def test_lookup_by_params(self):
"""Test errors in EC curve lookup by params"""
G, n = get_ec_curve_params(b'nistp256')
with self.subTest('Bad curve'):
with self.assertRaises(ValueError):
lookup_ec_curve_by_params(G.curve.p+1, G.curve.a, G.curve.b,
G.encode(), n)
with self.subTest('Unknown curve'):
with self.assertRaises(ValueError):
lookup_ec_curve_by_params(263, 2, 3,
encode_ec_point(2, 200, 39), 270)
def test_encode(self):
"""Unit test native Python EC point encoding"""
G, _ = get_ec_curve_params(b'nistp256')
with self.subTest('Encode infinity'):
self.assertEqual(encode_ec_point(None, None, None), b'\x00')
with self.subTest('Decode infinity'):
point = PrimePoint.decode(G.curve, b'\x00')
self.assertEqual((point.curve, point.x, point.y),
(None, None, None))
with self.subTest('Encode and decode'):
self.assertEqual(PrimePoint.decode(G.curve, G.encode()), G)
with self.subTest('Bad point type'):
with self.assertRaises(ValueError):
decode_ec_point(0, b'\x05')
with self.subTest('Bad point length'):
with self.assertRaises(ValueError):
decode_ec_point(G.curve.keylen, G.encode()[:-1])
