title: _fastmath error in python: HAVE_DECL_MPZ_POWM_SEC
body: <p>I am running python 2.6 on Red Hat 6.4</p>
  
  <p>I had a script running on one machine using paramiko sftp. When I transferred it to another machine I got an exception: <code>SFTP file has no attribute __exit__</code> (something along those lines).</p>
  
  <p>I decided to upgrade paramiko (thought it would solve the problem) with pip. Now I am getting this the moment I run a python script:</p>
  
  <pre><code>  ...
    File "/usr/lib/python2.6/site-packages/paramiko/__init__.py", line 64, in &lt;module&gt;
      from transport import SecurityOptions, Transport
    File "/usr/lib/python2.6/site-packages/paramiko/transport.py", line 33, in &lt;module&gt;
      from paramiko import util
    File "/usr/lib/python2.6/site-packages/paramiko/util.py", line 33, in &lt;module&gt;
      from paramiko.common import *
    File "/usr/lib/python2.6/site-packages/paramiko/common.py", line 98, in &lt;module&gt;
      from Crypto import Random
    File "/usr/lib64/python2.6/site-packages/Crypto/Random/__init__.py", line 29, in &lt;module&gt;
      from Crypto.Random import _UserFriendlyRNG
    File "/usr/lib64/python2.6/site-packages/Crypto/Random/_UserFriendlyRNG.py", line 38, in &lt;module&gt;
      from Crypto.Random.Fortuna import FortunaAccumulator
    File "/usr/lib64/python2.6/site-packages/Crypto/Random/Fortuna/FortunaAccumulator.py", line 39, in &lt;module&gt;
      import FortunaGenerator
    File "/usr/lib64/python2.6/site-packages/Crypto/Random/Fortuna/FortunaGenerator.py", line 34, in &lt;module&gt;
      from Crypto.Util.number import ceil_shift, exact_log2, exact_div
    File "/usr/lib64/python2.6/site-packages/Crypto/Util/number.py", line 56, in &lt;module&gt;
      if _fastmath is not None and not _fastmath.HAVE_DECL_MPZ_POWM_SEC:
  AttributeError: 'module' object has no attribute 'HAVE_DECL_MPZ_POWM_SEC'
  </code></pre>
  
  <p>So help!!</p>