def test_register_errors(self):
"""Unit test of native Python EC registration errors"""
G, n = get_ec_curve_params(b'nistp256')
p, a, b, Gx, Gy = G.curve.p, G.curve.a, G.curve.b, G.x, G.y
with self.subTest('Bad prime'):
with self.assertRaises(ValueError):
register_prime_curve(b'bad', p+1, a, b, Gx, Gy, n)
with self.subTest('Bad a, b pair'):
with self.assertRaises(ValueError):
register_prime_curve(b'bad', p, a+1, b, Gx, Gy, n)
with self.subTest('Bad generator point'):
with self.assertRaises(ValueError):
register_prime_curve(b'bad', p, a, b, Gx+1, Gy, n)
with self.subTest('Bad order'):
with self.assertRaises(ValueError):
register_prime_curve(b'bad', p, a, b, Gx, Gy, n+1)
with self.subTest('Weak prime'):
with self.assertRaises(ValueError):
register_prime_curve(b'bad', 263, 2, 3, 200, 39, 270)
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_math(self):
"""Unit test native Python EC point math"""
G, n = get_ec_curve_params(b'nistp256')
G2, _ = get_ec_curve_params(b'nistp521')
Inf = PrimePoint.construct(G.curve, None, None)
with self.subTest('Add to infinity'):
self.assertEqual(G + Inf, G)
with self.subTest('Negate'):
negG = -G
self.assertEqual(-negG, G)
with self.subTest('Negate infinity'):
self.assertEqual(-Inf, Inf)
with self.subTest('Multiply returning infinity'):
self.assertEqual(n * G, Inf)
with self.subTest('Add from different curves'):
with self.assertRaises(ValueError):
_ = G + G2
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])
def test_get_params(self):
"""Test errors getting EC curve params"""
with self.subTest('Get params'):
with self.assertRaises(ValueError):
get_ec_curve_params(b'xxx')