QMC2-Decode

See the new repository https://github.com/bczhc/qmc-decrypt, written in Rust

Downstream updates

Usage

qmc-decode <input> <output> [<ekey>]

When input is a directory, it decrypts in batch mode, but only supports qmcflac and qmc0 formats (due to mflac0 and mgg1 need ekey)

when output is a directory, the output filename is automatically assigned from the extension of the input file.

ekey is a 704- or 364-byte Base64-encoded cipher text

Supported file formats:

• qmcflac (to flac)
• qmc0 (to mp3)
• mflac0 with STag or QTag file trailing mark (to flac; EKey is required when decrypting STag)
• mgg1 with STag or QTag file trailing mark (to ogg; EKey is required when decrypting STag)

Original README

Click here for English readme

用于解密 mflac / mgg1 文件的小工具。

构建

同仓库的 submodule 一同克隆，然后在终端构建：

mkdir -p build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make

注：

1. 你需要安装 CMake 以及一个支持的 C++ 编译器 (如：g++, MSVC)。
2. 编译好的二进制文件可以在 build/QMC2-decoder 目录下找到。
3. 你也可以使用 Visual Studio 2022 进行构建，文件位置在 out 目录下。

可执行文件下载

你可以在 Release 找到 Linux x86_64、Win (32 位) 及 Win (64 位) 的二进制文件下载。

同时亦提供转译 WASM 的版本 (需要现代浏览器)：QMC2-WASM

注：Windows 版本需要最新的 VC++ x64 运行时。

使用方式

./QMC2-decoder "encrypted_file.mflac" "decrypted.flac"

注：如果解密失败，可以尝试将文件名中的非 ASCII 字符去掉后尝试。 Linux 因为使用 UTF-8 编码因而没有该问题。

支持的加密格式

• 文件末端为 'QTag' 字样的 mgg1 / mflac0 文件；或许也支持其它的该结尾的文件。
• 文件末端为 0x?? 0x01 0x00 0x00 的 mflac 与 mgg 文件；
• 文件末端为 0x?? 0x02 0x00 0x00 的 mgg 文件；

Node 包

安装：

npm i @jixun/qmc2-crypto

引入后使用即可，默认使用的是不依赖 wasm 的版本。

详细请参见包的说明以及使用文档/用例。

致谢

• 2021/08/26 MGG/MFLAC 研究进展 by @ix64 & @Akarinnnnn
• unlock-music 项目
• 使用 Visual Studio 2022 进行开发

---

English

Decryptor for files with mflac / mgg1 extension.

Build

Clone with submodules, then:

mkdir -p build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
make

Note:

1. CMake and a supported C++ compiler (i.e. g++, MSVC) is required.
2. Binary will be built at build/QMC-decoder folder.
3. You can also build with Visual Studio 2022, where the binary will be found at out.

Pre-built binaries

You can find Linux (x86_64), Win (32-bit) and Win (64-bit) binaries at Release section.

WASM transpiled version is also available (modern browser required): QMC2-WASM

Note: Windows binary requires latest VC++ x64 Runtime.

Usage

./QMC2-decoder "encrypted_file.mflac" "decrypted.flac"

If decryption fails in Windows, please try again with non-ASCII characters in the file path. Linux uses UTF-8 encoding so is safe.

Supported format

• Ending with characters 'QTag', with extension mgg1 / mflac0;
  might also work for other extensions with this ending.
• Ending with 0x?? 0x01 0x00 0x00 with extension mflac & mgg;
• Ending with 0x?? 0x02 0x00 0x00 with extension mgg;

Node Package

Install:

npm i @jixun/qmc2-crypto

It uses the legacy build by default that does not require WASM.

See package readme and usage document for details.

Credits

• 2021/08/26 MGG/MFLAC 研究进展 by @ix64 & @Akarinnnnn
• unlock-music
• Developed with Visual Studio 2022