By John Smith, March 10, 2026

FFS Institute

Introduction to Secure PHAR Automation

In today’s digital landscape, the ease of software distribution is paramount. As developers, we often face the challenge of delivering applications securely and efficiently. One effective method is through PHAR (PHP Archive) files, which bundle PHP applications into a single file for easier distribution. However, while PHAR offers convenience, it also presents certain security vulnerabilities. My journey into creating a secure PHAR utility has been enlightening, and in this article, I will share concrete steps to help you secure your own PHAR downloads.

Understanding the PHAR Security Landscape

As highlighted by experts like Pádraic Brady, distributing PHAR files necessitates a rigorous approach to security. This is especially true given the potential for vulnerabilities during download and update processes. The roadmap to secure PHAR automation includes critical steps:

• Ensure distribution via TLS-secured HTTPS.
• Sign your PHAR with a private key for authenticity.
• Implement secure self-update mechanisms, ensuring updates occur over TLS and the updated PHAR files are signed using the same private key.

With this foundation, I devised a coherent plan to automate the creation, distribution, and updating of PHAR files.

Creating an OpenSSL Key

The first step in our secure automation journey is generating an OpenSSL private key, which is crucial for signing our packages. You can create a private key using the following command:

$ openssl genrsa -des3 -out phar-private.pem 4096

This command prompts you for a passphrase to encrypt the key. However, for automation purposes, you will want to remove this passphrase:

$ cp phar-private.pem phar-private.pem.passphrase-protected$ openssl rsa -in phar-private.pem -out phar-private-nopassphrase.pem$ cp phar-private-nopassphrase.pem phar-private.pem

Once created, it’s essential to maintain security by storing your key in a .travis/ subdirectory and ensuring it’s ignored by Git:

$ mkdir .travis$ mv phar-private.pem .travis/$ echo ".travis/phar-private.pem" >> .gitignore

Utilizing Box for PHAR Creation

With a key in hand, the next phase is creating our PHAR file. Although PHP provides extensive functionality for handling PHARs, the documentation can be lacking in detail. To streamline this process, I recommend using the Box Project, designed specifically for building PHAR files efficiently.

To get started, you can install Box with the following command:

$ curl -LSs https://box-project.github.io/box2/installer.php | php

This will yield an executable file, typically placed in your $PATH, which allows easy access.

To configure Box, you will need a box.json.dist file detailing the files to include, compression methods, and signing parameters. Below is a sample configuration:

{ "algorithm": "OPENSSL", "chmod": "0755", "compression": "GZ", "directories": [ "src" ], "files": [ "LICENSE.md" ], "finder": [ { "name": "*.php", "exclude": [ "tests", "test" ], "in": "vendor" } ], "git-version": "package_version", "intercept": true, "key": ".travis/phar-private.pem", "main": "bin/command.php", "output": "command.phar", "stub": true}

This configuration is crucial for ensuring that the PHAR file is created correctly, considering factors such as file permissions and signing algorithms.

Building Your PHAR

Once the configuration is set, the build process can be initiated with the following command:

$ box build -vv

Using the -vv flag provides verbose output, allowing you to identify any issues that may arise during the build. If you aim to streamline the process further, it’s beneficial to execute:

$ composer install --no-dev

This step eliminates development dependencies, resulting in a more compact and efficient build.

Distributing Your PHAR Securely

Upon successful build completion, your repository will contain two files: the command.phar and its associated public key, command.phar.pubkey—both essential for users to verify the integrity of the PHAR file. Ensure you include these files in your .gitignore to avoid accidental commits:

$ echo "command.phar" >> .gitignore$ echo "command.phar.pubkey" >> .gitignore

Implementing Version Control

To track which version of the PHAR is in use, you can generate a SHA1 checksum and write it to a version file:

$ sha1sum command.phar > command.phar.version

This version file is also vital for informing users of available updates. Similar to the PHAR and its public key, make sure to exclude it from Git:

$ echo "command.phar.version" >> .gitignore

Utilizing GitHub Pages for Distribution

GitHub Pages provides a free and secure option to host your PHAR file. For this step, we’ll establish a gh-pages branch within your repository. First, ensure you have committed all necessary files on the master branch:

$ git add .gitignore box.json.dist$ git commit -m 'Build tools for PHAR file'

Create an orphan branch and clear any previous files:

$ git checkout --orphan gh-pages$ git rm -rf .

This allows the addition of your generated files while keeping the history clean. Add the public and version files, then commit and push to GitHub:

$ git add command.phar command.phar.pubkey command.phar.version index.html$ git commit -m 'Initial gh-pages files'$ git push -u origin gh-pages

Users will soon be able to access the files at "

Next, add the public key to your GitHub repository settings under deploy keys. Copy the private key into the project, ensuring it is ignored by Git:

$ cp $HOME/.ssh/_rsa .travis/build-key.pem$ echo ".travis/build-key.pem" >> .gitignore

$ cd .travis$ tar cvf secrets.tar *.pem$ cd ..$ gem install travis$ travis login$ travis encrypt-file .travis/secrets.tar .travis/secrets.tar.enc --add

#!/bin/bashtar xvf .travis/secrets.tar -C .traviseval "$(ssh-agent -s)" # Start the ssh agentchmod 600 .travis/build-key.pemssh-add .travis/build-key.pemgit config --global user.email ""git config --global user.name ""git remote add deploy git@github.com:yourusername/yourrepo.gitgit fetch deploywget -O box.phar ./box.phar build -vv# ... continue to checkout gh-pages and add files

Additionally, developers can utilize resources like FFS Institute to explore more topics on effective software distribution strategies.

With these tools in mind, you are well-equipped to manage PHAR files securely, ensuring user trust and smooth operational flow.