diff options
Diffstat (limited to 'pkd_stub.py')
| -rw-r--r-- | pkd_stub.py | 142 |
1 files changed, 126 insertions, 16 deletions
diff --git a/pkd_stub.py b/pkd_stub.py index ef5818d..c8e2ae4 100644 --- a/pkd_stub.py +++ b/pkd_stub.py @@ -1,4 +1,4 @@ -import os, sys, socket, threading, signal, json +import os, sys, socket, threading, signal, json, traceback from concurrent.futures import ThreadPoolExecutor # initial crypto config @@ -37,6 +37,9 @@ def dispatch_command(sock, command, rpubkey): global bits send_encrypted(sock, command, rpubkey['e'], rpubkey['n'], bits=bits) +def dispatch_ccmd(client, command): + dispatch_command(client['sock'], command, client['pubkey']) + # brint takes a string def brint(*args, sep=' ', end='\n', prompt=True): s = '%s%s' % (sep.join(map(lambda s: betterstr(s), args)), end) @@ -95,8 +98,10 @@ def blast_command(cmd, orig_screen, targets=set()): i = 0 while alive and i < len(tcp_clients): try: + if tcp_clients[i]['pty']: + continue if wildcard or i in targets: - dispatch_command(tcp_clients[i]['sock'], cmd, tcp_clients[i]['pubkey']) + dispatch_ccmd(tcp_clients[i], cmd) if wildcard: tcp_clients[i]['qidx'] += 1 except: @@ -115,12 +120,12 @@ def tcp_handshake(sock): sock.sendall(nbytes.to_bytes(headsz, 'big')) if rnbytes != nbytes: + brint('[ERROR] nbytes mismatch with client: %d vs %d' % (rnbytes, nbytes)) return False rpubkey = { 'n': int.from_bytes(recv_encrypted(sock, privkey['d'], privkey['n'], bits=bits),\ 'big'), 'e': exp } - dispatch_command(sock, 'set -i', rpubkey) return rpubkey def tcp_disconnect(client): @@ -144,10 +149,12 @@ def transport_tcp(client): global tcp_clients, tcpc_lock try: rpk = tcp_handshake(client['sock']) - except: + except Exception as e: + brint('[ERROR] %s' % repr(e)) rpk = False if not rpk: brint('[INFO] Handshake failed; disconnecting client:', client['addr']) + client['alive'] = False tcp_disconnect(client) return client['pubkey'] = rpk @@ -157,8 +164,8 @@ def transport_tcp(client): if not client['alive']: tcp_disconnect(client) return - - if len(cmdq) > client['qidx']: + + if not client['pty'] and len(cmdq) > client['qidx']: cmdq_lock.acquire() if not alive: cmdq_lock.release() @@ -167,7 +174,7 @@ def transport_tcp(client): cmdq_lock.release() tcp_disconnect(client) return - if len(cmdq) <= client['qidx']: + if client['pty'] or len(cmdq) <= client['qidx']: cmdq_lock.release() continue @@ -175,22 +182,34 @@ def transport_tcp(client): client['qidx'] += 1 cmdq_lock.release() try: - dispatch_command(client['sock'], cmd, client['pubkey']) + dispatch_ccmd(client, cmd) except: + client['alive'] = False tcp_disconnect(client) return else: try: data = recv_encrypted(client['sock'], privkey['d'], privkey['n'], bits=bits) except: - data = b'\xde\xad' + data = False if not alive: return - elif data == b'\xde\xad': + elif not data or data == b'\xde\xad': + client['alive'] = False tcp_disconnect(client) + if client['pty']: + unpty(client) return - elif len(data) > 0: + elif not client['pty']: bnnl(data, logging=False) + elif data == b'\xc0\xdenpty': + unpty(client) + else: + try: + client['pty'].sendall(data) + except: + unpty(client) + print('Screen failed to receive PTY data:', data) def serve_tcp(): global sockets, tcp_port @@ -228,6 +247,7 @@ def serve_tcp(): 'addr': ca, 'sock': cs, 'qidx': 0, + 'pty': False, 'alive': True } tcpc_lock.acquire() @@ -239,7 +259,6 @@ def serve_tcp(): try: pool.submit(transport_tcp, tcpcli) except RuntimeError: - print('OUCH') return def detach_screen(screen): @@ -280,6 +299,69 @@ def cliinfo(clients): except Exception as e: return repr(e) +def unpty(client): + global alive, tcp_clients, tcpc_lock + tcpc_lock.acquire() + if not alive: + tcpc_lock.release() + return + client['pty'] = False + tcpc_lock.release() + +def run_pty(screen, cn): + global alive, tcp_clients, tcpc_lock, privkey, bits + tcpc_lock.acquire() + if not alive: + tcpc_lock.release() + return + + if cn >= len(tcp_clients): + tcpc_lock.release() + return 'Client %d disconnected while attaching PTY.' % cn + client = tcp_clients[cn] + client['pty'] = screen + tcpc_lock.release() + + try: + dispatch_ccmd(client, b'pty') + if 'TERM' not in os.environ: + os.environ['TERM'] = 'xterm-256color' + dispatch_ccmd(client, os.environ['TERM']) + except: + client['alive'] = False + return 'Client %d failed PTY handshake.' % cn + + try: + screen.sendall(b'\xc0\xdepty') + except: + unpty(client) + return False + + + while True: + if not alive: + return + elif not client['alive']: + return 'PTY session terminated due to client disconnect.' + elif not client['pty']: + return 'PTY session ended normally.' + elif client['pty'] != screen: + return 'PTY session seized by another screen.' + + try: + data = screen.recv(1024) + if not alive: + return False + except: + data = b'\xde\xad' + if not data or data == b'\xde\xad': + unpty(client) + return False + try: + dispatch_ccmd(client, data) + except: + client['alive'] = False + def screen_reader(screen): global alive, screens, screens_lock, cmdq, cmdq_lock, tcp_clients, tcpc_lock @@ -340,6 +422,35 @@ def screen_reader(screen): cmdq_lock.release() elif cmd == b'show-serverkey': resp = showcrypto() + elif cmd == b'pty': + resp = '[pk] Must specify a client to connect to via PTY.' + elif cmd[:4] == b'pty ': + try: + cn = int(cmd[4:]) + except: + cn = -1 + if cn < 0 or cn >= len(tcp_clients): + resp = '[pk] Cannot attach PTY to invalid TCP client.' + else: + pty_out = run_pty(screen, cn) + if not alive: + return + if not pty_out: + detach_screen(screen) + return + try: + screen.sendall(b'\xc0\xdenpty') + except: + detach_screen(screen) + return + resp = '[pk] %s' % pty_out + elif cmd == b'\xc0\xdeprompt': + try: + screen.sendall(prompt_str()) + except: + detach_screen(screen) + return + continue elif len(cmd) > 0: shcmd = True targets = [] @@ -356,10 +467,9 @@ def screen_reader(screen): else: resp = '[pk] Can\'t target null command.' blast_command(cmd, screen, targets=targets) + if not alive: + return try: - if cmd == b'\xc0\xdeprompt': - screen.sendall(prompt_str()) - continue if len(resp) > 0: screen.sendall(bytes('%s\n' % resp, 'utf-8')) if len(tcp_clients) < 1: @@ -441,7 +551,7 @@ def cleanup(*args): tcpc_lock.acquire() for client in tcp_clients: try: - send_encrypted(client['sock'], b'tunnel', client['pubkey']['e'], client['pubkey']['n'], bits=bits) + dispatch_ccmd(client, b'tunnel') except: pass client['sock'].close() |