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Miscellaneous

The german original can be downloaded from here.

Sign with a visible signature

This demo shows you how to create a visible signature. The visible part of the signature is a single page of another PDF. We make use of a helper class that uses FPDF and FPDI to create the appearance.

<?php

require_once("Signer/SetaPDF_Signer.php");

$signer = SetaPDF_Signer::factory('Example-PDF-1.pdf');
// set some signature properties
$signer->setReason("Just for testing");
$signer->setLocation('www.setasign.de');
$signer->setContactInfo('+49 5361 3099400');

// require a signature appearances class
require_once('SignatureAppearance.php');

// load the certificate
$certificate = file_get_contents('certificate.pem');

// create the signature appearance
$app = new SignatureAppearance($signer, $certificate);
$app->setConfig('background_logo', 'images/SetaPDF-Signer-Logo.pdf'); // Set a background "image"
$app->setConfig('graphic', 'images/Signature-SetaPDF-Demo.pdf'); // Set signature graphic

$appearanceFileName = $app->generate();

$signer->setAppearance(
    $appearanceFileName,            // PDF appearance
    'LT',                           // LeftTop
    array('x' => 50, 'y' => -50),   // Translate the position
    180,                            // Set the width to 180 points
    null,                           // Set the height to be auto calculated
    1                               // put appearance on page 1
);

// require the OpenSSL signing module
require_once("Signer/Module/OpenSsl.php");
$module = new SetaPDF_Signer_Module_OpenSsl();
$module->setSignCert($certificate);
$module->setPrivateKey(array($certificate, ''));

// sign the document and send it to the client
$res = $signer->sign($module, 'signed.pdf', 'D');
if (SetaPDF::isError($res)) // check for errors
    var_dump($res);

The SignatureAppearance class

A simple class which creates the signature appearance.

<?php

require_once('fpdf.php');
require_once('fpdi.php');

class SignatureAppearance {
    
    /**
     * The page/appearance width
     *
     * @var float
     */
    var $width = 160;
    
    /**
     * The page/appearance height
     *
     * @var float
     */
    var $height = 50;
    
    /**
     * A configuration array
     *
     * @var array
     */
    var $config = array(
        /**
         * null         = no background
         * filename.pdf = PDF holding the background
         */
        'background_logo' => null,
        
        /**
         * false        = no graphic
         * true         = common name as graphic
         * filename.pdf = path to a graphic file (PDF - 1st Page)
         */
        'graphic' => true,
        
        // text configuration
        'text_align' => 'L',
        'show_lables' => true,
        
        'show_name' => true,
        'show_name_tpl' => 'Digitally signed by %s',
        
        'show_distinguished_name' => true,
        'show_distinguished_name_tpl' => 'DN: %s',
        
        'show_reason' => true,
        'show_reason_tpl' => 'Reason: %s',
        
        'show_location' => true,
        'show_location_tpl' => 'Location: %s',
        
        'show_date' => true,
        'show_date_tpl' => 'Date: %s',
        'show_date_format' => 'd.m.Y H:i:s O', // see date()
    );
    
    /**
     * An array with certificate information
     *
     * @var array
     */
    var $certificateInfo;
    
    /**
     * The common name of the certificate
     *
     * @var string
     */
    var $commonName;
    
    /**
     * All subject entries of the certificate
     *
     * @var array
     */
    var $subject;
    
    /**
     * The instance of the SetaPDF-Signer class
     *
     * @var SetaPDF_Signer
     */
    var $_signer;
    
    function SignatureAppearance(&$signer, $certificate) {
        $this->_signer =& $signer;
        
        $this->certificateInfo = openssl_x509_parse($certificate);
        
        $this->subject = $this->certificateInfo['subject'];
        $this->commonName = $this->subject['CN'];
    }
    
    function setConfig($key, $value) {
        if (array_key_exists($key, $this->config)) {
            $this->config[$key] = $value;
            return true;
        }
        return false;
    }
    
    function generate() {
        $pdf = new FPDI('P', 'pt', array($this->width, $this->height));
        $pdf->setMargins(0, 0, 0);
        $pdf->setAutoPageBreak(false, 0);
        $pdf->AddPage();
        
        $text = array();
        
        // DN
        if ($this->config['show_distinguished_name']) {
            $subjectPieces = array();
            foreach ($this->subject AS $k => $v) {
                $k = strtolower($k);
                if ($k == 'emailaddress')
                    $k = 'email';
                $subjectPieces[] = $k.'='.$v;
            }
            
            $distinguishedName = join(', ', $subjectPieces);
            if ($distinguishedName) {
                $text[] = $this->config['show_lables']
                        ? sprintf($this->config['show_distinguished_name_tpl'], $distinguishedName)
                        : $distinguishedName;
            }
        }
        
        // Reason
        if ($this->config['show_reason']) {
            $reason = $this->_signer->getReason();
            if ($reason) {
                $text[] = $this->config['show_lables']
                        ? sprintf($this->config['show_reason_tpl'], $reason)
                        : $reason;
            }
        }
        
        // Location
        if ($this->config['show_location']) {
            $location = $this->_signer->getLocation();
            if ($location) {
                $text[] = $this->config['show_lables']
                        ? sprintf($this->config['show_location_tpl'], $location)
                        : $location;
            }
        }
        
        // Date
        if ($this->config['show_date']) {
            $date = $this->_signer->getTimeOfSigning();
            if (!$date) {
                $date = time();
                $this->_signer->setTimeOfSigning($date);
            }
            
            if ($date) {
                $date = date($this->config['show_date_format'], $date);
                $text[] = $this->config['show_lables']
                        ? sprintf($this->config['show_date_tpl'], $date)
                        : $date;
            }
        }
        
        // Name
        if ($this->config['show_name'] || (count($text) == 0 && $this->config['graphic'] === false)) {
            $name = $this->commonName;
            if ($name) {
                array_unshift($text, $this->config['show_lables']
                        ? sprintf($this->config['show_name_tpl'], $name)
                        : $name);
            }
        }
        
        $textWidth    = $this->config['graphic'] === false ? $this->width : $this->width/2;
        $graphicWidth = $this->width - $textWidth;
        
        // Background
        if ($this->config['background_logo']) {
            $pdf->setSourceFile($this->config['background_logo']);
            $tplIdx = $pdf->importPage(1);
            $size = $pdf->getTemplateSize($tplIdx, $this->width);
            if ($size['h'] > $this->height) {
                $size = $pdf->getTemplateSize($tplIdx, 0, $this->height);
                $pdf->useTemplate($tplIdx, $this->width/2 - $size['w']/2, 0, 0, $this->height);
            } else {
                $pdf->useTemplate($tplIdx, 0, $this->height/2 - $size['h']/2, $this->width);
            }
        }
        
        // Graphic
        if ($this->config['graphic'] !== false) {
            if ($this->config['graphic'] === true) {
                $pdf->SetFont('Arial');
                
                $lineHeightFactor = 1.1;
                $fontSize = 30;
                list($fontSize, $lines) = $this->calculateFixedFontSize($pdf, $this->commonName, $fontSize, $graphicWidth, $this->height);
                $neededHeight = $lines * $fontSize * $lineHeightFactor;
                $pdf->SetXY(0, $this->height/2 - $neededHeight/2);
                $pdf->SetFontSize($fontSize);
                $pdf->MultiCell($graphicWidth, $fontSize * $lineHeightFactor, $this->commonName, 0, $this->config['text_align']);
                
            } elseif (is_string($this->config['graphic'])) {
                
                $pdf->setSourceFile($this->config['graphic']);
                $tplIdx = $pdf->importPage(1);
                
                $size = $pdf->getTemplateSize($tplIdx, $graphicWidth);
                if ($size['h'] > $this->height) {
                    $size = $pdf->getTemplateSize($tplIdx, 0, $this->height);
                    $pdf->useTemplate($tplIdx, $graphicWidth/2 - $size['w']/2, 0, 0, $this->height);
                } else {
                    $pdf->useTemplate($tplIdx, 0, $this->height/2 - $size['h']/2, $graphicWidth);
                }
            }
        }
        
        // Text
        $pdf->SetFont('Arial');
        $text = join("\n", $text);
        
        $lineHeightFactor = 1.1;
        $fontSize = 40;
        list($fontSize, $lines) = $this->calculateFixedFontSize($pdf, $text, $fontSize, $textWidth, $this->height);
        $neededHeight = $lines * $fontSize * $lineHeightFactor;
        $pdf->SetXY($graphicWidth, $this->height/2 - $neededHeight/2);
        $pdf->SetFontSize($fontSize);
        $pdf->MultiCell($textWidth, $fontSize * $lineHeightFactor, $text, 0, $this->config['text_align']);
        
        $fn = $this->_signer->createNewTmpFileName();
        $pdf->output($fn, "F");
        return $fn;
    }
    
    function calculateFixedFontSize(&$fpdf, $text, $fontSize, $width, $height) {
        while(floor($height / ($fontSize*1.1)) <= ($lines = $this->FpdfNbLines($fpdf, $width, $text, $fontSize))) {
            $fontSize -= .1;
        } 
        
        return array($fontSize, $lines);
    }
    
    function FpdfNbLines(&$fpdf, $w, $txt, $fontSize)
    {
        //Computes the number of lines a MultiCell of width w will take
        $cw=&$fpdf->CurrentFont['cw'];
        if($w==0)
            $w=$fpdf->w-$fpdf->rMargin-$fpdf->x;
        $wmax=($w-2*$fpdf->cMargin)*1000/$fontSize;
        $s=str_replace("\r",'',$txt);
        $nb=strlen($s);
        if($nb>0 and $s[$nb-1]=="\n")
            $nb--;
        $sep=-1;
        $i=0;
        $j=0;
        $l=0;
        $nl=1;
        while($i<$nb)
        {
            $c=$s[$i];
            if($c=="\n")
            {
                $i++;
                $sep=-1;
                $j=$i;
                $l=0;
                $nl++;
                continue;
            }
            if($c==' ')
                $sep=$i;
            $l+=$cw[$c];
            if($l>$wmax)
            {
                if($sep==-1)
                {
                    if($i==$j)
                        $i++;
                }
                else
                    $i=$sep+1;
                $sep=-1;
                $j=$i;
                $l=0;
                $nl++;
            }
            else
                $i++;
        }
        return $nl;
    }
}

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