Remove extraneous calls to .strip() in Chunked Encoding

To be valid chunked encoding we should not be removing any whitespace as
the standard does not allow for optional whitespace.

If whitespace is encountered in the wrong place, it should lead to a 400
Bad Request instead.

src/waitress/receiver.py

@@ -135,7 +135,6 @@ def received(self, s):
                     line = s[:pos]
                     s = s[pos + 2 :]
                     self.control_line = b""
-                    line = line.strip()
 
                     if line:
                         # Begin a new chunk.
@@ -153,9 +152,6 @@ def received(self, s):
 
                             line = line[:semi]
 
-                        # Remove any whitespace
-                        line = line.strip()
-
                         if not ONLY_HEXDIG_RE.match(line):
                             self.error = BadRequest("Invalid chunk size")
                             self.all_chunks_received = True
@@ -164,7 +160,7 @@ def received(self, s):
 
                         # Can not fail due to matching against the regular
                         # expression above
-                        sz = int(line.strip(), 16)  # hexadecimal
+                        sz = int(line, 16)  # hexadecimal
 
                         if sz > 0:
                             # Start a new chunk.

tests/test_receiver.py

@@ -262,7 +262,9 @@ def test_received_valid_extensions(self, valid_extension):
         assert result == len(data)
         assert inst.error == None
 
-    @pytest.mark.parametrize("invalid_size", [b"0x04", b"+0x04", b"x04", b"+04"])
+    @pytest.mark.parametrize(
+        "invalid_size", [b"0x04", b"+0x04", b"x04", b"+04", b" 04", b" 0x04"]
+    )
     def test_received_invalid_size(self, invalid_size):
         from waitress.utilities import BadRequest