ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/gvpe/doc/gvpe.5
Revision: 1.3
Committed: Thu Jan 27 06:58:48 2005 UTC (19 years, 3 months ago) by pcg
Branch: MAIN
Changes since 1.2: +13 -13 lines
Log Message:
*** empty log message ***

File Contents

# Content
1 .\" Automatically generated by Pod::Man v1.37, Pod::Parser v1.14
2 .\"
3 .\" Standard preamble:
4 .\" ========================================================================
5 .de Sh \" Subsection heading
6 .br
7 .if t .Sp
8 .ne 5
9 .PP
10 \fB\\$1\fR
11 .PP
12 ..
13 .de Sp \" Vertical space (when we can't use .PP)
14 .if t .sp .5v
15 .if n .sp
16 ..
17 .de Vb \" Begin verbatim text
18 .ft CW
19 .nf
20 .ne \\$1
21 ..
22 .de Ve \" End verbatim text
23 .ft R
24 .fi
25 ..
26 .\" Set up some character translations and predefined strings. \*(-- will
27 .\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
28 .\" double quote, and \*(R" will give a right double quote. | will give a
29 .\" real vertical bar. \*(C+ will give a nicer C++. Capital omega is used to
30 .\" do unbreakable dashes and therefore won't be available. \*(C` and \*(C'
31 .\" expand to `' in nroff, nothing in troff, for use with C<>.
32 .tr \(*W-|\(bv\*(Tr
33 .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
34 .ie n \{\
35 . ds -- \(*W-
36 . ds PI pi
37 . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
38 . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch
39 . ds L" ""
40 . ds R" ""
41 . ds C`
42 . ds C'
43 'br\}
44 .el\{\
45 . ds -- \|\(em\|
46 . ds PI \(*p
47 . ds L" ``
48 . ds R" ''
49 'br\}
50 .\"
51 .\" If the F register is turned on, we'll generate index entries on stderr for
52 .\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
53 .\" entries marked with X<> in POD. Of course, you'll have to process the
54 .\" output yourself in some meaningful fashion.
55 .if \nF \{\
56 . de IX
57 . tm Index:\\$1\t\\n%\t"\\$2"
58 ..
59 . nr % 0
60 . rr F
61 .\}
62 .\"
63 .\" For nroff, turn off justification. Always turn off hyphenation; it makes
64 .\" way too many mistakes in technical documents.
65 .hy 0
66 .if n .na
67 .\"
68 .\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
69 .\" Fear. Run. Save yourself. No user-serviceable parts.
70 . \" fudge factors for nroff and troff
71 .if n \{\
72 . ds #H 0
73 . ds #V .8m
74 . ds #F .3m
75 . ds #[ \f1
76 . ds #] \fP
77 .\}
78 .if t \{\
79 . ds #H ((1u-(\\\\n(.fu%2u))*.13m)
80 . ds #V .6m
81 . ds #F 0
82 . ds #[ \&
83 . ds #] \&
84 .\}
85 . \" simple accents for nroff and troff
86 .if n \{\
87 . ds ' \&
88 . ds ` \&
89 . ds ^ \&
90 . ds , \&
91 . ds ~ ~
92 . ds /
93 .\}
94 .if t \{\
95 . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
96 . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
97 . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
98 . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
99 . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
100 . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
101 .\}
102 . \" troff and (daisy-wheel) nroff accents
103 .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
104 .ds 8 \h'\*(#H'\(*b\h'-\*(#H'
105 .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
106 .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
107 .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
108 .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
109 .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
110 .ds ae a\h'-(\w'a'u*4/10)'e
111 .ds Ae A\h'-(\w'A'u*4/10)'E
112 . \" corrections for vroff
113 .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
114 .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
115 . \" for low resolution devices (crt and lpr)
116 .if \n(.H>23 .if \n(.V>19 \
117 \{\
118 . ds : e
119 . ds 8 ss
120 . ds o a
121 . ds d- d\h'-1'\(ga
122 . ds D- D\h'-1'\(hy
123 . ds th \o'bp'
124 . ds Th \o'LP'
125 . ds ae ae
126 . ds Ae AE
127 .\}
128 .rm #[ #] #H #V #F C
129 .\" ========================================================================
130 .\"
131 .IX Title "GVPE 5"
132 .TH GVPE 5 "2005-01-27" "1.7" "GNU Virtual Private Ethernet"
133 .SH "NAME"
134 GNU\-VPE \- Overview of the GNU Virtual Private Ethernet suite.
135 .SH "DESCRIPTION"
136 .IX Header "DESCRIPTION"
137 \&\s-1GVPE\s0 is a suite designed to provide a virtual private network for multiple
138 nodes over an untrusted network.
139 .IP "\(bu" 4
140 .IX Xref "Virtual"
141 Virtual means that no physical network is created (of course), but an
142 ethernet is emulated by creating multiple tunnels between the member
143 nodes.
144 .IP "\(bu" 4
145 .IX Xref "Private"
146 Private means that non-participating nodes cannot decode (\*(L"sniff)\*(R" nor
147 inject (\*(L"spoof\*(R") packets.
148 .Sp
149 In the case of gvpe, even participating nodes cannot sniff packets send to
150 other nodes or spoof packets as if sent from other nodes.
151 .IP "\(bu" 4
152 .IX Xref "Network"
153 Network means that more than two parties can participate in the network,
154 so for instance it's possible to connect multiple branches of a company
155 into a single network. Many so-called \*(L"vpn\*(R" solutions only create
156 point-to-point tunnels.
157 .Sh "\s-1DESIGN\s0 \s-1GOALS\s0"
158 .IX Subsection "DESIGN GOALS"
159 .IP "\s-1SIMPLE\s0 \s-1DESIGN\s0" 4
160 .IX Item "SIMPLE DESIGN"
161 Cipher, \s-1HMAC\s0 algorithms and other key parameters must be selected
162 at compile time \- this makes it possible to only link in algorithms
163 you actually need. It also makes the crypto part of the source very
164 transparent and easy to inspect.
165 .IP "\s-1EASY\s0 \s-1TO\s0 \s-1SETUP\s0" 4
166 .IX Item "EASY TO SETUP"
167 A few lines of config (the config file is shared unmodified between all
168 hosts) and a single run of \f(CW\*(C`gvpectrl\*(C'\fR to generate the keys suffices to
169 make it work.
170 .IP "MAC-BASED \s-1SECURITY\s0" 4
171 .IX Item "MAC-BASED SECURITY"
172 Since every host has it's own private key, other hosts cannot spoof
173 traffic from this host. That makes it possible to filter packet by \s-1MAC\s0
174 address, e.g. to ensure that packets from a specific \s-1IP\s0 address come, in
175 fact, from a specific host that is associated with that \s-1IP\s0 and not from
176 another host.
177 .SH "PROGRAMS"
178 .IX Header "PROGRAMS"
179 Vpe comes with two programs: one daemon (\f(CW\*(C`gvpe\*(C'\fR) and one control program
180 (\f(CW\*(C`gvpectrl\*(C'\fR).
181 .IP "gvpectrl" 4
182 .IX Item "gvpectrl"
183 Is used to generate the keys, check and give an overview of of the
184 configuration and contorl the daemon (restarting etc.).
185 .IP "gvpe" 4
186 .IX Item "gvpe"
187 Is the daemon used to establish and maintain connections to the other
188 network members. It should be run on the gateway machine.
189 .SH "COMPILETIME CONFIGURATION"
190 .IX Header "COMPILETIME CONFIGURATION"
191 Please have a look at the \f(CW\*(C`gvpe.osdep(5)\*(C'\fR manpage for platform-specific
192 information.
193 .PP
194 Here are a few recipes for compiling your gvpe:
195 .Sh "\s-1AS\s0 \s-1LOW\s0 \s-1PACKET\s0 \s-1OVERHEAD\s0 \s-1AS\s0 \s-1POSSIBLE\s0"
196 .IX Subsection "AS LOW PACKET OVERHEAD AS POSSIBLE"
197 .Vb 1
198 \& ./configure --enable-hmac-length=4 --enable-rand-length=0
199 .Ve
200 .PP
201 Minimize the header overhead of \s-1VPN\s0 packets (the above will result in only
202 4 bytes of overhead over the raw ethernet frame).
203 .Sh "\s-1MINIMIZE\s0 \s-1CPU\s0 \s-1TIME\s0 \s-1REQUIRED\s0"
204 .IX Subsection "MINIMIZE CPU TIME REQUIRED"
205 .Vb 1
206 \& ./configure --enable-cipher=bf --enable-digest=md4
207 .Ve
208 .PP
209 Use the fastest cipher and digest algorithms currently available in gvpe.
210 .Sh "\s-1MAXIMIZE\s0 \s-1SECURITY\s0"
211 .IX Subsection "MAXIMIZE SECURITY"
212 .Vb 1
213 \& ./configure --enable-hmac-length=16 --enable-rand-length=8 --enable-digest=sha1
214 .Ve
215 .PP
216 This uses a 16 byte \s-1HMAC\s0 checksum to authenticate packets (I guess 8\-12
217 would also be pretty secure ;) and will additionally prefix each packet
218 with 8 bytes of random data. In the long run, people should move to
219 \&\s-1SHA\-224\s0 and beyond, but support in openssl is missing as of writing this
220 document.
221 .PP
222 In general, remember that \s-1AES\-128\s0 seems to be more secure and faster than
223 \&\s-1AES\-192\s0 or \s-1AES\-256\s0, more randomness helps against sniffing and a longer
224 \&\s-1HMAC\s0 helps against spoofing. \s-1MD4\s0 is a fast digest, \s-1SHA1\s0 or \s-1RIPEMD160\s0 are
225 better, and Blowfish is a fast cipher (and also quite secure).
226 .SH "HOW TO SET UP A SIMPLE VPN"
227 .IX Header "HOW TO SET UP A SIMPLE VPN"
228 In this section I will describe how to get a simple \s-1VPN\s0 consisting of
229 three hosts up and running.
230 .Sh "\s-1STEP\s0 1: configuration"
231 .IX Subsection "STEP 1: configuration"
232 First you have to create a daemon configuation file and put it into the
233 configuration directory. This is usually \f(CW\*(C`/etc/gvpe\*(C'\fR, depending on how you
234 configured gvpe, and can be overwritten using the \f(CW\*(C`\-c\*(C'\fR commandline switch.
235 .PP
236 Put the following lines into \f(CW\*(C`/etc/gvpe/gvpe.conf\*(C'\fR:
237 .PP
238 .Vb 3
239 \& udp-port = 50000 # the external port to listen on (configure your firewall)
240 \& mtu = 1400 # minimum MTU of all outgoing interfaces on all hosts
241 \& ifname = vpn0 # the local network device name
242 .Ve
243 .PP
244 .Vb 2
245 \& node = first # just a nickname
246 \& hostname = first.example.net # the DNS name or IP address of the host
247 .Ve
248 .PP
249 .Vb 2
250 \& node = second
251 \& hostname = 133.55.82.9
252 .Ve
253 .PP
254 .Vb 2
255 \& node = third
256 \& hostname = third.example.net
257 .Ve
258 .PP
259 The only other file neccessary if the \f(CW\*(C`if\-up\*(C'\fR script that initializes the
260 local ethernet interface. Put the following lines into \f(CW\*(C`/etc/gvpe/if\-up\*(C'\fR
261 and make it execute (\f(CW\*(C`chmod 755 /etc/gvpe/if\-up\*(C'\fR):
262 .PP
263 .Vb 6
264 \& #!/bin/sh
265 \& ip link set $IFNAME address $MAC mtu $MTU up
266 \& [ $NODENAME = first ] && ip addr add 10.0.1.1 dev $IFNAME
267 \& [ $NODENAME = second ] && ip addr add 10.0.2.1 dev $IFNAME
268 \& [ $NODENAME = third ] && ip addr add 10.0.3.1 dev $IFNAME
269 \& ip route add 10.0.0.0/16 dev $IFNAME
270 .Ve
271 .PP
272 This script will give each node a different \s-1IP\s0 address in the \f(CW\*(C`10.0/16\*(C'\fR
273 network. The internal network (e.g. the \f(CW\*(C`eth0\*(C'\fR interface) should then be
274 set to a subset of that network, e.g. \f(CW\*(C`10.0.1.0/24\*(C'\fR on node \f(CW\*(C`first\*(C'\fR,
275 \&\f(CW\*(C`10.0.2.0/24\*(C'\fR on node \f(CW\*(C`second\*(C'\fR, and so on.
276 .PP
277 By enabling routing on the gateway host that runs \f(CW\*(C`gvpe\*(C'\fR all nodes will
278 be able to reach the other nodes. You can, of course, also use proxy arp
279 or other means of pseudo-bridging (or even real briding), or (best) full
280 routing \- the choice is yours.
281 .Sh "\s-1STEP\s0 2: create the \s-1RSA\s0 key pairs for all hosts"
282 .IX Subsection "STEP 2: create the RSA key pairs for all hosts"
283 Run the following command to generate all key pairs (that might take a
284 while):
285 .PP
286 .Vb 1
287 \& gvpectrl -c /etc/gvpe -g
288 .Ve
289 .PP
290 This command will put the public keys into \f(CW\*(C`/etc/gvpe/pubkeys/\f(CInodename\f(CW\*(C'\fR and the private keys into \f(CW\*(C`/etc/gvpe/hostkeys/\f(CInodename\f(CW\*(C'\fR.
291 .Sh "\s-1STEP\s0 3: distribute the config files to all nodes"
292 .IX Subsection "STEP 3: distribute the config files to all nodes"
293 Now distribute the config files to the other nodes. This should be done in two steps, since the
294 private keys should not be distributed. The example uses rsync-over-ssh
295 .PP
296 First all the config files without the hostkeys should be distributed:
297 .PP
298 .Vb 3
299 \& rsync -avzessh /etc/gvpe first.example.net:/etc/. --exclude hostkeys
300 \& rsync -avzessh /etc/gvpe 133.55.82.9:/etc/. --exclude hostkeys
301 \& rsync -avzessh /etc/gvpe third.example.net:/etc/. --exclude hostkeys
302 .Ve
303 .PP
304 Then the hostkeys should be copied:
305 .PP
306 .Vb 3
307 \& rsync -avzessh /etc/gvpe/hostkeys/first first.example.net:/etc/hostkey
308 \& rsync -avzessh /etc/gvpe/hostkeys/second 133.55.82.9:/etc/hostkey
309 \& rsync -avzessh /etc/gvpe/hostkeys/third third.example.net:/etc/hostkey
310 .Ve
311 .PP
312 You should now check the configration by issuing the command \f(CW\*(C`gvpectrl \-c
313 /etc/gvpe \-s\*(C'\fR on each node and verify it's output.
314 .Sh "\s-1STEP\s0 4: starting gvpe"
315 .IX Subsection "STEP 4: starting gvpe"
316 You should then start gvpe on each node by issuing a command like:
317 .PP
318 .Vb 1
319 \& gvpe -D -linfo first # first is the nodename
320 .Ve
321 .PP
322 This will make the gvpe stay in foreground. You should then see
323 \&\*(L"connection established\*(R" messages. If you don't see them check your
324 firewall and routing (use tcpdump ;).
325 .PP
326 If this works you should check your networking setup by pinging various
327 endpoints.
328 .PP
329 To make gvpe run more permanently you can either run it as a daemon
330 (by starting it without the \f(CW\*(C`\-D\*(C'\fR switch), or, much better, from your
331 inittab. I use a line like this on my systems:
332 .PP
333 .Vb 1
334 \& t1:2345:respawn:/opt/gvpe/sbin/gvpe -D -L first >/dev/null 2>&1
335 .Ve
336 .Sh "\s-1STEP\s0 5: enjoy"
337 .IX Subsection "STEP 5: enjoy"
338 \&... and play around. Sending a \-HUP (\f(CW\*(C`gvpectrl \-kHUP\*(C'\fR) to the daemon
339 will make it try to connect to all other nodes again. If you run it from
340 inittab, as is recommended, \f(CW\*(C`gvpectrl \-k\*(C'\fR (or simply \f(CW\*(C`killall gvpe\*(C'\fR) will
341 kill the daemon, start it again, making it read it's configuration files
342 again.
343 .SH "SEE ALSO"
344 .IX Header "SEE ALSO"
345 \&\fIgvpe.osdep\fR\|(5) for OS-depedendent information, \fIgvpe.conf\fR\|(5), \fIgvpectrl\fR\|(8), and
346 for a description of the protocol and routing algorithms, \fIgvpe.protocol\fR\|(7).
347 .SH "AUTHOR"
348 .IX Header "AUTHOR"
349 Marc Lehmann <gvpe@plan9.de>
350 .SH "COPYRIGHTS AND LICENSES"
351 .IX Header "COPYRIGHTS AND LICENSES"
352 \&\s-1GVPE\s0 itself is distributed under the \s-1GENERAL\s0 \s-1PUBLIC\s0 \s-1LICENSE\s0 (see the file
353 \&\s-1COPYING\s0 that should be part of your distribution).
354 .PP
355 In some configurations it uses modified versions of the tinc vpn suite,
356 which is also available under the \s-1GENERAL\s0 \s-1PUBLIC\s0 \s-1LICENSE\s0.