PHP Extract binary data from header - php

Question

I am working on my PHP to extract the binary data that I stored the email header in the mysql database. I need some help with extract the binary data to get the attachment binary data.
Example:
UEsDBBQAAAAIAEpZrEjPyoXURw....etc
I don't know how do you extract the binary data if you are looking for a filename, example: email_example1.zip.
Here is the header:
Return-Path: <sender#domain.com>
Delivered-To: chris#domain.com
Received: from domain.com
------=_Part_4094373_1508330616.1564422111167
Content-Type: application/zip
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="email_example1.zip"
Content-ID: <05063d19-5033-af14-87e2-d2fbf22d5857#yahoo.com>
UEsDBBQAAAAIAEpZrEjPyoXURw....etc
------=_Part_4094373_1508330616.1564422111167
Content-Type: application/zip
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="example2.zip"
Content-ID: <3b2c4fee-2b28-778b-b27f-c63881d64e17#domain.com>
UEsDBBQAAAAIALtk6U5W+XzU7iM....etc
Here is the PHP:
<?php
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
//Connect to the database
include('config.php');
$id = $_GET['id'];
$attid = $_GET['attid'];
$message_id = $_GET['msgid'];
$mailbox_sql = 'SELECT * FROM ' . $mailfolder . ' WHERE email_id = ? AND message_id = ?';
$mailbox = $link->prepare($mailbox_sql);
$mailbox->execute([$id,$message_id]);
// set the resulting array to associative
$row = $mailbox->fetch(PDO::FETCH_ASSOC);
if (is_array($row)) {
$attached = $row['attached_files'];
$attached_arr = explode("\n", $attached);
}
foreach ($attached_arr as $files) {
$attached_file = 'attid: ' . $attid . ' filename:';
$attached = '';
if (strpos($files, ' attid: ') !== false) {
$filename = trim(strrchr($files, ':'), ': ');
$files = 'attid: ' . $attid . ' filename: ' . $filename;
}
if (strpos($files, $attached_file) !== false) {
$attached = trim(strrchr($files, ':'), ': ');
}
mailbox = null;
?>
Do you know how I can search the filename in the email header to extract the binary data?
Any advice would be much appreicated.

Answer 1

You need get the input stream directly from the body because your content is application/zip Content-Type: application/zip .
To do that u can use php://input :
$input = file_get_contents('php://input');
$binary = base64ToBinary($input);
function base64ToBinary(string $string): string {
if (strpos($string, ';base64,') !== false) {
$string = explode(';base64,', $string)[1];
}
return base64_decode($string);
}
The file name is exposed via Content-Disposition Header:
In your post you have Content-Disposition: attachment; filename="email_example1.zip" you can just parse it from there.
EDIT
How to parse your file name from Header:
$value = $_SERVER['HTTP_CONTENT_DISPOSITION'];
$filename = 'default_name.zip';
if (preg_match('/filename="-(.*?)-"/', $value, $match) == 1) {
$filename = $match[1];
}
The code I provided works 100% for the Content Disposition Header you provided:
If it doesn't work for you that means the format you posted is wrong and check this Question for an answer on how to get file name from content disposition header .
Otherwise your request has nothing to do about Binary data it's parsing about parsing value from string. Please update your question description to match what you want to achieve.