[3.7] bpo-34922: Fix integer overflow in the digest() and hexdigest() methods (GH-9751) (GH-9798)
for the SHAKE algorithm in the hashlib module.
(cherry picked from commit 9b8c2e767643256202bb11456ba8665593b9a500)
diff --git a/Lib/test/test_hashlib.py b/Lib/test/test_hashlib.py
index 5b7f408..fc0649d 100644
--- a/Lib/test/test_hashlib.py
+++ b/Lib/test/test_hashlib.py
@@ -230,6 +230,20 @@
self.assertIsInstance(h.digest(), bytes)
self.assertEqual(hexstr(h.digest()), h.hexdigest())
+ def test_digest_length_overflow(self):
+ # See issue #34922
+ large_sizes = (2**29, 2**32-10, 2**32+10, 2**61, 2**64-10, 2**64+10)
+ for cons in self.hash_constructors:
+ h = cons()
+ if h.name not in self.shakes:
+ continue
+ for digest in h.digest, h.hexdigest:
+ with self.assertRaises((ValueError, OverflowError)):
+ digest(-10)
+ for length in large_sizes:
+ with self.assertRaises((ValueError, OverflowError)):
+ digest(length)
+
def test_name_attribute(self):
for cons in self.hash_constructors:
h = cons()
diff --git a/Misc/NEWS.d/next/Library/2018-10-07-21-18-52.bpo-34922.37IdsA.rst b/Misc/NEWS.d/next/Library/2018-10-07-21-18-52.bpo-34922.37IdsA.rst
new file mode 100644
index 0000000..6463886
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-10-07-21-18-52.bpo-34922.37IdsA.rst
@@ -0,0 +1,3 @@
+Fixed integer overflow in the :meth:`~hashlib.shake.digest()` and
+:meth:`~hashlib.shake.hexdigest()` methods for the SHAKE algorithm
+in the :mod:`hashlib` module.
diff --git a/Modules/_sha3/sha3module.c b/Modules/_sha3/sha3module.c
index d879e92..9b07cf0 100644
--- a/Modules/_sha3/sha3module.c
+++ b/Modules/_sha3/sha3module.c
@@ -594,7 +594,10 @@
if (digestlen == (unsigned long) -1 && PyErr_Occurred()) {
return NULL;
}
-
+ if (digestlen >= (1 << 29)) {
+ PyErr_SetString(PyExc_ValueError, "length is too large");
+ return NULL;
+ }
/* ExtractLane needs at least SHA3_MAX_DIGESTSIZE + SHA3_LANESIZE and
* SHA3_LANESIZE extra space.
*/