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- try:
- import unittest2 as unittest
- except ImportError:
- import unittest
-
- import base64
- import pytest
- from .curves import (
- Curve,
- NIST256p,
- curves,
- UnknownCurveError,
- PRIME_FIELD_OID,
- curve_by_name,
- )
- from .ellipticcurve import CurveFp, PointJacobi, CurveEdTw
- from . import der
- from .util import number_to_string
-
-
- class TestParameterEncoding(unittest.TestCase):
- @classmethod
- def setUpClass(cls):
- # minimal, but with cofactor (excludes seed when compared to
- # OpenSSL output)
- cls.base64_params = (
- "MIHgAgEBMCwGByqGSM49AQECIQD/////AAAAAQAAAAAAAAAAAAAAAP/////////"
- "//////zBEBCD/////AAAAAQAAAAAAAAAAAAAAAP///////////////AQgWsY12K"
- "o6k+ez671VdpiGvGUdBrDMU7D2O848PifSYEsEQQRrF9Hy4SxCR/i85uVjpEDyd"
- "wN9gS3rM6D0oTlF2JjClk/jQuL+Gn+bjufrSnwPnhYrzjNXazFezsu2QGg3v1H1"
- "AiEA/////wAAAAD//////////7zm+q2nF56E87nKwvxjJVECAQE="
- )
-
- def test_from_pem(self):
- pem_params = (
- "-----BEGIN EC PARAMETERS-----\n"
- "MIHgAgEBMCwGByqGSM49AQECIQD/////AAAAAQAAAAAAAAAAAAAAAP/////////\n"
- "//////zBEBCD/////AAAAAQAAAAAAAAAAAAAAAP///////////////AQgWsY12K\n"
- "o6k+ez671VdpiGvGUdBrDMU7D2O848PifSYEsEQQRrF9Hy4SxCR/i85uVjpEDyd\n"
- "wN9gS3rM6D0oTlF2JjClk/jQuL+Gn+bjufrSnwPnhYrzjNXazFezsu2QGg3v1H1\n"
- "AiEA/////wAAAAD//////////7zm+q2nF56E87nKwvxjJVECAQE=\n"
- "-----END EC PARAMETERS-----\n"
- )
- curve = Curve.from_pem(pem_params)
-
- self.assertIs(curve, NIST256p)
-
- def test_from_pem_with_explicit_when_explicit_disabled(self):
- pem_params = (
- "-----BEGIN EC PARAMETERS-----\n"
- "MIHgAgEBMCwGByqGSM49AQECIQD/////AAAAAQAAAAAAAAAAAAAAAP/////////\n"
- "//////zBEBCD/////AAAAAQAAAAAAAAAAAAAAAP///////////////AQgWsY12K\n"
- "o6k+ez671VdpiGvGUdBrDMU7D2O848PifSYEsEQQRrF9Hy4SxCR/i85uVjpEDyd\n"
- "wN9gS3rM6D0oTlF2JjClk/jQuL+Gn+bjufrSnwPnhYrzjNXazFezsu2QGg3v1H1\n"
- "AiEA/////wAAAAD//////////7zm+q2nF56E87nKwvxjJVECAQE=\n"
- "-----END EC PARAMETERS-----\n"
- )
- with self.assertRaises(der.UnexpectedDER) as e:
- Curve.from_pem(pem_params, ["named_curve"])
-
- self.assertIn("explicit curve parameters not", str(e.exception))
-
- def test_from_pem_with_named_curve_with_named_curve_disabled(self):
- pem_params = (
- "-----BEGIN EC PARAMETERS-----\n"
- "BggqhkjOPQMBBw==\n"
- "-----END EC PARAMETERS-----\n"
- )
- with self.assertRaises(der.UnexpectedDER) as e:
- Curve.from_pem(pem_params, ["explicit"])
-
- self.assertIn("named_curve curve parameters not", str(e.exception))
-
- def test_from_pem_with_wrong_header(self):
- pem_params = (
- "-----BEGIN PARAMETERS-----\n"
- "MIHgAgEBMCwGByqGSM49AQECIQD/////AAAAAQAAAAAAAAAAAAAAAP/////////\n"
- "//////zBEBCD/////AAAAAQAAAAAAAAAAAAAAAP///////////////AQgWsY12K\n"
- "o6k+ez671VdpiGvGUdBrDMU7D2O848PifSYEsEQQRrF9Hy4SxCR/i85uVjpEDyd\n"
- "wN9gS3rM6D0oTlF2JjClk/jQuL+Gn+bjufrSnwPnhYrzjNXazFezsu2QGg3v1H1\n"
- "AiEA/////wAAAAD//////////7zm+q2nF56E87nKwvxjJVECAQE=\n"
- "-----END PARAMETERS-----\n"
- )
- with self.assertRaises(der.UnexpectedDER) as e:
- Curve.from_pem(pem_params)
-
- self.assertIn("PARAMETERS PEM header", str(e.exception))
-
- def test_to_pem(self):
- pem_params = (
- b"-----BEGIN EC PARAMETERS-----\n"
- b"BggqhkjOPQMBBw==\n"
- b"-----END EC PARAMETERS-----\n"
- )
- encoding = NIST256p.to_pem()
-
- self.assertEqual(pem_params, encoding)
-
- def test_compare_with_different_object(self):
- self.assertNotEqual(NIST256p, 256)
-
- def test_named_curve_params_der(self):
- encoded = NIST256p.to_der()
-
- # just the encoding of the NIST256p OID (prime256v1)
- self.assertEqual(b"\x06\x08\x2a\x86\x48\xce\x3d\x03\x01\x07", encoded)
-
- def test_verify_that_default_is_named_curve_der(self):
- encoded_default = NIST256p.to_der()
- encoded_named = NIST256p.to_der("named_curve")
-
- self.assertEqual(encoded_default, encoded_named)
-
- def test_encoding_to_explicit_params(self):
- encoded = NIST256p.to_der("explicit")
-
- self.assertEqual(encoded, bytes(base64.b64decode(self.base64_params)))
-
- def test_encoding_to_unsupported_type(self):
- with self.assertRaises(ValueError) as e:
- NIST256p.to_der("unsupported")
-
- self.assertIn("Only 'named_curve'", str(e.exception))
-
- def test_encoding_to_explicit_compressed_params(self):
- encoded = NIST256p.to_der("explicit", "compressed")
-
- compressed_base_point = (
- "MIHAAgEBMCwGByqGSM49AQECIQD/////AAAAAQAAAAAAAAAAAAAAAP//////////"
- "/////zBEBCD/////AAAAAQAAAAAAAAAAAAAAAP///////////////AQgWsY12Ko6"
- "k+ez671VdpiGvGUdBrDMU7D2O848PifSYEsEIQNrF9Hy4SxCR/i85uVjpEDydwN9"
- "gS3rM6D0oTlF2JjClgIhAP////8AAAAA//////////+85vqtpxeehPO5ysL8YyVR"
- "AgEB"
- )
-
- self.assertEqual(
- encoded, bytes(base64.b64decode(compressed_base_point))
- )
-
- def test_decoding_explicit_from_openssl(self):
- # generated with openssl 1.1.1k using
- # openssl ecparam -name P-256 -param_enc explicit -out /tmp/file.pem
- p256_explicit = (
- "MIH3AgEBMCwGByqGSM49AQECIQD/////AAAAAQAAAAAAAAAAAAAAAP//////////"
- "/////zBbBCD/////AAAAAQAAAAAAAAAAAAAAAP///////////////AQgWsY12Ko6"
- "k+ez671VdpiGvGUdBrDMU7D2O848PifSYEsDFQDEnTYIhucEk2pmeOETnSa3gZ9+"
- "kARBBGsX0fLhLEJH+Lzm5WOkQPJ3A32BLeszoPShOUXYmMKWT+NC4v4af5uO5+tK"
- "fA+eFivOM1drMV7Oy7ZAaDe/UfUCIQD/////AAAAAP//////////vOb6racXnoTz"
- "ucrC/GMlUQIBAQ=="
- )
-
- decoded = Curve.from_der(bytes(base64.b64decode(p256_explicit)))
-
- self.assertEqual(NIST256p, decoded)
-
- def test_decoding_well_known_from_explicit_params(self):
- curve = Curve.from_der(bytes(base64.b64decode(self.base64_params)))
-
- self.assertIs(curve, NIST256p)
-
- def test_decoding_with_incorrect_valid_encodings(self):
- with self.assertRaises(ValueError) as e:
- Curve.from_der(b"", ["explicitCA"])
-
- self.assertIn("Only named_curve", str(e.exception))
-
- def test_compare_curves_with_different_generators(self):
- curve_fp = CurveFp(23, 1, 7)
- base_a = PointJacobi(curve_fp, 13, 3, 1, 9, generator=True)
- base_b = PointJacobi(curve_fp, 1, 20, 1, 9, generator=True)
-
- curve_a = Curve("unknown", curve_fp, base_a, None)
- curve_b = Curve("unknown", curve_fp, base_b, None)
-
- self.assertNotEqual(curve_a, curve_b)
-
- def test_default_encode_for_custom_curve(self):
- curve_fp = CurveFp(23, 1, 7)
- base_point = PointJacobi(curve_fp, 13, 3, 1, 9, generator=True)
-
- curve = Curve("unknown", curve_fp, base_point, None)
-
- encoded = curve.to_der()
-
- decoded = Curve.from_der(encoded)
-
- self.assertEqual(curve, decoded)
-
- expected = "MCECAQEwDAYHKoZIzj0BAQIBFzAGBAEBBAEHBAMEDQMCAQk="
-
- self.assertEqual(encoded, bytes(base64.b64decode(expected)))
-
- def test_named_curve_encode_for_custom_curve(self):
- curve_fp = CurveFp(23, 1, 7)
- base_point = PointJacobi(curve_fp, 13, 3, 1, 9, generator=True)
-
- curve = Curve("unknown", curve_fp, base_point, None)
-
- with self.assertRaises(UnknownCurveError) as e:
- curve.to_der("named_curve")
-
- self.assertIn("Can't encode curve", str(e.exception))
-
- def test_try_decoding_binary_explicit(self):
- sect113r1_explicit = (
- "MIGRAgEBMBwGByqGSM49AQIwEQIBcQYJKoZIzj0BAgMCAgEJMDkEDwAwiCUMpufH"
- "/mSc6Fgg9wQPAOi+5NPiJgdEGIvg6ccjAxUAEOcjqxTWluZ2h1YVF1b+v4/LSakE"
- "HwQAnXNhbzX0qxQH1zViwQ8ApSgwJ3lY7oTRMV7TGIYCDwEAAAAAAAAA2czsijnl"
- "bwIBAg=="
- )
-
- with self.assertRaises(UnknownCurveError) as e:
- Curve.from_der(base64.b64decode(sect113r1_explicit))
-
- self.assertIn("Characteristic 2 curves unsupported", str(e.exception))
-
- def test_decode_malformed_named_curve(self):
- bad_der = der.encode_oid(*NIST256p.oid) + der.encode_integer(1)
-
- with self.assertRaises(der.UnexpectedDER) as e:
- Curve.from_der(bad_der)
-
- self.assertIn("Unexpected data after OID", str(e.exception))
-
- def test_decode_malformed_explicit_garbage_after_ECParam(self):
- bad_der = bytes(
- base64.b64decode(self.base64_params)
- ) + der.encode_integer(1)
-
- with self.assertRaises(der.UnexpectedDER) as e:
- Curve.from_der(bad_der)
-
- self.assertIn("Unexpected data after ECParameters", str(e.exception))
-
- def test_decode_malformed_unknown_version_number(self):
- bad_der = der.encode_sequence(der.encode_integer(2))
-
- with self.assertRaises(der.UnexpectedDER) as e:
- Curve.from_der(bad_der)
-
- self.assertIn("Unknown parameter encoding format", str(e.exception))
-
- def test_decode_malformed_unknown_field_type(self):
- curve_p = NIST256p.curve.p()
- bad_der = der.encode_sequence(
- der.encode_integer(1),
- der.encode_sequence(
- der.encode_oid(1, 2, 3), der.encode_integer(curve_p)
- ),
- der.encode_sequence(
- der.encode_octet_string(
- number_to_string(NIST256p.curve.a() % curve_p, curve_p)
- ),
- der.encode_octet_string(
- number_to_string(NIST256p.curve.b(), curve_p)
- ),
- ),
- der.encode_octet_string(
- NIST256p.generator.to_bytes("uncompressed")
- ),
- der.encode_integer(NIST256p.generator.order()),
- )
-
- with self.assertRaises(UnknownCurveError) as e:
- Curve.from_der(bad_der)
-
- self.assertIn("Unknown field type: (1, 2, 3)", str(e.exception))
-
- def test_decode_malformed_garbage_after_prime(self):
- curve_p = NIST256p.curve.p()
- bad_der = der.encode_sequence(
- der.encode_integer(1),
- der.encode_sequence(
- der.encode_oid(*PRIME_FIELD_OID),
- der.encode_integer(curve_p),
- der.encode_integer(1),
- ),
- der.encode_sequence(
- der.encode_octet_string(
- number_to_string(NIST256p.curve.a() % curve_p, curve_p)
- ),
- der.encode_octet_string(
- number_to_string(NIST256p.curve.b(), curve_p)
- ),
- ),
- der.encode_octet_string(
- NIST256p.generator.to_bytes("uncompressed")
- ),
- der.encode_integer(NIST256p.generator.order()),
- )
-
- with self.assertRaises(der.UnexpectedDER) as e:
- Curve.from_der(bad_der)
-
- self.assertIn("Prime-p element", str(e.exception))
-
-
- class TestCurveSearching(unittest.TestCase):
- def test_correct_name(self):
- c = curve_by_name("NIST256p")
- self.assertIs(c, NIST256p)
-
- def test_openssl_name(self):
- c = curve_by_name("prime256v1")
- self.assertIs(c, NIST256p)
-
- def test_unknown_curve(self):
- with self.assertRaises(UnknownCurveError) as e:
- curve_by_name("foo bar")
-
- self.assertIn(
- "name 'foo bar' unknown, only curves supported: "
- "['NIST192p', 'NIST224p'",
- str(e.exception),
- )
-
- def test_with_None_as_parameter(self):
- with self.assertRaises(UnknownCurveError) as e:
- curve_by_name(None)
-
- self.assertIn(
- "name None unknown, only curves supported: "
- "['NIST192p', 'NIST224p'",
- str(e.exception),
- )
-
-
- @pytest.mark.parametrize("curve", curves, ids=[i.name for i in curves])
- def test_curve_params_encode_decode_named(curve):
- ret = Curve.from_der(curve.to_der("named_curve"))
-
- assert curve == ret
-
-
- @pytest.mark.parametrize("curve", curves, ids=[i.name for i in curves])
- def test_curve_params_encode_decode_explicit(curve):
- if isinstance(curve.curve, CurveEdTw):
- with pytest.raises(UnknownCurveError):
- curve.to_der("explicit")
- else:
- ret = Curve.from_der(curve.to_der("explicit"))
-
- assert curve == ret
-
-
- @pytest.mark.parametrize("curve", curves, ids=[i.name for i in curves])
- def test_curve_params_encode_decode_default(curve):
- ret = Curve.from_der(curve.to_der())
-
- assert curve == ret
-
-
- @pytest.mark.parametrize("curve", curves, ids=[i.name for i in curves])
- def test_curve_params_encode_decode_explicit_compressed(curve):
- if isinstance(curve.curve, CurveEdTw):
- with pytest.raises(UnknownCurveError):
- curve.to_der("explicit", "compressed")
- else:
- ret = Curve.from_der(curve.to_der("explicit", "compressed"))
-
- assert curve == ret
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