commit 9b8c2e767643256202bb11456ba8665593b9a500
author Serhiy Storchaka <storchaka@gmail.com> Thu Oct 11 07:41:00 2018 +0300
committer GitHub <noreply@github.com> Thu Oct 11 07:41:00 2018 +0300
tree 92b674df44b5bb6d14583e910cf38f0ead9837bb
parent f1aa8aed4a8ce9753ffa8713e7d3461663e0624d

bpo-34922: Fix integer overflow in the digest() and hexdigest() methods (GH-9751)

for the SHAKE algorithm in the hashlib module.

Modules/_sha3/sha3module.c

diff --git a/Modules/_sha3/sha3module.c b/Modules/_sha3/sha3module.c
index 46c1ff1..b737363 100644
--- a/Modules/_sha3/sha3module.c
+++ b/Modules/_sha3/sha3module.c
@@ -589,6 +589,10 @@
     int res;
     PyObject *result = 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.
      */