Replace security-critical assert statements with explicit exceptions

sanic/app.py

@@ -924,10 +924,11 @@ def handler(request):
                 self.blueprint(item, **params)
             return
         if blueprint.name in self.blueprints:
-            assert self.blueprints[blueprint.name] is blueprint, (
-                'A blueprint with the name "%s" is already registered.  '
-                "Blueprint names must be unique." % (blueprint.name,)
-            )
+            if self.blueprints[blueprint.name] is not blueprint:
+                raise ValueError(
+                    f"A blueprint with the name '{blueprint.name}' is "
+                    "already registered. Blueprint names must be unique."
+                )
         else:
             self.blueprints[blueprint.name] = blueprint
             self._blueprint_order.append(blueprint)

sanic/headers.py

@@ -409,7 +409,8 @@ def parse_xforwarded(headers, config) -> Options | None:
     proxies_count = config.PROXIES_COUNT
     addr = real_ip_header and headers.getone(real_ip_header, None)
     if not addr and proxies_count:
-        assert proxies_count > 0
+        if proxies_count <= 0:
+            raise ValueError("PROXIES_COUNT must be a positive integer")
         try:
             # Combine, split and filter multiple headers' entries
             forwarded_for = headers.getall(config.FORWARDED_FOR_HEADER)

tests/test_blueprints.py

@@ -884,12 +884,12 @@ def test_duplicate_blueprint(app: Sanic):
 
     app.blueprint(bp)
 
-    with pytest.raises(AssertionError) as excinfo:
+    with pytest.raises(ValueError) as excinfo:
         app.blueprint(bp1)
 
     assert str(excinfo.value) == (
-        f'A blueprint with the name "{bp_name}" is already registered.  '
-        "Blueprint names must be unique."
+        f"A blueprint with the name '{bp_name}' is "
+        "already registered. Blueprint names must be unique."
     )