title: SALT_LEN = m2.PKCS5_SALT_LEN AttributeError: 'module' object has no attribute 'PKCS5_SALT_LEN'
body: <p>I installed M2Crypto as per this guide: 
  <a href="https://github.com/dsoprea/M2CryptoWindows" rel="nofollow">https://github.com/dsoprea/M2CryptoWindows</a></p>
  
  <p>I run this command: </p>
  
  <pre><code>C:\grr-build\M2Crypto-master&gt;C:\Python27\python.exe setup.py install
  </code></pre>
  
  <p>Then, I got this which confirms to me that the M2Crypto module has been successfully installed:</p>
  
  <pre><code>Installed c:\python27\lib\site-packages\m2crypto-0.22.3-py2.7-win-amd64.egg
  Processing dependencies for M2Crypto==0.22.3
  Finished processing dependencies for M2Crypto==0.22.3 
  </code></pre>
  
  <p>When I try to test the <code>import M2Crypto</code> in a python script, when I run the test script, I get this error:</p>
  
  <blockquote>
    <p>Traceback (most recent call last):   File
    "C:\Users\Administrator.e-Administrator\Desktop\Pytest\test.py", line
    2, in 
        import M2Crypto   File "C:\Python27\lib\site-packages\M2Crypto__init__.py", line 24, in
    
        import ASN1   File "C:\Python27\lib\site-packages\M2Crypto\ASN1.py", line 12, in 
        import BIO   File "C:\Python27\lib\site-packages\M2Crypto\BIO.py", line 221, in 
        class CipherStream(BIO):   File "C:\Python27\lib\site-packages\M2Crypto\BIO.py", line 227, in
    CipherStrea m
        SALT_LEN = m2.PKCS5_SALT_LEN AttributeError: 'module' object has no attribute 'PKCS5_SALT_LEN'</p>
  </blockquote>
  
  <p>Knowing that I skipped one step in the guide given in the link above which was about installing M2Crypto patch because I did not get how to perform it.</p>
  
  <p>Can you please help me? What is the problem with M2Crypto and how to solve it? </p>