feat: added feature flag to enable blake2b hashing

common/djangoapps/util/memcache.py

@@ -7,6 +7,7 @@ so that we can cache any keys, not just ones that memcache would ordinarily acce
 import hashlib
 from urllib.parse import quote_plus
 
+from django.conf import settings
 from django.utils.encoding import smart_str
 
 
@@ -14,9 +15,12 @@ def fasthash(string):
     """
     Hashes `string` into a string representation of a 128-bit digest.
     """
-    md4 = hashlib.new("md4")
-    md4.update(string.encode('utf-8'))
-    return md4.hexdigest()
+    if settings.FEATURES.get("ENABLE_BLAKE2B_HASHING", False):
+        hash_obj = hashlib.new("blake2b", digest_size=16)
+    else:
+        hash_obj = hashlib.new("md4")
+    hash_obj.update(string.encode('utf-8'))
+    return hash_obj.hexdigest()
 
 
 def cleaned_string(val):