Ah, good question. Like this 
https://github.com/pyca/cryptography/blob/3d5d6471b10e5f46eb8b40a9a41eb16e657d25b8/tests/hazmat/backends/test_openssl.py#L149


On 2 April 2014 09:06:18 Mohammed Attia <notifications@github.com> wrote:

> > @@ -157,6 +166,34 @@ class TestDSA(object):
> >          'f90f7dff6d2bae'
> >      }
> > +    def test_generate_dsa_parameters(self, backend):
> > +        parameters = dsa.DSAParameters.generate(1024, backend)
>
> The vectors are not 1024 only. We only support 1024, 2048, 3072 bits for 
> DSA so I can't use the same bit lengths that we test for in RSA. This is 
> still not done, I left it till I find out how we check for OpenSSL versions 
> cause 0.9.8 supports a maximum bit length of 1024.
>
> ---
> Reply to this email directly or view it on GitHub:
> https://github.com/pyca/cryptography/pull/739/files#r11195740