Allow creating a Context with SSLv2_METHOD

[andrew-d]

Hi there,

It appears that it's not possible to create a new Context with SSLv2_METHOD. I realize this is horribly insecure, but I'm attempting to use pyOpenSSL to scan for insecure HTTPS settings, and this error occurs. Here's the message:

$ python
Python 2.7.6 (default, Feb 19 2014, 19:58:32)
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> from OpenSSL import SSL
>>> ctx = SSL.Context(SSL.SSLv2_METHOD)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Users/andrew/.virtualenvs/ssl/lib/python2.7/site-packages/OpenSSL/SSL.py",
 line 261, in __init__
    raise ValueError("No such protocol")
ValueError: No such protocol
>>>

I've attached a patch that fixes this.

Thanks! 😄

[exarkun]

Thanks. Can you add a unit test as well? I see the documentation doesn't need updating because it already claims SSLv2_METHOD is supported.

[exarkun]

Hm. Or maybe you can't. There is already a unit test that tries to create a Context with SSLv2_METHOD. Apparently it's hard to distinguish between the bug being fixed here and the case where OpenSSL doesn't support SSLv2...

[andrew-d]

Yes, I looked at the test to see if I could add it, but the only thing I could think of was to refactor the way pyOpenSSL handles unknown methods vs. OpenSSL not supporting them - creating a new exception, for example. That seemed like overkill to me...

[exarkun]

Thanks!