bpo-28503: Use crypt_r() when available instead of crypt() (GH-11373)

Use crypt_r() when available instead of crypt() in the crypt module.

As a nice side effect: This also avoids a memory sanitizer flake as clang msan doesn't know about crypt's internal libc allocated buffer.

1 files changed, 9 insertions, 1 deletions

diff --git a/Modules/_cryptmodule.c b/Modules/_cryptmodule.c
index 58d179e..5d03f45 100644
--- a/Modules/_cryptmodule.c
+++ b/Modules/_cryptmodule.c
@@ -34,7 +34,15 @@ static PyObject *
 crypt_crypt_impl(PyObject *module, const char *word, const char *salt)
 /*[clinic end generated code: output=0512284a03d2803c input=0e8edec9c364352b]*/
 {
-    return Py_BuildValue("s", crypt(word, salt));
+    char *crypt_result;
+#ifdef HAVE_CRYPT_R
+    struct crypt_data data;
+    memset(&data, 0, sizeof(data));
+    crypt_result = crypt_r(word, salt, &data);
+#else
+    crypt_result = crypt(word, salt);
+#endif
+    return Py_BuildValue("s", crypt_result);
 }