Motivation:

• Adds PyPy support
• Performance improvement
• OpenSSL and friends are better audited than PyCrypto
• Easier windows install flow (Cryptography provides statically linked wheels on Windows)

This PR is basically complete on the code side, of course it can always use more review :-)

Tests all pass locally (tested with PyPy!)

Still needs some docs work, and to figure out how to do this with the version numbers so people's stuff doesn't suddenly get broken.

I have Paramiko running on Python 3 at https://github.com/goertzenator/paramiko

All unit tests, except for sftp, pass. Needs documentation updates for the many str -> bytes changes.

Looking for advice on what to do with this. Adding a python 3 branch to paramiko would have a lot of complications...

I have extended the RSAKey class to support the [email protected] type of certificate authentication in a new RSACert class. A test case was added to test_pkey.py to test loading an RSA certificate (a signed public key that's the same one given in the tests already). I think this class should be a reasonable example from which DSS and ECDSA certificate classes can also be created.

Let me know what you think!

Jason

Fix to #949 - thanks @agronick for discovering and debugging the problem.

Caused by a fix in #891. But, it's a matter of choice and policy.

This should also be back-ported to 1.17.z

(This issue description has been updated.)

The back-reference from Transport to SSHClient was added because the SSHClient had a destructor that would close the Transport, and some users did not want the Transport closed when the SSHClient was garbage collected.

The SSHClient destructor was not a normal destructor, it was implemented with the ResourceManager singleton. This sometimes prevented the GC cycle detector from freeing the SSHClient and Transport even after the Transport Thread stopped running.

We can simplify these problems by just getting rid of the ResourceManager, and the back-reference. Transports cannot be garbage-collected while their Thread is running, .close() must be called (on the SSHClient or the Transport).

These are specified in RFC 8332 (https://tools.ietf.org/html/rfc8332) and proposed by recent OpenSSH versions as a drop-in replacement for the deprecated ssh-rsa algorithm. The advantage is that the same RSA keys can be used without relying on the SHA-1 digest now considered insecure.

This is based on forks by EtiennePerot and ashb who did most of the work. Changing the remaining sha1 references in transport.py let's me connect to hardened openssh servers again.

How I got here:

$ git checkout scottkmaxwell/py3-support-without-py25
$ python test.py # verified
$ git checkout -b python3 master
$ git merge scottkmaxwell/py3-support-without-py25 -Xignore-space-change

Then poking at all the conflicts, some of which required the following (given that I shuffled some files around in #256, this made it a lot easier to figure out what the incoming branch had actually changed):

$ git show master:paramiko/<module>.py > paramiko/<module>.py
$ vim paramiko/<module>.py
$ git diff 28d78e4e6a33d2e23af196db632e6eeda4167e24 scottkmaxwell/py3-support-without-py25 -- paramiko/<module>.py
<manually apply changes as needed>

And now trying to ensure that the test suite passes again.

Hi Robey,

Your download url to lag.net is not currently working. Would you mind uploading the 1.7.6 zip file to paramiko's pypi page instead of using the download url that points to lag.net?

~Justin

This adds pkcs11 support to enable using paramiko with smartcards. I have a forked version of Ansible that uses this feature and its working great.

I have tested on python 2.7 and python 3.6.2

Multithreading Example:

import paramiko
from multiprocessing import Queue
from threading import Thread

pkcs11provider="/usr/local/lib/opensc-pkcs11.so"
smartcard_pin="123456"

def do_it(q):
    session = q.get()
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect("HOSTNAME", username="USERNAME", pkcs11_session=session)
    stdin, stdout, stderr = ssh.exec_command("uname -a")
    for line in stdout:
        print(line)

q = Queue()
session = paramiko.pkcs11.open_session(pkcs11provider, smartcard_pin)
mythread = Thread(target=do_it, args=(q,))
q.put(session)
mythread.start()
mythread.join()
paramiko.pkcs11.close_session(session)

Basic Example:

import paramiko

pkcs11provider="/usr/local/lib/opensc-pkcs11.so"
smartcard_pin="123456"

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
session = paramiko.pkcs11.open_session(pkcs11provider, smartcard_pin)
ssh.connect("HOSTNAME", username="USERNAME", pkcs11_session=session)
paramiko.pkcs11.close_session(session)
stdin, stdout, stderr = ssh.exec_command("uname -a")
for line in stdout:
    print(line)

Exception in thread Thread-12 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/local/lib/python2.5/threading.py", line 486, in __bootstrap_inner
  File "build/bdist.freebsd-8.2-RELEASE-i386/egg/paramiko/transport.py", line 1574, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'
Exception in thread Thread-13 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/local/lib/python2.5/threading.py", line 486, in __bootstrap_inner
  File "build/bdist.freebsd-8.2-RELEASE-i386/egg/paramiko/transport.py", line 1574, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'
Exception in thread Thread-9 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/local/lib/python2.5/threading.py", line 486, in __bootstrap_inner
  File "build/bdist.freebsd-8.2-RELEASE-i386/egg/paramiko/transport.py", line 1574, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'
Exception in thread Thread-8 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/local/lib/python2.5/threading.py", line 486, in __bootstrap_inner
  File "build/bdist.freebsd-8.2-RELEASE-i386/egg/paramiko/transport.py", line 1574, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'
Exception in thread Thread-3 (most likely raised during interpreter shutdown):
Traceback (most recent call last):
  File "/usr/local/lib/python2.5/threading.py", line 486, in __bootstrap_inner
  File "build/bdist.freebsd-8.2-RELEASE-i386/egg/paramiko/transport.py", line 1574, in run
<type 'exceptions.AttributeError'>: 'NoneType' object has no attribute 'error'

Edited to add: this ticket began life under assumption the issues were Travis-specific, but it seems more likely that Travis and/or the test suite are just exacerbating underlying, real problems. Specifically, a race condition shown in test_L_handshake_timeout.

The other issue, centering on test_3_multiple_key_files, seems unrelated & received at least some workarounds/fixes mid-ticket, and should be considered closed for now.

Original description follows.

These were most often seen under Python 3.2, which has been nixed, but they pop up on other interpreters as well (for example https://travis-ci.org/paramiko/paramiko/builds/89238099 hit them 3 times in one build!) and it seems to be getting worse.

The problems appear to be most easily replicated under Python 3 but we've had at least a few confirmed reports of it occurring on Python 2 as well (though as per below comments I've been unable to reproduce it locally - only on Travis).

The specific examples that appear to occur are:

• test_L_handshake_timeout fails with AssertionError: EOFError not raised by connect: https://travis-ci.org/paramiko/paramiko/jobs/89548222#L505
• No output has been received in the last 10 minutes hangs/kills, often (always? needs lots of scanning) while running test_3_multiple_key_files (test_client.SSHClientTest): https://travis-ci.org/paramiko/paramiko/jobs/89548214#L464

I'm trying to ssh to Tmate, a popular terminal sharing server. Via ssh, the process is easy: ssh {user_name}/{sess_name}@sgp1.tmate.io

But Paramiko doesn't seem to be able to do that. I get those types of errors:

IncompatiblePeer: Incompatible ssh server (no acceptable compression) [] [] ('none',)

or 

SSHException: Error reading SSH protocol banner

Is this possible at all? What is missing here?

On Linux & Solaris 10, the following code works but if it is Solaris 11, it throws the following error message paramiko.ssh_exception.AuthenticationException: Authentication failed.. The credentials/authentication details are correct. The host, username and password are all correct but for some reason it complains about Authentication failure. I know that Solaris 11 has much more beefed up security. Is there any thing else I need to add to my code to get this to work? (more details below):

` def setup_remote_gateway_client_connection(self, gateway_host, gateway_username, gateway_password, client_host, client_username, client_password, gateway_port=22, client_port=22): self.gateway_host=paramiko.SSHClient() self.gateway_host.set_missing_host_key_policy(paramiko.AutoAddPolicy()) self.gateway_host.connect(gateway_host, username=gateway_username, password=gateway_password )

    gateway_transport = self.gateway_host.get_transport()
    src_addr = (gateway_host, gateway_port)
    dest_addr = (client_host, client_port)
    gateway_channel = gateway_transport.open_channel("direct-tcpip", dest_addr, src_addr)

    client_host=paramiko.SSHClient()
    client_host.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    client_host.connect(client_host, username=client_username, password=client_password, sock=gateway_channel)

    stdin, stdout, stderr = client_host.exec_command('ls -la')
    for line in stdout.read().split(b'\n'):
      print(str(line))

    stdin, stdout, stderr = client_host.exec_command('hostname')
    for line in stdout.read().split(b'\n'):
      print(str(line))

    client_host.close()
    self.gateway_host.close()`

Upon execution, I get the following:

`fixture.py:28: in setup_remote_gateway_client_connection client_host.connect(client_host, username=client_username, password=client_password, sock=gateway_channel) /usr/local/lib/python3.10/site-packages/paramiko/client.py:450: in connect self._auth( /usr/local/lib/python3.10/site-packages/paramiko/client.py:781: in _auth raise saved_exception /usr/local/lib/python3.10/site-packages/paramiko/client.py:768: in _auth self._transport.auth_password(username, password) /usr/local/lib/python3.10/site-packages/paramiko/transport.py:1564: in auth_password return self.auth_handler.wait_for_response(my_event)

self = <paramiko.auth_handler.AuthHandler object at 0x107691ae0> event = <threading.Event object at 0x107691a20>

def wait_for_response(self, event):
    max_ts = None
    if self.transport.auth_timeout is not None:
        max_ts = time.time() + self.transport.auth_timeout
    while True:
        event.wait(0.1)
        if not self.transport.is_active():
            e = self.transport.get_exception()
            if (e is None) or issubclass(e.__class__, EOFError):
                e = AuthenticationException("Authentication failed.")
            raise e
        if event.is_set():
            break
        if max_ts is not None and max_ts <= time.time():
            raise AuthenticationException("Authentication timeout.")

    if not self.is_authenticated():
        e = self.transport.get_exception()
        if e is None:
            e = AuthenticationException("Authentication failed.")
        # this is horrible.  Python Exception isn't yet descended from
        # object, so type(e) won't work. :(
        if issubclass(e.__class__, PartialAuthentication):
            return e.allowed_types

      raise e

E paramiko.ssh_exception.AuthenticationException: Authentication failed.

/usr/local/lib/python3.10/site-packages/paramiko/auth_handler.py:259: AuthenticationException`

Documentation for the NoValidConnectionsError states that:

This exception class wraps multiple “real” underlying connection errors, all of which represent failed connection attempts. Because these errors are not guaranteed to all be of the same error type (i.e. different errno, socket.error subclass, message, etc) we expose a single unified error message and a None errno so that instances of this class match most normal handling of socket.error objects.

IOW it wraps all various kinds of socket errors. However, this doesn't include calls to getaddrinfo in the _self._families_and_addresses method. IMO issuing getaddr is an inherent part of establishing connection and hence socket.gaierror exceptions should be wrapped like any other exception coming from socket.socket. This forces library users to handle both types of errors not just NoValidConnectionsError which is IMO in contradiction to the docs linked above since from client's POV both exceptions came from the same library (paramiko in this case).

To provide a bit more background, I'm using paramiko to test whether a fresh VM I created is ready to be connected to over SSH. It takes a little while until the VM reaches a state where the network is up and the VM got a DHCP lease, so naturally getaddr must fail, but that is expected, it doesn't change anything on the fact, that gaierror caused as part of client.connect should not be wrapped with NoValidConnectionsError.

#!/usr/bin/env python3

import paramiko
import os
from datetime import datetime

client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())

time1 = datetime.now()
client.connect('192.168.1.1', username='user', key_filename='/path/to/keyfile')
time2 = datetime.now()
print(time2 - time1)

output = client.exec_command('...')[1]
client.close()

The above code takes for the line client.connect() about 35 seconds each time. The device to connect to is on the same local network. Connecting via PuTTY takes about 1.5 seconds. How can this be improved? Is there a way to track in more detail the cause of the delay?