Digital Sign PDF File with PHP and laravel

Question

Hello i search a lot before make this question. I know there is a paied option to sign pdf setasign.com

I try to use php function:

openssl_pkcs7_sign( FULL_PATH . "/pdforiginal.pdf", //ORIGIANL PDF
                    FULL_PATH ."signedPDF.pdf", // SIGNED PDF
                    "file://" . FULL_PATH . "signing_cert.pem", 
                     array(  "file://" . FULL_PATH. "private_key.pem",""),array());

signing_cert.pem <- // I Dont understand what is this i just have private_key and public_key. I see some examples where people use private_key here.

My private key dont have password shoud i use blank "" or null ?

If anyone can give me little information about this topic would be really helpful.

Possible duplicate of [Create certificate for openssl\_pkcs7\_sign in php](http://stackoverflow.com/questions/15237941/create-certificate-for-openssl-pkcs7-sign-in-php) — mkl, Jan 19 '16 at 16:29
The correct path to key would be file://home... not file:///home... Correct ? Still dont understand how to handle no password and if private_key is the same has signing_cert. So i believe its not duplicated. — Carlos Branco, Jan 19 '16 at 16:39

score 12 · Accepted Answer · answered Feb 22 '16 at 14:53

12

I find the solution. I use FPDI library to open pdf and use tcpdf library to sign it. That makes the process really simple.

require_once('tcpdf_include.php');

require_once "fpdi.php";

$pdf = new FPDI('P', 'mm', 'A4'); //FPDI extends TCPDF

$pages = $pdf->setSourceFile('document.pdf');



/*
NOTES:
 - To create self-signed signature: openssl req -x509 -nodes -days 365000 -newkey rsa:1024 -keyout tcpdf.crt -out tcpdf.crt
 - To export crt to p12: openssl pkcs12 -export -in tcpdf.crt -out tcpdf.p12
 - To convert pfx certificate to pem: openssl pkcs12 -in tcpdf.pfx -out tcpdf.crt -nodes
*/

$certificate = 'file://data/cert/tcpdf.crt';

// set additional information
$info = array(
    'Name' => 'TCPDF',
    'Location' => 'Office',
    'Reason' => 'Testing TCPDF',
    'ContactInfo' => 'http://www.tcpdf.org',
    );

for ($i = 1; $i <= $pages; $i++)
    {
        $pdf->AddPage();
        $page = $pdf->importPage($i);
        $pdf->useTemplate($page, 0, 0);


        // set document signature
        $pdf->setSignature($certificate, $certificate, 'tcpdfdemo', '', 2, $info);      

}

answered Feb 22 '16 at 14:53

Carlos Branco

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Which certificate provider did you use? – Gaia Oct 30 '18 at 20:02
I generate my own certificate. With the commands on the commented on the code. – Carlos Branco Oct 30 '18 at 21:41
@CarlosBranco which package you have used here. Can you attached the link. – yetanothersourav Mar 06 '19 at 03:48
Hi, I have a question, does this line $pdf->setSignature($certificate, $certificate, 'tcpdfdemo', '', 2, $info); sign the document or make it signable? – digitalway Dec 08 '20 at 08:43
Hi, sign the document. At least when I open the document i can see the certificate. – Carlos Branco Dec 08 '20 at 14:19

score 1 · Answer 2 · answered Jan 08 '21 at 01:29

Now Digital Certificates are being issued on cryptographic devices viz. USB Toke and Smartcards, and user will be holding the same, server might not have private key of the user's certificate. In web application, you need to get the pdf (hash) signed from USB Token or Smartcard connected to client's (browser) device.

You need to get pdf signed from browser itself, since, private key never comes out of USB Token. Please refer to answer https://stackoverflow.com/a/55676351/9659885

For PHP, easily available Java pdf library or any pdf component may be used through JavaBridge running on Tomcat through Apache proxy to digitally sign PDF from Browser USB token and PHP on server side.

score -1 · Answer 3 · answered Mar 17 '21 at 14:03

I found a better solution to sign, but not only with PHP. You'll need to used the exec() command to do this.

1 - Need to install java. Linux sudo apt install /select_folder/default-jre

2 - Need to instal Portable Signer. Download the ZIP file and run the file jar ( https://sourceforge.net/projects/portablesigner/files/portablesigner/2.0-Release/PortableSigner-Generic-2.0.38c0573.zip/download ). Linux sudo java -jar /select_folder/PortableSigner.jar

3 - After install Portable Signer and choose the installation folder execute the app using the manual ( http://portablesigner.sourceforge.net/ ) with command exec() in php.

Example: exec("java -jar PortableSigner.jar -n /Users/pfp/Desktop/unsigned.pdf -o /Users/pfp/Desktop/signed.pdf -s /Users/pfp/Desktop/certificate.pfx -p MySecretPassword");

In documentation you have many options to sign. I hope this ll help a lot the PHP comumunity here.

Digital Sign PDF File with PHP and laravel

3 Answers3