SNI Proxy

Proxies incoming HTTP and TLS connections based on the hostname contained in the initial request of the TCP session. This enables HTTPS name-based virtual hosting to separate backend servers without installing the private key on the proxy machine.

Features

• Name-based proxying of HTTPS without decrypting traffic. No keys or certificates required.
• Supports both TLS and HTTP protocols.
• Supports IPv4, IPv6 and Unix domain sockets for both back end servers and listeners.
• Supports multiple listening sockets per instance.

Usage

Usage: sniproxy [-c <config>] [-f] [-n <max file descriptor limit>] [-V]
    -c  configuration file, defaults to /etc/sniproxy.conf
    -f  run in foreground, do not drop privileges
    -n  specify file descriptor limit
    -V  print the version of SNIProxy and exit

Installation

For Debian or Fedora based Linux distributions see building packages below.

Prerequisites

• Autotools (autoconf, automake, gettext and libtool)
• libev4, libpcre and libudns development headers
• Perl and cURL for test suite

Install

./autogen.sh && ./configure && make check && sudo make install

Building Debian/Ubuntu package

This is the preferred installation method on recent Debian based distributions:

1. Install required packages

    sudo apt-get install autotools-dev cdbs debhelper dh-autoreconf dpkg-dev gettext libev-dev libpcre3-dev libudns-dev pkg-config fakeroot devscripts
   

2. Build a Debian package

    ./autogen.sh && dpkg-buildpackage
   

3. Install the resulting package

    sudo dpkg -i ../sniproxy_<version>_<arch>.deb
   

Building Fedora/RedHat package

This is the preferred installation method for modern Fedora based distributions.

1. Install required packages

    sudo yum install autoconf automake curl gettext-devel libev-devel pcre-devel perl pkgconfig rpm-build udns-devel
   

2. Build a distribution tarball:

    ./autogen.sh && ./configure && make dist
   

3. Build a RPM package

    rpmbuild --define "_sourcedir `pwd`" -ba redhat/sniproxy.spec
   

4. Install resulting RPM

    sudo yum install ../sniproxy-<version>.<arch>.rpm
   

I've used Scientific Linux 6 a fair amount, but I prefer Debian based distributions. RPM builds are tested in Travis-CI on Ubuntu, but not natively. This build process may not follow the current Fedora packaging standards, and may not even work.

Building on OS X with Homebrew

1. install dependencies.

    brew install libev pcre udns autoconf automake gettext libtool
   

2. Read the warning about gettext and force link it so autogen.sh works. We need the GNU gettext for the macro AC_LIB_HAVE_LINKFLAGS which isn't present in the default OS X package.

    brew link --force gettext
   

3. Make it so

    ./autogen.sh && ./configure && make
   

OS X support is a best effort, and isn't a primary target platform.

Configuration Syntax

user daemon

pidfile /tmp/sniproxy.pid

error_log {
    syslog daemon
    priority notice
}

listener 127.0.0.1:443 {
    protocol tls
    table TableName

    # Specify a server to use if the initial client request doesn't contain
    # a hostname
    fallback 192.0.2.5:443
}

table TableName {
    # Match exact request hostnames
    example.com 192.0.2.10:4343
    # If port is not specified the listener port will be used
    example.net [2001:DB8::1:10]
    # Or use regular expression to match
    .*\\.com    [2001:DB8::1:11]:443
    # Combining regular expression and wildcard will resolve the hostname
    # client requested and proxy to it
    .*\\.edu    *:443
}

DNS Resolution

Using hostnames or wildcard entries in the configuration requires sniproxy to be built with UDNS. SNIProxy will still build without UDNS, but these features will be unavailable.

UDNS uses a single UDP socket for all queries, so it is recommended you use a local caching DNS resolver (with a single socket each DNS query is protected by spoofing by a single 16 bit query ID, which makes it relatively easy to spoof).

UDNS is currently not available in Debian stable, but a package can be easily built from the Debian testing or Ubuntu source packages:

mkdir udns_packaging
cd udns_packaging
wget http://archive.ubuntu.com/ubuntu/pool/universe/u/udns/udns_0.4-1.dsc
wget http://archive.ubuntu.com/ubuntu/pool/universe/u/udns/udns_0.4.orig.tar.gz
wget http://archive.ubuntu.com/ubuntu/pool/universe/u/udns/udns_0.4-1.debian.tar.gz
tar xfz udns_0.4.orig.tar.gz
cd udns-0.4/
tar xfz ../udns_0.4-1.debian.tar.gz
dpkg-buildpackage
cd ..
sudo dpkg -i libudns-dev_0.4-1_amd64.deb libudns0_0.4-1_amd64.deb