1 SILC - Secure Internet Live Conferencing
2 ========================================
4 [NOTE: SILC is still in middle of development and this package is known
5 as Developer's Version which means that the package is in no means stable
6 or ready to be in production use. This package is for those who wants
7 to test SILC, find bugs and maybe contribute some time and code for the
8 SILC project. There is no guarantees that this package even compiles and
9 even if it compiles there is no guarantees that it would work, and even
10 if it works there is no guarantees that it would work correctly, and even
11 if it seems to work correctly it may be just plain luck.]
17 SILC (Secure Internet Live Conferencing) is a protocol which provides
18 secure conferencing services in the Internet over insecure channel.
19 SILC is IRC like softwarre although internally they are very different.
20 Biggest similarity between SILC and IRC is that they both provide
21 conferencing services and that SILC has almost same commands as IRC. Other
22 than that they are nothing alike. Biggest differences are that SILC is
23 secure what IRC is not in any way. The network model is also entirely
24 different compared to IRC.
30 The development version is still preliminary version and requires some
31 work to get it working. You should, first of all, check the example
32 configuration files in ./doc/ directory. Change them according to your
38 ./silc -f <config file>
43 ./silcd -f <config file>
49 Following commands has been, at least partly, implemented:
52 /SERVER [<server>[:<port>]]
54 Connects to remote SILC server.
58 Changes/sets nickname. Note that in SILC there can be
59 multiple same nicknames. However, the logic on working
60 with multiple nicknames on user interface is pretty much
61 still missing. Also note that nicknames in SILC are
66 Joins to a channel. Channel names start with `#'
71 Leaves the channel. If /leave * is given the client
72 leaves the current channel.
74 /MSG <nickname> <message>
76 Sends private message to remote client. Support for
77 handling multiple same nicknames with /MSG command is
80 /WHOIS <nickname>[@<server>] [<count>]
82 Gives a little information about a client. Support for
83 handling multiple same nicknames with this command is
88 Pings server. Only locally connected server may be
93 Requests information about a server. If argument is
94 not specified current server is used.
98 Sets away message. When private message is received and
99 away message is set the client automatically replies to
100 the sender with the away message. To remove away message
101 give the command without arguments.
105 Quits session. Connection to remote server is closed.
109 Clears current screen.
113 Shows client version.
119 Features to be included into the final release of SILC. [Note that the
120 current Developer's Version does not include all of these features, read
121 TODO file for more information.]
123 o Normal conferencing services such as private messages, channels,
124 channel messages, etc. All traffic is secured and authenticated.
126 o No unique nicknames. There can same nicknames in SILC without
127 collisions. SILC has unique Client ID's, Server ID's and Channel ID's
128 to assure that there are no collisions.
130 o Secure key exchange and authentication protocol. SILC Key Exchange
131 protocol provides key material used in the SILC sessions in secure
132 manner. The protocol is immune for example to man-in-the-middle
133 attacks. The SILC Authentication protocol provides strong
134 authentication. Authentication may be based on passphrase or public
135 key (RSA) authentication. For clients there is an option not to
136 use authentication when connecting to servers.
138 o All traffic is encrypted and authenticated using the best cryptographic
139 algorithms out there. Command messages, private messages and channel
140 messages are all protected by encryption. User can set private keys
141 for both private message and for channels so that even SILC servers do
142 not know the keys. Cipher keys are, by default, 128 bits in length and
143 public keys, by default, 1024 bits in length.
145 o Supports data compression with GZIP to improve performance.
147 o Supports SOCKS4 and SOCKS5 firewall traversal protocols.
149 o SIM (SILC Module) support. Support for loading of shared objects at
150 run-time that provides new and extended features to both SILC client
151 and server. These can provide extra ciphers and extra features to
154 o SILC client can be installed and used without root privileges.
156 o SILC client can be configured by system wide configuration files but
157 with user specific configuration files as well.
163 Even though SILC were just released to the public the idea and the protocol
164 itself is quite old. I got the idea about SILC in its current form in
165 the year 1996 and first lines of codes were written in early 1997. This
166 release is now third rewrite of the SILC. The very first version were
167 written in 1997 and it included SILC client and very very preliminary
168 SILC server. The server actually weren't usable but the client looked
169 pretty much the same as it does now. At that time the SILC also included
170 RSA implementation and 3DES implementation. The random number generator
171 that exists in this current release is actually based on the RNG written
172 in 1997. The RNG written in 1997, on the other hand, were based on
173 the SSH's random number generator. The RNG has been rewritten twice
174 since the first version.
176 I stopped writing the SILC later in 1997 when I got busy at school and
177 in work. The pause lasted several months. The development resumed in
178 1998 when my friend (Juha Räsänen) and I implemented ElGamal algorithm.
179 I rewrote some other parts as well. However, for the same reasons as
180 previously the development stopped again. I resumed the development
181 later in 1998 by doing rewrite of the SILC in C++. This was obviously
182 a mistake but at that time it seemed like a good idea. Again, in the
183 winter 1999 I got very busy writing my thesis and was forced to stop the
184 development again. I also, started a new job in the spring.
186 Later, in 1999, I decided that this time I'm going to make it the right
187 way. C++ was obviously a bad choice so I decided to fall back to plain
188 C language. I also decided to do complete rewrite and started doing
189 more thorough planning of what the SILC actually should include. I also
190 decided that this time it is going to kill me before I stop the
191 development. I started writing SILC in the weekends and actually
192 everytime I had some spare time. I also started a new job but I didn't
193 let that get to my way. The result of this development effort is the
194 release now in public.
196 I've learned a lot by doing the SILC. I guess, when I started it I wasn't
197 that good of a C programmer. That alone was a reason why SILC hasn't
198 seen the day of light before now. My programming style has also changed
199 dramatically during these years. Actually, it has changed couple times
200 since this last rewrite as well. However, the code style of current SILC
201 release is quite consistent (actually the coding style SILC has been
202 written now I've learned in my current job).
204 There is probably over 85% of new code in this third rewrite. Rest has
205 just been copied from the old versions and only minor changes has been
206 made (like changed function names and overall coding style). I've
207 preserved the dates of the old files (dating back to 1997) that has
208 existed in some forms in the old versions. There is a lot of new code but
209 already I see a lot that needs rewriting. The development continues.
215 Feedback and comments are welcome. You can reach me in the following
218 [Note that generally bug reports should not be sent just yet as the
219 Developer's Version is full of them and the bug hunt has not even started
222 Pekka Riikonen <priikone@poseidon.pspt.fi>