fix: support duplicated query param values (#617)

Author: childish-sambino

tests/unit/test_request_validator.py

@@ -47,15 +47,16 @@ def test_compute_signature_duplicate_multi_dict(self):
         params = MultiDict([
             ("Sid", "CA123"),
             ("SidAccount", "AC123"),
-            ("Digits", "5678"),
-            ("Digits", "1234"),
+            ("Digits", "5678"),  # Ensure keys are sorted.
+            ("Digits", "1234"),  # Ensure values are sorted.
+            ("Digits", "1234"),  # Ensure duplicates are removed.
         ])
         signature = self.validator.compute_signature(self.uri, params)
         assert signature == expected
 
     def test_compute_signature_duplicate_query_dict(self):
         expected = self.duplicate_expected
-        params = QueryDict('Sid=CA123&SidAccount=AC123&Digits=5678&Digits=1234', encoding='utf-8')
+        params = QueryDict('Sid=CA123&SidAccount=AC123&Digits=5678&Digits=1234&Digits=1234', encoding='utf-8')
         signature = self.validator.compute_signature(self.uri, params)
         assert signature == expected
 

twilio/request_validator.py

@@ -76,7 +76,7 @@ def compute_signature(self, uri, params):
             for param_name in sorted(set(params)):
                 values = self.get_values(params, param_name)
 
-                for value in sorted(values):
+                for value in sorted(set(values)):
                     s += param_name + value
 
         # compute signature and compare signatures