Source Code for Module dkim.tests.test_crypto

  1  # This software is provided 'as-is', without any express or implied 
  2  # warranty.  In no event will the author be held liable for any damages 
  3  # arising from the use of this software. 
  4  # 
  5  # Permission is granted to anyone to use this software for any purpose, 
  6  # including commercial applications, and to alter it and redistribute it 
  7  # freely, subject to the following restrictions: 
  8  # 
  9  # 1. The origin of this software must not be misrepresented; you must not 
 10  #    claim that you wrote the original software. If you use this software 
 11  #    in a product, an acknowledgment in the product documentation would be 
 12  #    appreciated but is not required. 
 13  # 2. Altered source versions must be plainly marked as such, and must not be 
 14  #    misrepresented as being the original software. 
 15  # 3. This notice may not be removed or altered from any source distribution. 
 16  # 
 17  # Copyright (c) 2011 William Grant <me@williamgrant.id.au> 
 18   
 19  import base64 
 20  import binascii 
 21  import hashlib 
 22  import unittest 
 23   
 24  from dkim.crypto import ( 
 25      DigestTooLargeError, 
 26      UnparsableKeyError, 
 27      EMSA_PKCS1_v1_5_encode, 
 28      int2str, 
 29      parse_pem_private_key, 
 30      parse_public_key, 
 31      RSASSA_PKCS1_v1_5_sign, 
 32      RSASSA_PKCS1_v1_5_verify, 
 33      str2int, 
 34      ) 
 35  from dkim.tests.test_dkim import read_test_data 
 36  from dkim.util import parse_tag_value 
 37   
 38   
 39  # These are extracted from dkim/tests/data/test.private. 
 40  TEST_KEY_MODULUS = int( 
 41      '160190232090260054474895273563294777865179886824815261110923286158270437' 
 42      '657769966074370477716411064825849317279563494735400250019233722215662302' 
 43      '997403060159149904218292658425241195497467863155064737257198115261596066' 
 44      '733086923624062366294295557722551666415445482671442053150678674937682352' 
 45      '837105556539434741981') 
 46  TEST_KEY_PUBLIC_EXPONENT = 65537 
 47  TEST_KEY_PRIVATE_EXPONENT = int( 
 48      '219642251791061057038224045690185219631125389170665415924249912174530136' 
 49      '074693824121380763959239792563755125360354847443780863736947713174228520' 
 50      '489900956461640273471526152019568303807247290486052565153701534491987040' 
 51      '131529720476525111651818771481293273124837542067061293644354088836358900' 
 52      '29771161475005043329') 
 53  TEST_KEY_PRIME1 = int( 
 54      '127343333492908149956322715568115237787784712176275919666517073343689103' 
 55      '280591709737233188193431204382936008602497360201661766158158969883295914' 
 56      '16266272177') 
 57  TEST_KEY_PRIME2 = int( 
 58      '125793967926229270607412639516115399484604596465353856808629588968254772' 
 59      '302339293254103556785310783521521266982500068526354237606773478050287350' 
 60      '33316975853') 
 61  TEST_KEY_EXPONENT1 = int( 
 62      '971401692373919639404678505179789291960987093676634885925231250693661495' 
 63      '080125935714710587508461815572290443270923375888685273287584323569222368' 
 64      '5450962737') 
 65  TEST_KEY_EXPONENT2 = int( 
 66      '405135004809332318340885085107137607293826268763328174261828392259785080' 
 67      '028911220030572618988900118679333717167345003034279703551607153395397272' 
 68      '3014807045') 
 69  TEST_KEY_COEFFICIENT = int( 
 70      '933140693852464192207530806898449261372116224159220632563973880414444021' 
 71      '989007318611849609226428922185905596238131661588470844906391982906126973' 
 72      '1282880267') 
 73  TEST_PK = { 
 74      'version': 0, 
 75      'modulus': TEST_KEY_MODULUS, 
 76      'publicExponent': TEST_KEY_PUBLIC_EXPONENT, 
 77      'privateExponent': TEST_KEY_PRIVATE_EXPONENT, 
 78      'prime1': TEST_KEY_PRIME1, 
 79      'prime2': TEST_KEY_PRIME2, 
 80      'exponent1': TEST_KEY_EXPONENT1, 
 81      'exponent2': TEST_KEY_EXPONENT2, 
 82      'coefficient': TEST_KEY_COEFFICIENT, 
 83  } 
 84   
 85   
 86 -class TestStrIntConversion(unittest.TestCase): 
 87   
 88 -    def test_str2int(self): 
 89          self.assertEqual(1234, str2int(b'\x04\xd2')) 
 90   
 91 -    def test_int2str(self): 
 92          self.assertEqual(b'\x04\xd2', int2str(1234)) 
 93   
 94 -    def test_int2str_with_length(self): 
 95          self.assertEqual(b'\x00\x00\x04\xd2', int2str(1234, 4)) 
 96   
 97 -    def test_int2str_fails_on_negative(self): 
 98          self.assertRaises(AssertionError, int2str, -1) 
 99   
100   
101 -class TestParseKeys(unittest.TestCase): 
102   
103 -    def test_parse_pem_private_key(self): 
104          key = parse_pem_private_key(read_test_data('test.private')) 
105          self.assertEqual(key, TEST_PK) 
106   
107 -    def test_parse_public_key(self): 
108          data = read_test_data('test.txt') 
109          key = parse_public_key(base64.b64decode(parse_tag_value(data)[b'p'])) 
110          self.assertEqual(key['modulus'], TEST_KEY_MODULUS) 
111          self.assertEqual(key['publicExponent'], TEST_KEY_PUBLIC_EXPONENT) 
112          try: 
113            data = read_test_data('test_bad.txt') 
114            key = parse_public_key(base64.b64decode(parse_tag_value(data)[b'p'])) 
115          except UnparsableKeyError: return 
116          self.fail("failed to reject invalid public key") 
117   
118   
119 -class TestEMSA_PKCS1_v1_5(unittest.TestCase): 
120   
121 -    def test_encode_sha256(self): 
122          hash = hashlib.sha256(b'message') 
123          self.assertEqual( 
124              b'\x00\x01\xff\xff\xff\xff\xff\xff\xff\xff\x00' 
125              b'010\x0d\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01\x05\x00\x04' 
126              b' ' + hash.digest(), 
127              EMSA_PKCS1_v1_5_encode(hash, 62)) 
128   
129 -    def test_encode_sha1(self): 
130          hash = hashlib.sha1(b'message') 
131          self.assertEqual( 
132              b'\x00\x01\xff\xff\xff\xff\xff\xff\xff\xff\x00' 
133              b'0!0\x09\x06\x05\x2b\x0e\x03\x02\x1a\x05\x00\x04\x14' 
134              + hash.digest(), 
135              EMSA_PKCS1_v1_5_encode(hash, 46)) 
136   
137 -    def test_encode_forbids_too_short(self): 
138          # PKCS#1 requires at least 8 bytes of padding, so there must be 
139          # at least that much space. 
140          hash = hashlib.sha1(b'message') 
141          self.assertRaises( 
142              DigestTooLargeError, 
143              EMSA_PKCS1_v1_5_encode, hash, 45) 
144   
145   
146 -class TestRSASSA(unittest.TestCase): 
147   
148 -    def setUp(self): 
149          self.key = parse_pem_private_key(read_test_data('test.private')) 
150          self.hash = hashlib.sha1(self.test_digest) 
151   
152      test_digest = b'0123456789abcdef0123' 
153      test_signature = binascii.unhexlify( 
154          b'cc8d3647d64dd3bc12984947a27bdfbb565041fcc9db781afb4b60d29d288d8d60d' 
155          b'e9e1916d6f81569c3e72af442538dd6aecb50a6de9a14565fdd679c46ff7842482e' 
156          b'15e5aa078549621b6f12ca8cd57ecfad95b18e53581e131c6c3c7cd01cb153adeb4' 
157          b'39d2d6ab8b215b19be0e69ef490885004a474eb26d747a219693e8c') 
158   
159 -    def test_sign_and_verify(self): 
160          signature = RSASSA_PKCS1_v1_5_sign(self.hash, TEST_PK) 
161          self.assertEqual(self.test_signature, signature) 
162          self.assertTrue( 
163              RSASSA_PKCS1_v1_5_verify( 
164                  self.hash, signature, TEST_PK)) 
165   
166 -    def test_invalid_signature(self): 
167          invalid_key = TEST_PK.copy() 
168          invalid_key['modulus'] += 1 
169          self.assertFalse( 
170              RSASSA_PKCS1_v1_5_verify( 
171                  self.hash, self.test_signature, invalid_key)) 
172   
173   
174 -def test_suite(): 
175      from unittest import TestLoader 
176      return TestLoader().loadTestsFromName(__name__) 
177