INSTALLATION INSTRUCTIONS for SECNET USE AT YOUR OWN RISK. THIS IS ALPHA TEST SOFTWARE. I DO NOT GUARANTEE THAT THERE WILL BE PROTOCOL COMPATIBILITY BETWEEN DIFFERENT VERSIONS. * Preparation ** System software support Ensure that you have libgmp3-dev and adns installed (and bison and flex, and for that matter gcc...). [On BSD install /usr/ports/devel/bison] If you intend to configure secnet to obtain packets from the kernel through userv-ipif, install and configure userv-ipif. It is part of userv-utils, available from ftp.chiark.greenend.org.uk in /users/ian/userv If you intend to configure secnet to obtain packets from the kernel using the universal TUN/TAP driver, make sure it's configured in your kernel (it's under "network device support" in Linux-2.4) and that you've created the appropriate device files; see linux/Documentation/networking/tuntap.txt If you're using TUN/TAP on a platform other than Linux-2.4, see http://vtun.sourceforge.net/tun/ You will probably be using the supplied `make-secnet-sites' program to generate your VPN's list of sites as a secnet configuration from a more-human-writeable form. If so you need to install the standard `ipaddr' Python module (python-ipaddr on Debian-derived systems). ** System and network configuration If you intend to start secnet as root, I suggest you create a userid for it to run as once it's ready to drop its privileges. Example (on Debian): # adduser --system --no-create-home secnet If you're using the 'soft routes' feature (for some classes of mobile device) you'll have to run as root all the time, to enable secnet to add and remove routes from your kernel's routing table. (This restriction may be relaxed later if someone writes a userv service to modify the routing table.) If you are joining an existing VPN, read that VPN's documentation now. It may supersede the next paragraph. In most configurations, you will need to allocate two IP addresses for use by secnet. One will be for the tunnel interface on your tunnel endpoint machine (i.e. the address you see in 'ifconfig' when you look at the tunnel interface). The other will be for secnet itself. These addresses should probably be allocated from the range used by your internal network: if you do this, you should provide appropriate proxy-ARP on the internal network interface of the machine running secnet (eg. add an entry net/ipv4/conf/eth_whatever/proxy_arp = 1 to /etc/sysctl.conf on Debian systems and run sysctl -p). Alternatively the addresses could be from some other range - this works well if the machine running secnet is the default route out of your network - but this requires more thought. http://www.ucam.org/cam-grin/ may be useful. * Installation If you installed the Debian package of secnet, skip to "If installing for the first time", below, and note that example.conf can be found in /usr/share/doc/secnet/examples. To install secnet do $ ./configure $ make # make install # mkdir /etc/secnet (Note: you may see the following warning while compiling conffile.tab.c; this is a bug in bison-1.28: /usr/share/bison/bison.simple: In function `yyparse': /usr/share/bison/bison.simple:285: warning: `yyval' might be used uninitialized in this function You may if you wish apply the following patch to bison.simple: diff -pu -r1.28.0.1 -r1.28.0.3 --- bison.s1 1999/08/30 19:23:24 1.28.0.1 +++ bison.s1 1999/08/30 21:15:18 1.28.0.3 @@ -523,8 +523,14 @@ yydefault: /* Do a reduction. yyn is the number of a rule to reduce with. */ yyreduce: yylen = yyr2[yyn]; - if (yylen > 0) - yyval = yyvsp[1-yylen]; /* implement default value of the action */ + + /* If yylen is nonzero, implement the default value of the action. + Otherwise, the following line sets yyval to the semantic value of + the lookahead token. This behavior is undocumented and bison + users should not rely upon it. Assigning to yyval + unconditionally makes the parser a bit smaller, and it avoids a + GCC warning that yyval may be used uninitialized. */ + yyval = yyvsp[1-yylen]; #if YYDEBUG != 0 if (yydebug) ) Any other warnings or errors should be reported to steve@greenend.org.uk. If installing for the first time, do # cp example.conf /etc/secnet/secnet.conf # cd /etc/secnet # ssh-keygen -f key -t rsa1 -N "" (You may need ssh-keygen1, instead, which might be found in openssh-client-ssh1.) [On BSD use $ LDFLAGS="-L/usr/local/lib" ./configure $ gmake CFLAGS="-I/usr/local/include" LDFLAGS="-L/usr/local/lib" XXX this should eventually be worked out automatically by 'configure'.] Generate a site file fragment for your site (see your VPN's documentation, or see below), and submit it for inclusion in your VPN's 'sites' file. Download the vpn-sites file to /etc/secnet/sites - MAKE SURE YOU GET AN AUTHENTIC COPY because the sites file contains public keys for all the sites in the VPN. Use the make-secnet-sites program provided with the secnet distribution to convert the distributed sites file into one that can be included in a secnet configuration file: # make-secnet-sites /etc/secnet/sites /etc/secnet/sites.conf * Configuration Should be reasonably obvious - edit /etc/secnet/secnet.conf as prompted by the comments in example.conf. XXX Fuller documentation of the configuration file format should be forthcoming in time. Its syntax is described in the README file at the moment. * Constructing your site file fragment You need the following information: 1. the name of your VPN. 2. the name of your location(s). 3. a short name for your site, eg. "sinister". This is used to identify your site in the vpn-sites file, and should probably be the same as its hostname. 4. the DNS name of the machine that will be the "front-end" for your secnet installation. This will typically be the name of the gateway machine for your network, eg. sinister.dynamic.greenend.org.uk secnet does not actually have to run on this machine, as long as the machine can be configured to forward UDP packets to the machine that is running secnet. 5. the port number used to contact secnet at your site. This is the port number on the front-end machine, and does not necessarily have to match the port number on the machine running secnet. If you want to use a privileged port number we suggest 410. An appropriate unprivileged port number is 51396. 6. the list of networks accessible at your site over the VPN. 7. the public part of the RSA key you generated during installation (in /etc/secnet/key.pub if you followed the installation instructions). This file contains three numbers and a comment on one line. If you are running secnet on a particularly slow machine, you may like to specify a larger value for the key setup retry timeout than the default, to prevent unnecessary retransmissions of key setup packets. See the notes in the example configuration file for more on this. The site file fragment should look something like this: vpn sgo location greenend contact steve@greenend.org.uk site sinister networks 192.168.73.0/24 192.168.1.0/24 172.19.71.0/24 address sinister.dynamic.greenend.org.uk 51396 pubkey 1024 35 142982503......[lots more].....0611 steve@sinister