How To Extract Files From A Password-Protected 7-Zip Archive In C# & .NET

Our previous post, How To Extract Files From A 7-Zip Archive In C# & .NET, looked at how to extract files from a 7z 7-Zip archive.

In this post, we will look at how to extract files from a password-protected 7z archive.

Our project structure is as follows:

To ensure that the 7z is copied to the output folder, add the following element:

<ItemGroup>
  <None Include="Books.7z">
  	<CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
  </None>
</ItemGroup>

We then add the CliWrap library. This is orders of magnitude easier and more flexible than the native .NET Process class.

dotnet add package CliWrap

The next order of business is that you need to know

1. The name of the 7-Zip executable
2. Where it is

In macOS (that I am using), the executable is actually named 7zz.

You can find out where it is using the where command.

where 7zz

For Windows, the executable is named 7z.exe, and is usually in the Program Files folder.

The code itself is as follows:

using System.IO;
using System.Reflection;
using CliWrap;
using CliWrap.Buffered;
using Serilog;

Log.Logger = new LoggerConfiguration()
    .WriteTo.Console().CreateLogger();

// Extract the current folder where the executable is running
var currentFolder = Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location)!;

// Set the folder we want our files extracted to
var outputFolder = Path.Combine(currentFolder, "ExtractedBooks");

// Construct the full path to the zip file
var source7ZipFile = Path.Combine(currentFolder, "Books.7z");

// Archive password
const string password = "A$tr0ngP@ssw0rD";

// Path to 7zip executable
const string executablePath = "/opt/homebrew/bin/7zz";

var result = await Cli.Wrap(executablePath) // Set the path to the executable
    .WithArguments(args => args
            .Add("x") //Specify to extract an archive
            .Add(source7ZipFile) // Source zip file
            .Add($"-o{outputFolder}") // The output folder
            .Add($"-p{password}") // The archive password
            .Add("-y") // Say yes to all prompts
    )
    .ExecuteBufferedAsync();

// Check if the process succeeded
if (result.ExitCode != 0)
    Log.Error("7-Zip failed: {Message}", result.StandardError);
else
    Log.Information("Extracted files in {SourceFiles} to {TargetFolder} {Message}", source7ZipFile, outputFolder,
        result.StandardOutput);

If we run this code, we should see the following output:

And if we view the output folder, we can see our output folder:

TLDR

You can extract password-protected 7z archives by passing the password to the command-line tool in your code.

The code is in my GitHub.

Happy hacking!