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/sha1module.c b/Modules/sha1module.c
index 4d8ed1d..a7f6ad2 100644
--- a/Modules/sha1module.c
+++ b/Modules/sha1module.c
@@ -17,6 +17,7 @@
 /* SHA1 objects */
 
 #include "Python.h"
+#include "hashlib.h"
 
 
 /* Some useful types */
@@ -387,11 +388,14 @@
 static PyObject *
 SHA1_update(SHA1object *self, PyObject *args)
 {
+    PyObject *obj;
     Py_buffer buf;
 
-    if (!PyArg_ParseTuple(args, "s*:update", &buf))
+    if (!PyArg_ParseTuple(args, "O:update", &obj))
         return NULL;
 
+    GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);
+
     sha1_process(&self->hash_state, buf.buf, buf.len);
 
     PyBuffer_Release(&buf);
@@ -487,14 +491,17 @@
 {
     static char *kwlist[] = {"string", NULL};
     SHA1object *new;
+    PyObject *data_obj = NULL;
     Py_buffer buf;
-    buf.buf = NULL;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s*:new", kwlist,
-                                     &buf)) {
+    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|O:new", kwlist,
+                                     &data_obj)) {
         return NULL;
     }
 
+    if (data_obj)
+        GET_BUFFER_VIEW_OR_ERROUT(data_obj, &buf);
+
     if ((new = newSHA1object()) == NULL)
         return NULL;
 
@@ -504,7 +511,7 @@
         Py_DECREF(new);
         return NULL;
     }
-    if (buf.buf) {
+    if (data_obj) {
         sha1_process(&new->hash_state, buf.buf, buf.len);
 	PyBuffer_Release(&buf);
     }