[silc.git] / TODO

TODO
====

This is more or less complete list of tasks that has to be done before
SILC 1.0 could ever be released.  It is clear that the list does not
include all the bugs that exists.  At the end of list are tasks that 
needs to be done but are probably post 1.0.

Feel free to contribute if you have the ability and free time - all the
help is really appreciated - and needed.

                                                        - Pekka


New features TODO
=================

 o Extended SIM (SILC Module) support.  Currently only SILC Cipher API
   and SILC Hash API may be used as SIM's.  What I have in mind is to
   have extended support for SIM's so that basically any SILC API could
   be used as SIM's.  This would open tremendous possiblities but
   opens also issues on security that needs to be dealt with.

   Some sort of SIM compilation environment should be defined so that
   the SIM's could use SILC specific symbols from the modules (which they
   cannot do currently).  In the future modules could add new features
   to SILC easily with this support.  I'm more thinking this from client's
   perspective to add new features to client (such as IRC support as SIM)
   but server should have the support as well.  Anyhow, this is an 
   interesting feature...

   This maybe post 1.0 task - dunno.

 o SIM support for other platforms than just for Linux.  Apache has
   example code (code that we could use directly pretty easily) for
   other platforms.

 o We should replace all short, int, long, unsigned short, unsigned int,
   unsigned long with some pre-defined datatypes that really are what
   we want on all platforms.  int16, uint16, int32, uint32 etc. are
   what we could use or maybe SilcInt16, SilcUInt16 etc.  Also, boolean
   datatype should be defined.

 o More platform supports should be added.  The code is pretty much
   generic but there are some parts that require porting (SIM).  Also, 
   some support for different platforms is needed into configure.in.

 o SILC requires currently GCC to work because we use GCC specific 
   compilation options.  Generally any compiler that supports inline
   functions and can build shared libraries (for SIMs) should work.  
   These cases should be included into configure.in.


TODO In SILC Client
===================

 o Implement all commands.  A lot of commands are still yet to be
   implemented.  Most of them are trivial but some will require some
   planning.  Go see the command.c for unimplemented commands.

 o Non-blocking connection on the background must be stopped if some
   other connection on same window has established.  Now it is possible
   that some non-blocking connection timeouts on the background when
   we already have a working connection to some other place; things
   goes bad.

 o Finish WHOIS, finish JOIN and other commands that are partly
   implemented.

 o Input line on UI is buggy.  Cursor movement etc bugs.  Too lazy to
   fix it.

 o Logic for handling multiple same nicknames for example in private
   message sending.  I guess the logic is done in server side but is
   missing from client.

 o Private message key setting is missing and must be implemented.
   Currently private messages are encrypted with session keys.  This
   is required by the protocol.

 o Channel private key setting is missing and must be implemented.
   Currently there cannot be private keys for channels.  Normal channel
   keys (generated by server) are used.  This is required by the protocol.

 o I guess, public key authentication (when connecting to a server)
   is not working currently.  It is just matter of loading the keys
   from file and using them (see corresponding code in server, it should
   support public key authentication already).

 o Multiple windows support.  Basic support for multiple windows already
   exists but a lot is still missing to get it working.  Also, some
   of the existing stuff probably needs to be tweaked a bit before the
   multiple windows support could be done.  And of course the actual
   commands that control the windows needs to be written (/WINDDOW).

 o Implement /KEYMAP (or similiar) command to remap control and function
   keys.

 o Implement /ALIAS command to make command aliases.

 o Implement /set/if/do/while etc as in IRC2.  Maybe post 1.0 task.
   Some scripting would be good.

 o Connection Authentication request resolving is missing and must be
   done.  This is required by the protocol.

 o Key Exchange protocol's responder side is missing from client.  
   Generally it is possible for the client to be responder so it should
   be implemented (See corresponding code from server).  Error handling
   in the KE protocol is also in pretty bad shape in client.

 o Configuration file format - could be better.

 o Write help files for commands.  Nice format for the help files should
   be selected.  I'm open for ideas.

 o All allocations and freeing needs to be checked for memory leaks.


TODO In SILC Server
===================

 o Implement all commands on server side.  A lot of commands are still yet
   to be implemented.  Most of them are trivial but some will require some
   planning.  Go see the command.c for unimplemented commands.

 o DNS/IP lookup blocks the server.  This must be fixed.  Check the
   resolver stuff (resolver(3), resolver(5)).  Either we have to do the
   own resolver stuff (through scheduler, if possible without writing
   too much own stuff) or use threads.

 o Length of the packet processing timeouts needs to be checked whether
   they are too short or too long.  I haven't really tested whether they
   are suitable.  They should be tested on high load which I haven't done
   at all yet.

 o INVITE command must set the channel's invite list if channel is 
   invite-only channel.

 o Server says that it is able to listen on multiple ports but currently
   that is bogus.  It can, but internals are for single server.

 o Command flag usage in general is not implemented yet.

 o Client history must be implemented.  Protocol says that server must
   keep history information about clients for some period of time.

 o Channel flags and user modes on channels are not implemented yet as
   /MODE command is not implemented yet in client and server.

 o Protocol execution timeouts are hard coded, should be configurable.

 o serverutil.c I guess should be created for util-like functions that
   now resides in server.c, which is getting too big.

 o serverconfig.c and the function naming in it is inconsistent.  It is 
   not silc_config_server* it should be silc_server_config*.  As should
   all the SilcConfigServer* types be SilcServerConfig*.

 o Implement DENY_CONNECTION section in serverconfig.c and in server.

 o Implement REDIRECT_CLIENT section in serverconfig.c and in server.

 o Configuration file format - could be better.

 o IP address fields in configuration file should accept mask format
   as well, IP/MASK, and not just plain IP.

 o Connection classes should be actually implemented in serverconfig.c.
   They can be defined but they are totally ignored currently.

 o Acceptance of incoming connections (client and server connections)
   should be checked before key exchange protocol.  Currently it is
   checked at the authentication phase after KE, that is ok, but it should
   be checked before starting KE, as well.

 o Statistics are totally missing from the server.  It would be nice
   to gather some statistics.

 o All allocations and freeing needs to be checked for memory leaks.


TODO In SILC Libraries
======================

 o Implement PFS (Perfect Forward Secrecy) flag in SKE (and in client and
   server, actually).  If PFS is set, re-key must cause new key exchange.
   This is required by the SILC protocol.

 o Re-key in general is actually missing (from everywhere) and must be done.

 o SKE does not send correct status types.  Types are defined but not
   sent.

 o Connection authentication protocol does not send correct status types.
   These types are not defined currently at all.

 o PKCS#1 style RSA public key encryption/decryption/sign/verify is 
   missing, and should be added for interoperability reasons.  The thing 
   I've done now is bad and should be removed as soon as possible (or 
   the protocol should then state the method of how they should be done).

 o Slow ciphers should be removed.  I think we don't need more than
   the AES finalists plus blowfish and RC5.

 o These slow ciphers actually don't work currently as I've tested
   only the ones that are worth testing.  The CBC mode on these slow
   ciphers probably don't work.  No need to worry, these ciphers should
   be removed.

 o Scheduler needs to be analyzed on high load as it might be unfair
   towards select() because it may run timeout tasks before select() and
   after select().  If it is found to be unfair the timeout task running
   before select() should probably be removed.

 o On select() issue; maybe we should use poll() instead if it is
   available? poll() doesn't have max fd limit...

 o SIM support for SILC PKCS API needs to made so that they could be
   used as SIM's.  At the same time some work is required on prime
   generation as the way it is done now sucks.  Read from code for
   more (silcpkcs.h).

 o Compression routines are missing.  The protocol supports packet
   compression thus it must be implemented.  SILC Comp API must be
   defined.  zlib package is already included into the lib dir (in CVS,
   not in distribution), but it is not used yet, and it requires some
   tweaking on the Makefiles (we want static lib not shared).

 o Cipher API needs to be made more consistent.  Some parts of the
   code generated with current Cipher API looks really bad.  Same
   is with PKCS API, even worse actually.  They need to be made
   cleaner.  Introducing silc_cipher_encrypt/decrypt/set_key etc.
   functions (I actually don't understand why have I left these un-done).

 o Packet processing routines in client and server are actually pretty
   much generic and should be moved from the client/server to the library
   as generic routines (silc_<client/server>_packet_decrypt_rest* etc).
   This requires heavy changes to the client and server.

 o Random Number Generator needs some tweaking.  Reading /dev/random may
   block resulting slow initialization of RNG.  Some other things in the
   RNG may block as well.  Also, I have some pending changes to the RNG 
   that needs to be commited (from Schneier's Yarrow-160 paper).  They 
   should make the RNG even better.

 o Logging should be made more generic in a way that application can
   set to where the logging is destined to.  Now, it is always destined
   to stdout (or stderr) which is a bad thing for client.  Ie. some
   sort of logging registration functions or similiar should be done
   (silclog.[ch] in core).  The actual output of logs should be done
   by callback function in the application not in lib.

 o All allocations and freeing needs to be checked for memory leaks.

 o silc_buffer_[un]format() needs to be made more stable as it may
   crash the SILC if malformed data is sent as argument.  There are a
   lot of places in client and server where we trust directly data coming
   from network and try to unformat it.  The unformatting routine needs
   to be able handle situations where data sent is malformed, by mistake
   or intentionally.  This is important as it is easy to crash the SILC
   now by just sending malformed data.  Also, in client and server we
   must start checking the return value from silc_buffer_[un]format.


Other Things TODO
=================

 o Write manuals for server.

 o Write manuals for client.

 o Write SILC Library Reference manual.  This would include all the SILC
   API's with simple examples how the functions are to be used.  This is
   pretty easy to create by taking all the functions plus their comments
   from source/header files.  However, same sort of reference manual 
   should be written for client and server as well.


TODO After 1.0
==============

 o Pthreads support.  A lot of problems are solved with server (and with
   client as well) if we add pthread support.  We can forget things such
   as non-blocking connecting etc, and we can do things such as DNS/IP
   lookups async.  The server itself also benefits great deal from 
   threads, especially from performance point of view.

   But, this is not a small task and almost entire SILC Library has to
   be made re-entrant.  Own API is probably added for the threads support
   to make changes in the future as painless as possible.  So the API 
   would have things like silc_mutex_lock, silc_mutex_unlock and 
   friends...

 o X.509 certificate support.  SILC protocol supports certificates and
   it would be great to have support for them.  This is a big task as
   support has to be made for ASN.1 as well.  I've looked into OpenSSL 
   package as it has X.509 certificate support (and ASN.1 as well).  
   The code does not look very good to my eye but it has some potentials.
   This should be looked at more closely.

   Naturally own SILC Certificate API has to be defined regardles what
   the actual X.509 library is (OpenSSL X.509 or something else).  Other
   choice is to write own X.509 library but I'm not going to do it - 
   I can help to migrate the OpenSSL X.509 into SILC and I can help if 
   someone would like to write the X.509 library - but I'm not going 
   to start writing one myself.  Anyhow, the OpenSSL X.509 lib should
   be checked.

 o SSH2 public keys support.  Maybe - not really needed but could be
   nice as SSH is widely used all over the place.  SILC Protocol 
   supports SSH2 public keys.

 o IRC support for SILC client.  This would be nice to have on client
   as it could be used to connect to SILC and IRC.  People wouldn't
   have to have two different clients when same would work on both.
   I'd like to see this done as SIM, after the extended SIM support
   has been added to SILC.

 o Cipher optimizations (asm, that this) at least for i386 would be nice.