Ticket #19799: 19799-identify_hasher.diff

django/contrib/auth/hashers.py

@@ -123 +123 @@
     """
     Returns an instance of a loaded password hasher.
 
-    Identifies hasher algorithm by examining encoded hash, and calls
-    get_hasher() to return hasher. Raises ValueError if
-    algorithm cannot be identified, or if hasher is not loaded.
+    Identifies hasher algorithm by asking each hasher in turn if they are
+    accepting the encoded hash format. Raises ValueError if
+    algorithm cannot be identified.
     """
-    if ((len(encoded) == 32 and '$' not in encoded) or
-            (len(encoded) == 37 and encoded.startswith('md5$$'))):
-        algorithm = 'unsalted_md5'
-    else:
-        algorithm = encoded.split('$', 1)[0]
-    return get_hasher(algorithm)
+    if HASHERS is None:
+        load_hashers()
+    for algorithm, hasher in HASHERS.items():
+        if hasher.supports(encoded):
+            return hasher
+    raise ValueError(
+        "Unable to find any hasher accepting a hash starting with '%s...'" % (
+            encoded[:12],))
 
 
 def mask_hash(hash, show=6, char="*"):
@@ -172 +174 @@
         raise ValueError("Hasher '%s' doesn't specify a library attribute" %
                          self.__class__)
 
+    def supports(self, hash_):
+        """
+        Return True if hash_ is supported by this hasher.
+        """
+        return self.algorithm == hash_.split('$', 1)[0]
+
     def salt(self):
         """
         Generates a cryptographically secure nonce salt in ascii
@@ -361 +369 @@
     """
     algorithm = "unsalted_md5"
 
+    def supports(self, hash_):
+        return (len(hash_) == 32 and '$' not in hash_) or \
+               (len(hash_) == 37 and hash_.startswith('md5$$'))
+
     def salt(self):
         return ''