Python Fabric run command returns “binascii.Error: Incorrect padding”

Question

I\'m trying to connect to connect to amazon EC2 via fabric using the script below. But I\'m met with a problem that I\'m not sure how to solve it.

import os
         


        

Answer 1

Look at your ~/.ssh/known_hosts file. It may contain lines with duplicate entries or be corrupted in some other way.

Answer 2

I saw some places where Incorrect Padding error was resulted from binascii module and it was mostly when the string you pass has some extraneous white-space characters.

>>> import binascii
>>> binascii.a2b_base64('a')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
binascii.Error: Incorrect padding

In your case, it the various properties you set for your env object. Do something like this for your key file location and see if that works.

filelocation = os.path.join(WORK,'aws/myproject.pem')
env.key_filename = [filelocation]

Answer 3

I had a similar problem and tracked it down to some corruption in my .ssh/known_hosts file.

I thus added to my .bashrc

alias deploy='mv ~/.ssh/known_hosts ~/.ssh/known_hosts.tmp; fab <myfabscript>; mv ~/.ssh/known_hosts.old ~/.ssh/known_hosts'

(obviously putting the right fabric script where <myfabscript> is) and now all works fine when I simply run "deploy"!