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3 | GNU-VPE - Overview of the GNU Virtual Private Ethernet suite. |
3 | GNU-VPE - Overview of the GNU Virtual Private Ethernet suite. |
4 | |
4 | |
5 | =head1 DESCRIPTION |
5 | =head1 DESCRIPTION |
6 | |
6 | |
7 | GVPE is a suite designed to provide a virtual private network for multiple |
7 | GVPE is a suite designed to provide a virtual private network for multiple |
8 | nodes over an untrusted network. |
8 | nodes over an untrusted network. This document first gives an introduction |
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9 | to VPNs in general and then describes the specific implementation of GVPE. |
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10 | |
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11 | =head2 WHAT IS A VPN? |
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12 | |
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13 | VPN is an acronym, it stands for: |
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14 | |
10 | =over 4 |
15 | =over 4 |
11 | |
16 | |
12 | =item X<Virtual> |
17 | =item X<Virtual> |
13 | |
18 | |
14 | Virtual means that no physical network is created (of course), but an |
19 | Virtual means that no physical network is created (of course), but a |
15 | ethernet is emulated by creating multiple tunnels between the member |
20 | network is I<emulated> by creating multiple tunnels between the member |
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21 | nodes by encapsulating and sending data over another transport network. |
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22 | |
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23 | Usually the emulated network is a normal IP or Ethernet, and the transport |
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24 | network is the Internet. However, using a VPN system like GVPE to connect |
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25 | nodes over other untrusted networks such as Wireless LAN is not uncommon. |
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26 | |
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27 | =item X<Private> |
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28 | |
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29 | Private means that non-participating nodes cannot decode ("sniff)" nor |
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30 | inject ("spoof") packets. This means that nodes can be connected over |
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31 | untrusted networks such as the public Internet without fear of being |
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32 | eavesdropped while at the same time being able to trust data sent by other |
16 | nodes. |
33 | nodes. |
17 | |
34 | |
18 | =item X<Private> |
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19 | |
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20 | Private means that non-participating nodes cannot decode ("sniff)" nor |
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21 | inject ("spoof") packets. |
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22 | |
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23 | In the case of gvpe, even participating nodes cannot sniff packets send to |
35 | In the case of GVPE, even participating nodes cannot sniff packets |
24 | other nodes or spoof packets as if sent from other nodes. |
36 | send to other nodes or spoof packets as if sent from other nodes, so |
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37 | communications between any two nodes is private to those two nodes. |
25 | |
38 | |
26 | =item X<Network> |
39 | =item X<Network> |
27 | |
40 | |
28 | Network means that more than two parties can participate in the network, |
41 | Network means that more than two parties can participate in the network, |
29 | so for instance it's possible to connect multiple branches of a company |
42 | so for instance it's possible to connect multiple branches of a company |
30 | into a single network. Many so-called "vpn" solutions only create |
43 | into a single network. Many so-called "vpn" solutions only create |
31 | point-to-point tunnels. |
44 | point-to-point tunnels, which in turn can be used to build larger |
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45 | networks. |
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46 | |
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47 | GVPE provides a true multi-point network in wich any number of nodes (at |
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48 | least a few dozen in practise, the theoretical limit is 4095 nodes) can |
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49 | participate. |
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50 | |
33 | =back |
51 | =back |
34 | |
52 | |
35 | =head2 DESIGN GOALS |
53 | =head2 GVPE DESIGN GOALS |
36 | |
54 | |
37 | =over 4 |
55 | =over 4 |
38 | |
56 | |
39 | =item SIMPLE DESIGN |
57 | =item SIMPLE DESIGN |
40 | |
58 | |
41 | Cipher, HMAC algorithms and other key parameters must be selected |
59 | Cipher, HMAC algorithms and other key parameters must be selected |
42 | at compile time - this makes it possible to only link in algorithms |
60 | at compile time - this makes it possible to only link in algorithms |
43 | you actually need. It also makes the crypto part of the source very |
61 | you actually need. It also makes the crypto part of the source very |
44 | transparent and easy to inspect. |
62 | transparent and easy to inspect, and last not least this makes it possible |
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63 | to hardcode the layout of all packets into the binary. GVPE goes a step |
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64 | further and internally reserves blocks of the same length for all packets, |
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65 | which virtually removes all possibilities of buffer overflows, as there is |
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66 | only a single type of buffer and it's always of fixed length. |
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67 | |
46 | =item EASY TO SETUP |
68 | =item EASY TO SETUP |
47 | |
69 | |
48 | A few lines of config (the config file is shared unmodified between all |
70 | A few lines of config (the config file is shared unmodified between all |
49 | hosts) and a single run of C<gvpectrl> to generate the keys suffices to |
71 | hosts) and a single run of C<gvpectrl> to generate the keys suffices to |
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223 | kill the daemon, start it again, making it read it's configuration files |
245 | kill the daemon, start it again, making it read it's configuration files |
224 | again. |
246 | again. |
225 | |
247 | |
226 | =head1 SEE ALSO |
248 | =head1 SEE ALSO |
227 | |
249 | |
228 | gvpe.osdep(5) for OS-depedendent information, gvpe.conf(5), gvpectrl(8), and |
250 | gvpe.osdep(5) for OS-depedendent information, gvpe.conf(5), gvpectrl(8), |
229 | for a description of the protocol and routing algorithms, gvpe.protocol(7). |
251 | and for a description of the transports, protocol, and routing algorithm, |
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252 | gvpe.protocol(7). |
230 | |
253 | |
231 | =head1 AUTHOR |
254 | =head1 AUTHOR |
232 | |
255 | |
233 | Marc Lehmann <gvpe@plan9.de> |
256 | Marc Lehmann <gvpe@plan9.de> |
234 | |
257 | |