From 195ea69537287d1dcf2a4111818704ec5541cf7b Mon Sep 17 00:00:00 2001
From: Martin Rys <martin@rys.rs>
Date: Sun, 27 Oct 2024 22:56:15 +0100
Subject: [PATCH] DeDRM ion: Clean out errorneous whitespace and UTF8
 definition from python 2 times

---
 DeDRM_plugin/ion.py | 56 +++++++++++++++++++++------------------------
 1 file changed, 26 insertions(+), 30 deletions(-)

diff --git a/DeDRM_plugin/ion.py b/DeDRM_plugin/ion.py
index 7dd39a5..9d9e49c 100644
--- a/DeDRM_plugin/ion.py
+++ b/DeDRM_plugin/ion.py
@@ -1,24 +1,17 @@
 #!/usr/bin/env python3
-# -*- coding: utf-8 -*-
+"""ion.py: Decrypt Kindle KFX files.
 
-# ion.py
-# Copyright © 2013-2020 Apprentice Harper et al.
+Revision history:
+  Pascal implementation by lulzkabulz.
+  BinaryIon.pas + DrmIon.pas + IonSymbols.pas
+  1.0   - Python translation by apprenticenaomi.
+  1.1   - DeDRM integration by anon.
+  1.2   - Added pylzma import fallback
+  1.3   - Fixed lzma support for calibre 4.6+
+  2.0   - VoucherEnvelope v2/v3 support by apprenticesakuya.
+  3.0   - Added Python 3 compatibility for calibre 5.0
 
-__license__ = 'GPL v3'
-__version__ = '3.0'
-
-# Revision history:
-#  Pascal implementation by lulzkabulz.
-#  BinaryIon.pas + DrmIon.pas + IonSymbols.pas
-#  1.0   - Python translation by apprenticenaomi.
-#  1.1   - DeDRM integration by anon.
-#  1.2   - Added pylzma import fallback
-#  1.3   - Fixed lzma support for calibre 4.6+
-#  2.0   - VoucherEnvelope v2/v3 support by apprenticesakuya.
-#  3.0   - Added Python 3 compatibility for calibre 5.0
-
-"""
-Decrypt Kindle KFX files.
+Copyright © 2013-2020 Apprentice Harper et al.
 """
 
 import collections
@@ -30,6 +23,9 @@ import struct
 
 from io import BytesIO
 
+__license__ = 'GPL v3'
+__version__ = '3.0'
+
 #@@CALIBRE_COMPAT_CODE@@
 
 
@@ -1096,11 +1092,11 @@ def process_V9888(st):
     ws.sbox(d0x6a0bf4d0,d0x6a0dab50,[1,2])
     ws.sbox(d0x6a0ba4d0,d0x6a0dab50,[1,2])
     ws.shuffle(repl)
-    ws.shuffle(repl)    
+    ws.shuffle(repl)
     ws.shuffle(repl)
     ws.sbox(d0x6a0bf4d0,d0x6a0dab50,[1,2])
     ws.sbox(d0x6a0ba4d0,d0x6a0dab50,[1,2])
-    ws.exlookup(d0x6a0be4d0)    
+    ws.exlookup(d0x6a0be4d0)
     dat=ws.mask(st[sto:sto+16])
     out+=dat
     sto+=16
@@ -1124,7 +1120,7 @@ def process_V4648(st):
     ws.sbox(d0x6a0c51a8,d0x6a0dab50,[1,3])
     ws.shuffle(repl)
     ws.shuffle(repl)
-    ws.exlookup(d0x6a0c91a8)    
+    ws.exlookup(d0x6a0c91a8)
     dat=ws.mask(st[sto:sto+16])
     out+=dat
     sto+=16
@@ -1148,7 +1144,7 @@ def process_V5683(st):
     ws.shuffle(repl)
     ws.sbox(d0x6a0cfe80,d0x6a0dab50,[])
     ws.shuffle(repl)
-    ws.exlookup(d0x6a0d3e80)    
+    ws.exlookup(d0x6a0d3e80)
     dat=ws.mask(st[sto:sto+16])
     out+=dat
     sto+=16
@@ -1163,12 +1159,12 @@ def process_V5683(st):
 #     if a<0: a=256+a
 #     ax.append(ha[(a>>4)]+ha[a%16])
 #   return "".join(ax)
-# 
+#
 # def memhex(adr,sz):
 #   emu=EmulatorHelper(currentProgram)
 #   arr=emu.readMemory(getAddress(adr),sz)
 #   return a2hex(arr)
-# 
+#
 
 
 
@@ -1254,7 +1250,7 @@ def scramble3(st,magic):
             iVar5 = iVar5 - magic
             index -= 1
             if uVar4<=-1: break
-      else: 
+      else:
         if (offset < magic):
           iVar3 = 0
         else :
@@ -1274,9 +1270,9 @@ def scramble3(st,magic):
             index=index-1
             iVar5 = iVar5 + magic;
             cntr += 1;
-            if iVar3>=divs: break 
+            if iVar3>=divs: break
       offset = offset + 1
-      if offset >= ((magic - 1) + divs) :break 
+      if offset >= ((magic - 1) + divs) :break
   return ret
 
 #not sure if the third variant is used anywhere, but it is in Kindle, so I tried to add it
@@ -1342,12 +1338,12 @@ class DrmIonVoucher(object):
                 _assert(False, "Unknown lock parameter: %s" % param)
 
 
-        # i know that version maps to scramble pretty much 1 to 1, but there was precendent where they changed it, so... 
+        # i know that version maps to scramble pretty much 1 to 1, but there was precendent where they changed it, so...
         sharedsecrets = [obfuscate(shared, self.version),obfuscate2(shared, self.version),obfuscate3(shared, self.version),
                          process_V9708(shared), process_V1031(shared), process_V2069(shared), process_V9041(shared),
                          process_V3646(shared), process_V6052(shared), process_V9479(shared), process_V9888(shared),
                          process_V4648(shared), process_V5683(shared)]
-        
+
         decrypted=False
         ex=None
         for sharedsecret in sharedsecrets:
@@ -1361,7 +1357,7 @@ class DrmIonVoucher(object):
 
                 _assert(self.drmkey.hasnext() and self.drmkey.next() == TID_LIST and self.drmkey.gettypename() == "com.amazon.drm.KeySet@1.0",
                     "Expected KeySet, got %s" % self.drmkey.gettypename())
-                decrypted=True 
+                decrypted=True
 
                 print("Decryption succeeded")
                 break