Package Family Name

A Rust library for calculating MSIX Package Family Name values.

This is a #![no_std] library.

Every MSIX application has a package family name value, which looks a bit like AppName_zj75k085cmj1a. This value can easily be found by running Get-AppxPackage <name> in PowerShell for an installed MSIX package and scrolling to PackageFullName.

However, we can work out a package family name value without needing to install the package at all. That's where this library comes into play.

Usage

Add this to your Cargo.toml:

[dependencies]
package-family-name = "1.0"

This library currently only has one function, get_package_family_name, that takes in an identity name and an identity publisher:

let package_family_name = get_package_family_name("AppName", "Publisher Software"); // AppName_zj75k085cmj1a

How a package family name is calculated

In short, a package family name is made up of two parts:

• Identity name (AppName)
• Identity publisher (Publisher Software)

These steps are then taken:

1. UTF-16 encode the identity publisher
2. Calculate a SHA256 hash of the encoded publisher
3. Take the first 8 bytes of the hash
4. Encode the result with Douglas Crockford Base32
5. Join the identity name and the encoded value with an underscore (AppName_zj75k085cmj1a)

Why would I need to calculate a package family name?

Whilst this is a niche library, there are use cases. For example, when submitting an MSIX package to winget-pkgs, a package family name value is a required as part of the manifest.

Acknowledgements

@marcinotorowski has produced a step by step explanation of how to calculate the hash part of the package family name. This post can be found here.

License

Licensed under either of:

• Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.