Merge pull request #3 from GZH2K19/main

Main

Decrypter3000.py

@@ -1,82 +1,113 @@
-#!/usr/bin/env python3
-# -*- coding: utf-8 -*-
 from sys import argv
 from pathlib import Path
-import os
 import json
 
-def transEncKey(key:str):
-    import hashlib
-    md5 = hashlib.md5(key.encode()).hexdigest()
-    lis = [int(md5[i:i+2], 16) for i in range(0, len(md5), 2)]
-    lis += lis[::-1]
-    return lis
 
-def decrypt(data:bytes, tEncKey:list[int]):
-    try:
-        header = ",".join("{:02x}".format(i) for i in data[:32])
-        if header != "41,52,54,00,45,4e,43,52,59,50,54,45,52,31,30,30,46,52,45,45,00,56,45,52,53,49,4f,4e,00,00,00,00":
-            raise Exception
-        num = min(len(data), len(tEncKey))
-        data = bytearray(data[num:])
-        for i in range(num):
-            data[i] ^= tEncKey[i]
-        return bytes(data)
-    except:
-        return
+class E3000D:
+    """3000 Decrypter"""
+    HEADER_STR = "41,52,54,00,45,4e,43,52,59,50,54,45,52,31,30,30,46,52,45,45,00,56,45,52,53,49,4f,4e,00,00,00,00"
+    def __init__(self, key:str):
+        self.key = self.trans_key(key)
+        self.key_len = len(self.key)
+
+    @staticmethod
+    def trans_key(key:str):
+        import hashlib
+        md5 = hashlib.md5(key.encode()).hexdigest()
+        lis = [int(md5[i:i+2], 16) for i in range(0, len(md5), 2)]
+        return lis + lis[::-1]
+
+    def decrypt(self, data:bytes):
+        try:
+            header = ','.join("{:02x}".format(i) for i in data[:32])
+            if header != E3000D.HEADER_STR:
+                raise Exception("Invalid E3000 header")
+            leng = min(len(data), self.key_len)
+            data = bytearray(data[leng:])
+            for i in range(leng):
+                data[i] ^= self.key[i]
+            return bytes(data)
+        except:
+            return None
+
+class NKD:
+    """No-Key Decrypter"""
+    HEADER_STR = "89,50,4E,47,0D,0A,1A,0A,00,00,00,0D,49,48,44,52"
+    def __init__(self):
+        self.HEADER_LEN = 16
+        self.HEADER = self.get_header(self.HEADER_LEN)
+
+    @staticmethod
+    def get_header(header_len:int=16):
+        header_array = NKD.HEADER_STR.split(',')
+        png_header = bytearray(header_len)
+        for r in range(header_len):
+            png_header[r] = int(header_array[r], 16)
+        return png_header
 
+    def decrypt(self, data:bytes):
+        data = data[self.HEADER_LEN*2:]
+        arr = bytearray(self.HEADER_LEN + len(data))
+        arr[:self.HEADER_LEN] = self.HEADER
+        arr[self.HEADER_LEN:] = data
+        return arr
 
-def process_game(game_path:str):
-    game = Path(game_path)
-    print("Processing:", game)
+def process_project(project_path:Path):
+    print("Processing:", project_path)
 
-    json_system = game/"data"/"System.json"
-    if not json_system.exists():
+    sys_json = project_path / "data/System.json"
+    if not sys_json.exists():
         print("Error: System.json not found.\n")
         return
-    with open(json_system, "r", encoding="utf-8-sig") as f:
-        data = json.load(f)
-    encKey = data.get("encryptionKey")
-    if not encKey:
-        print("Error: Encryption key not found.\n")
-        return
-    print("Encryption key:", encKey)
-    tEncKey = transEncKey(encKey)
-
+    with open(sys_json, "r", encoding="utf-8-sig") as f:
+        sys_info = json.load(f)
     folderList = []
-    if data.get("hasEncryptedImages"):
+    if sys_info.get("hasEncryptedImages"):
         folderList.append("img")
-    if data.get("hasEncryptedAudio"):
+    if sys_info.get("hasEncryptedAudio"):
         folderList.append("audio")
     if not folderList:
-        print("Error: Encrypted files not found.\n")
+        print("Warning: Encrypted files not found.\n")
         return
 
+    if (project_path / "js/plugins/Art_Decrypterator3000.js").exists():
+        dec_type = "E3000"
+        encKey = sys_info.get("encryptionKey")
+        if not encKey:
+            print("Error: Encryption key not found.\n")
+            return
+        print("Encryption key:", encKey)
+        decrypter = E3000D(encKey)
+    else:
+        dec_type = "default"
+        decrypter = NKD()
+    print("Decryption type:", dec_type)
+
     for folder in folderList:
-        print("Decrypting", folder, "files...")
-        ori = game/folder
-        new = game/(folder+"_decrypted")
-        for r in ori.rglob("*.*_"):
-            with open(r, "rb") as f:
-                byt = decrypt(f.read(), tEncKey)
-            if not byt:
-                print("Failed to decrypt:", r.relative_to(game))
+        print("Decrypting folder:", folder)
+        ori = project_path / folder
+        new = project_path / (folder+"_dec")
+        for file in ori.rglob("*.*_"):
+            with open(file, "rb") as f:
+                data = decrypter.decrypt(f.read())
+            if not data:
+                print("Failed to decrypt:", file.relative_to(project_path))
                 continue
-            file = str(new/r.relative_to(ori))[:-1]
-            os.makedirs(os.path.dirname(file), exist_ok=True)
-            with open(file, "wb") as f:
-                f.write(byt)
+            new_file = new / file.relative_to(ori).parent / file.name[:-1]
+            new_file.parent.mkdir(parents=True, exist_ok=True)
+            with open(new_file, "wb") as f:
+                f.write(data)
     print("Done.\n")
 
 
 if __name__ == "__main__":
     if not argv[1:]:
-        print("No arguments provided. Please drag the game folder onto this script.")
+        print("No arguments provided. Please drag the project folder onto this script.\n")
     else:
-        try:
-            for game_path in argv[1:]:
-                process_game(game_path)
-        except:
-            from traceback import format_exc
-            print(format_exc())
-    os.system("pause")
+        for path in argv[1:]:
+            try:
+                process_project(Path(path))
+            except:
+                from traceback import format_exc
+                print(format_exc(), '\n')
+    input("Press ENTER to exit...")

README.md

@@ -1,5 +1,9 @@
 ## Instruction
-Just drag the game folder onto this script (on Windows). The decrypted resource folder will be created in the same directory as the source folder.
+Just drag the project folder onto this script. The decrypted resource folder will be created in the same directory as the source folder.
+
+Supported encryption types:
+- Default
+- Encrypterator 3000
 
 ## Disclaimer
-All code is for research and educational purposes only. Do not use for illegal activities. The author is also not responsible for any consequences arising from the use of this code.
+All code is for research and educational purposes only. Do not use for illegal activities. The author is also not responsible for any consequences arising from the use of the code.