mv JWK-canonicalization util.security.fingerprint

util/security/fingerprint.py

@@ -0,0 +1,35 @@
+import collections
+import json
+
+from hashlib import sha256
+
+
+def canonicalize(json_obj):
+  """This function canonicalizes a Python object that will be serialized as JSON.
+
+  Args:
+    json_obj (object): the Python object that will later be serialized as JSON.
+
+  Returns:
+    object: json_obj now sorted to its canonical form.
+
+  """
+  if isinstance(json_obj, collections.MutableMapping):
+    sorted_obj = sorted({key: canonicalize(val) for key, val in json_obj.items()}.items())
+    return collections.OrderedDict(sorted_obj)
+  elif isinstance(json_obj, (list, tuple)):
+    return [canonicalize(val) for val in json_obj]
+  return json_obj
+
+
+def canonical_kid(jwk):
+  """This function returns the SHA256 hash of a canonical JWK.
+
+  Args:
+    jwk (object): the JWK for which a kid will be generated.
+
+  Returns:
+    string: the unique kid for the given JWK.
+
+  """
+  return sha256(json.dumps(canonicalize(jwk), separators=(',', ':'))).hexdigest()