# Private Servers

## There are 3 servers

- EW (ew, why?): [source](https://git.ethanthesleepy.one/ethanaobrien/ew), [mirror](https://github.com/ethanaobrien/ew)
- Edelstein (in development): [source](https://github.com/Arasfon/Edelstein)
- alive-serv (in development): [source](https://github.com/miraclealive/alive-serv) (I found this while googling)

## Development stuff

### Asset tree

Sif2 uses unity assetbundles to distribute assets. They also verify the asset hashes, yayyy!!!! (sarcasm).

The initial request containing hashes, filenames, and assetbundle sizes has the name of `387b0126300c54515911bffb6540982d.unity3d`

Files are at `<FileHash>/<FileName>.ext`

### Masterdata

The masterdata is shipped under filename `6572ca8348bc566b8cf01d43c4cc1b58.unity3d`. Once extracted, all files were encrypted.

You can decrypt the masterdata with the following python function:

```py
def decrypt_mst(bin_file):
    salt = bin_file[16:32]
    pbk = hashlib.pbkdf2_hmac(
        "sha1", "3559b435f24b297a79c68b9709ef2125".encode("utf-8"), salt, 1000
    )
    key = pbk[:16]

    iv_length = bin_file[32]  # = 16
    iv = bin_file[36:36 + iv_length]
    data = bin_file[36 + iv_length:]

    cipher = Cipher(
        algorithms.AES(key), modes.CBC(iv), backend=default_backend()
    )
    decryptor = cipher.decryptor()
    decrypted = decryptor.update(data) + decryptor.finalize()
    return decrypted[:-decrypted[-1]]
```

All files are then binary serialized. I'll document that part later. Maybe...

### Modification

Please see the [SIF2 asset modification repository](https://git.ethanthesleepy.one/ethanaobrien/sif2-asset-modification). You will need to download SIF2 assets for the language of your choice.

### Downloading assets

Assets can be found on archive.org:

- JP: [https://archive.org/details/lovelive-sif2-jp-assets](https://archive.org/details/lovelive-sif2-jp-assets)
- GLOBAL: [https://archive.org/details/lovelive-sif2-gl-assets](https://archive.org/details/lovelive-sif2-gl-assets)

### Changing the server URL

TODO...