gh-128192: support HTTP sha-256 digest authentication as per RFC-7617 (GH-128193)

support sha-256 digest authentication

Co-authored-by: Peter Bierma <zintensitydev@gmail.com>
Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>
Co-authored-by: Gregory P. Smith <greg@krypto.org>

2 files changed, 27 insertions, 5 deletions

diff --git a/Lib/test/test_urllib2.py b/Lib/test/test_urllib2.py
index 4a9e653..96d91c1 100644
--- a/Lib/test/test_urllib2.py
+++ b/Lib/test/test_urllib2.py
@@ -1962,10 +1962,29 @@ class MiscTests(unittest.TestCase):
 
         self.assertRaises(ValueError, _parse_proxy, 'file:/ftp.example.com'),
 
-    def test_unsupported_algorithm(self):
-        handler = AbstractDigestAuthHandler()
+
+class TestDigestAlgorithms(unittest.TestCase):
+    def setUp(self):
+        self.handler = AbstractDigestAuthHandler()
+
+    def test_md5_algorithm(self):
+        H, KD = self.handler.get_algorithm_impls('MD5')
+        self.assertEqual(H("foo"), "acbd18db4cc2f85cedef654fccc4a4d8")
+        self.assertEqual(KD("foo", "bar"), "4e99e8c12de7e01535248d2bac85e732")
+
+    def test_sha_algorithm(self):
+        H, KD = self.handler.get_algorithm_impls('SHA')
+        self.assertEqual(H("foo"), "0beec7b5ea3f0fdbc95d0dd47f3c5bc275da8a33")
+        self.assertEqual(KD("foo", "bar"), "54dcbe67d21d5eb39493d46d89ae1f412d3bd6de")
+
+    def test_sha256_algorithm(self):
+        H, KD = self.handler.get_algorithm_impls('SHA-256')
+        self.assertEqual(H("foo"), "2c26b46b68ffc68ff99b453c1d30413413422d706483bfa0f98a5e886266e7ae")
+        self.assertEqual(KD("foo", "bar"), "a765a8beaa9d561d4c5cbed29d8f4e30870297fdfa9cb7d6e9848a95fec9f937")
+
+    def test_invalid_algorithm(self):
         with self.assertRaises(ValueError) as exc:
-            handler.get_algorithm_impls('invalid')
+            self.handler.get_algorithm_impls('invalid')
         self.assertEqual(
             str(exc.exception),
             "Unsupported digest authentication algorithm 'invalid'"
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index c5a6a18..0d1b594 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1048,7 +1048,7 @@ _randombytes = os.urandom
 
 
 class AbstractDigestAuthHandler:
-    # Digest authentication is specified in RFC 2617.
+    # Digest authentication is specified in RFC 2617/7616.
 
     # XXX The client does not inspect the Authentication-Info header
     # in a successful response.
@@ -1176,11 +1176,14 @@ class AbstractDigestAuthHandler:
         return base
 
     def get_algorithm_impls(self, algorithm):
+        # algorithm names taken from RFC 7616 Section 6.1
         # lambdas assume digest modules are imported at the top level
         if algorithm == 'MD5':
             H = lambda x: hashlib.md5(x.encode("ascii")).hexdigest()
-        elif algorithm == 'SHA':
+        elif algorithm == 'SHA':  # non-standard, retained for compatibility.
             H = lambda x: hashlib.sha1(x.encode("ascii")).hexdigest()
+        elif algorithm == 'SHA-256':
+            H = lambda x: hashlib.sha256(x.encode("ascii")).hexdigest()
         # XXX MD5-sess
         else:
             raise ValueError("Unsupported digest authentication "