Python Connect over HTTP proxy with pysftp

Question

Currently, I am doing SFTP transfer using Python subprocess.POPEN and PuTTY psftp.exe.

It is working, but not really clean nor transportable.

I would like to reproduce the same behavior using Python pysftp, but I do not know where to input all the parameters. I have in PuTTY the following configuration:

• Server IP : 123.123.123.255
• Server Port : 22
• Connection Type : SSH
• AutoLogin UserName : MyUser
• Proxy type : HTTP
• Proxy Hostname : gw.proxy.fr
• Proxy port : 1234
• Proxy Username : ProxyUser
• Proxy Password: ProxyPass

How should I input all these parameters in pysftp so I can retrieve my files?

EDIT: Using the answer from Martin Prikryl, I found some new stuffs to explore. If I understand well, I need to use a socket. Put I still have some problem to input all the information I need.

import socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
proxy = ("gw.proxy.fr",1234)
sock.connect(proxy)
target=("123.123.123.255",23)
cmd_connect = "CONNECT {}:{} HTTP/1.1\r\n\r\n".format(*target)
sock.sendall(cmd_connect)

The respond that I receive from this is HTTP/1.0 407 Proxy Authentication Required, which is kind of normal because I did not use the Proxy authentication information anywhere. So, do you have any idea how I can use them and input them into my socket ?

Answer 1

I do not think that the pysftp supports proxies. Though note that the pysftp is just a wrapper around Paramiko library, which does support proxies.

So I suggest you to use Paramiko directly.

For a start see How to ssh over HTTP proxy in Python Paramiko?, particularly the answer by @tintin.

---

To authenticate to the proxy, after the CONNECT command, add a Proxy-Authorization header like:

Proxy-Authorization: Basic <credentials>

where the <credentials> is base-64 encoded string username:password.

auth = 'Basic ' + base64.encodebytes("username:password".encode()).decode()
args = ("123.123.123.255", 23, auth)
cmd_connect = "CONNECT {}:{} HTTP/1.1\r\nProxy-Authorization: {}\r\n\r\n".format(*args)

Answer 2

In my case, I do this:

import pysftp
import paramiko

hostname, prot = 'some.host.name', 22
proxy = paramiko.proxy.ProxyCommand('/usr/bin/nc --proxy proxy.foobar:8080 %s %d' % (hostname, port))
t = paramiko.Transport(sock=proxy)
t.connect(username='abc', password='123')

sftp = paramiko.SFTPClient.from_transport(t) # back to pysftp wrapper
sftp.listdir('.')