Clean up unused EC bindings. (#4225)

* Clean up unused EC bindings.

A lot of these are really OpenSSL internals, like the EC_METHOD
business, support for custom curves which are a bad idea, and weird
non-standard serializations like taking the usual point serialization
and treating it as a single BIGNUM.

I also didn't remove things when they're arguably part of a set. E.g.
EC_POINT_add is used, but EC_POINT_dbl isn't. However, they both set at
the same abstraction level (basic point operations), so it's strange to
have one without the other.

I also kept EC_POINT_is_on_curve because, although it is not used,
OpenSSL prior to 1.1.0 doesn't perform this important check in
EC_POINT_set_affine_coordinates_GFp (though it does in some of the
functions which ultimately call it, like
EC_KEY_set_public_key_affine_coordinates, what cryptography.io actually
uses), so one should not expose the latter without the former.

* Fix build issue.

1 files changed, 0 insertions, 4 deletions

diff --git a/src/cryptography/hazmat/bindings/openssl/_conditional.py b/src/cryptography/hazmat/bindings/openssl/_conditional.py
index 971e540c..761124f5 100644
--- a/src/cryptography/hazmat/bindings/openssl/_conditional.py
+++ b/src/cryptography/hazmat/bindings/openssl/_conditional.py
@@ -7,13 +7,9 @@ from __future__ import absolute_import, division, print_function
 
 def cryptography_has_ec2m():
     return [
-        "EC_GF2m_simple_method",
         "EC_POINT_set_affine_coordinates_GF2m",
         "EC_POINT_get_affine_coordinates_GF2m",
         "EC_POINT_set_compressed_coordinates_GF2m",
-        "EC_GROUP_set_curve_GF2m",
-        "EC_GROUP_get_curve_GF2m",
-        "EC_GROUP_new_curve_GF2m",
     ]