Implemented auth widget object and auth data validator.

aiogram/utils/auth_widget.py

@@ -0,0 +1,25 @@
+import collections
+import hashlib
+import hmac
+
+
+def check_token(data, token):
+    """
+    Validate auth token
+    https://core.telegram.org/widgets/login#checking-authorization
+
+    Source: https://gist.github.com/xen/e4bea72487d34caa28c762776cf655a3
+
+    :param data:
+    :param token:
+    :return:
+    """
+    secret = hashlib.sha256()
+    secret.update(token.encode('utf-8'))
+    sorted_params = collections.OrderedDict(sorted(data.items()))
+    param_hash = sorted_params.pop('hash', '') or ''
+    msg = "\n".join(["{}={}".format(k, v) for k, v in sorted_params.items()])
+
+    if param_hash == hmac.new(secret.digest(), msg.encode('utf-8'), digestmod=hashlib.sha256).hexdigest():
+        return True
+    return False