socks.py (8861B)
1 # Public Domain SOCKS proxy protocol implementation 2 # Adapted from https://gist.github.com/bluec0re/cafd3764412967417fd3 3 4 from __future__ import unicode_literals 5 6 # References: 7 # SOCKS4 protocol http://www.openssh.com/txt/socks4.protocol 8 # SOCKS4A protocol http://www.openssh.com/txt/socks4a.protocol 9 # SOCKS5 protocol https://tools.ietf.org/html/rfc1928 10 # SOCKS5 username/password authentication https://tools.ietf.org/html/rfc1929 11 12 import collections 13 import socket 14 15 from .compat import ( 16 compat_ord, 17 compat_struct_pack, 18 compat_struct_unpack, 19 ) 20 21 __author__ = 'Timo Schmid <coding@timoschmid.de>' 22 23 SOCKS4_VERSION = 4 24 SOCKS4_REPLY_VERSION = 0x00 25 # Excerpt from SOCKS4A protocol: 26 # if the client cannot resolve the destination host's domain name to find its 27 # IP address, it should set the first three bytes of DSTIP to NULL and the last 28 # byte to a non-zero value. 29 SOCKS4_DEFAULT_DSTIP = compat_struct_pack('!BBBB', 0, 0, 0, 0xFF) 30 31 SOCKS5_VERSION = 5 32 SOCKS5_USER_AUTH_VERSION = 0x01 33 SOCKS5_USER_AUTH_SUCCESS = 0x00 34 35 36 class Socks4Command(object): 37 CMD_CONNECT = 0x01 38 CMD_BIND = 0x02 39 40 41 class Socks5Command(Socks4Command): 42 CMD_UDP_ASSOCIATE = 0x03 43 44 45 class Socks5Auth(object): 46 AUTH_NONE = 0x00 47 AUTH_GSSAPI = 0x01 48 AUTH_USER_PASS = 0x02 49 AUTH_NO_ACCEPTABLE = 0xFF # For server response 50 51 52 class Socks5AddressType(object): 53 ATYP_IPV4 = 0x01 54 ATYP_DOMAINNAME = 0x03 55 ATYP_IPV6 = 0x04 56 57 58 class ProxyError(socket.error): 59 ERR_SUCCESS = 0x00 60 61 def __init__(self, code=None, msg=None): 62 if code is not None and msg is None: 63 msg = self.CODES.get(code) or 'unknown error' 64 super(ProxyError, self).__init__(code, msg) 65 66 67 class InvalidVersionError(ProxyError): 68 def __init__(self, expected_version, got_version): 69 msg = ('Invalid response version from server. Expected {0:02x} got ' 70 '{1:02x}'.format(expected_version, got_version)) 71 super(InvalidVersionError, self).__init__(0, msg) 72 73 74 class Socks4Error(ProxyError): 75 ERR_SUCCESS = 90 76 77 CODES = { 78 91: 'request rejected or failed', 79 92: 'request rejected because SOCKS server cannot connect to identd on the client', 80 93: 'request rejected because the client program and identd report different user-ids' 81 } 82 83 84 class Socks5Error(ProxyError): 85 ERR_GENERAL_FAILURE = 0x01 86 87 CODES = { 88 0x01: 'general SOCKS server failure', 89 0x02: 'connection not allowed by ruleset', 90 0x03: 'Network unreachable', 91 0x04: 'Host unreachable', 92 0x05: 'Connection refused', 93 0x06: 'TTL expired', 94 0x07: 'Command not supported', 95 0x08: 'Address type not supported', 96 0xFE: 'unknown username or invalid password', 97 0xFF: 'all offered authentication methods were rejected' 98 } 99 100 101 class ProxyType(object): 102 SOCKS4 = 0 103 SOCKS4A = 1 104 SOCKS5 = 2 105 106 107 Proxy = collections.namedtuple('Proxy', ( 108 'type', 'host', 'port', 'username', 'password', 'remote_dns')) 109 110 111 class sockssocket(socket.socket): 112 def __init__(self, *args, **kwargs): 113 self._proxy = None 114 super(sockssocket, self).__init__(*args, **kwargs) 115 116 def setproxy(self, proxytype, addr, port, rdns=True, username=None, password=None): 117 assert proxytype in (ProxyType.SOCKS4, ProxyType.SOCKS4A, ProxyType.SOCKS5) 118 119 self._proxy = Proxy(proxytype, addr, port, username, password, rdns) 120 121 def recvall(self, cnt): 122 data = b'' 123 while len(data) < cnt: 124 cur = self.recv(cnt - len(data)) 125 if not cur: 126 raise EOFError('{0} bytes missing'.format(cnt - len(data))) 127 data += cur 128 return data 129 130 def _recv_bytes(self, cnt): 131 data = self.recvall(cnt) 132 return compat_struct_unpack('!{0}B'.format(cnt), data) 133 134 @staticmethod 135 def _len_and_data(data): 136 return compat_struct_pack('!B', len(data)) + data 137 138 def _check_response_version(self, expected_version, got_version): 139 if got_version != expected_version: 140 self.close() 141 raise InvalidVersionError(expected_version, got_version) 142 143 def _resolve_address(self, destaddr, default, use_remote_dns): 144 try: 145 return socket.inet_aton(destaddr) 146 except socket.error: 147 if use_remote_dns and self._proxy.remote_dns: 148 return default 149 else: 150 return socket.inet_aton(socket.gethostbyname(destaddr)) 151 152 def _setup_socks4(self, address, is_4a=False): 153 destaddr, port = address 154 155 ipaddr = self._resolve_address(destaddr, SOCKS4_DEFAULT_DSTIP, use_remote_dns=is_4a) 156 157 packet = compat_struct_pack('!BBH', SOCKS4_VERSION, Socks4Command.CMD_CONNECT, port) + ipaddr 158 159 username = (self._proxy.username or '').encode('utf-8') 160 packet += username + b'\x00' 161 162 if is_4a and self._proxy.remote_dns: 163 packet += destaddr.encode('utf-8') + b'\x00' 164 165 self.sendall(packet) 166 167 version, resp_code, dstport, dsthost = compat_struct_unpack('!BBHI', self.recvall(8)) 168 169 self._check_response_version(SOCKS4_REPLY_VERSION, version) 170 171 if resp_code != Socks4Error.ERR_SUCCESS: 172 self.close() 173 raise Socks4Error(resp_code) 174 175 return (dsthost, dstport) 176 177 def _setup_socks4a(self, address): 178 self._setup_socks4(address, is_4a=True) 179 180 def _socks5_auth(self): 181 packet = compat_struct_pack('!B', SOCKS5_VERSION) 182 183 auth_methods = [Socks5Auth.AUTH_NONE] 184 if self._proxy.username and self._proxy.password: 185 auth_methods.append(Socks5Auth.AUTH_USER_PASS) 186 187 packet += compat_struct_pack('!B', len(auth_methods)) 188 packet += compat_struct_pack('!{0}B'.format(len(auth_methods)), *auth_methods) 189 190 self.sendall(packet) 191 192 version, method = self._recv_bytes(2) 193 194 self._check_response_version(SOCKS5_VERSION, version) 195 196 if method == Socks5Auth.AUTH_NO_ACCEPTABLE or ( 197 method == Socks5Auth.AUTH_USER_PASS and (not self._proxy.username or not self._proxy.password)): 198 self.close() 199 raise Socks5Error(Socks5Auth.AUTH_NO_ACCEPTABLE) 200 201 if method == Socks5Auth.AUTH_USER_PASS: 202 username = self._proxy.username.encode('utf-8') 203 password = self._proxy.password.encode('utf-8') 204 packet = compat_struct_pack('!B', SOCKS5_USER_AUTH_VERSION) 205 packet += self._len_and_data(username) + self._len_and_data(password) 206 self.sendall(packet) 207 208 version, status = self._recv_bytes(2) 209 210 self._check_response_version(SOCKS5_USER_AUTH_VERSION, version) 211 212 if status != SOCKS5_USER_AUTH_SUCCESS: 213 self.close() 214 raise Socks5Error(Socks5Error.ERR_GENERAL_FAILURE) 215 216 def _setup_socks5(self, address): 217 destaddr, port = address 218 219 ipaddr = self._resolve_address(destaddr, None, use_remote_dns=True) 220 221 self._socks5_auth() 222 223 reserved = 0 224 packet = compat_struct_pack('!BBB', SOCKS5_VERSION, Socks5Command.CMD_CONNECT, reserved) 225 if ipaddr is None: 226 destaddr = destaddr.encode('utf-8') 227 packet += compat_struct_pack('!B', Socks5AddressType.ATYP_DOMAINNAME) 228 packet += self._len_and_data(destaddr) 229 else: 230 packet += compat_struct_pack('!B', Socks5AddressType.ATYP_IPV4) + ipaddr 231 packet += compat_struct_pack('!H', port) 232 233 self.sendall(packet) 234 235 version, status, reserved, atype = self._recv_bytes(4) 236 237 self._check_response_version(SOCKS5_VERSION, version) 238 239 if status != Socks5Error.ERR_SUCCESS: 240 self.close() 241 raise Socks5Error(status) 242 243 if atype == Socks5AddressType.ATYP_IPV4: 244 destaddr = self.recvall(4) 245 elif atype == Socks5AddressType.ATYP_DOMAINNAME: 246 alen = compat_ord(self.recv(1)) 247 destaddr = self.recvall(alen) 248 elif atype == Socks5AddressType.ATYP_IPV6: 249 destaddr = self.recvall(16) 250 destport = compat_struct_unpack('!H', self.recvall(2))[0] 251 252 return (destaddr, destport) 253 254 def _make_proxy(self, connect_func, address): 255 if not self._proxy: 256 return connect_func(self, address) 257 258 result = connect_func(self, (self._proxy.host, self._proxy.port)) 259 if result != 0 and result is not None: 260 return result 261 setup_funcs = { 262 ProxyType.SOCKS4: self._setup_socks4, 263 ProxyType.SOCKS4A: self._setup_socks4a, 264 ProxyType.SOCKS5: self._setup_socks5, 265 } 266 setup_funcs[self._proxy.type](address) 267 return result 268 269 def connect(self, address): 270 self._make_proxy(socket.socket.connect, address) 271 272 def connect_ex(self, address): 273 return self._make_proxy(socket.socket.connect_ex, address)