TODO for 1.2 And Beyond
   =======================
   
   NOTE: Any item that doesn't have (***DONE) in it, isn't done yet.  The
   (***TESTING NEEDED) means that the item has been done but not yet properly
   tested.
   
   NOTE: A TODO entry does not mean that it is ever going to be done.  Some
   of the entries may be just ideas, good, bad or ugly.  If you want to work
  on some of the TODO entries simply let us know about it by dropping a note
  to silc-devel mailing list or appear on 'silc' channel on SILCNet.
  
  
  General
  =======
  
   o Create apps/tutorial containing various Toolkit API tutorials.
  
   o The Toolkit split.  The Toolkit is to be splitted in parts.  How many
     parts and what the parts are isn't decided yet.  Each part is a separate
     software package.  Current thinking is of the following:
  
     SILC Toolkit                 SILC protocol, client and server library
     SILC Runtime Toolkit         runtime library
     SILC Crypto Toolkit          crypto, asn1, math, skr, pgp, etc.
  
     The rationale for this is of course that other than SILC projects
     might like to use the various libraries SILC Toolkit provides, but
     naturally they don't want the bloat of SILC protocol related stuff.
  
     The Runtime library in SILC Toolkit is a general purpose runtime library,
     like Glib and APR are.  The runtime library is to be developed further
     to provide alternative to Glib and APR.
  
     The Crypto library in SILC Toolkit is a general purpose crypto library
     providing pretty nice APIs compared to many other crypto libraries,
     especially OpenSSL.  The Crypto library is to be developed further
     to include support for OpenPGP, X.509 and SSH2.
  
  
  lib/silccore
  ============
  
   o SILC_PACKET_FLAG_ACK support.  Implement ACK packet and packet payload
     to silcpacket.c.
  
   o All payload encoding routines should take SilcStack as argument.
  
   o Remove SilcCommandCb from silccommand.h.
  
   o All payload test routines into lib/silccore/tests/.
  
  
  lib/silcclient, The Client Library
  ==================================
  
   o UDP SILC connection support to SILC server
  
   o Giving WHOIS for nick that doesn't exist should remove any same
     named entries from the client cache.
  
   o peer-to-peer private messages
  
   o Private message key request notification to application.  See XXX in
     client_prvmsg.c.
  
   o in JOIN notify handle resolving that timedout.  Currently the user is
     never joined the channel if this happens.  What to do if message is
     received from user that hasn't been resolved/joined?
  
   o Add the SilcStream (socket stream) from the SilcPacketStream and
     SilcSocket from the socket stream to SilcClientConnection for easier
     access to them for programmers.  Currently these have to be digged up
     from the packet stream.
  
   o Connection option that attemps to connect to remot host with various
     different mechanisms: UDP 706, TCP 706, TCP 80, TCP 443, UDP 7706 and
     TCP 7706.  This is the so called hole punching mechanism.
  
   o Message ACKing support.
  
   o in /cmode and /cumode with +r, maybe the public key and private key
     could be just some "string", which would then match to "string.pub" and
     "string.prv".
  
   o If the SILC Events (see below) are implemented, perhaps client library
     should provide events so that application developer has a choice of
     developing the SILC app with callbacks or with events.
  
   o Ability to recover from rekey errors, at least try to.
  
  
  Runtime library, lib/silcutil/
  ==============================
  
   o silc_malloc et. al. to respect --with-alignment.
  
   o Fix universal time decoding (doesn't accept all formats) in silctime.c.
  
  o Additional scheduler changes: optimize silc_schedule_wakeup.  Wakeup
    only if the scheduler is actually waiting something.  If it is
    delivering tasks wakeup is not needed.
 
  o silc_stringprep to non-allocating version.
 
  o Add builtin SOCKS and HTTP Proxy support, well the SOCKS at least.
    SILC currently supports SOCKS4 and SOCKS5 but it needs to be compiled
    in separately.
 
  o Add directory opening/traversing functions (***DONE, TODO Windows & Symbian)
 
  o regex from /lib/contrib to lib/silcutil, define SILC Regex API. (***DONE)
 
  o Add functions to manipulate environment variables. (***DONE)
 
  o Add functions to loading shared/dynamic object symbols (replaces the
    SIM library (lib/silcsim) and introduces generic library).  Add this
    to lib/silcutil/silcdll.[ch].  (***TESTING NEEDED WIN32, TODO Symbian)
 
  o silc_getopt routines (***DONE)
 
  o The SILC Event signals.  Asynchronous events that can be created,
    connected to and signalled.  Either own event routines or glued into
    SilcSchedule. (***DONE)
 
  o If the event signals are added, the SILC_PARAM_* stuff needs to be
    moved from silcbuffmt.h to silctypes.h or something similar. (***DONE)
 
  o In case the SILC Events are done we shall create a new concept of
    parent and child SilcSchedule's.  When new SilcSchedule is created a
    parent can be associated to it.  This association could be done either
    directly by the parent or by any other children.  This way the signals
    would in effect be global and would reach all children schedulers.
 
    This relationship would be associative only.  The schedulers are still
    independent and run independently from each other.   All schedulers
    would be linked and could be accessed from any of the schedulers.
    It should be possible to retrieve the parent and enumerate all children
    from any of the schedulers.
    (***DONE)
 
  o Base64 to an own API (***DONE)
 
  o Timer API (***DONE)
 
  o silc_hash_table_replace -> silc_hash_table_set.  Retain support for
    silc_hash_table_replace as macro. (***DONE)
 
  o SilcStack aware SilcHashTable. (***DONE)
 
  o SilcStack aware SilcDList. (***DONE)
 
  o Thread pool API.  Add this to lib/silcutil/silcthread.[ch].  (***DONE)
 
  o Add new functions to SilcStack API in lib/silcutil/silcstack.[ch].  Add
    silc_stack_[set|get]_alignment.  It defines the default alignment used
    when allocating memory from stack.  It can be used to specify special
    alignments too when needed (such as for hardware devices like crypto
    accelerators).  Move also the low level silc_stack_malloc and
    silc_stack_realloc from silcstack_i.h to silcstack.h.  Remove the
    _ua unaligned memory allocation routines.  Remove unaligned memory
    allocation possibility. (***DONE)
 
  o silc_stack_alloc shouldn't require multiple by 8 size argument, it
    should figure it out itself. (***DONE)
 
  o Add '%@' format to silc_snprintf functions.
    (***DONE)
 
  o SILC Tls (Thread-local storage) API to lib/silcutil/silcthread.[ch].
    (***DONE)
 
  o Change silc_gettimeofday on Unix to use clock_gettime with REALTIME
    clock if it is available, otherwise use gettimeofday(). (***DONE)
 
  o Generic SilcResult that includes all possible status and
    error conditions and generic errno API. (***DONE)
 
  (o Structured log messages to Log API.  Allows machine readable log
    messages.  Would allow sending of any kind of data in a log message.) maybe
 
  (o Change some stream routines (like socket stream API) to accept ANY
    stream and use silc_stream_get_root to get the socket stream from the
    given stream.  This will make various stream APIs more easier to use
    when user doesn't have to dig up the correct stream.
 
    Add silc_stream_get_root and add get_root stream operation.  It
    returns the root of the stream or NULL if stream doesn't have root.) maybe
 
  (o Compression routines are missing.  The protocol supports packet
    compression thus it must be implemented.  SILC Zip API must be
    defined.) maybe
 
  (o SilcIpAddr abstraction.  Ipv4 and Ipv6 support to the abstaction.)
   maybe
 
  (o SILC specific socket creation/closing routines to silcnet.h, wrappers
   to all send(), recv(), sendto() etc.  Bad thing is that we'd have to
   define all socket options, sockaddrs, etc.) maybe
 
  (o Fast mutex implementation.  Fast rwlock implementation.  Mutex and
    rwlock implementation using atomic operations.) not for now.
 
  (o mmap) maybe
 
 
 lib/silcutil/symbian/
 =====================
 
  o Something needs to be thought to the logging globals as well,
    like silc_debug etc.  They won't work on EPOC.  Perhaps logging
    and debugging is to be disabled on EPOC.  The logging currently works
    by it cannot be controlled, same with debugging.
 
 
 SFTP Library, lib/silcsftp/
 ===========================
 
  o Read prefetch (read-ahead, reading ahead of time).  Maybe if this can
    be done easily.
 
 
 SKR Library, lib/silcskr/
 =========================
 
  o Add fingerprint as search constraint.
 
  o Add OpenPGP support.  Adding, removing, fetching PGP keys.  (Keyring
    support?)
 
  o Add support for importing public keys from a directory and/or from a
    file.  Add support for exporting the repository (different formats for
    different key types?).
 
  o Change the entire silc_skr_find API.  Remove SilcSKRFind and just simply
    add the find constraints as variable argument list to silc_skr_find, eg:
 
   silc_skr_find(skr, schedule, callback, context,
                 SILC_SKR_FIND_PUBLIC_KEY, public_key,
                 SILC_SKR_FIND_COUNTRY, "FI",
                 SILC_SKR_FIND_USAGE, SILC_SKR_USAGE_AUTH,
                 SILC_SKR_FIND_END);
 
    NULL argument would be ignored and skipped.
 
  o Add OR logical rule in addition of the current default AND, eg:
 
   // Found key(s) MUST have this public key AND this country.
   silc_skr_find(skr, schedule, callback, context,
                 SILC_SKR_FIND_RULE_AND,
                 SILC_SKR_FIND_PUBLIC_KEY, public_key,
                 SILC_SKR_FIND_COUNTRY, "FI",
                 SILC_SKR_FIND_END);
 
   // Found key(s) MUST have this public key OR this key context
   silc_skr_find(skr, schedule, callback, context,
                 SILC_SKR_FIND_RULE_OR,
                 SILC_SKR_FIND_PUBLIC_KEY, public_key,
                 SILC_SKR_FIND_CONTEXT, key_context,
                 SILC_SKR_FIND_END);
 
  o SilcStack to SKR API.
 
 
 Crypto Library, lib/silccrypt/
 ==============================
 
  o Add silc_crypto_init and silc_crypto_uninit.  The _init should take
    SilcStack that will act as global memory pool for all of crypto
    library.  It should not be necessary anymore to separately register
    default ciphers, HMACs, etc, the _init would do that.  However, if
    user after _init calls silc_pkcs_register, for example, it would take
    preference over the default once, ie. user can always dictate the
    order of algorithms. (***DONE)
 
  o Add fingerprint to SilcSILCPublicKey and retrieval to silcpk.h, and
    possibly to silcpkcs.h.
 
    /* Return fingerprint of the `public_key'.  Returns also the algorithm
       that has been used to make the fingerprint. */
    const unsigned char *
    silc_pkcs_get_fingerprint(SilcPublicKey public_key,
                              const char **hash_algorithm,
                              SilcUInt32 *fingerprint_len);
 
  o Change SILC PKCS API to asynchronous, so that accelerators can be used.
    All PKCS routines should now take callbacks as argument and they should
    be delivered to SilcPKCSObject and SilcPKCSAlgorithm too. (***DONE)
 
  o The asynchronous functions to perhaps to _async to preserve backwards
    compatibility with synchronous versions, and make easier to migrate
    from 1.1 to 1.2.
 
  o Change PKCS Algorithm API to take SilcPKCSAlgorithm as argument to
    encrypt, decrypt, sign and verify functions.  We may need to for exmaple
    check the alg->hash, supported hash functions.  Maybe deliver it also
    to all other functions in SilcPKCSAlgorithm to be consistent. (***DONE)
 
  o Add DSA support to SILC public key.
 
  o Add DSS support. (***DONE)
 
  o Implement the defined SilcDH API.  The definition is in
    lib/silccrypt/silcdh.h.  Make sure it is asynchronous so that it can
    be accelerated.  Also take into account that it could use elliptic
    curves.
 
  o Add ECDSA support.
 
  o Add ECDH support.
 
  o AES CBC is missing proper alignment code (see silc_1_1_branch).
 
  o All cipher, hash, hmac etc. allocation routines should take their name
    in as const char * not const unsigned char *. (***DONE)
 
 
 SILC Accelerator Library
 ========================
 
  o SILC Accelerator API.  Provides generic way to use different kind of
    accelerators.  Basically implements SILC PKCS API so that SilcPublicKey
    and SilcPrivateKey can be used but they call the accelerators.
    (***DONE)
 
  o Implement software accelerator.  It is a thread pool system where the
    public key and private key operations are executed in threads.
    (***DONE)
 
  o Add init options to SilcAcceleratorObject as a SilcAcceleratorOption
    structure.  Each accelerator defines the options that they support and
    can be retrieved from the SilcAccelerator with silc_acc_get_options.
    The format must also be machine parseable.  The structure can be of the
    following format:
 
         typedef struct SilcAcceleratorOptionStruct {
           const char *option;                   /* Option name */
           const char *display_name;             /* Option displayable name */
           SilcParamType type;                   /* Option data format */
           void *default_value;                  /* Option's default value */
           SilcUInt32 default_value_len;         /* Default value length */
         } *SilcAcceleratorOption;
 
    For software accelerator it could be for example:
 
    { "min_threads", "Minimum threads", SILC_PARAM_UINT32, (void *)2, 4 },
    { "max_threads", "Maximum threads", SILC_PARAM_UINT32, (void *)4, 4 },
 
  o Diffie-Hellman acceleration
 
  (o Symmetric key cryptosystem acceleration?  They are always sycnhronouos
    even with hardware acceleration so the crypto API shouldn't require
    changes.) maybe
 
 
 lib/silcmath
 ============
 
  o Import TFM.  We want TFM's speed but its memory requirements are
    just too much.  By default it uses large pre-allocated tables which
    will eat memory when there are thousands of public keys in system.
    We probably want to change TFM's fp_int dynamic so that a specific
    size can be allocated for the int.  We could have two new functions:
 
    SilcBool silc_mp_init_size(SilcMPInt *mp, SilcUInt32 bit_size);
    SilcBool silc_mp_sinit_size(SilcStack stack, SilcMPInt *mp,
                                SilcUInt32 bit_size);
 
    Which by default allocates `bit_size' bits instead of some default
    value.  silc_mp_init would allocate the default FP_SIZE with TFM
    and do normal init with TMA and GMP.  _init_size with TMA and GMP
    would be same as _init.
 
  o Add AND, OR and XOR support to TFM or ask Tom to do it.
 
  o The SILC MP API function must start returning indication of success
    and failure of the operation.
 
  o Do SilcStack support for silc_mp_init, silc_mp_init_size and other
    any other MP function (including utility ones) that may allocate
    memory.
 
  o Prime generation progress using callback instead of printing to
    stdout.
 
  o All utility functions should be made non-allocating ones.
 
 
 SILC XML Library, lib/silcxml/
 ==============================
 
  o SILC XML API (wrapper to expat).  Look at the expat API and simplify
    it.  The SILC XML API should have at most 8-10 API functions.  It should
    be possible to create full XML parser with only one function.  And, it
    should be possible to have a function that is able to parse an entire
    XML document.  It should also have a parser function to be able to
    parse a stream of XML data (SilcStream).  It MUST NOT have operations
    that require multiple function calls to be able to execute that one
    operation (like creating parser).
 
 
 lib/silcske/silcske.[ch]
 ========================
 
  o Ratelimit to UDP/IP transport for incoming packets.
 
 
 lib/silcasn1
 ============
 
  o Negative integer encoding is missing, add it.
 
  o SILC_ASN1_CHOICE should perhaps return an index what choice in the
    choice list was found.  Currently it is left for caller to figure out
    which choice was found. (***DONE)
 
  o SILC_ASN1_NULL in decoding should return SilcBool whether or not
    the NULL was present.  It's important when it's SILC_ASN1_OPTIONAL
    and we need to know whether it was present or not. (***DONE)
 
 
 lib/silcpgp
 ===========
 
  o OpenPGP certificate support, allowing the use of PGP public keys.
 
 
 lib/silcssh
 ===========
 
  o SSH2 public key/private key support, allowing the use of SSH2 keys.
    RFC 4716.  (***DONE)
 
 
 lib/silcpkix
 ============
 
  o PKIX implementation
 
 
 apps/silcd
 ==========
 
  o Deprecate the old server.  Write interface for the new lib/silcserver
    server library.  The interface should work on Unix/Linux systems.
 
  o Consider deprecating also the old config file format and use XML
    istead.  This should require SILC XML API implementation first.
 
  o The configuration must support dynamic router and server connections.
    The silcd must work without specifying any servers or routers to
    connect to.
 
  o The configuration must support specifying whether the server is
    SILC Server or SILC Router.  This should not be deduced from the
    configuration as it was in < 1.2.
 
  o The configuration must support specifying the ciphers and hmacs and
    their order so that user can specify which algorithms take preference.
 
 
 lib/silcserver
 ==============
 
  o Rewrite the entire server.  Deprecate apps/silcd as the main server
    implementation and create lib/silcserver/.  It is a platform
    independent server library.  The apps/silcd will merely provide a
    a simple interface for the library.
 
  o Write the SILC Server library extensively using SILC FSM.
 
  o Server library must support multiple networks.  This means that one
    server must be able to create multiple connections that each reach
    different SILC network.  This means also that all cache's etc. must
    be either connection-specific or network-specific.
 
  o Library must support dynamic router and server connections.  This means
    that connections are create only when they are needed, like when someone
    says JOIN foo@foo.bar.com or WHOIS foobar@silcnet.org.
 
  o Library must support server-to-server connections even though protocol
    prohibits that.  The responder of the connection should automatically
    act as a router.  The two servers create an own, isolated, SILC network.
    To be used specifically with dynamic connections.
 
  o Library must support multiple threads and must be entirely thread safe.
 
  o Library must have support for SERVICE command.
 
  o Both UDP and TCP support for incoming connecetions.  Maintaining long
    term UDP sessions.
 
  o The server must be able to run behind NAT device.  This means that
    Server ID must be based on public IP instead of private IP (See
    also NAT detection protocol in SILC protocol specification).
 
  o The following data must be in per-connection context: client id cache,
    server id cache, channel id cache, all statistics must be
    per-connection.
 
  o The following data must be in per-thread context: command context
    freelist/pool, pending commands, random number generator.
 
  o Do inccoming packet processing in an own FSM thread in the
    server-threads FSM.  Same as in client library.
 
  o Binding to other ports than 706 too.  To allow easier traversing
    through NATs and firewalls server should also bind to 80, 443 and 7706
    by default (at least try to bind).  Connections must work normally
    even if they were established to some other port other than 706.
 
    Connection option that attemps to connect to remot server with various
    different mechanisms: UDP 706, TCP 706, TCP 80, TCP 443, UDP 7706 and
    TCP 7706.  This is the so called hole punching mechanism.
 
  o Ability to recover from rekey errors, at least try to.
 
  o Reference count all Silc*Entry structures.
 
  Some issues that must be kept in mind from 1.0 and 1.1 silcd's:
 
  o The server and router software MUST work out of the box.  After
    installation the server must not require any configuration to run the
    most basic working configuration.  No defining IP addresses, etc.
    The server must work just by running it.
 
  o The SERVER_SIGNOFF notify handing is not optimal, because it'll
    cause sending of multiple SIGNOFF notify's instead of the one
    SERVER_SIGNOFF notify that the server received.  This should be
    optimized so that the only SERVER_SIGNOFF is sent and not
    SIGNOFF of notify at all (using SIGNOFF takes the idea about
    SERVER_SIGNOFF away entirely).
 
  o Another SERVER_SIGNOFF opt/bugfix:  Currently the signoff is
    sent to a client if it is on same channel as the client that
    signoffed.  However, the entire SERVER_SIGNOFF list is sent to
    the client, ie. it may receive clients that was not on the
    same channel.  This is actually against the specs.  It must be
    done per channel.  It shouldn't receive the whole list just
    because one client happened to be on same channel.
 
  o If client's public key is saved in the server (and doing public key
    authentication) then the hostname and the username information could
    be taken from the public key.  Should be a configuration option!
 
  o Add a timeout to handling incoming JOIN commands.  It should be
    enforced that JOIN command is executed only once in a second or two
    seconds.  Now it is possible to accept n incoming JOIN commands
    and process them without any timeouts.  THis must be employed because
    each JOIN command will create and distribute the new channel key
    to everybody on the channel.
 
  o Related to above.  If multiple JOINs are received in sequence perhaps
    new key should be created only once, if the JOINs are handeled at the same
    time.  Now we create multiple keys and never end up using them because
    many JOINs are processed at the same time in sequence.  Only the last
    key ends up being used.