README

A PHP package for encrypting and decrypting files. Also offers the possibility of streaming decryption of file data.

DISCLAIMER

This package is still a work in progress. This means that Method signatures and return values will change over time. Implementation specifics will also change.

If you do wish to use or test this package, do so with care. Everything has been "humanly" tested, still working on writing proper tests.

If you wish to contribute please start of with creating new issues before sending in pull requests.

Info

The goal of this project is to offer a simple method of working with encrypted files in PHP. There are some great (shell) tools out there that can do the same thing. But when decrypting streams becomes necessary, I've found it to be more and more difficult to implement properly.

This package uses stream filters for encryption and decryption, using box standard mcrypt ciphers. This allows for streaming decryption.

Default encryption

By default the package uses the AES encryption standard. This means that files that have been encrypted with this package can be decrypted by any other tool that supports AES, provided you have a string representation of the used Key and IV.

Installation and Requirements

You can install the package easily using composer

$ composer require wubbajack/filecrypt

The minimum requirements are:

• PHP 5.6
• Mcrypt extension

Test

To test this package just run

$ php vendor/bin/phpunit

Examples and usage

Below are some examples on how to use the FileEncrypter class

Encrypting files

<?php

/**
 * This creates a new instance of the FileEncrypter. By default
 * it uses RIJNDAEL-128 with a 16 bit block size, which corresponds with the AES standard.
 */
$fileEncrypter = new Wubbajack\Encryption\FileEncrypter($key);
$source_file   = '/path/to/source/file.jpg';
$target_file   = '/path/to/encryted/file.enc';

/**
 * Encrypts a source file to a target file and returns an EncryptedFile instance
 */
$encryptedFile = $fileEncrypter->encrypt($source_file, $target_file);

Decrypting files

<?php

/**
 * In this example we assume that we already have an EncryptedFile instance
 * where we can extract the required information from
 */
$fileCrypt   = new Wubbajack\Encryption\FileEncrypter($key);
$target_file = '/path/to/decrypted/file.jpg';

// Decrypts our encrypted file and returns the path to the file
$fileCrypt->decrypt($encryptedFile, $target_file);

Streaming decryption

<?php

/**
 * In this example we also assume that we already have an EncryptedFile instance
 */
$fileCrypt = new Wubbajack\Encryption\FileEncrypter($key);

/**
 * The streamDecrypt method allows you to supply a callback and manipulate or echo the data.
 * This can be very useful when streaming encrypted media back to a client.
 *
 * The padding is automatically stripped from the data, so no worries there.
 */
$fileCrypt->streamDecrypt($encryptedFile, function ($data, $stream) {
    echo $data;

    if (feof($stream)) {
        // I have finished!
    }
});