Chapter 1. Installing PHPUnit

Globally installing the PHAR involves the same procedure as manually installing Composer on Windows:

For Cygwin and/or MingW32 (e.g., TortoiseGit) shell environments, you may skip step 5. above, simply save the file as phpunit (without .phar extension), and make it executable via chmod 775 phpunit.

All official releases of code distributed by the PHPUnit Project are signed by the release manager for the release. PGP signatures and SHA1 hashes are available for verification on phar.phpunit.de.

The following example details how release verification works. We start by downloading phpunit.phar as well as its detached PGP signature phpunit.phar.asc:

wget https://phar.phpunit.de/phpunit.phar
wget https://phar.phpunit.de/phpunit.phar.asc

We want to verify PHPUnit's PHP Archive (phpunit.phar) against its detached signature (phpunit.phar.asc):

gpg phpunit.phar.asc
gpg: Signature made Sat 19 Jul 2014 01:28:02 PM CEST using RSA key ID 6372C20A
gpg: Can't check signature: public key not found

We don't have the release manager's public key (6372C20A) in our local system. In order to proceed with the verification we need to retrieve the release manager's public key from a key server. One such server is pgp.uni-mainz.de. The public key servers are linked together, so you should be able to connect to any key server.

gpg --keyserver pgp.uni-mainz.de --recv-keys 0x4AA394086372C20A
gpg: requesting key 6372C20A from hkp server pgp.uni-mainz.de
gpg: key 6372C20A: public key "Sebastian Bergmann <sb@sebastian-bergmann.de>" imported
gpg: Total number processed: 1
gpg:               imported: 1  (RSA: 1)

Now we have received a public key for an entity known as "Sebastian Bergmann <sb@sebastian-bergmann.de>". However, we have no way of verifying this key was created by the person known as Sebastian Bergmann. But, let's try to verify the release signature again.

gpg phpunit.phar.asc
gpg: Signature made Sat 19 Jul 2014 01:28:02 PM CEST using RSA key ID 6372C20A
gpg: Good signature from "Sebastian Bergmann <sb@sebastian-bergmann.de>"
gpg:                 aka "Sebastian Bergmann <sebastian@php.net>"
gpg:                 aka "Sebastian Bergmann <sebastian@thephp.cc>"
gpg:                 aka "Sebastian Bergmann <sebastian@phpunit.de>"
gpg:                 aka "Sebastian Bergmann <sebastian.bergmann@thephp.cc>"
gpg:                 aka "[jpeg image of size 40635]"
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: D840 6D0D 8294 7747 2937  7831 4AA3 9408 6372 C20A

At this point, the signature is good, but we don't trust this key. A good signature means that the file has not been tampered. However, due to the nature of public key cryptography, you need to additionally verify that key 6372C20A was created by the real Sebastian Bergmann.

Any attacker can create a public key and upload it to the public key servers. They can then create a malicious release signed by this fake key. Then, if you tried to verify the signature of this corrupt release, it would succeed because the key was not the "real" key. Therefore, you need to validate the authenticity of this key. Validating the authenticity of a public key, however, is outside the scope of this documentation.

It may be prudent to create a shell script to manage PHPUnit installation that verifies the GnuPG signature before running your test suite. For example:

#!/usr/bin/env bash
clean=1 # Delete phpunit.phar after the tests are complete?
aftercmd="php phpunit.phar --bootstrap bootstrap.php src/tests"
gpg --fingerprint D8406D0D82947747293778314AA394086372C20A
if [ $? -ne 0 ]; then
    echo -e "\033[33mDownloading PGP Public Key...\033[0m"
    gpg --recv-keys D8406D0D82947747293778314AA394086372C20A
    # Sebastian Bergmann <sb@sebastian-bergmann.de>
    gpg --fingerprint D8406D0D82947747293778314AA394086372C20A
    if [ $? -ne 0 ]; then
        echo -e "\033[31mCould not download PGP public key for verification\033[0m"
        exit
    fi
fi

if [ "$clean" -eq 1 ]; then
    # Let's clean them up, if they exist
    if [ -f phpunit.phar ]; then
        rm -f phpunit.phar
    fi
    if [ -f phpunit.phar.asc ]; then
        rm -f phpunit.phar.asc
    fi
fi

# Let's grab the latest release and its signature
if [ ! -f phpunit.phar ]; then
    wget https://phar.phpunit.de/phpunit.phar
fi
if [ ! -f phpunit.phar.asc ]; then
    wget https://phar.phpunit.de/phpunit.phar.asc
fi

# Verify before running
gpg --verify phpunit.phar.asc phpunit.phar
if [ $? -eq 0 ]; then
    echo
    echo -e "\033[33mBegin Unit Testing\033[0m"
    # Run the testing suite
    `$after_cmd`
    # Cleanup
    if [ "$clean" -eq 1 ]; then
        echo -e "\033[32mCleaning Up!\033[0m"
        rm -f phpunit.phar
        rm -f phpunit.phar.asc
    fi
else
    echo
    chmod -x phpunit.phar
    mv phpunit.phar /tmp/bad-phpunit.phar
    mv phpunit.phar.asc /tmp/bad-phpunit.phar.asc
    echo -e "\033[31mSignature did not match! PHPUnit has been moved to /tmp/bad-phpunit.phar\033[0m"
    exit 1
fi