This is very similar with `test_generate_ssh_key_default_values`. I would rewrite these tests to reduce duplication to a minimum.

For instance: write a test that checks that when `u'DSA'` and `u'RSA'` are specified, the correct constant values from `crypto` are passed on.

The same goes for `size=1024`. This can also use `mk.number()`, in this way we can really test that the provided value is passed on, otherwise it might just be a coincidence.