EOFError when transferring a file to dropbear with paramiko

Question

I want to transfer a file to a dropbear ssh server with paramiko. I use this file (ssh_own.py):

#!/usr/bin/python3.6

import paramiko
import paramiko

from paramiko import client
class ssh:
    client = None

    def __init__(self, address, username, password):
        print("Connecting to server.")
        self.client = client.SSHClient()
        self.client.set_missing_host_key_policy(client.AutoAddPolicy())
        self.client.connect(address,
                username = username,
                password = password,
                look_for_keys=False)

    def sendCommand(self,
                command):
        if(self.client):
            stdin, stdout, stderr = self.client.exec_command(command)

            output = []
            while not stdout.channel.exit_status_ready():
                portion = stdout.readlines()
#               print(portion)
                if len(portion) > 0:
                    output.append(portion)
            result = self.output_to_string(output)
            return result
        else:
            raise Exception("Connection not opened.")

    def output_to_string(self, output):
        result = ""
        for line in output:
            for el in line:
#               result += str(line, "utf8")
                result += el
        return result

and another small file to make the request (test.py):

#!/usr/bin/python3.6

import ssh_own
import os

home = os.environ["HOME"]

ssh_client = ssh_own.ssh("ip", "username", "password")
ftp_client = ssh_client.client.open_sftp()
ftp_client.put("/home/localuser/README.md", "/home/username/README.md")
ftp_client.close()

When I run ssh_own.py, I get this error:

Connecting to server.
Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/paramiko/sftp_client.py", line 103, in __init__
    server_version = self._send_version()
  File "/usr/local/lib/python3.6/dist-packages/paramiko/sftp.py", line 107, in _send_version
    t, data = self._read_packet()
  File "/usr/local/lib/python3.6/dist-packages/paramiko/sftp.py", line 174, in _read_packet
    x = self._read_all(4)
  File "/usr/local/lib/python3.6/dist-packages/paramiko/sftp.py", line 161, in _read_all
    raise EOFError()
EOFError

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "./test.py", line 13, in <module>
    ftp_client = ssh_client.client.open_sftp()
  File "/usr/local/lib/python3.6/dist-packages/paramiko/client.py", line 521, in open_sftp
    return self._transport.open_sftp_client()
  File "/usr/local/lib/python3.6/dist-packages/paramiko/transport.py", line 980, in open_sftp_client
    return SFTPClient.from_transport(self)
  File "/usr/local/lib/python3.6/dist-packages/paramiko/sftp_client.py", line 140, in from_transport
    return cls(chan)
  File "/usr/local/lib/python3.6/dist-packages/paramiko/sftp_client.py", line 105, in __init__
    raise SSHException('EOF during negotiation')
paramiko.ssh_exception.SSHException: EOF during negotiation

Does anyone know whether it is possible to do a file transfer to a dropbear server from paramiko? Or is it just not compatible? I also tested this with another Ubuntu machine running openssh and there it worked fine.

Answer 1

It turns out I had to install stfp since dropbear seems to not have this and paramiko uses sftp for file transfer. scp worked fine with dropbear, however, that's what confused me firsthand. After installing sftp, all file transfers with paramiko worked fine.