Fixes Issue #3745: Fix hashlib to always reject unicode and non
buffer-api supporting objects as input no matter how it was compiled
(built in implementations or external openssl library).
diff --git a/Modules/hashlib.h b/Modules/hashlib.h
new file mode 100644
index 0000000..db39cea
--- /dev/null
+++ b/Modules/hashlib.h
@@ -0,0 +1,28 @@
+/* Common code for use by all hashlib related modules. */
+
+/*
+ * Given a PyObject* obj, fill in the Py_buffer* viewp with the result
+ * of PyObject_GetBuffer. Sets and exception and issues a return NULL
+ * on any errors.
+ */
+#define GET_BUFFER_VIEW_OR_ERROUT(obj, viewp) do { \
+ if (PyUnicode_Check((obj))) { \
+ PyErr_SetString(PyExc_TypeError, \
+ "Unicode-objects must be encoded before hashing");\
+ return NULL; \
+ } \
+ if (!PyObject_CheckBuffer((obj))) { \
+ PyErr_SetString(PyExc_TypeError, \
+ "object supporting the buffer API required"); \
+ return NULL; \
+ } \
+ if (PyObject_GetBuffer((obj), (viewp), PyBUF_SIMPLE) == -1) { \
+ return NULL; \
+ } \
+ if ((viewp)->ndim > 1) { \
+ PyErr_SetString(PyExc_BufferError, \
+ "Buffer must be single dimension"); \
+ PyBuffer_Release((viewp)); \
+ return NULL; \
+ } \
+ } while(0);