回答

可以使用TCPDF，代码如下：

<?php
require('../lib/php/vendor/autoload.php');

// create new PDF document
$pdf = new TCPDF(PDF_PAGE_ORIENTATION, PDF_UNIT, PDF_PAGE_FORMAT, true, 'UTF-8', false);

// set document information
$pdf->SetCreator(PDF_CREATOR);
$pdf->SetAuthor('Nicola Asuni');
$pdf->SetTitle('TCPDF Example 052');
$pdf->SetSubject('TCPDF Tutorial');
$pdf->SetKeywords('TCPDF, PDF, example, test, guide');

// set default header data
$pdf->SetHeaderData(PDF_HEADER_LOGO, PDF_HEADER_LOGO_WIDTH, PDF_HEADER_TITLE.' 052', PDF_HEADER_STRING);

// set header and footer fonts
$pdf->setHeaderFont(Array(PDF_FONT_NAME_MAIN, '', PDF_FONT_SIZE_MAIN));
$pdf->setFooterFont(Array(PDF_FONT_NAME_DATA, '', PDF_FONT_SIZE_DATA));

// set default monospaced font
$pdf->SetDefaultMonospacedFont(PDF_FONT_MONOSPACED);

// set margins
$pdf->SetMargins(PDF_MARGIN_LEFT, PDF_MARGIN_TOP, PDF_MARGIN_RIGHT);
$pdf->SetHeaderMargin(PDF_MARGIN_HEADER);
$pdf->SetFooterMargin(PDF_MARGIN_FOOTER);

// set auto page breaks
$pdf->SetAutoPageBreak(TRUE, PDF_MARGIN_BOTTOM);

// set image scale factor
$pdf->setImageScale(PDF_IMAGE_SCALE_RATIO);

// set some language-dependent strings (optional)
if (@file_exists(dirname(__FILE__).'/lang/eng.php')) {
    require_once(dirname(__FILE__).'/lang/eng.php');
    $pdf->setLanguageArray($l);
}

// ---------------------------------------------------------

/*
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
*/

// 设置签名证书
$certificate = '/data/wwwroot/default/asset/tcpdf.crt';


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

// set document signature
$pdf->setSignature('file:///data/wwwroot/default/asset/filename.crt', 'file:///data/wwwroot/default/asset/filename.key', '123456', '', 2, $info);



// add a page
$pdf->AddPage();

// print a line of text
$text = '你好，This is a <b color="#FF0000">digitally signed document</b> using the default (example) <b>tcpdf.crt</b> certificate.<br />To validate this signature you have to load the <b color="#006600">tcpdf.fdf</b> on the Arobat Reader to add the certificate to <i>List of Trusted Identities</i>.<br /><br />For more information check the source code of this example and the source code documentation for the <i>setSignature()</i> method.<br /><br /><a href="http://www.tcpdf.org">www.tcpdf.org</a>';
$pdf->writeHTML($text, true, 0, true, 0);

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// *** set signature appearance ***

// create content for signature (image and/or text)
$pdf->Image('/data/wwwroot/default/asset/logo.png', 180, 60, 15, 15, 'PNG');

// define active area for signature appearance
$pdf->setSignatureAppearance(180, 60, 15, 15);

// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

// *** set an empty signature appearance ***
$pdf->addEmptySignatureAppearance(180, 80, 15, 15);

// ---------------------------------------------------------

//Close and output PDF document
$pdf->Output('example_sign.pdf', 'D');

//============================================================+
// END OF FILE
//============================================================+