Hash: Generic Crypto.Hash.new(algo, [data]) function

This allows us to instantiate a new hash given only an existing hash
object.

1 files changed, 35 insertions, 0 deletions

diff --git a/lib/Crypto/SelfTest/Hash/common.py b/lib/Crypto/SelfTest/Hash/common.py
index fa9fd22..487e2cb 100644
--- a/lib/Crypto/SelfTest/Hash/common.py
+++ b/lib/Crypto/SelfTest/Hash/common.py
@@ -29,6 +29,7 @@ __revision__ = "$Id$"
 import sys
 import unittest
 import binascii
+import Crypto.Hash
 from Crypto.Util.py3compat import *
 
 # For compatibility with Python 2.1 and Python 2.2
@@ -100,6 +101,19 @@ class HashSelfTest(unittest.TestCase):
         out5 = binascii.b2a_hex(h2.digest())
         self.assertEqual(self.expected, out5)
 
+        # Verify that Crypto.Hash.new(h) produces a fresh hash object
+        h3 = Crypto.Hash.new(h)
+        h3.update(self.input)
+        out6 = binascii.b2a_hex(h3.digest())
+        self.assertEqual(self.expected, out6)
+
+        if hasattr(h, 'name'):
+            # Verify that Crypto.Hash.new(h.name) produces a fresh hash object
+            h4 = Crypto.Hash.new(h.name)
+            h4.update(self.input)
+            out7 = binascii.b2a_hex(h4.digest())
+            self.assertEqual(self.expected, out7)
+
 class HashTestOID(unittest.TestCase):
     def __init__(self, hashmod, oid):
         unittest.TestCase.__init__(self)
@@ -111,6 +125,25 @@ class HashTestOID(unittest.TestCase):
         h = self.hashmod.new()
         self.assertEqual(PKCS1_v1_5._HASH_OIDS[h.name], self.oid)
 
+class GenericHashConstructorTest(unittest.TestCase):
+    def __init__(self, hashmod):
+        unittest.TestCase.__init__(self)
+        self.hashmod = hashmod
+
+    def runTest(self):
+        obj1 = self.hashmod.new("foo")
+        obj2 = self.hashmod.new()
+        obj3 = Crypto.Hash.new(obj1.name, "foo")
+        obj4 = Crypto.Hash.new(obj1.name)
+        obj5 = Crypto.Hash.new(obj1, "foo")
+        obj6 = Crypto.Hash.new(obj1)
+        self.assert_(isinstance(self.hashmod, obj1))
+        self.assert_(isinstance(self.hashmod, obj2))
+        self.assert_(isinstance(self.hashmod, obj3))
+        self.assert_(isinstance(self.hashmod, obj4))
+        self.assert_(isinstance(self.hashmod, obj5))
+        self.assert_(isinstance(self.hashmod, obj6))
+
 class MACSelfTest(unittest.TestCase):
 
     def __init__(self, hashmod, description, expected_dict, input, key, hashmods):
@@ -175,6 +208,8 @@ def make_hash_tests(module, module_name, test_data, digest_size, oid=None):
     tests.append(HashDigestSizeSelfTest(module, name, digest_size))
     if oid is not None:
         tests.append(HashTestOID(module, b(oid)))
+    if getattr(module, 'name', None) is not None:
+        tests.append(GenericHashConstructorTest(module))
     return tests
 
 def make_mac_tests(module, module_name, test_data, hashmods):