file integrity checker

.env

@@ -1 +1,2 @@
-SECRET_KEY="rahul_chavan"
+SECRET_KEY="rahul_chavan"
+FILE_NAME='/home/rahul/Documents/hashlist'

src/Exception/FileEncryptorException.php

@@ -7,7 +7,7 @@
 
 class FileEncryptorException extends Exception
 {
-    public function __construct($message = "could not encrypt file", $code = 0, Throwable $previous = null)
+    public function __construct(string $message = "could not encrypt file", int $code = 0, Throwable $previous = null)
     {
         parent::__construct($message, $code, $previous);
     }

src/Exception/FileHandlerException.php

@@ -7,7 +7,7 @@
 
 class FileHandlerException extends Exception
 {
-    public function __construct($message = "There was an error", $code = 0, Throwable $previous = null)
+    public function __construct(string $message = "There was an error", int $code = 0, Throwable $previous = null)
     {
         parent::__construct($message, $code, $previous);
     }

src/Exception/HashException.php

@@ -0,0 +1,14 @@
+<?php
+
+namespace rcsofttech85\FileHandler\Exception;
+
+use Exception;
+use Throwable;
+
+class HashException extends Exception
+{
+    public function __construct(string $message = "There was an error", int $code = 0, Throwable $previous = null)
+    {
+        parent::__construct($message, $code, $previous);
+    }
+}

src/Exception/StreamException.php

@@ -7,7 +7,7 @@
 
 class StreamException extends Exception
 {
-    public function __construct($message = "could not stream file", $code = 0, Throwable $previous = null)
+    public function __construct(string $message = "could not stream file", int $code = 0, Throwable $previous = null)
     {
         parent::__construct($message, $code, $previous);
     }

src/FileHashChecker.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace rcsofttech85\FileHandler;
+
+use rcsofttech85\FileHandler\Exception\HashException;
+
+class FileHashChecker
+{
+    const ALGO_256 = 'sha3-256';
+    const ALGO_512 = 'sha3-512';
+
+    /**
+     * @param string $filename
+     * @throws HashException
+     */
+    public function __construct(private readonly string $filename)
+    {
+        if (!file_exists($this->filename)) {
+            throw new HashException('file not found');
+        }
+    }
+
+    /**
+     * @param object $fileHandler
+     * @param string $storedHashesFile
+     * @param string $algo
+     * @return bool
+     * @throws Exception\FileHandlerException
+     * @throws HashException
+     */
+
+    public function verifyHash(object $fileHandler, string $storedHashesFile, string $algo = self::ALGO_256): bool
+    {
+        if (!$fileHandler instanceof FileHandler) {
+            throw new HashException("object must be instance of " . FileHandler::class);
+        }
+
+        if (!$storedHashesFile) {
+            throw new HashException('file not found');
+        }
+
+        $file = $fileHandler->open(filename: $storedHashesFile)->searchInCsvFile(
+            $this->filename,
+            'File',
+            FileHandler::ARRAY_FORMAT
+        );
+
+        if (!$file) {
+            throw new HashException('this file is not hashed');
+        }
+
+        $expectedHash = $file['Hash'];
+        $hash = $this->hashFile($algo);
+
+        if ($hash !== $expectedHash) {
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * @param string $algo
+     * @return string
+     * @throws HashException
+     */
+
+    public function hashFile(string $algo = self::ALGO_256): string
+    {
+        if (!in_array($algo, [self::ALGO_512, self::ALGO_256])) {
+            throw new HashException('algorithm not supported');
+        }
+        return hash_file($algo, $this->filename);
+    }
+}

tests/unit/FileEncryptorTest.php

@@ -14,12 +14,26 @@ class FileEncryptorTest extends TestCase
 
     private static string $secret;
 
+    protected function setUp(): void
+    {
+        $this->fileEncryptor = new FileEncryptor('movie.csv', self::$secret);
+        parent::setUp();
+    }
+
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+        $this->fileEncryptor = null;
+    }
+
 
     public static function setUpBeforeClass(): void
     {
         $dotenv = new Dotenv();
         $dotenv->load('.env');
-        self::$secret = getenv('SECRET_KEY');
+        self::$secret = $_ENV['SECRET_KEY'];
+
+
         $content = "Film,Genre,Lead Studio,Audience score %,Profitability,Rotten Tomatoes %,Worldwide Gross,Year\n"
             . "Zack and Miri Make a Porno,Romance,The Weinstein Company,70,1.747541667,64,$41.94 ,2008\n"
             . "Youth in Revolt,Comedy,The Weinstein Company,52,1.09,68,$19.62 ,2010\n"
@@ -62,7 +76,7 @@ public function throwExceptionIfAlreadyEncrypted()
     #[Test]
     public function throwExceptionIfDecryptionFails()
     {
-        $this->fileEncryptor = new FileEncryptor("movie.csv", 'wrongSecret');
+        $this->fileEncryptor = new FileEncryptor("movie.csv", 'wrong');
         $this->expectException(FileEncryptorException::class);
         $this->expectExceptionMessage('could not decrypt file');
         $this->fileEncryptor->decryptFile();
@@ -75,16 +89,4 @@ public function canDecryptFile()
 
         $this->assertTrue($isFileDecrypted);
     }
-
-    protected function setUp(): void
-    {
-        $this->fileEncryptor = new FileEncryptor('movie.csv', self::$secret);
-        parent::setUp();
-    }
-
-    protected function tearDown(): void
-    {
-        parent::tearDown();
-        $this->fileEncryptor = null;
-    }
 }

tests/unit/FileHashCheckerTest.php

@@ -0,0 +1,106 @@
+<?php
+
+namespace unit;
+
+use PHPUnit\Framework\Attributes\Test;
+use PHPUnit\Framework\TestCase;
+use rcsofttech85\FileHandler\Exception\HashException;
+use rcsofttech85\FileHandler\FileHandler;
+use rcsofttech85\FileHandler\FileHashChecker;
+use Symfony\Component\Dotenv\Dotenv;
+
+class FileHashCheckerTest extends TestCase
+{
+    private static string $file;
+    private FileHashChecker|null $fileHasher = null;
+
+    public static function setUpBeforeClass(): void
+    {
+        parent::setUpBeforeClass();
+
+        $dotenv = new Dotenv();
+        $dotenv->load('.env');
+
+        $file = $_ENV['FILE_NAME']; // this file contains list of all hashes
+
+        self::$file = $file;
+
+
+        file_put_contents("test", "hello world");
+    }
+
+    public static function tearDownAfterClass(): void
+    {
+        parent::tearDownAfterClass();
+        unlink("test");
+        unlink("sample");
+    }
+
+    #[Test]
+    public function shouldGenerateValidHashForDifferentAlgo()
+    {
+        $expectedHash = "644bcc7e564373040999aac89e7622f3ca71fba1d972fd94a31c3bfbf24e3938";
+
+        $actualHash = $this->fileHasher->hashFile(); //default ALGO_256
+
+        $this->assertEquals($expectedHash, $actualHash);
+
+        $expectedHash = "840006653e9ac9e95117a15c915caab81662918e925de9e004f774ff82d7079a40d4d27b1b372657c61d46d470304c88c788b3a4527ad074d1dccbee5dbaa99a";
+
+        $actualHash = $this->fileHasher->hashFile(FileHashChecker::ALGO_512);
+
+        $this->assertEquals($expectedHash, $actualHash);
+    }
+
+    #[Test]
+    public function checkFileIntegrityReturnsTrueIfHashMatch()
+    {
+        $isVerified = $this->fileHasher->verifyHash(new FileHandler(), self::$file);
+
+        $this->assertTrue($isVerified);
+    }
+
+    #[Test]
+    public function shouldReturnFalseIfFileIsModified()
+    {
+        $backup = file_get_contents("test");
+        file_put_contents("test", "modified", FILE_APPEND);
+
+        $isVerified = $this->fileHasher->verifyHash(new FileHandler(), self::$file);
+
+        $this->assertfalse($isVerified);
+
+        file_put_contents("test", $backup);
+    }
+
+    #[Test]
+    public function shouldReturnFalseIfDifferentAlgoIsUsedForVerifyHash()
+    {
+        $isVerified = $this->fileHasher->verifyHash(new FileHandler(), self::$file, FileHashChecker::ALGO_512);
+
+        $this->assertFalse($isVerified);
+    }
+
+    #[Test]
+    public function shouldThrowExceptionIfFileIsNotHashed()
+    {
+        file_put_contents("sample", "this file is not hashed");
+        $this->fileHasher = new FileHashChecker("sample");
+
+        $this->expectException(HashException::class);
+        $this->expectExceptionMessage("this file is not hashed");
+        $this->fileHasher->verifyHash(new FileHandler(), self::$file, FileHashChecker::ALGO_512);
+    }
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->fileHasher = new FileHashChecker("test");
+    }
+
+    protected function tearDown(): void
+    {
+        parent::tearDown();
+        $this->fileHasher = null;
+    }
+}