From 7a99290a14aa77231f29252dda5e6962de1b6e8c Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Wed, 27 Feb 2019 08:35:49 +0530
Subject: [PATCH] Port msdes to python 3

Fixes #937 (Port msdes plugin to build on python2/python3 )
---
 src/calibre/utils/msdes/msdesmodule.c | 60 ++++++++++++++++++++-------
 1 file changed, 45 insertions(+), 15 deletions(-)

diff --git a/src/calibre/utils/msdes/msdesmodule.c b/src/calibre/utils/msdes/msdesmodule.c
index 66844fa510..8fa98d10e1 100644
--- a/src/calibre/utils/msdes/msdesmodule.c
+++ b/src/calibre/utils/msdes/msdesmodule.c
@@ -9,8 +9,7 @@
 
 #include <d3des.h>
 
-static char msdes_doc[] = 
-"Provide LIT-specific DES en/decryption.";
+static const char msdes_doc[] = "Provide LIT-specific DES en/decryption.";
 
 static PyObject *MsDesError = NULL;
 
@@ -21,7 +20,11 @@ msdes_deskey(PyObject *self, PyObject *args)
     unsigned int len = 0;
     short int edf = 0;
 
+#if PY_MAJOR_VERSION >= 3
+    if (!PyArg_ParseTuple(args, "y#h", &key, &len, &edf)) {
+#else
     if (!PyArg_ParseTuple(args, "s#h", &key, &len, &edf)) {
+#endif
         return NULL;
     }
 
@@ -33,10 +36,10 @@ msdes_deskey(PyObject *self, PyObject *args)
     if ((edf != EN0) && (edf != DE1)) {
         PyErr_SetString(MsDesError, "En/decryption direction invalid");
         return NULL;
-    }    
+    }
 
     deskey(key, edf);
-    
+
     Py_RETURN_NONE;
 }
 
@@ -49,7 +52,11 @@ msdes_des(PyObject *self, PyObject *args)
     unsigned int off = 0;
     PyObject *retval = NULL;
 
+#if PY_MAJOR_VERSION >= 3
+    if (!PyArg_ParseTuple(args, "y#", &inbuf, &len)) {
+#else
     if (!PyArg_ParseTuple(args, "s#", &inbuf, &len)) {
+#endif
         return NULL;
     }
 
@@ -59,16 +66,16 @@ msdes_des(PyObject *self, PyObject *args)
         return NULL;
     }
 
-    retval = PyString_FromStringAndSize(NULL, len);
+    retval = PyBytes_FromStringAndSize(NULL, len);
     if (retval == NULL) {
         return NULL;
     }
-    outbuf = (unsigned char *)PyString_AS_STRING(retval);
+    outbuf = (unsigned char *)PyBytes_AS_STRING(retval);
 
     for (off = 0; off < len; off += 8) {
         des((inbuf + off), (outbuf + off));
     }
-    
+
     return retval;
 }
 
@@ -78,21 +85,44 @@ static PyMethodDef msdes_methods[] = {
     { NULL, NULL }
 };
 
-CALIBRE_MODINIT_FUNC
-initmsdes(void)
-{
+#if PY_MAJOR_VERSION >= 3
+#define INITERROR return NULL
+#define INITMODULE PyModule_Create(&msdes_module)
+static struct PyModuleDef msdes_module = {
+    /* m_base     */ PyModuleDef_HEAD_INIT,
+    /* m_name     */ "msdes",
+    /* m_doc      */ msdes_doc,
+    /* m_size     */ -1,
+    /* m_methods  */ msdes_methods,
+    /* m_slots    */ 0,
+    /* m_traverse */ 0,
+    /* m_clear    */ 0,
+    /* m_free     */ 0,
+};
+CALIBRE_MODINIT_FUNC PyInit_msdes(void) {
+#else
+#define INITERROR return
+#define INITMODULE Py_InitModule3("msdes", msdes_methods, msdes_doc)
+CALIBRE_MODINIT_FUNC initmsdes(void) {
+#endif
+
     PyObject *m;
 
-    m = Py_InitModule3("msdes", msdes_methods, msdes_doc);
+    m = INITMODULE;
     if (m == NULL) {
-        return;
+        INITERROR;
     }
-    
+
     MsDesError = PyErr_NewException("msdes.MsDesError", NULL, NULL);
     Py_INCREF(MsDesError);
     PyModule_AddObject(m, "MsDesError", MsDesError);
+#if PY_MAJOR_VERSION >= 3
+    PyModule_AddObject(m, "EN0", PyLong_FromLong(EN0));
+    PyModule_AddObject(m, "DE1", PyLong_FromLong(DE1));
+
+    return m;
+#else
     PyModule_AddObject(m, "EN0", PyInt_FromLong(EN0));
     PyModule_AddObject(m, "DE1", PyInt_FromLong(DE1));
-    
-    return;
+#endif
 }