Newbie Spellweaver
- Joined
- Jul 31, 2026
- Messages
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Hello there,
Sharing with you a 100% compatible License Server for MuDevs Season 21 Part 1-2 and Part 2-3 (not sure).
Before anything else, I'd like to thank the different people who helped me throughout this research. Whether it was by sharing information, discussing ideas, or simply pointing me in the right direction, they all contributed in one way or another. I won't mention anyone by name unless they explicitly ask me to.
I'll also be publishing the source code on GitHub soon in case someone from the community wants to fork the project and continue maintaining or improving it. There isn't much magic behind it—almost the entire project lives in a single source file. If is not that muc
I'd also like to make one thing very clear: this application does not modify files, inject code, install drivers, or perform any suspicious actions. Its only purpose is to intercept the license server communication and reply with a valid license response. If you're unsure, feel free to inspect the source code and verify everything yourself. You still need to edit your host file.
ie
sha: a51537ce91260fd6ec718c6fa49386a95571725bd1fcad8ff4fc69e3c18c4620
user limit cap: 9999
At the moment, MuDevs still relies on the CustomerName value as part of its license validation. This means the CustomerName must match exactly on both the client and the server.
The included client already comes with a main.devs configured using CustomerName 511. All you need to do is change the server IP and configure the same CustomerName on your server.
As usual, the Version, Serial, and any other client settings must also match the server configuration.
If you generate a new main.devs file later, don't forget to update the server configuration as well so both sides continue using the same values.
Launcher
you need to use a laucnher.
source: unkwnown
The server configuration is basically the same as any other mu server. You'll only need to change a few IP addresses and not much else. There's really nothing complicated about it.
With this configuration, I was able to connect and stay online for more than 6 hours without any issues. So far, I haven't encountered any problems.
That said, there are probably better ways to configure it, so don't treat these settings as the only or "correct" way to do it. Time will tell as more people test and refine the setup.
Also included as a little bonus is a script to read and write any main.devs file. It was the same tool I used throughout the research process.
If anyone feels like building a native Windows application around it, that would be awesome.
The goal has been accomplished.
I'd really like to see the community keep sharing and releasing new things whenever possible. This game was a big part of my teenage years, just like it was for many of you. I hope this release helps others learn, build new projects, and keep the community moving forward.
There's still plenty to discover, improve, and share. Hopefully this is just another step that encourages more people to contribute.
Enjoy, and make good use of it.
rivotril_ out.
Sharing with you a 100% compatible License Server for MuDevs Season 21 Part 1-2 and Part 2-3 (not sure).
Before anything else, I'd like to thank the different people who helped me throughout this research. Whether it was by sharing information, discussing ideas, or simply pointing me in the right direction, they all contributed in one way or another. I won't mention anyone by name unless they explicitly ask me to.
What's included in this release?
- MuDevLicenseEmulator v1.1.1 (latest version and probably my last release for this project).
- Trust Client S21 Part 1-2.
- MuDevs PREMIUM S21 Server.
MuDevLicenseEmulator v1.1.1
The emulator is provided completely unpacked and unobfuscated. There are no protectors, packers, or anything hidden. I'd say almost anyone, especially with today's AI tools, can inspect the code, understand how it works, and even create their own revisions. If it's not too much to ask... please don't remove my name from the credits.I'll also be publishing the source code on GitHub soon in case someone from the community wants to fork the project and continue maintaining or improving it. There isn't much magic behind it—almost the entire project lives in a single source file. If is not that muc
I'd also like to make one thing very clear: this application does not modify files, inject code, install drivers, or perform any suspicious actions. Its only purpose is to intercept the license server communication and reply with a valid license response. If you're unsure, feel free to inspect the source code and verify everything yourself. You still need to edit your host file.
ie
Code:
127.0.0.1 l1.mudevs.com
127.0.0.1 l2.mudevs.com
127.0.0.1 l3.mudevs.comsha: a51537ce91260fd6ec718c6fa49386a95571725bd1fcad8ff4fc69e3c18c4620
user limit cap: 9999
To view the content, you need to sign in or register
Trust Client S21 Part 1-2
A compatible client is included with this release.At the moment, MuDevs still relies on the CustomerName value as part of its license validation. This means the CustomerName must match exactly on both the client and the server.
The included client already comes with a main.devs configured using CustomerName 511. All you need to do is change the server IP and configure the same CustomerName on your server.
As usual, the Version, Serial, and any other client settings must also match the server configuration.
If you generate a new main.devs file later, don't forget to update the server configuration as well so both sides continue using the same values.
To view the content, you need to sign in or register
Launcher
you need to use a laucnher.
source: unkwnown
To view the content, you need to sign in or register
MuDevs PREMIUM S21
The original MuDevs PREMIUM S21 server is included and is fully compatible with the License Emulator provided in this release.
To view the content, you need to sign in or register
The server configuration is basically the same as any other mu server. You'll only need to change a few IP addresses and not much else. There's really nothing complicated about it.
With this configuration, I was able to connect and stay online for more than 6 hours without any issues. So far, I haven't encountered any problems.
That said, there are probably better ways to configure it, so don't treat these settings as the only or "correct" way to do it. Time will tell as more people test and refine the setup.
Also included as a little bonus is a script to read and write any main.devs file. It was the same tool I used throughout the research process.
If anyone feels like building a native Windows application around it, that would be awesome.
Python:
#!/usr/bin/env python3
from __future__ import annotations
import hashlib
import json
import sys
from pathlib import Path
XOR_KEY = 0xDA
SUB_KEY = 0x65
LATIN_TEXT_BYTES = {
0xC1, 0xC3, 0xC7, 0xC9, 0xCD, 0xD1, 0xD3, 0xD5, 0xDA,
0xE1, 0xE3, 0xE7, 0xE9, 0xED, 0xF1, 0xF3, 0xF5, 0xFA,
}
def decrypt(data: bytes) -> bytes:
return bytes(
((value + (SUB_KEY ^ ((index >> 8) & 0xFF))) & 0xFF)
^ (XOR_KEY ^ (index & 0xFF))
for index, value in enumerate(data)
)
def encrypt(data: bytes) -> bytes:
return bytes(
(
(value ^ (XOR_KEY ^ (index & 0xFF)))
- (SUB_KEY ^ ((index >> 8) & 0xFF))
)
& 0xFF
for index, value in enumerate(data)
)
def fixed_string(data: bytes) -> str:
return data.split(b"\0", 1)[0].decode("ascii", "replace")
def ascii_strings(data: bytes, minimum: int = 4) -> list[dict[str, object]]:
results: list[dict[str, object]] = []
start = None
for index, value in enumerate(data + b"\0"):
if 32 <= value <= 126 or value in LATIN_TEXT_BYTES:
if start is None:
start = index
elif start is not None:
if index - start >= minimum:
results.append(
{
"offset": start,
"offset_hex": f"0x{start:08X}",
"encoding": "windows-1252",
"value": data[start:index].decode("windows-1252", "replace"),
}
)
start = None
return results
def utf16le_strings(data: bytes, minimum: int = 4) -> list[dict[str, object]]:
results: list[dict[str, object]] = []
index = 0
while index + 1 < len(data):
start = index
chars = []
while index + 1 < len(data) and 32 <= data[index] <= 126 and data[index + 1] == 0:
chars.append(chr(data[index]))
index += 2
if len(chars) >= minimum:
results.append(
{
"offset": start,
"offset_hex": f"0x{start:08X}",
"encoding": "utf-16le",
"value": "".join(chars),
}
)
index = max(index + 1, start + 1)
return results
source = Path(sys.argv[1])
output = Path(sys.argv[2])
output.mkdir(parents=True, exist_ok=True)
encrypted = source.read_bytes()
plain = decrypt(encrypted)
round_trip = encrypt(plain)
fields = {
"launcher_type": plain[0],
"customer_name": fixed_string(plain[1:33]),
"ip": fixed_string(plain[33:65]),
"port": int.from_bytes(plain[66:68], "little"),
"version": fixed_string(plain[68:76]),
"serial": fixed_string(plain[76:93]),
"window_name": fixed_string(plain[380:412]),
"screenshot_path": fixed_string(plain[412:462]),
"client_name": fixed_string(plain[462:494]),
"main_dll": fixed_string(plain[686:718]),
"lang_mpr_password": fixed_string(plain[718:750]),
}
strings = ascii_strings(plain) + utf16le_strings(plain)
strings.sort(key=lambda item: (int(item["offset"]), str(item["encoding"])))
report = {
"source": str(source),
"size": len(encrypted),
"encrypted_sha256": hashlib.sha256(encrypted).hexdigest(),
"decrypted_sha256": hashlib.sha256(plain).hexdigest(),
"round_trip_exact": round_trip == encrypted,
"fields": fields,
"string_count": len(strings),
"strings": strings,
}
(output / "main.devs.decrypted.bin").write_bytes(plain)
(output / "main.devs.reencrypted.bin").write_bytes(round_trip)
(output / "main.devs.report.json").write_text(
json.dumps(report, indent=2, ensure_ascii=True) + "\n", encoding="ascii"
)
with (output / "main.devs.strings.txt").open("w", encoding="utf-8") as handle:
for item in strings:
handle.write(f"{item['offset_hex']} [{item['encoding']}] {item['value']}\n")
with (output / "main.devs.hex.txt").open("w", encoding="ascii") as handle:
for offset in range(0, len(plain), 16):
chunk = plain[offset:offset + 16]
hex_bytes = " ".join(f"{value:02X}" for value in chunk)
text = "".join(chr(value) if 32 <= value <= 126 else "." for value in chunk)
handle.write(f"{offset:08X} {hex_bytes:<47} {text}\n")
print(json.dumps({key: value for key, value in report.items() if key != "strings"}, indent=2))The goal has been accomplished.
I'd really like to see the community keep sharing and releasing new things whenever possible. This game was a big part of my teenage years, just like it was for many of you. I hope this release helps others learn, build new projects, and keep the community moving forward.
There's still plenty to discover, improve, and share. Hopefully this is just another step that encourages more people to contribute.
Enjoy, and make good use of it.
rivotril_ out.
Last edited:
