Addedet length parameter to Digest.update

diff --git a/ctypescrypto/digest.py b/ctypescrypto/digest.py
index df4e58071a13c98e96b05e56710e86141407bd5b..0098ab4109a36c15b3dd144624a62a18b5530317 100644 (file)
--- a/ctypescrypto/digest.py
+++ b/ctypescrypto/digest.py
@@ -81,15 +81,23 @@ class Digest:
        def __del__(self):\r
                self._clean_ctx()\r
 \r
-       def update(self, data):\r
+       def update(self, data, length=None):\r
                """\r
-                       Hashes given byte string as data\r
+                       Hashes given byte string \r
+\r
+                       @param data - string to hash\r
+                       @param length - if not specifed, entire string is hashed,\r
+                                       otherwise only first length bytes\r
                """\r
                if self.digest_finalized:\r
                        raise DigestError, "No updates allowed"\r
                if type(data) != type(""):\r
                        raise TypeError, "A string is expected"\r
-               result = libcrypto.EVP_DigestUpdate(self.ctx, c_char_p(data), len(data))\r
+               if length is None:\r
+                       length=len(data)\r
+               elif length> len(data):\r
+                       raise ValueError("Specified length is greater than length of data")\r
+               result = libcrypto.EVP_DigestUpdate(self.ctx, c_char_p(data), length)\r
                if result != 1:\r
                        raise DigestError, "Unable to update digest"\r
                \r

diff --git a/tests/testdigest.py b/tests/testdigest.py
index 4c4b4edf86830265155edd304f9a37c49ef602d8..e8400809e08713903092ae279ce571aaab9f222f 100644 (file)
--- a/tests/testdigest.py
+++ b/tests/testdigest.py
@@ -38,23 +38,52 @@ class TestDigestType(unittest.TestCase):
 
 class TestIface(unittest.TestCase):
        """ Test all methods with one algorithms """
+       msg="A quick brown fox jumps over the lazy dog."
+       dgst="00CFFE7312BF9CA73584F24BDF7DF1D028340397"
        def test_cons(self):
                md=digest.DigestType("sha1")
                dgst=digest.Digest(md)
-               dgst.update("A quick brown fox jumps over the lazy dog.")
+               dgst.update(self.msg)
                self.assertEqual(dgst.digest_size,20)
-               self.assertEqual(dgst.hexdigest(),"00CFFE7312BF9CA73584F24BDF7DF1D028340397")
+               self.assertEqual(dgst.hexdigest(),self.dgst)
+       def test_length(self):
+               l=len(self.msg)
+               msg=self.msg+" Dog barks furiously."
+               dgst=digest.new("sha1")
+               dgst.update(msg,length=l)
+               self.assertEqual(dgst.hexdigest(),self.dgst)
+       def test_badlength(self):
+               l=len(self.msg)
+               dgst=digest.new("sha1")
+               with self.assertRaises(ValueError):
+                       dgst.update(self.msg,length=l+1)
        def test_bindigest(self):
                dgst=digest.new("sha1")
-               dgst.update("A quick brown fox jumps over the lazy dog.")
+               dgst.update(self.msg)
                self.assertEqual(dgst.digest_size,20)
-               self.assertEqual(dgst.digest(),b16decode("00CFFE7312BF9CA73584F24BDF7DF1D028340397",True)) 
+               self.assertEqual(dgst.digest(),b16decode(self.dgst,True)) 
        def test_duplicatedigest(self):
                dgst=digest.new("sha1")
-               dgst.update("A quick brown fox jumps over the lazy dog.")
+               dgst.update(self.msg)
                v1=dgst.digest()
                v2=dgst.digest()
                self.assertEqual(v1,v2)
+       def test_updatefinalized(self):
+               dgst=digest.new("sha1")
+               dgst.update(self.msg)
+               h=dgst.hexdigest()
+               with self.assertRaises(digest.DigestError):
+                       dgst.update(self.msg)
+       def test_wrongtype(self):
+               dgst=digest.new("sha1")
+               with self.assertRaises(TypeError):
+                       dgst.update(['a','b','c'])
+               with self.assertRaises(TypeError):
+                       dgst.update(18)
+               with self.assertRaises(TypeError):
+                       dgst.update({"a":"b","c":"D"})
+               with self.assertRaises(TypeError):
+                       dgst.update(u'\u0430\u0431')
        def test_copy(self):
                dgst=digest.new("sha1")
                dgst.update("A quick brown fox jumps over ")
@@ -93,6 +122,9 @@ class TestAlgo(unittest.TestCase):
                self.assertEqual(d.digest_size,64)
                d.update("A quick brown fox jumps over the lazy dog.")
                self.assertEqual(d.hexdigest(),"3045575CF3B873DD656F5F3426E04A4ACD11950BB2538772EE14867002B408E21FF18EF7F7B2CAB484A3C1C0BE3F8ACC4AED536A427353C7748DC365FC1A8646")
+       def test_wrongdigest(self):
+               with self.assertRaises(digest.DigestError):
+                       dgst=digest.new("no-such-digest")
 
 if __name__ == "__main__":
        unittest.main()