aboutsummaryrefslogtreecommitdiff
path: root/youtube_dl/socks.py
blob: fece280626606453f378d44a533bb167e656a30f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
# Public Domain SOCKS proxy protocol implementation
# Adapted from https://gist.github.com/bluec0re/cafd3764412967417fd3

from __future__ import unicode_literals

# References:
# SOCKS4 protocol http://www.openssh.com/txt/socks4.protocol
# SOCKS4A protocol http://www.openssh.com/txt/socks4a.protocol
# SOCKS5 protocol https://tools.ietf.org/html/rfc1928
# SOCKS5 username/password authentication https://tools.ietf.org/html/rfc1929

import collections
import socket

from .compat import (
    compat_ord,
    compat_struct_pack,
    compat_struct_unpack,
)

__author__ = 'Timo Schmid <coding@timoschmid.de>'

SOCKS4_VERSION = 4
SOCKS4_REPLY_VERSION = 0x00
# Excerpt from SOCKS4A protocol:
# if the client cannot resolve the destination host's domain name to find its
# IP address, it should set the first three bytes of DSTIP to NULL and the last
# byte to a non-zero value.
SOCKS4_DEFAULT_DSTIP = compat_struct_pack('!BBBB', 0, 0, 0, 0xFF)

SOCKS5_VERSION = 5
SOCKS5_USER_AUTH_VERSION = 0x01
SOCKS5_USER_AUTH_SUCCESS = 0x00


class Socks4Command(object):
    CMD_CONNECT = 0x01
    CMD_BIND = 0x02


class Socks5Command(Socks4Command):
    CMD_UDP_ASSOCIATE = 0x03


class Socks5Auth(object):
    AUTH_NONE = 0x00
    AUTH_GSSAPI = 0x01
    AUTH_USER_PASS = 0x02
    AUTH_NO_ACCEPTABLE = 0xFF  # For server response


class Socks5AddressType(object):
    ATYP_IPV4 = 0x01
    ATYP_DOMAINNAME = 0x03
    ATYP_IPV6 = 0x04


class ProxyError(IOError):
    ERR_SUCCESS = 0x00

    def __init__(self, code=None, msg=None):
        if code is not None and msg is None:
            msg = self.CODES.get(code) or 'unknown error'
        super(ProxyError, self).__init__(code, msg)


class InvalidVersionError(ProxyError):
    def __init__(self, expected_version, got_version):
        msg = ('Invalid response version from server. Expected {0:02x} got '
               '{1:02x}'.format(expected_version, got_version))
        super(InvalidVersionError, self).__init__(0, msg)


class Socks4Error(ProxyError):
    ERR_SUCCESS = 90

    CODES = {
        91: 'request rejected or failed',
        92: 'request rejected because SOCKS server cannot connect to identd on the client',
        93: 'request rejected because the client program and identd report different user-ids'
    }


class Socks5Error(ProxyError):
    ERR_GENERAL_FAILURE = 0x01

    CODES = {
        0x01: 'general SOCKS server failure',
        0x02: 'connection not allowed by ruleset',
        0x03: 'Network unreachable',
        0x04: 'Host unreachable',
        0x05: 'Connection refused',
        0x06: 'TTL expired',
        0x07: 'Command not supported',
        0x08: 'Address type not supported',
        0xFE: 'unknown username or invalid password',
        0xFF: 'all offered authentication methods were rejected'
    }


class ProxyType(object):
    SOCKS4 = 0
    SOCKS4A = 1
    SOCKS5 = 2


Proxy = collections.namedtuple('Proxy', (
    'type', 'host', 'port', 'username', 'password', 'remote_dns'))


class sockssocket(socket.socket):
    def __init__(self, *args, **kwargs):
        self._proxy = None
        super(sockssocket, self).__init__(*args, **kwargs)

    def setproxy(self, proxytype, addr, port, rdns=True, username=None, password=None):
        assert proxytype in (ProxyType.SOCKS4, ProxyType.SOCKS4A, ProxyType.SOCKS5)

        self._proxy = Proxy(proxytype, addr, port, username, password, rdns)

    def recvall(self, cnt):
        data = b''
        while len(data) < cnt:
            cur = self.recv(cnt - len(data))
            if not cur:
                raise IOError('{0} bytes missing'.format(cnt - len(data)))
            data += cur
        return data

    def _recv_bytes(self, cnt):
        data = self.recvall(cnt)
        return compat_struct_unpack('!{0}B'.format(cnt), data)

    @staticmethod
    def _len_and_data(data):
        return compat_struct_pack('!B', len(data)) + data

    def _check_response_version(self, expected_version, got_version):
        if got_version != expected_version:
            self.close()
            raise InvalidVersionError(expected_version, got_version)

    def _resolve_address(self, destaddr, default, use_remote_dns):
        try:
            return socket.inet_aton(destaddr)
        except socket.error:
            if use_remote_dns and self._proxy.remote_dns:
                return default
            else:
                return socket.inet_aton(socket.gethostbyname(destaddr))

    def _setup_socks4(self, address, is_4a=False):
        destaddr, port = address

        ipaddr = self._resolve_address(destaddr, SOCKS4_DEFAULT_DSTIP, use_remote_dns=is_4a)

        packet = compat_struct_pack('!BBH', SOCKS4_VERSION, Socks4Command.CMD_CONNECT, port) + ipaddr

        username = (self._proxy.username or '').encode('utf-8')
        packet += username + b'\x00'

        if is_4a and self._proxy.remote_dns:
            packet += destaddr.encode('utf-8') + b'\x00'

        self.sendall(packet)

        version, resp_code, dstport, dsthost = compat_struct_unpack('!BBHI', self.recvall(8))

        self._check_response_version(SOCKS4_REPLY_VERSION, version)

        if resp_code != Socks4Error.ERR_SUCCESS:
            self.close()
            raise Socks4Error(resp_code)

        return (dsthost, dstport)

    def _setup_socks4a(self, address):
        self._setup_socks4(address, is_4a=True)

    def _socks5_auth(self):
        packet = compat_struct_pack('!B', SOCKS5_VERSION)

        auth_methods = [Socks5Auth.AUTH_NONE]
        if self._proxy.username and self._proxy.password:
            auth_methods.append(Socks5Auth.AUTH_USER_PASS)

        packet += compat_struct_pack('!B', len(auth_methods))
        packet += compat_struct_pack('!{0}B'.format(len(auth_methods)), *auth_methods)

        self.sendall(packet)

        version, method = self._recv_bytes(2)

        self._check_response_version(SOCKS5_VERSION, version)

        if method == Socks5Auth.AUTH_NO_ACCEPTABLE:
            self.close()
            raise Socks5Error(method)

        if method == Socks5Auth.AUTH_USER_PASS:
            username = self._proxy.username.encode('utf-8')
            password = self._proxy.password.encode('utf-8')
            packet = compat_struct_pack('!B', SOCKS5_USER_AUTH_VERSION)
            packet += self._len_and_data(username) + self._len_and_data(password)
            self.sendall(packet)

            version, status = self._recv_bytes(2)

            self._check_response_version(SOCKS5_USER_AUTH_VERSION, version)

            if status != SOCKS5_USER_AUTH_SUCCESS:
                self.close()
                raise Socks5Error(Socks5Error.ERR_GENERAL_FAILURE)

    def _setup_socks5(self, address):
        destaddr, port = address

        ipaddr = self._resolve_address(destaddr, None, use_remote_dns=True)

        self._socks5_auth()

        reserved = 0
        packet = compat_struct_pack('!BBB', SOCKS5_VERSION, Socks5Command.CMD_CONNECT, reserved)
        if ipaddr is None:
            destaddr = destaddr.encode('utf-8')
            packet += compat_struct_pack('!B', Socks5AddressType.ATYP_DOMAINNAME)
            packet += self._len_and_data(destaddr)
        else:
            packet += compat_struct_pack('!B', Socks5AddressType.ATYP_IPV4) + ipaddr
        packet += compat_struct_pack('!H', port)

        self.sendall(packet)

        version, status, reserved, atype = self._recv_bytes(4)

        self._check_response_version(SOCKS5_VERSION, version)

        if status != Socks5Error.ERR_SUCCESS:
            self.close()
            raise Socks5Error(status)

        if atype == Socks5AddressType.ATYP_IPV4:
            destaddr = self.recvall(4)
        elif atype == Socks5AddressType.ATYP_DOMAINNAME:
            alen = compat_ord(self.recv(1))
            destaddr = self.recvall(alen)
        elif atype == Socks5AddressType.ATYP_IPV6:
            destaddr = self.recvall(16)
        destport = compat_struct_unpack('!H', self.recvall(2))[0]

        return (destaddr, destport)

    def _make_proxy(self, connect_func, address):
        if not self._proxy:
            return connect_func(self, address)

        result = connect_func(self, (self._proxy.host, self._proxy.port))
        if result != 0 and result is not None:
            return result
        setup_funcs = {
            ProxyType.SOCKS4: self._setup_socks4,
            ProxyType.SOCKS4A: self._setup_socks4a,
            ProxyType.SOCKS5: self._setup_socks5,
        }
        setup_funcs[self._proxy.type](address)
        return result

    def connect(self, address):
        self._make_proxy(socket.socket.connect, address)

    def connect_ex(self, address):
        return self._make_proxy(socket.socket.connect_ex, address)