1 files changed, 3 insertions, 0 deletions
diff --git a/Lib/urllib/request.py b/Lib/urllib/request.py
index 4c16518..fc8ef7f 100644
--- a/Lib/urllib/request.py
+++ b/Lib/urllib/request.py
@@ -1111,6 +1111,9 @@ class AbstractDigestAuthHandler:
         elif algorithm == 'SHA':
             H = lambda x: hashlib.sha1(x.encode("ascii")).hexdigest()
         # XXX MD5-sess
+        else:
+            raise ValueError("Unsupported digest authentication "
+                             "algorithm %r" % algorithm)
         KD = lambda s, d: H("%s:%s" % (s, d))
         return H, KD