos += 4 + len; /* Advance to the next extension header */
+    }
+
+    /* Check we ended where we expected to */
+    if (pos != data_len)
+        return -5;
+
+    return -2;
+}
+
+static int
+parse_server_name_extension(const struct TLSProtocol *tls_data, const char *data, size_t data_len) {
+    size_t pos = 2; /* skip server name list length */
+    size_t len;
+
+    while (pos + 3 < data_len) {
+        len = ((unsigned char)data[pos + 1] << 8) +
+              (unsigned char)data[pos + 2];
+
+        if (pos + 3 + len > data_len)
+            return -5;
+
+        switch (data[pos]) { /* name type */
+            case 0x00: /* host_name */
+                if(has_match(tls_data->sni_hostname_list, data + pos + 3, len)) {
+                    return len;
+                } else {
+                    return -2;
+                }
+            default:
+                if (verbose) fprintf(stderr, "Unknown server name extension name type: %d\n",
+                      data[pos]);
+        }
+        pos += 3 + len;
+    }
+    /* Check we ended where we expected to */
+    if (pos != data_len)
+        return -5;
+
+    return -2;
+}
+
+static int
+parse_alpn_extension(const struct TLSProtocol *tls_data, const char *data, size_t data_len) {
+    size_t pos = 2;
+    size_t len;
+
+    while (pos + 1 < data_len) {
+        len = (unsigned char)data[pos];
+
+        if (pos + 1 + len > data_len)
+            return -5;
+
+        if (len > 0 && has_match(tls_data->alpn_protocol_list, data + pos + 1, len)) {
+            return len;
+        } else if (len > 0) {
+            if (verbose) fprintf(stderr, "Unknown ALPN name: %.*s\n", (int)len, data + pos + 1);
+        }
+        pos += 1 + len;
+    }
+    /* Check we ended where we expected to */
+    if (pos != data_len)
+        return -5;
+
+    return -2;
+}
+
+static int
+has_match(char** list, const char* name, size_t name_len) {
+    char **item;
+
+    for (item = list; *item; item++) {
+        if (verbose) fprintf(stderr, "matching [%.*s] with [%s]\n", (int)name_len, name, *item);
+        if(!strncmp(*item, name, name_len)) {
+            return 1;
+        }
+    }
+    return 0;
+}
+
+struct TLSProtocol *
+new_tls_data() {
+    struct TLSProtocol *tls_data = malloc(sizeof(struct TLSProtocol));
+    if (tls_data != NULL) {
+        tls_data->use_alpn = -1;
+    }
+
+    return tls_data;
+}
+
+struct TLSProtocol *
+tls_data_set_list(struct TLSProtocol *tls_data, int alpn, char** list) {
+    if (alpn) {
+        tls_data->alpn_protocol_list = list;
+        if(tls_data->use_alpn == 0)
+            tls_data->use_alpn = 2;
+        else
+            tls_data->use_alpn = 1;
+    } else {
+        tls_data->sni_hostname_list = list;
+        if(tls_data->use_alpn == 1)
+            tls_data->use_alpn = 2;
+        else
+            tls_data->use_alpn = 0;
+    }
+
+    return tls_data;
+}

tls.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2011 and 2012, Dustin Lundquist <dustin@null-ptr.net>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef TLS_H
+#define TLS_H
+
+#include "common.h"
+
+struct TLSProtocol;
+
+int parse_tls_header(const struct TLSProtocol *tls_data, const char *data, size_t data_len);
+
+struct TLSProtocol *new_tls_data();
+struct TLSProtocol *tls_data_set_list(struct TLSProtocol *, int, char**);
+
+#endif