[CVE-2020-27619]No longer call eval() on content received via HTTP in the CJK codec...

In Python 3 through 3.9.0, the Lib/test/multibytecodec_support.py
CJK codec tests call eval() on content retrieved via HTTP.

Change-Id: I1fe49373b30007f2140a06d74dd21dbd6fd1ea5a
Signed-off-by: JinWang An <jinwang.an@samsung.com>

diff --git a/Lib/test/multibytecodec_support.py b/Lib/test/multibytecodec_support.py
index cca8af67d6d1d6cc65f586517981b3a04aaf865d..31d5e0be9bd54800178d3d369d93235eca94b771 100644 (file)
--- a/Lib/test/multibytecodec_support.py
+++ b/Lib/test/multibytecodec_support.py
@@ -305,29 +305,21 @@ class TestBase_Mapping(unittest.TestCase):
             self._test_mapping_file_plain()
 
     def _test_mapping_file_plain(self):
-        unichrs = lambda s: ''.join(map(chr, map(eval, s.split('+'))))
+        def unichrs(s):
+            return ''.join(chr(int(x, 16)) for x in s.split('+'))
         urt_wa = {}
 
         with self.open_mapping_file() as f:
             for line in f:
                 if not line:
                     break
-                data = line.split('#')[0].strip().split()
+                data = line.split('#')[0].split()
                 if len(data) != 2:
                     continue
-
-                csetval = eval(data[0])
-                if csetval <= 0x7F:
-                    csetch = bytes([csetval & 0xff])
-                elif csetval >= 0x1000000:
-                    csetch = bytes([(csetval >> 24), ((csetval >> 16) & 0xff),
-                                    ((csetval >> 8) & 0xff), (csetval & 0xff)])
-                elif csetval >= 0x10000:
-                    csetch = bytes([(csetval >> 16), ((csetval >> 8) & 0xff),
-                                    (csetval & 0xff)])
-                elif csetval >= 0x100:
-                    csetch = bytes([(csetval >> 8), (csetval & 0xff)])
-                else:
+                if data[0][:2] != '0x':
+                    self.fail(f"Invalid line: {line!r}")
+                csetch = bytes.fromhex(data[0][2:])
+                if len(csetch) == 1 and 0x80 <= csetch[0]:
                     continue
 
                 unich = unichrs(data[1])