An FTP client implementation that supports sending and receiving data via SOCKS proxy using PASV transfers

ftplib_simple_proxy.py

import ftplib
import socket
import socks  # socksipy (https://github.com/mikedougherty/SocksiPy)


class FTP(ftplib.FTP):
    def __init__(self, host='', user='', passwd='', acct='',
                 timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
                 proxyconfig=None):
        """Like ftplib.FTP constructor, but with an added `proxyconfig` kwarg

        `proxyconfig` should be a dictionary that may contain the following
        keys:

        proxytype - The type of the proxy to be used. Three types
                are supported: PROXY_TYPE_SOCKS4 (including socks4a),
                PROXY_TYPE_SOCKS5 and PROXY_TYPE_HTTP
        addr -      The address of the server (IP or DNS).
        port -      The port of the server. Defaults to 1080 for SOCKS
                servers and 8080 for HTTP proxy servers.
        rdns -      Should DNS queries be preformed on the remote side
                (rather than the local side). The default is True.
                Note: This has no effect with SOCKS4 servers.
        username -  Username to authenticate with to the server.
                The default is no authentication.
        password -  Password to authenticate with to the server.
                Only relevant when username is also provided.
        """
        self.proxyconfig = proxyconfig or {}
        ftplib.FTP.__init__(self, host, user, passwd, acct, timeout)

    def connect(self, host='', port=0, timeout=-999):
        '''Connect to host.  Arguments are:
         - host: hostname to connect to (string, default previous host)
         - port: port to connect to (integer, default previous port)
        '''
        if host != '':
            self.host = host
        if port > 0:
            self.port = port
        if timeout != -999:
            self.timeout = timeout
        self.sock = self.create_connection(self.host, self.port)
        self.af = self.sock.family
        self.file = self.sock.makefile('rb')
        self.welcome = self.getresp()
        return self.welcome

    def create_connection(self, host=None, port=None):
        host, port = host or self.host, port or self.port
        if self.proxyconfig:

            phost, pport = self.proxyconfig['addr'], self.proxyconfig['port']
            err = None
            for res in socket.getaddrinfo(phost, pport, 0, socket.SOCK_STREAM):
                af, socktype, proto, canonname, sa = res
                sock = None
                try:
                    sock = socks.socksocket(af, socktype, proto)
                    sock.setproxy(**self.proxyconfig)

                    if self.timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
                        sock.settimeout(self.timeout)
                    sock.connect((host, port))
                    return sock

                except socket.error as _:
                    err = _
                    if sock is not None:
                        sock.close()

            if err is not None:
                raise err
            else:
                raise socket.error("getaddrinfo returns an empty list")
        else:
            sock = socket.create_connection((host, port), self.timeout)
        return sock

    def ntransfercmd(self, cmd, rest=None):
        size = None
        if self.passiveserver:
            host, port = self.makepasv()
            conn = self.create_connection(host, port)
            try:
                if rest is not None:
                    self.sendcmd("REST %s" % rest)
                resp = self.sendcmd(cmd)
                # Some servers apparently send a 200 reply to
                # a LIST or STOR command, before the 150 reply
                # (and way before the 226 reply). This seems to
                # be in violation of the protocol (which only allows
                # 1xx or error messages for LIST), so we just discard
                # this response.
                if resp[0] == '2':
                    resp = self.getresp()
                if resp[0] != '1':
                    raise ftplib.error_reply, resp
            except:
                conn.close()
                raise
        else:
            raise Exception("Active transfers not supported")
        if resp[:3] == '150':
            # this is conditional in case we received a 125
            size = ftplib.parse150(resp)
        return conn, size


if __name__ == '__main__':
    ftp = FTP(host='ftp.gnu.org', user='anonymous', passwd='guest',
              proxyconfig=dict(proxytype=socks.PROXY_TYPE_SOCKS5, rdns=False,
                               addr='localhost', port=1080))
    with open('autoconf-2.69.tar.xz', mode='w') as f:
        ftp.retrbinary("RETR /gnu/autoconf/autoconf-2.69.tar.xz", f.write)