title: issue with python 2.7 paramiko , in MAC OS Elcapitan
body: <p>I have an issue with paramiko in Mac OS Elcapitan, after installing it, it does not work</p>
  
  <pre><code>DEB [20160517-10:48:54.068] thr=1   paramiko.transport: starting thread (client mode): 0xa552350L
  DEB [20160517-10:48:54.068] thr=1   paramiko.transport: Local version/idstring: SSH-2.0-paramiko_2.0.0
  DEB [20160517-10:48:54.477] thr=1   paramiko.transport: Remote version/idstring: SSH-2.0-OpenSSH_6.0
  INF [20160517-10:48:54.477] thr=1   paramiko.transport: Connected (version 2.0, client OpenSSH_6.0)
  DEB [20160517-10:48:54.890] thr=1   paramiko.transport: kex algos:[u'ecdh-sha2-nistp256', u'ecdh-sha2-nistp384', u'ecdh-sha2-nistp521', u'diffie-hellman-group-exchange-sha256', u'diffie-hellman-group-exchange-sha1', u'diffie-hellman-group14-sha1', u'diffie-hellman-group1-sha1'] server key:[u'ssh-rsa', u'ssh-dss', u'ecdsa-sha2-nistp256'] client encrypt:[u'aes128-ctr', u'aes192-ctr', u'aes256-ctr', u'arcfour256', u'arcfour128', u'aes128-cbc', u'3des-cbc', u'blowfish-cbc', u'cast128-cbc', u'aes192-cbc', u'aes256-cbc', u'arcfour', u'rijndael-cbc@lysator.liu.se'] server encrypt:[u'aes128-ctr', u'aes192-ctr', u'aes256-ctr', u'arcfour256', u'arcfour128', u'aes128-cbc', u'3des-cbc', u'blowfish-cbc', u'cast128-cbc', u'aes192-cbc', u'aes256-cbc', u'arcfour', u'rijndael-cbc@lysator.liu.se'] client mac:[u'hmac-md5', u'hmac-sha1', u'umac-64@openssh.com', u'hmac-sha2-256', u'hmac-sha2-256-96', u'hmac-sha2-512', u'hmac-sha2-512-96', u'hmac-ripemd160', u'hmac-ripemd160@openssh.com', u'hmac-sha1-96', u'hmac-md5-96'] server mac:[u'hmac-md5', u'hmac-sha1', u'umac-64@openssh.com', u'hmac-sha2-256', u'hmac-sha2-256-96', u'hmac-sha2-512', u'hmac-sha2-512-96', u'hmac-ripemd160', u'hmac-ripemd160@openssh.com', u'hmac-sha1-96', u'hmac-md5-96'] client compress:[u'none', u'zlib@openssh.com'] server compress:[u'none', u'zlib@openssh.com'] client lang:[u''] server lang:[u''] kex follows?False
  DEB [20160517-10:48:54.890] thr=1   paramiko.transport: Kex agreed: diffie-hellman-group1-sha1
  DEB [20160517-10:48:54.890] thr=1   paramiko.transport: Cipher agreed: aes128-ctr
  DEB [20160517-10:48:54.890] thr=1   paramiko.transport: MAC agreed: hmac-sha2-256
  DEB [20160517-10:48:54.891] thr=1   paramiko.transport: Compression agreed: none
  ERR [20160517-10:48:55.333] thr=1   paramiko.transport: Unknown exception: dlopen(/Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/bindings/_openssl.so, 2): Symbol not found: _BIO_new_CMS
    Referenced from: /Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/bindings/_openssl.so
    Expected in: flat namespace
   in /Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/bindings/_openssl.so
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport: Traceback (most recent call last):
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/paramiko/transport.py", line 1757, in run
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:     self.kex_engine.parse_next(ptype, m)
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/paramiko/kex_group1.py", line 75, in parse_next
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:     return self._parse_kexdh_reply(m)
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/paramiko/kex_group1.py", line 111, in _parse_kexdh_reply
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:     self.transport._verify_key(host_key, sig)
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/paramiko/transport.py", line 1602, in _verify_key
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:     key = self._key_info[self.host_key_type](Message(host_key))
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/paramiko/rsakey.py", line 58, in __init__
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:     ).public_key(default_backend())
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/backends/__init__.py", line 35, in default_backend
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:     _default_backend = MultiBackend(_available_backends())
  ERR [20160517-10:48:55.336] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/backends/__init__.py", line 22, in _available_backends
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:     "cryptography.backends"
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:   File "build/bdist.macosx-10.11-intel/egg/pkg_resources/__init__.py", line 2235, in resolve
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:     module = __import__(self.module_name, fromlist=['__name__'], level=0)
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/backends/openssl/__init__.py", line 7, in &lt;module&gt;
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:     from cryptography.hazmat.backends.openssl.backend import backend
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:   File "/Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/backends/openssl/backend.py", line 45, in &lt;module&gt;
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:     from cryptography.hazmat.bindings._openssl import ffi as _ffi
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport: ImportError: dlopen(/Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/bindings/_openssl.so, 2): Symbol not found: _BIO_new_CMS
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:   Referenced from: /Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/bindings/_openssl.so
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:   Expected in: flat namespace
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:  in /Library/Python/2.7/site-packages/cryptography-1.3.2-py2.7-macosx-10.11-intel.egg/cryptography/hazmat/bindings/_openssl.so
  ERR [20160517-10:48:55.337] thr=1   paramiko.transport:
  </code></pre>