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File: test/Picamator/SteganographyKit/StegoSystem/BaseLsbTest.php

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File: test/Picamator/SteganographyKit/StegoSystem/BaseLsbTest.php
Role: Unit test script
Content type: text/plain
Description: Unit test script
Class: PHP Steganography Kit
Library of algorithms to encode messages in images
Author: By
Last change:
Date: 9 years ago
Size: 6,765 bytes
 

Contents

Class file image Download
<?php
/**
 * StegoSystem Base LSB UnitTest
 *
 * @link https://github.com/picamator/SteganographyKit
 * @license http://opensource.org/licenses/BSD-3-Clause New BSD License
 */

use Picamator\SteganographyKit\SecretText\PlainText;
use
Picamator\SteganographyKit\Image\Image;
use
Picamator\SteganographyKit\StegoSystem\StegoSystemInterface;

abstract class
BaseLsbTest extends BaseTest
{
   
/**
     * SecretText file
     *
     * @var string
     */
   
protected $secretFile = 'secret_text.txt';
   
   
/**
     * CoverText options
     *
     * @var array
     */
   
static protected $optionsCoverText = array(
       
'path' => 'original_200_200.png',
       
'savePath' => 'original_%s.png'
   
);
   
   
/**
     * Remove files in stegoPath after runs each test
     */
   
public function tearDown()
    {
       
$this->clearStegoPath();
    }
   
   
/**
     * Base Encode Decode
     *
     * @param array $optionsCoverText
     * @param array $optionsSecretText
     * @param array $channels
     * @param StegoSystemInterface $stegoSystem
     */
   
protected function encodeDecode(array $optionsCoverText,
        array
$optionsSecretText, array $channels, StegoSystemInterface $stegoSystem
   
) {
       
// encode
       
$optionsCoverText['path'] = $this->getDataPath($optionsCoverText['path']);
       
$optionsCoverText['savePath'] = dirname($optionsCoverText['path']) . '/'
           
. $optionsCoverText['savePath'];
              
       
$coverText = new Image($optionsCoverText);
       
$secretText = new PlainText($optionsSecretText);
       
       
$encode = $stegoSystem->setChannels($channels)->encode($secretText, $coverText);
       
       
$this->assertTrue($encode);
       
       
// decode
       
$stegoText = new Image(array('path' => $optionsCoverText['savePath']));
       
$decodeText = $stegoSystem->decode($stegoText, $secretText);
       
       
$this->assertEquals($optionsSecretText['text'], $decodeText);
    }
   
   
/**
     * Generate data provider
     * It's use secret_text.txt as a secret text and
     * original_200_200.png as a cover tet
     *
     * @param integer $resultCount - number of providers data
     * @param integer $textLength - text length, if not set random data is used
     * @param integer $channel - channel, if not set random data is used
     */
   
protected function generateProvider($resultCount,
       
$textLength = null, array $channel = []
    ) {
       
$supportedChannel = array('red', 'green', 'blue');
       
$supportedChannelSize = count($supportedChannel);
       
       
// 200*200*3/8 = 15000 characters max to cover
        // 19433 secret text length
       
$secretText = $this->getSecretFileData();
       
$secretTextLength = strlen($secretText);
       
       
// validate parameters
       
self::validatePrameters($textLength, $secretTextLength, $channel, $supportedChannelSize);
       
       
// generate provider data set
       
$providerData = [];
        for(
$i = 0; $i < $resultCount; $i++) {
           
// generate secretText item
           
$secretTextItem = (is_null($textLength))?
               
self::getRandomText($secretText, $secretTextLength):
               
substr($secretText, 0, $textLength);
           
           
// generate use channel
           
$useChannel = (empty($channel))?
               
self::getRandomChannel($supportedChannel, $supportedChannelSize):
               
$channel;
           
           
// set coverText options
           
$providerData[$i][] = self::getProviderDataItem($useChannel, $secretTextItem);
           
           
// set secretText option
           
$providerData[$i][] = array('text' => $secretTextItem);
           
           
// set use channel
           
$providerData[$i][] = $useChannel;
        }

        return
$providerData;
    }
   
   
/**
     * Gets secret data from file
     *
     * @return string|false
     * @throws \PHPUnit_Framework_Exception
     */
   
protected function getSecretFileData()
    {
       
$result = file_get_contents($this->getDataPath($this->secretFile));
        if (
$result === false) {
            throw new \
PHPUnit_Framework_Exception('Can not read secretFile: ' . $this->secretFile);
        }
       
        return
$result;
    }
   
   
/**
     * Validate provider paramters
     *
     * @param integer $textLength
     * @param integer $secretTextLength
     * @param array $channel
     * @param integer $supportedChannelSize
     * @throws \PHPUnit_Framework_Exception
     */
   
static protected function validatePrameters($textLength,
       
$secretTextLength, array $channel, $supportedChannelSize
   
) {
        if ((!
is_null($textLength) && $textLength > $secretTextLength)
            || (!empty(
$channel) && count($channel) > $supportedChannelSize)) {
           
            throw new \
PHPUnit_Framework_Exception('Used parameters are out of data source length: text ['
               
. $secretTextLength . '], channels [' . $supportedChannelSize . ']');
        }
    }
   
   
/**
     * Gets provider's data item
     *
     * @param array $useChannel
     * @param string $secretTextItem
     * @return array - array('path' => ..., 'savePath' => ...);
     */
   
static protected function getProviderDataItem(array $useChannel, $secretTextItem)
    {
       
$args = microtime(true) . '_secret_length_' . strlen($secretTextItem)
            .
'_' . implode('_', $useChannel);
       
       
$result = array(
           
'path' => self::$optionsCoverText['path'],
           
'savePath' => self::$stegoPath . '/' . sprintf(self::$optionsCoverText['savePath'], $args)
        );
       
        return
$result;
    }
   
   
/**
     * Gets random channel
     *
     * @return array
     */
   
static protected function getRandomChannel(array $channel, $channelSize = null)
    {
       
$channelSize = $channelSize ? : count($channel);
       
$useChannelSize = mt_rand(1, $channelSize);
       
$useChannelKey = (array)array_rand($channel, $useChannelSize);

       
$result = [];
        foreach(
$useChannelKey as $value) {
           
$result[] = $channel[$value];
        }
       
        return
$result;
    }
   
    static protected function
getRandomText($text, $textLength = null)
    {
       
$textLength = $textLength ? : strlen($text);
       
$itemStart = mt_rand(0, $textLength - 1);
       
$itemLength = mt_rand(1, $textLength);

       
$result = substr($text, $itemStart, $itemLength);
       
        return
str_shuffle($result);
    }
}