[Fab-user] pubkey authentication

[Ney, Daniel]

Hi All,

I have been chasing an intermittent issue. I have tried multiple versions of paramiko (1.10, 1.11, 1.12) and fabric (1.6, 1.8). My test bed is currently running Python 2.7, Fabric 1.8.1, Paramiko 1.12.1 and Crypto 2.6.1. I am using public key authentication and the authentication fails about 1 out of 100 times. The code below reproduces the issue:


#!/usr/bin/env python

# -*- coding: utf-8 -*-
"""
Created on Tue Jan 28 08:13:08 2014
@author: dney
"""

from fabric.api import *

env.key_filename = '/home/dney/.ssh/key.pub'
env.hosts = [ '192.168.224.63' ]
env.shell = '/bin/sh -c'
env.path = '/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin:/sbin'
env.user = 'root'
env.eagerly_disconnect = True

@task
def run_hostname():
run('hostname')

for x in xrange(1000):
execute(run_hostname)
print 'Ran ', x, ' times'


When the code above is run, it eventually hits the exception in client.py at line 470. At the time of the exception, the server-side of the session displays:

Jan 1 02:43:58 ut authpriv.warn dropbear[8649]: pubkey auth bad signature for 'root'

So I guess the private key is not being generated in correctly and causes the signing encryption of the key to be incorrect 1% of the time. I was wondering if anyone has any insights into this issue and how to fix it?

Thanks in advance,
Dan