SILC or Secure Internet Live Conferencing (http://silcnet.org/) - [code]Secure Internet Live Conferencing, or SILC in short, is a modern conferencing protocol which provides rich conferencing features with high security. One of the main design principles of the protocol was security. Many of the SILC features are found in traditional chat protocols such as IRC but many of the SILC features can also be found in Instant Message (IM) style protocols.

SILC combines features from both of these chat protocol styles, and can be implemented as either IRC-like system or IM-like system. In fact, SILC removes the need to make such distinction between these two protocol styles. Some of the more advanced and security features of the protocol are new to all conferencing protocols. SILC also supports multimedia messages and can also be implemented as a video and audio conferencing system. [/code]

SILC comes with a Toolkit, that provides an API to easily make a SILC Client, however it's example is in C++, where usually this wouldn't be a problem as I would just use DLL Import, it seems I may have a problem, I was hoping someone could elaborate as to how I would accomplish this:

C++ Example:
[code]
/*

  mybot.c

  Author: Pekka Riikonen <priikone@silcnet.org>, November 2002, 2007
  This code is Public Domain.

  MyBot

  Example SILC client called "mybot".  It is a robot client which
  connects to SILC Network into silc.silcnet.org server and joins
  channel called "mybot" and says "hello" on the channel.

  This code use the SILC Client Library provided by the SILC
  Toolkit distribution.

  Compilation:

  gcc -o mybot mybot.c -I/usr/local/silc/include -L/usr/local/silc/lib \
      -lsilc -lsilcclient -lpthread -ldl

*/

#include "silc.h" /* Mandatory include for SILC applications */
#include "silcclient.h" /* SILC Client Library API */

SilcClientOperations ops;

static void silc_running(SilcClient client, void *application);
static void silc_stopped(SilcClient client, void *context);

/******* MyBot code **********************************************************/

/* This is context for our MyBot client */
typedef struct {
  SilcClient client; /* The actual SILC Client */
  SilcClientConnection conn; /* Connection to the server */
  SilcPublicKey public_key;    /* My public key */
  SilcPrivateKey private_key;  /* My private key */
} *MyBot;

/* Connect callback called after connected to remote server. */

static void
silc_connected(SilcClient client, SilcClientConnection conn,
      SilcClientConnectionStatus status,
      SilcStatus error, const char *message,
      void *context)
{
  MyBot mybot = client->application;

  if (status == SILC_CLIENT_CONN_DISCONNECTED) {
    SILC_LOG_DEBUG(("Disconnected %s", message ? message : ""));
    silc_client_stop(client, silc_stopped, mybot);
    return;
  }

  if (status != SILC_CLIENT_CONN_SUCCESS &&
      status != SILC_CLIENT_CONN_SUCCESS_RESUME) {
    SILC_LOG_DEBUG(("Error connecting to server %d", status));
    silc_client_stop(client, silc_stopped, mybot);
    return;
  }

  fprintf(stdout, "\nMyBot: Connected to server\n\n");

  /* Now that we have connected to server, let's join a channel named
    "mybot". */
  silc_client_command_call(client, conn, "JOIN mybot");

  /* Save the connection context */
  mybot->conn = conn;
}

/* Running callback given to silc_client_init called to indicate that the
  Client Library is running.  After this Client API functions can be
  called. */

static void silc_running(SilcClient client, void *application)
{
  MyBot mybot = application;

  SILC_LOG_DEBUG(("Client is running"));

  /* Connect to server.  The silc_connected callback will be called after
    the connection is established or if an error occurs during connecting. */
  silc_client_connect_to_server(mybot->client, NULL,
mybot->public_key, mybot->private_key,
"silc.silcnet.org", 706,
silc_connected, mybot);
}

/* Client stopped callback given to silc_client_stop.  Called to indicate
  that Client Library is stopped. */

static void silc_stopped(SilcClient client, void *context)
{
  SILC_LOG_DEBUG(("Client stopped"));
}

/* Start the MyBot, by creating the SILC Client entity by using the
  SILC Client Library API. */
int mybot_start(void)
{
  MyBot mybot;
  SilcClientParams params;

  /* Allocate the MyBot structure */
  mybot = silc_calloc(1, sizeof(*mybot));
  if (!mybot) {
    perror("Out of memory");
    return 1;
  }

  memset(&params, 0, sizeof(params));
  params.threads = TRUE;
  mybot->client = silc_client_alloc(&ops, &params, mybot, NULL);
  if (!mybot->client) {
    perror("Could not allocate SILC Client");
    return 1;
  }

  /* Now we initialize the client. */
  if (!silc_client_init(mybot->client, silc_get_username(),
silc_net_localhost(), "I am the MyBot",
silc_running, mybot)) {
    perror("Could not init client");
    return 1;
  }

  if (!silc_load_key_pair("mybot.pub", "mybot.prv", "",
  &mybot->public_key,
  &mybot->private_key)) {
    /* The keys don't exist.  Let's generate us a key pair then!  There's
      nice ready routine for that too.  Let's do 2048 bit RSA key pair. */
    fprintf(stdout, "MyBot: Key pair does not exist, generating it.\n");
    if (!silc_create_key_pair("rsa", 2048, "mybot.pub", "mybot.prv", NULL, "",
      &mybot->public_key,
      &mybot->private_key, FALSE)) {
      perror("Could not generated key pair");
      return 1;
    }
  }

  /* And, then we are ready to go.  Since we are really simple client we
    don't have user interface and we don't have to deal with message loops
    or interactivity.  That's why we can just hand over the execution
    to the library by calling silc_client_run.  */
  silc_client_run(mybot->client);

  /* When we get here, we have quit the client, so clean up and exit */
  silc_client_free(mybot->client);
  silc_free(mybot);
  return 0;
}

/******* SILC Client Operations **********************************************/

/* The SILC Client Library requires these "client operations".  They are
  functions that the library may call at any time to indicate to application
  that something happened, like message was received, or authentication
  is required or something else.  Since our MyBot is really simple client
  we don't need most of the operations, so we just define them and don't
  do anything in them. */

/* "say" client operation is a message from the client library to the
  application.  It may include error messages or something else.  We
  just dump them to screen. */

static void
silc_say(SilcClient client, SilcClientConnection conn,
SilcClientMessageType type, char *msg, ...)
{
  char str[200];
  va_list va;
  va_start(va, msg);
  vsnprintf(str, sizeof(str) - 1, msg, va);
  fprintf(stdout, "MyBot: %s\n", str);
  va_end(va);
}


/* Message for a channel. The `sender' is the sender of the message
  The `channel' is the channel. The `message' is the message.  Note
  that `message' maybe NULL.  The `flags' indicates message flags
  and it is used to determine how the message can be interpreted
  (like it may tell the message is multimedia message). */

static void
silc_channel_message(SilcClient client, SilcClientConnection conn,
    SilcClientEntry sender, SilcChannelEntry channel,
    SilcMessagePayload payload,
    SilcChannelPrivateKey key,
    SilcMessageFlags flags, const unsigned char *message,
    SilcUInt32 message_len)
{
  /* Yay! We got a message from channel. */

  if (flags & SILC_MESSAGE_FLAG_SIGNED)
    fprintf(stdout, "[SIGNED] <%s> %s\n", sender->nickname, message);
  else
    fprintf(stdout, "<%s> %s\n", sender->nickname, message);
}


/* Private message to the client. The `sender' is the sender of the
  message. The message is `message'and maybe NULL.  The `flags'
  indicates message flags  and it is used to determine how the message
  can be interpreted (like it may tell the message is multimedia
  message). */

static void
silc_private_message(SilcClient client, SilcClientConnection conn,
    SilcClientEntry sender, SilcMessagePayload payload,
    SilcMessageFlags flags,
    const unsigned char *message,
    SilcUInt32 message_len)
{
  /* MyBot does not support private message receiving */
}


/* Notify message to the client. The notify arguments are sent in the
  same order as servers sends them. The arguments are same as received
  from the server except for ID's.  If ID is received application receives
  the corresponding entry to the ID. For example, if Client ID is received
  application receives SilcClientEntry.  Also, if the notify type is
  for channel the channel entry is sent to application (even if server
  does not send it because client library gets the channel entry from
  the Channel ID in the packet's header). */

static void
silc_notify(SilcClient client, SilcClientConnection conn,
    SilcNotifyType type, ...)
{
  char *str;
  va_list va;

  va_start(va, type);

  /* Here we can receive all kinds of different data from the server, but
    our simple bot is interested only in receiving the "not-so-important"
    stuff, just for fun. :) */
  switch (type) {
  case SILC_NOTIFY_TYPE_NONE:
    /* Received something that we are just going to dump to screen. */
    str = va_arg(va, char *);
    fprintf(stdout, "--- %s\n", str);
    break;

  case SILC_NOTIFY_TYPE_MOTD:
    /* Received the Message of the Day from the server. */
    str = va_arg(va, char *);
    fprintf(stdout, "%s", str);
    fprintf(stdout, "\n");
    break;

  default:
    /* Ignore rest */
    break;
  }

  va_end(va);
}


/* Command handler. This function is called always in the command function.
  If error occurs it will be called as well. `conn' is the associated
  client connection. `cmd_context' is the command context that was
  originally sent to the command. `success' is FALSE if error occurred
  during command. `command' is the command being processed. It must be
  noted that this is not reply from server. This is merely called just
  after application has called the command. Just to tell application
  that the command really was processed. */

static void
silc_command(SilcClient client, SilcClientConnection conn,
    SilcBool success, SilcCommand command, SilcStatus status,
    SilcUInt32 argc, unsigned char **argv)
{
  /* If error occurred in client library with our command, print the error */
  if (status != SILC_STATUS_OK)
    fprintf(stderr, "MyBot: COMMAND %s: %s\n",
    silc_get_command_name(command),
    silc_get_status_message(status));
}


/* Command reply handler. This function is called always in the command reply
  function. If error occurs it will be called as well. Normal scenario
  is that it will be called after the received command data has been parsed
  and processed. The function is used to pass the received command data to
  the application.

  `conn' is the associated client connection. `cmd_payload' is the command
  payload data received from server and it can be ignored. It is provided
  if the application would like to re-parse the received command data,
  however, it must be noted that the data is parsed already by the library
  thus the payload can be ignored. `success' is FALSE if error occurred.
  In this case arguments are not sent to the application. The `status' is
  the command reply status server returned. The `command' is the command
  reply being processed. The function has variable argument list and each
  command defines the number and type of arguments it passes to the
  application (on error they are not sent). */

static void
silc_command_reply(SilcClient client, SilcClientConnection conn,
  SilcCommand command, SilcStatus status,
  SilcStatus error, va_list ap)
{
  /* If error occurred in client library with our command, print the error */
  if (status != SILC_STATUS_OK)
    fprintf(stderr, "MyBot: COMMAND REPLY %s: %s\n",
    silc_get_command_name(command),
    silc_get_status_message(status));

  /* Check for successful JOIN.  See
    http://silcnet.org/docs/toolkit/command_reply_args.html for the
    different arguments the client library returns. */
  if (command == SILC_COMMAND_JOIN) {
    SilcChannelEntry channel;
    SilcHash sha1hash;

    (void)va_arg(ap, SilcClientEntry);
    channel = va_arg(ap, SilcChannelEntry);

    fprintf(stdout, "MyBot: Joined '%s' channel\n", channel->channel_name);

    /* Now send the "hello" to the channel */
    silc_client_send_channel_message(client, conn, channel, NULL, 0, NULL,
    "hello", strlen("hello"));
    fprintf(stdout, "MyBot: Sent 'hello' to channel\n");

    /* Now send digitally signed "hello" to the channel.  We have to allocate
      hash function for the signature process. */
    silc_hash_alloc("sha1", &sha1hash);
    silc_client_send_channel_message(client, conn, channel, NULL,
    SILC_MESSAGE_FLAG_SIGNED, sha1hash,
    "hello, with signature",
    strlen("hello, with signature"));
    silc_hash_free(sha1hash);
    fprintf(stdout, "MyBot: Sent 'hello, with signature' to channel\n");
  }
}

/* Find authentication method and authentication data by hostname and
  port. The hostname may be IP address as well. When the authentication
  method has been resolved the `completion' callback with the found
  authentication method and authentication data is called. The `conn'
  may be NULL. */

static void
silc_get_auth_method(SilcClient client, SilcClientConnection conn,
    char *hostname, SilcUInt16 port,
    SilcAuthMethod auth_method,
    SilcGetAuthMeth completion,
    void *context)
{
  /* MyBot assumes that there is no authentication requirement in the
    server and sends nothing as authentication.  We just reply with
    TRUE, meaning we know what is the authentication method. :). */
  completion(SILC_AUTH_NONE, NULL, 0, context);
}


/* Verifies received public key. The `conn_type' indicates which entity
  (server, client etc.) has sent the public key. If user decides to trust
  the application may save the key as trusted public key for later
  use. The `completion' must be called after the public key has been
  verified. */

static void
silc_verify_public_key(SilcClient client, SilcClientConnection conn,
      SilcConnectionType conn_type,
      SilcPublicKey public_key,
      SilcVerifyPublicKey completion, void *context)
{
  fprintf(stdout, "MyBot: server's public key\n");
  silc_show_public_key(public_key);
  completion(TRUE, context);
}


/* Ask (interact, that is) a passphrase from user. The passphrase is
  returned to the library by calling the `completion' callback with
  the `context'. The returned passphrase SHOULD be in UTF-8 encoded,
  if not then the library will attempt to encode. */

static void
silc_ask_passphrase(SilcClient client, SilcClientConnection conn,
    SilcAskPassphrase completion, void *context)
{
  /* MyBot does not support asking passphrases from users since there
    is no user in our little client.  We just reply with nothing. */
  completion(NULL, 0, context);
}


/* Asks whether the user would like to perform the key agreement protocol.
  This is called after we have received an key agreement packet or an
  reply to our key agreement packet. This returns TRUE if the user wants
  the library to perform the key agreement protocol and FALSE if it is not
  desired (application may start it later by calling the function
  silc_client_perform_key_agreement). If TRUE is returned also the
  `completion' and `context' arguments must be set by the application. */

static void
silc_key_agreement(SilcClient client, SilcClientConnection conn,
  SilcClientEntry client_entry, const char *hostname,
  SilcUInt16 protocol, SilcUInt16 port)
{
  /* MyBot does not support incoming key agreement protocols, it's too
    simple for that. */
}


/* Notifies application that file transfer protocol session is being
  requested by the remote client indicated by the `client_entry' from
  the `hostname' and `port'. The `session_id' is the file transfer
  session and it can be used to either accept or reject the file
  transfer request, by calling the silc_client_file_receive or
  silc_client_file_close, respectively. */

static void
silc_ftp(SilcClient client, SilcClientConnection conn,
SilcClientEntry client_entry, SilcUInt32 session_id,
const char *hostname, SilcUInt16 port)
{
  /* MyBot does not support file transfer, it's too simple for that too. */
}


/* Our client operations for the MyBot.  This structure is filled with
  functions and given as argument to the silc_client_alloc function.
  Even though our little bot does not need all these functions we must
  provide them since the SILC Client Library wants them all. */
/* This structure and all the functions were taken from the
  lib/silcclient/client_ops_example.c. */
SilcClientOperations ops = {
  silc_say,
  silc_channel_message,
  silc_private_message,
  silc_notify,
  silc_command,
  silc_command_reply,
  silc_get_auth_method,
  silc_verify_public_key,
  silc_ask_passphrase,
  silc_key_agreement,
  silc_ftp
};

int main(int argc, char **argv)
{
  /* Start mybot */
  return mybot_start();
}
[/code]

As you can see it says:[code]#include "silc.h" /* Mandatory include for SILC applications */
#include "silcclient.h" /* SILC Client Library API */[/code]
I'm not sure how that's possible in C#?

You have to port the headers from silcclient.h and possibly silc.h as DllImport functions.

In the future, please remember that we can click links to internet files, too, and so it's not always necessary to post an entire long-ass text file.

[quote author=MyndFyre[vL] link=topic=17440.msg177625#msg177625 date=1208123322]
You have to port the headers from silcclient.h and possibly silc.h as DllImport functions.

In the future, please remember that we can click links to internet files, too, and so it's not always necessary to post an entire long-ass text file.
[/quote]

Have you ever hear of / used SILC or a protocol like it?

[quote author=Smarter link=topic=17440.msg177634#msg177634 date=1208138989]
[quote author=MyndFyre[vL] link=topic=17440.msg177625#msg177625 date=1208123322]
You have to port the headers from silcclient.h and possibly silc.h as DllImport functions.

In the future, please remember that we can click links to internet files, too, and so it's not always necessary to post an entire long-ass text file.
[/quote]

Have you ever hear of / used SILC or a protocol like it?
[/quote]

No, I've never used SILC specifically, though I have used other IM protocols.