PDF Decoded Base64 PDF can be open by chrome and browsers but not with adobe

Question

I have a problem with a php generated pdf file. The generation of the pdf works very fine. After I saved the file to my webserver i can download it and open it with my Mac or with Browsers like Edge Chrome and Firefox. Only if i open the file with Adobe Acrobat Reader it didnt open the file.

Error: An Error occured by opening this file. The file is damaged and cant be repaired.

I have created the file with javascript and a little php. In JS i used the libary pdfLib to create the pdf File.

const existingPdfBytes = await fetch(url).then(res => res.arrayBuffer());
const pdfDoc = await PDFDocument.load(existingPdfBytes);
.
.
...changes in the pdf File...
.
.
const pdfBytes = await pdfDoc.save();
const dateOfToday = getDateofToday();
const dateTimeStamp = new Date().getTime();
const fileName = "Vertrag_von_" + dateOfToday + "_ID_" + dateTimeStamp + ".pdf";
sendWithAjax(pdfBytes, studio[4], answers["email"], fileName, answers["telenummer"]);

function sendWithAjax(pdfBytes, studioMail, customerMail , fileName, customerPhoneNumber) {

        pdfBytes = bytesToBase64(pdfBytes);
        if (window.XMLHttpRequest) {
            // AJAX nutzen mit IE7+, Chrome, Firefox, Safari, Opera
                xmlhttp=new XMLHttpRequest();
            }
        else {
            // AJAX mit IE6, IE5
            xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
        }

        xmlhttp.open("POST", "sendContractEmail.php", true);
        var data = new FormData();
        data.append("byte", JSON.stringify(pdfBytes));
        data.append("studioMail", JSON.stringify(studioMail));
        data.append("customerMail", JSON.stringify(customerMail));
        data.append("fileName", JSON.stringify(fileName));
        data.append("customerPhoneNumber", JSON.stringify(customerPhoneNumber));
        xmlhttp.send(data);

    }

After the creation of the pdf file in JS i send the UInt8_Array and other informations with the help of ajax to my php file.

In the php.file i used following code to decode the Uint8_Array to a Base64 string and saved it in a file on my webserver.

if(!empty($_POST['byte'])){
        $data = json_decode($_POST['byte']);
        $fileName = json_decode($_POST['fileName']);
        $studioMail = json_decode($_POST['studioMail']);
        $customerMail = json_decode($_POST['customerMail']);
        $customerPhoneNumber = json_decode($_POST['customerPhoneNumber']);

        if (!empty($data)) {

            // Detects if there is base64 encoding header in the string.
            // If so, it needs to be removed prior to saving the content to a phisical file.
            if (strpos($data, ',') !== false) {
                @list($encode, $data) = explode(',', $data);
            }

            $base64data = base64_decode($data, true);

            $pdf = fopen ('contractPDFs/'.$fileName ,'w');
            fwrite ($pdf,$base64data);
            fclose ($pdf);
        }

        echo "Contract saved";

        sendEMailToStudio($fileName, $studioMail, $customerMail, $customerPhoneNumber);
        sendEMailToCustomer($customerMail);

    } else {
        echo "No Data Sent";
    }

Can somebody help me by my problem and explain me why i cant open the pdf file with Adobe Acrobat Reader?

Thanks

Answer 1

After a long time of research i found a solution.

I changed line to

const pdfBytes = await pdfDoc.save();
const pdfBytes = await pdfDoc.save({useObjectStreams: false});

This was the only change in my JS file. Now I send the data to my php file as before.

In my php file i changed:

if (!empty($data)) {

   // Detects if there is base64 encoding header in the string.
   // If so, it needs to be removed prior to saving the content to a phisical file.
   if (strpos($data, ',') !== false) {
      @list($encode, $data) = explode(',', $data);
   }

   $base64data = base64_decode($data, true);

   $pdf = fopen ('contractPDFs/'.$fileName ,'w');
   fwrite ($pdf,$base64data);
   fclose ($pdf);
}

to

  if (!empty($data)) {
            $pdf = file_put_contents('contractPDFs/'.$fileName, base64_decode($data));
        }

After this changes i can open the pdf with Adobe Acrobat Reader.

I hope i can help somebody and safe your time.