From b664a1df4ee71d3760ab937653b10997081b1794 Mon Sep 17 00:00:00 2001
From: "Miss Skeleton (bot)" <31488909+miss-islington@users.noreply.github.com>
Date: Tue, 6 Oct 2020 05:37:36 -0700
Subject: [PATCH] bpo-41944: No longer call eval() on content received via HTTP
 in the CJK codec tests (GH-22566)

(cherry picked from commit 2ef5caa58febc8968e670e39e3d37cf8eef3cab8)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>

Upstream-Status: Backport [https://github.com/python/cpython/commit/b664a1df4ee71d3760ab937653b10997081b1794]
CVE: CVE-2020-27619
Signed-off-by: Chee Yang Lee <chee.yang.lee@intel.com>

---
 Lib/test/multibytecodec_support.py            | 22 +++++++------------
 .../2020-10-05-17-43-46.bpo-41944.rf1dYb.rst  |  1 +
 2 files changed, 9 insertions(+), 14 deletions(-)
 create mode 100644 Misc/NEWS.d/next/Tests/2020-10-05-17-43-46.bpo-41944.rf1dYb.rst

diff --git a/Lib/test/multibytecodec_support.py b/Lib/test/multibytecodec_support.py
index cca8af67d6d1d..f76c0153f5ecf 100644
--- a/Lib/test/multibytecodec_support.py
+++ b/Lib/test/multibytecodec_support.py
@@ -305,29 +305,23 @@ def test_mapping_file(self):
             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])
diff --git a/Misc/NEWS.d/next/Tests/2020-10-05-17-43-46.bpo-41944.rf1dYb.rst b/Misc/NEWS.d/next/Tests/2020-10-05-17-43-46.bpo-41944.rf1dYb.rst
new file mode 100644
index 0000000000000..4f9782f1c85af
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2020-10-05-17-43-46.bpo-41944.rf1dYb.rst
@@ -0,0 +1 @@
+Tests for CJK codecs no longer call ``eval()`` on content received via HTTP.