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 /CMODE <channel> +|-<modes> [{ <arguments>}]
76 Changes/sets channel mode. Most of the modes require
77 special privileges, such as channel operator or channel
78 founder privileges to work. The mode is added by adding
79 + before the option(s) and removed by adding - before
80 the option(s). Following modes are available:
82 p Set/unset channel as private channel
83 s Set/unset channel as secret channel
84 k Set/unset that channel uses private channel key
85 i Set/unset channel as invite only channel
86 t Set/unset that only channel operator or
87 founder may set channel topic
88 l <limit> Set/unset channel's user limit
89 a <passphrase> Set/unset passphrase for channel that must
90 be provided when joining to the channel.
91 b <username!nickname@server>
92 Add client to/remove client from ban list
93 I <username!nickname@server>
94 Add client to/remove client from invite list
96 Set/unset channel's cipher
98 Multiple modes can be set/unset at once if the modes does not
99 require any arguments. If mode requires an argument then only
100 one mode can be set at once.
102 /CUMODE <channel> +|-<modes> <nickname>[@<server>]
104 Changes/set user's mode on a channel. Most of the modes
105 require that the client who changes some client's mode must
106 be channel founder or channel operator. Following channel
107 user modes are available:
109 a <nickname>[@<server>]
110 Set/unset all modes (cannot be used to set
111 both founder and operator rights, can be used
112 only to remove both modes at once).
113 f <nickname>[@<server>]
114 Unset channel founder. Channel founder rights
115 cannot be set by user (only by server) so this
116 can be used only to unset the mode.
117 o <nickname>[@<server>]
118 Set/unset channel operator. Requires that
119 you are channel operator or channel founder.
121 /MSG <nickname> <message>
123 Sends private message to remote client. Support for
124 handling multiple same nicknames with /MSG command is
127 /WHOIS <nickname>[@<server>] [<count>]
129 Gives a little information about a client. Support for
130 handling multiple same nicknames with this command is
135 Pings server. Only locally connected server may be
140 Requests information about a server. If argument is
141 not specified current server is used.
145 Sets away message. When private message is received and
146 away message is set the client automatically replies to
147 the sender with the away message. To remove away message
148 give the command without arguments.
152 Quits session. Connection to remote server is closed.
156 Clears current screen.
160 Shows client version.
166 Features to be included into the final release of SILC. [Note that the
167 current Developer's Version does not include all of these features, read
168 TODO file for more information.]
170 o Normal conferencing services such as private messages, channels,
171 channel messages, etc. All traffic is secured and authenticated.
173 o No unique nicknames. There can same nicknames in SILC without
174 collisions. SILC has unique Client ID's, Server ID's and Channel ID's
175 to assure that there are no collisions.
177 o Secure key exchange and authentication protocol. SILC Key Exchange
178 protocol provides key material used in the SILC sessions in secure
179 manner. The protocol is immune for example to man-in-the-middle
180 attacks. The SILC Authentication protocol provides strong
181 authentication. Authentication may be based on passphrase or public
182 key (RSA) authentication. For clients there is an option not to
183 use authentication when connecting to servers.
185 o All traffic is encrypted and authenticated using the best cryptographic
186 algorithms out there. Command messages, private messages and channel
187 messages are all protected by encryption. User can set private keys
188 for both private message and for channels so that even SILC servers do
189 not know the keys. Cipher keys are, by default, 128 bits in length and
190 public keys, by default, 1024 bits in length.
192 o Supports data compression with GZIP to improve performance.
194 o Supports SOCKS4 and SOCKS5 firewall traversal protocols.
196 o SIM (SILC Module) support. Support for loading of shared objects at
197 run-time that provides new and extended features to both SILC client
198 and server. These can provide extra ciphers and extra features to
201 o SILC client can be installed and used without root privileges.
203 o SILC client can be configured by system wide configuration files but
204 with user specific configuration files as well.
210 Even though SILC were just released to the public the idea and the protocol
211 itself is quite old. I got the idea about SILC in its current form in
212 the year 1996 and first lines of codes were written in early 1997. This
213 release is now third rewrite of the SILC. The very first version were
214 written in 1997 and it included SILC client and very very preliminary
215 SILC server. The server actually weren't usable but the client looked
216 pretty much the same as it does now. At that time the SILC also included
217 RSA implementation and 3DES implementation. The random number generator
218 that exists in this current release is actually based on the RNG written
219 in 1997. The RNG written in 1997, on the other hand, were based on
220 the SSH's random number generator. The RNG has been rewritten twice
221 since the first version.
223 I stopped writing the SILC later in 1997 when I got busy at school and
224 in work. The pause lasted several months. The development resumed in
225 1998 when my friend (Juha Räsänen) and I implemented ElGamal algorithm.
226 I rewrote some other parts as well. However, for the same reasons as
227 previously the development stopped again. I resumed the development
228 later in 1998 by doing rewrite of the SILC in C++. This was obviously
229 a mistake but at that time it seemed like a good idea. Again, in the
230 winter 1999 I got very busy writing my thesis and was forced to stop the
231 development again. I also, started a new job in the spring.
233 Later, in 1999, I decided that this time I'm going to make it the right
234 way. C++ was obviously a bad choice so I decided to fall back to plain
235 C language. I also decided to do complete rewrite and started doing
236 more thorough planning of what the SILC actually should include. I also
237 decided that this time it is going to kill me before I stop the
238 development. I started writing SILC in the weekends and actually
239 everytime I had some spare time. I also started a new job but I didn't
240 let that get to my way. The result of this development effort is the
241 release now in public.
243 I've learned a lot by doing the SILC. I guess, when I started it I wasn't
244 that good of a C programmer. That alone was a reason why SILC hasn't
245 seen the day of light before now. My programming style has also changed
246 dramatically during these years. Actually, it has changed couple times
247 since this last rewrite as well. However, the code style of current SILC
248 release is quite consistent (actually the coding style SILC has been
249 written now I've learned in my current job).
251 There is probably over 85% of new code in this third rewrite. Rest has
252 just been copied from the old versions and only minor changes has been
253 made (like changed function names and overall coding style). I've
254 preserved the dates of the old files (dating back to 1997) that has
255 existed in some forms in the old versions. There is a lot of new code but
256 already I see a lot that needs rewriting. The development continues.
262 Feedback and comments are welcome. You can reach me in the following
265 Official SILC project web site is : http://silc.pspt.fi
266 FTP archive for SILC project is : ftp://silc.pspt.fi/pub/silc/
267 Development mailing list address is : silc-devel@lists.sourceforge.net
269 Pekka Riikonen <priikone@poseidon.pspt.fi>