They looks like encrypted by the same key.
Unity bundles have large, mostly static header and this very helpful in our case:
So, if simple XOR is used for encryption, we can try to get key using marked ^ part of header, adapted for Unity version used in game:
(not sure in highlighted byte and too lazy to check, but it's better to note and change, if errors occurs)
XOR have some interesting features:
If you XOR 00 byte with any byte, you get this byte value in place of 00 - so, short keys can be visible with bare eyes if encrypted file have a lots of 00-bytes.
If you XOR encrypted file with original one - you'll get <key><key><key> sequence on whole file content.
We don't have original file, but we recreated first 35 bytes of it.
So, i renamed a copy of game bundle to "s1" and XOR it as new "s1x" file using reconstructed header bytes as key, with XOR tool from Luigi Auriemma:
xor s1 s1x 0x556E69747946530000000008352E782E7800323032312E332E39663100000000000000
And got partial <key><key> sequence:
So, XOR key is: EA7B2B092B59433996F0B470B7B3FEA7BC0AA57B0208A7314420
Decoding test bundle as "s1t" file with this key:
xor s1 s1t 0xEA7B2B092B59433996F0B470B7B3FEA7BC0AA57B0208A7314420
Looks very good )
Drag-and-drop "s1t" file to AssetStudioModGUI, and it loads without issues, so key is valid:
Dealing with 36K files in cache isn't easy task, so i done a python script for mass decrypt and save to separate folder:
# Mobile Suit Gundam - Iron-Blooded Orphans G bundles unxor
import os
xor_magic = b"\xBF\x15\x42\x7D"
# xor key: EA7B2B092B59433996F0B470B7B3FEA7BC0AA57B0208A7314420
xor_key = bytearray(b"\xea\x7b\x2b\x09\x2b\x59\x43\x39\x96\xf0\xb4\x70\xb7\xb3\xfe\xa7\xbc\x0a\xa5\x7b\x02\x08\xa7\x31\x44\x20")
output_path = R"C:\tmp\Cache"
with os.scandir('.') as file_paths:
for file_path in file_paths:
if file_path.is_dir(follow_symlinks=False):
pass
else:
with open(file_path, "rb") as work_file:
file_magic = work_file.read(4)
if file_magic == xor_magic:
print("Processing file:", file_path.name)
work_file.seek(0)
encrypted_content = work_file.read()
encrypted_content_size = len(encrypted_content)
decrypted_content = bytearray(encrypted_content_size)
xor_key_multiplier = int(encrypted_content_size / 26) + 1
xor_key_array = xor_key * xor_key_multiplier
for byte in range(encrypted_content_size):
decrypted_content[byte] = encrypted_content[byte] ^ xor_key_array[byte]
out_file_name = str(file_path.name) + ".unity3d"
write_path = output_path + "\\" + out_file_name
os.makedirs(os.path.dirname(write_path), exist_ok=True)
open(write_path, "wb").write(decrypted_content)
print("Decrypted file saved:", write_path)
work_file.close()
Must be run inside of "Cache\assets\asset\" folder, and output to temporary folder on disk C (it's SSD usualy, to speed up things).
But there's other problem occur - that cache folder taken from a game which survived many updates, so a lots of older copies of same file present here, they have same name in first part (before "_") and version code as second name part.
So, i done another python script to separate latest file versions to another folder:
# Mobile Suit Gundam - Iron-Blooded Orphans G cache sort
import os
import shutil
work_dictionary = {}
output_path = R"C:\tmp\Cache\Assets"
with os.scandir('.') as file_paths:
for file_path in file_paths:
if file_path.is_dir(follow_symlinks=False):
pass
elif len(os.path.splitext(file_path)[0]) - 2 != 52:
pass
else:
bundle_name = file_path.name[0:33]
bundle_version = int(file_path.name[34:52])
if bundle_name in work_dictionary:
if work_dictionary[bundle_name] >= bundle_version:
pass
else:
work_dictionary[bundle_name] = bundle_version
else:
work_dictionary[bundle_name] = bundle_version
for item in work_dictionary:
file_name = item + "_" + str(work_dictionary[item]) + ".unity3d"
destination = output_path + "\\" + file_name
os.makedirs(os.path.dirname(destination), exist_ok=True)
if os.path.isfile(file_name) == True:
shutil.move(file_name, destination)
print("Latest version file moved to:", destination)
Must be run in folder with decoded bundles, it moves latest version files to Assets subfolder.
Then you can move this folder to main game folder "G_2.0.2_apkcombo\assets\bin\Data\" and load game folder to AssetStudioModGUI (took 16+ Gb of RAM):
Model export works fine, with animations:
Files with names starting with "r" is not encrypted or encrypted using more secure algorithms - no luck here.
Mobile_Suit_Gundam_cache_scripts.7z
You're welcome ) Last three of your screenshots taken from different versions of one file, so it's another case, and most probably not standard Unity bundle, maybe database, because growing with version increase. Update: Did a search for XOR-key string in apk folder, and found it! Probably other keys can be around:
