error on validating image file on php api

Question

I'm developing an api on which it gets an image and resizes it into three sizes and zips it. I have some methods to validate the file, run the resizer class and its methods and finally give files as zip file and a link to download them. Now I have problem with content type validation and zipping. I searched a lot and I couldn't find any tutorial. I'd be thankful if you help me with my errors.

rest.php

<?php
require_once 'constants.php';

abstract class Rest
{
public array $request;
public array $errors = [];

public function __construct()
{
    if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
        $this->throwError(REQUEST_METHODS_NOT_VALID, 'Request method is not valid.');
    }

    $this->request = $_FILES + $_POST;
    $fileName = $_FILES['image']['name'];
    $fileType = $_FILES['image']['type'];

    $this->validateRequest($fileName);
    if (empty($this->errors)){
        $this->executeApi();
    }
    $this->response();
}

public abstract function validateRequest($request);

public abstract function executeApi();

public function validateParameters($fieldName, $value, $dataType, $required) {

}

public function throwError($code, $message) {
    header("content-type: application/json");
    $errorMsg = json_encode(['error'=>['status'=>$code, 'message'=>$message]]);
    echo $errorMsg;
    exit();
}

public function response() {
 //???
}
}

api.php

<?php
 require_once 'image-resizer.php';
 class Api extends Rest
{

public function validateRequest($request)
{
  //        if ($request !== 'image/jpeg') {
    if ($_SERVER['CONTENT_TYPE'] !== 'image/jpeg') {
        $this->throwError(REQUEST_CONTENT_TYPE_NOT_VALID, 'Request content type is not valid.');
        $errors = json_encode(array("message" => "Request content type is not valid.", "status" => false));
        echo $errors;
    }
    json_decode($request, true);
}

public function executeApi()
{
    $source = $this->request['image'];
    $resize = new Resizer();
    $resize->imageResizer($source);

}
}

D Coder · Accepted Answer · 2021-11-11T09:41:02.823

0

getimagesize is not to be used to validate a file as image

$imgsize = getimagesize($sourceFile);
$srcWidth = $imgsize[0];
$srcHeight = $imgsize[1];
$mime = $imgsize['mime'];

you can use: fileinfo

OR you may validate extension using pathinfo

$allowedExt = ['jpg', 'jpeg', 'png'];
$ext = strtolower(pathinfo($filename, PATHINFO_EXTENSION));
if (!in_array($ext, $allowedExt)) {
      return FALSE;
}

// filesize validation
if (filesize($tmpName) > MAX_FILE_SIZE) {
    
}

check more on filesize

Edit: You may check this link for zipping files with PHP

EDIT:

$this->request = $_FILES + $_POST; // this is insecure way to get the data

check $_POST data sanitization what is a good method to sanitize the whole $_POST array in php?

edited Nov 11 '21 at 09:41

answered Nov 11 '21 at 07:40

D Coder

331
2
10

Thanks for the answer. So I add this in my validateRequest(), right? – Mohammad Javad Farmani Nov 11 '21 at 08:29
Yes you can use it in that method, depends what type of validation does your requirement need, ( like- extension validation etc ) – D Coder Nov 11 '21 at 09:16
I want to validate whole request like size and type – Mohammad Javad Farmani Nov 11 '21 at 09:32
added file-size validation, you can check extension for type – D Coder Nov 11 '21 at 09:41

error on validating image file on php api

1 Answers1