title: Import Error from cyptography.hazmat.bindings._constant_time import lib
body: <p>So I'm trying to create an aws lambda function, to log in to an instance and do some stuff. And the script works fine outside of lambda, but when I package it using the same instructions as this <a href="https://aws.amazon.com/blogs/compute/scheduling-ssh-jobs-using-aws-lambda/" rel="noreferrer">https://aws.amazon.com/blogs/compute/scheduling-ssh-jobs-using-aws-lambda/</a> it doesn't work. It throws this error.</p>
  
  <pre><code>libffi-72499c49.so.6.0.4: cannot open shared object file: No such file or directory: ImportError
  Traceback (most recent call last):
    File "/var/task/lambda_function.py", line 12, in lambda_handler
      key = paramiko.RSAKey.from_private_key(key)
    File "/var/task/paramiko/pkey.py", line 217, in from_private_key
      key = cls(file_obj=file_obj, password=password)
    File "/var/task/paramiko/rsakey.py", line 42, in __init__
      self._from_private_key(file_obj, password)
    File "/var/task/paramiko/rsakey.py", line 168, in _from_private_key
      self._decode_key(data)
    File "/var/task/paramiko/rsakey.py", line 173, in _decode_key
      data, password=None, backend=default_backend()
    File "/var/task/cryptography/hazmat/backends/__init__.py", line 35, in default_backend
      _default_backend = MultiBackend(_available_backends())
    File "/var/task/cryptography/hazmat/backends/__init__.py", line 22, in _available_backends
      "cryptography.backends"
    File "/var/task/pkg_resources/__init__.py", line 2236, in resolve
      module = __import__(self.module_name, fromlist=['__name__'], level=0)
    File "/var/task/cryptography/hazmat/backends/openssl/__init__.py", line 7, in &lt;module&gt;
      from cryptography.hazmat.backends.openssl.backend import backend
    File "/var/task/cryptography/hazmat/backends/openssl/backend.py", line 15, in &lt;module&gt;
      from cryptography import utils, x509
    File "/var/task/cryptography/x509/__init__.py", line 7, in &lt;module&gt;
      from cryptography.x509.base import (
    File "/var/task/cryptography/x509/base.py", line 15, in &lt;module&gt;
      from cryptography.x509.extensions import Extension, ExtensionType
    File "/var/task/cryptography/x509/extensions.py", line 19, in &lt;module&gt;
      from cryptography.hazmat.primitives import constant_time, serialization
    File "/var/task/cryptography/hazmat/primitives/constant_time.py", line 9, in &lt;module&gt;
      from cryptography.hazmat.bindings._constant_time import lib
  ImportError: libffi-72499c49.so.6.0.4: cannot open shared object file: No such file or directory
  </code></pre>