dev-python/rencode: import fix CVE-2021-40839

Bug: https://bugs.gentoo.org/812437
Signed-off-by: Arthur Zamarin <arthurzam@gentoo.org>

dev-python/rencode/files/rencode-1.0.6-fix-CVE-2021-40839.patch

@@ -0,0 +1,34 @@
+From: Andrew Resch <andrewresch@gmail.com>
+Date: Mon, 9 Aug 2021 20:44:51 -0700
+Subject: [PATCH] Fix checking if typecode is valid while decoding.
+
+This bug will cause rencode to hang if the invalid typecode is included
+in a sequence type (list, dict) since the position will not change and
+the loop checking for the termination byte never returns.
+
+This change is a copy of PR #29 with a few aesthetic changes.
+
+--- a/rencode/rencode.pyx
++++ b/rencode/rencode.pyx
+@@ -527,6 +527,8 @@
+         return decode_fixed_dict(data, pos)
+     elif typecode == CHR_DICT:
+         return decode_dict(data, pos)
++    else:
++        raise ValueError("Invalid typecode: %d at pos: %d" % (typecode, pos[0]))
+ 
+ def loads(data, decode_utf8=False):
+     """
+--- a/tests/test_rencode.py
++++ b/tests/test_rencode.py
+@@ -223,5 +223,10 @@
+         assert rencode_orig.__version__
+         self.assertEqual(rencode.__version__[1:], rencode_orig.__version__[1:], "version number does not match")
+ 
++    def test_invalid_typecode(self):
++        s = b";\x2f\x7f"
++        with self.assertRaises(ValueError):
++            rencode.loads(s)
++
+ if __name__ == '__main__':
+     unittest.main()

dev-python/rencode/rencode-1.0.6-r2.ebuild

@@ -0,0 +1,35 @@
+# Copyright 1999-2021 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+PYTHON_COMPAT=( python3_{8..10} )
+
+inherit distutils-r1
+
+DESCRIPTION="similar to bencode from the BitTorrent project"
+HOMEPAGE="https://github.com/aresch/rencode"
+SRC_URI="https://github.com/aresch/${PN}/archive/v${PV}.tar.gz -> ${P}.tar.gz"
+
+LICENSE="GPL-3+"
+SLOT="0"
+KEYWORDS="~amd64 ~arm ~arm64 ~ppc ~sparc ~x86 ~amd64-linux ~x86-linux"
+
+BDEPEND="dev-python/cython[${PYTHON_USEDEP}]"
+
+distutils_enable_tests pytest
+
+PATCHES=(
+	# https://github.com/aresch/rencode/commit/16e61e1ff4294bddb7c881536d3d454355c78969
+	"${FILESDIR}/${P}-drop-wheel-dependency.patch"
+	# bug #812437
+	"${FILESDIR}/${P}-fix-CVE-2021-40839.patch"
+)
+
+python_test() {
+	# The C extension ("_rencode") can't be imported from "${S}/rencode"
+	# so we need to cd somewhere else to make sure "rencode" is imported
+	# from ${BUILD_DIR}/lib (thanks to PYTHONPATH).
+	cd "${T}" || die
+	epytest "${S}"
+}