diff options
| -rw-r--r-- | .gitignore | 2 | ||||
| -rw-r--r-- | pkd_stub.py | 69 |
2 files changed, 65 insertions, 6 deletions
@@ -2,9 +2,9 @@ *ptys.py pkd.py pkcli.py +devctl.py pkdnull.py pkdkey.json -warcrypto.py *.pid *.sock *.log diff --git a/pkd_stub.py b/pkd_stub.py index fb45875..3e71655 100644 --- a/pkd_stub.py +++ b/pkd_stub.py @@ -1,5 +1,7 @@ import os, sys, socket, signal, json, selectors +# basic magic number +DNS_UDP_PORT = 53 # initial crypto config SERVER_PROMPT = b'pk> ' CONNECTED_PROMPT = b'$ ' @@ -345,7 +347,7 @@ def tcp_process_data(sel, sock, client, data): print('[INFO] npty acknowledged') if idx+6 < len(data): - tcp_transport(sel, sock, client) + transport_tcp(sel, sock, client) else: try: client['pty']['sock'].sendall(data) @@ -353,7 +355,7 @@ def tcp_process_data(sel, sock, client, data): screens_detach(sel, client['pty']) tcp_send_npty(sel, client) -def tcp_transport(sel, sock, client): +def transport_tcp(sel, sock, client): if not client['alive']: return try: @@ -394,7 +396,7 @@ def tcp_accept(sel, sock): return tcp_clients.append(client) - sel.register(cs, selectors.EVENT_READ, {'callback': tcp_transport, 'close': tcp_close, 'args': [client]}) + sel.register(cs, selectors.EVENT_READ, {'callback': transport_tcp, 'close': tcp_close, 'args': [client]}) brint('[INFO] Connection from', ca[0], 'over TCP.', prompt=False) tcp_dumpq(sel, client) @@ -414,7 +416,63 @@ def register_tcp(sel, port): return sel.register(sock, selectors.EVENT_READ, tcp_accept) - print('[INFO] TCP listener started on port %d' % port) + print('[INFO] TCP listener started on port %d/tcp' % port) + +def transport_dns(sel, sock): + try: + req, addr = sock.recvfrom(1024) + except: + print('[WARNING] Error receiving DNS query.') + return + dns_refuse(sock, addr, req) + +def dns_refuse(sock, addr, req): + # ID = req.id + resp = bytearray(req[0:2]) + # QR = 1 | opcode[4] = req.opcode | AA = 0 | TC = 0 | RD = req.rd + resp.append((req[2] & 0b11111001) | 0b10000000) + # RA = 0 | Z[3] = 0 | rcode[4] = 5 (REFUSED) + resp.append(5) + # QDCount = req.QDCount + try: + qdcount = int.from_bytes(req[4:6], 'big') + resp.extend(req[4:6]) + except: + qdcount = 0 + resp.extend(b'\x00' * 2) + # ANCount = NSCount = ARCount = 0 + resp.extend(b'\x00' * 6) + # Copy question section + dns_copy_queries(qdcount, req[12:], resp) + + sock.sendto(resp, addr) + +def dns_copy_queries(qdcount, qdsect, buffer): + print('qdsect=', qdsect) + for _ in range(qdcount): + while True: + labelsize = qdsect[0] + 1 + buffer.extend(qdsect[:labelsize]) + qdsect = qdsect[labelsize:] + if labelsize < 2: + break + # QType | QClass + buffer.extend(qdsect[:4]) + qdsect = qdsect[4:] + +def register_dns(sel): + sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) + try: + sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) + sock.bind(('0.0.0.0', DNS_UDP_PORT)) + except: + brint('[WARNING] Error binding DNS socket, DNS listener will now die.') + sock.close() + return + + sel.register(sock, selectors.EVENT_READ, transport_dns) + print('[INFO] DNS listener started on port %d/udp' % DNS_UDP_PORT) + pass def stopsig(*args): global alive, breaker @@ -507,7 +565,7 @@ def main(args): signal.signal(signal.SIGTERM, stopsig) print('[INFO] Daemon started successfully.') - #register_dns(sel) + register_dns(sel) register_tcp(sel, tcp_port) register_screens(sel, socket_file) @@ -535,6 +593,7 @@ def main(args): sel.close() os.remove(pid_file) os.remove(socket_file) + print('[INFO] Daemon stopped.') os.close(sys.stdout.fileno()) os.close(sys.stderr.fileno()) sys.exit(0) |