Lib/test/test_pep247.py

   1 #
   2 # Test suite to check compliance with PEP 247, the standard API for
   3 # hashing algorithms.
   4 #
   5
   6 import md5, sha, hmac
   7
   8 def check_hash_module(module, key=None):
   9     assert hasattr(module, 'digest_size'), "Must have digest_size"
  10     assert (module.digest_size is None or
  11             module.digest_size > 0), "digest_size must be None or positive"
  12
  13     if key is not None:
  14         obj1 = module.new(key)
  15         obj2 = module.new(key, "string")
  16
  17         h1 = module.new(key, "string").digest()
  18         obj3 = module.new(key) ; obj3.update("string") ; h2 = obj3.digest()
  19         assert h1 == h2, "Hashes must match"
  20
  21     else:
  22         obj1 = module.new()
  23         obj2 = module.new("string")
  24
  25         h1 = module.new("string").digest()
  26         obj3 = module.new() ; obj3.update("string") ; h2 = obj3.digest()
  27         assert h1 == h2, "Hashes must match"
  28
  29     assert hasattr(obj1, 'digest_size'), "Objects must have digest_size attr"
  30     if module.digest_size is not None:
  31         assert obj1.digest_size == module.digest_size, "digest_size must match"
  32     assert obj1.digest_size == len(h1), "digest_size must match actual size"
  33     obj1.update("string")
  34     obj_copy = obj1.copy()
  35     assert obj1.digest() == obj_copy.digest(), "Copied objects must match"
  36     assert obj1.hexdigest() == obj_copy.hexdigest(), \
  37            "Copied objects must match"
  38     digest, hexdigest = obj1.digest(), obj1.hexdigest()
  39     hd2 = ""
  40     for byte in digest:
  41         hd2 += "%02x" % ord(byte)
  42     assert hd2 == hexdigest, "hexdigest doesn't appear correct"
  43
  44     print 'Module', module.__name__, 'seems to comply with PEP 247'
  45
  46
  47 if __name__ == '__main__':
  48     check_hash_module(md5)
  49     check_hash_module(sha)
  50     check_hash_module(hmac, key='abc')