contrib/tor-resolve.py

   1 #!/usr/bin/python
   2
   3 import socket
   4 import struct
   5 import sys
   6
   7 def socks4AResolveRequest(hostname):
   8     version = 4
   9     command = 0xF0
  10     port = 0
  11     addr = 0x0000001
  12     username = ""
  13     reqheader = struct.pack("!BBHL", version, command, port, addr)
  14     return "%s%s\x00%s\x00"%(reqheader,username,hostname)
  15
  16 def socks4AParseResponse(response):
  17     RESPONSE_LEN = 8
  18     if len(response) < RESPONSE_LEN:
  19         return None
  20     assert len(response) >= RESPONSE_LEN
  21     version,status,port = struct.unpack("!BBH",response[:4])
  22     assert version == 0
  23     assert port == 0
  24     if status == 90:
  25         return "%d.%d.%d.%d"%tuple(map(ord, response[4:]))
  26     else:
  27         return "ERROR (status %d)"%status
  28
  29 def socks5Hello():
  30     return "\x05\x01\x00"
  31 def socks5ParseHello(response):
  32     if response != "\x05\x00":
  33         raise ValueError("Bizarre socks5 response")
  34 def socks5ResolveRequest(hostname, atype=0x03, command=0xF0):
  35     version = 5
  36     rsv = 0
  37     port = 0
  38     reqheader = struct.pack("!BBBB",version, command, rsv, atype)
  39     if atype == 0x03:
  40         reqheader += struct.pack("!B", len(hostname))
  41     portstr = struct.pack("!H",port)
  42     return "%s%s%s"%(reqheader,hostname,portstr)
  43
  44 def socks5ParseResponse(r):
  45     if len(r)<8:
  46         return None
  47     version, reply, rsv, atype = struct.unpack("!BBBB",r[:4])
  48     assert version==5
  49     assert rsv==0
  50     if reply != 0x00:
  51         return "ERROR",reply
  52     assert atype in (0x01,0x03,0x04)
  53     if atype != 0x03:
  54         expected_len = 4 + ({1:4,4:16}[atype]) + 2
  55         if len(r) < expected_len:
  56             return None
  57         elif len(r) > expected_len:
  58             raise ValueError("Overlong socks5 reply!")
  59         addr = r[4:-2]
  60         if atype == 0x01:
  61             return "%d.%d.%d.%d"%tuple(map(ord,addr))
  62         else:
  63             # not really the right way to format IPv6
  64             return "IPv6: %s"%(":".join([hex(ord(c)) for c in addr]))
  65     else:
  66         hlen, = struct.unpack("!B", r[4])
  67         expected_len = 5 + hlen + 2
  68         if len(r) < expected_len:
  69             return None
  70         return r[5:-2]
  71
  72 def socks5ResolvePTRRequest(hostname):
  73     return socks5ResolveRequest(socket.inet_aton(hostname),
  74                                 atype=1, command = 0xF1)
  75
  76
  77 def parseHostAndPort(h):
  78     host, port = "localhost", 9050
  79     if ":" in h:
  80         i = h.index(":")
  81         host = h[:i]
  82         try:
  83             port = int(h[i+1:])
  84         except ValueError:
  85             print "Bad hostname %r"%h
  86             sys.exit(1)
  87     elif h:
  88         try:
  89             port = int(h)
  90         except ValueError:
  91             host = h
  92
  93     return host, port
  94
  95 def resolve(hostname, sockshost, socksport, socksver=4, reverse=0):
  96     assert socksver in (4,5)
  97     if socksver == 4:
  98         fmt = socks4AResolveRequest
  99         parse = socks4AParseResponse
 100     elif not reverse:
 101         fmt = socks5ResolveRequest
 102         parse = socks5ParseResponse
 103     else:
 104         fmt = socks5ResolvePTRRequest
 105         parse = socks5ParseResponse
 106
 107     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 108     s.connect((sockshost,socksport))
 109     if socksver == 5:
 110         s.send(socks5Hello())
 111         socks5ParseHello(s.recv(2))
 112     s.send(fmt(hostname))
 113     answer = s.recv(6)
 114     result = parse(answer)
 115     while result is None:
 116         more = s.recv(1)
 117         if not more:
 118             return None
 119         answer += more
 120         result = parse(answer)
 121     print "Got answer",result
 122     m = s.recv(1)
 123     if m:
 124         print "Got extra data too: %r"%m
 125     return result
 126
 127 if __name__ == '__main__':
 128     if len(sys.argv) not in (2,3,4):
 129         print "Syntax: resolve.py [-4|-5] hostname [sockshost:socksport]"
 130         sys.exit(0)
 131     socksver = 4
 132     reverse = 0
 133     while sys.argv[1][0] == '-':
 134         if sys.argv[1] in ("-4", "-5"):
 135             socksver = int(sys.argv[1][1])
 136             del sys.argv[1]
 137         elif sys.argv[1] == '-x':
 138             reverse = 1
 139             del sys.argv[1]
 140         elif sys.argv[1] == '--':
 141             break
 142
 143     if len(sys.argv) >= 4:
 144         print "Syntax: resolve.py [-x] [-4|-5] hostname [sockshost:socksport]"
 145         sys.exit(0)
 146     if len(sys.argv) == 3:
 147         sh,sp = parseHostAndPort(sys.argv[2])
 148     else:
 149         sh,sp = parseHostAndPort("")
 150
 151     if reverse and socksver == 4:
 152         socksver = 5
 153     resolve(sys.argv[1], sh, sp, socksver, reverse)