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 [Latest Note: The protocol has changed a bit in some parts which causes that the current implementation violates some requirements. These are not listed here, currently.] 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 Public and private key generation is now done everytime the program is run. Now, this is only for testing period as I've been lazy to do it any better for now. This must be fixed. 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 loading from global and from local dirs. This is currently missing and I guess the global is only used. Old SILC version (in 1997) had ~./silc directory that I guess should be done now as well. The code for handling those exists but not in current source tree. 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. Also, return values from various allocations and functions needs to checked. 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 Lenght 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 Public and private key generation is now done everytime the program is run. Now, this is only for testing period as I've been lazy to do it any better for now. This must be fixed. 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 lagging must implemented. Those commands (all currently) that has the LAG flag set they must not be allowed to be executed more than once, say, in 2 seconds. 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 Channel message sending routines uses a lot of common code. Should create a common function for those instead of writing the same code again everytime, as done now. 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. Also, return values from various allocations and functions needs to checked. TODO In SILC Libraries ====================== o Public key verification in SKE (SILC Key Exchange) protocol is missing, thus currently we trust on all public keys. This probably doesn't cause bad problems but the mechanism of verifying it from local database (from files) needs to be done (it can open man-in-the-middle-attacks). 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 SILC public key file type is bad. I'd like to see PEM encoded files. I have public domain code for base64 encoding but it needs to be rewritten. 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 Scheduler should automatically allocate task queues if NULL pointers are passed to the silc_schedule_init. Would make initialization cleaner. 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__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 I don't like the ID cache system currenly implemented. Ugly and not so good. Must be rewritten very soon. o All allocations and freeing needs to be checked for memory leaks. o There are also checks missing from allocations whether the allocation returns valid memory or NULL. These are missing in library as well in client and server. Either all checks has to be added or we will have to make sure that silc_*alloc()s always return valid memory and assert()s if the system's memory allocator (*alloc()) fails. 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.