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PHP Requires Chilkat v11.0.0+

Signed Zip as Base64 with XAdES-BES

See more XAdES Examples

This example is to help companies implement a solution for sending XAdES-BES to the Polish government for reporting purposes. Specifically:

Przed podpisaniem deklaracja zbiorcza (PIT-11Z, PIT-8CZ, PIT-40Z, PIT-RZ) musi zostać
umieszczona w archiwum ZIP. W tym przypadku, podpisywany jest plik archiwum ZIP,
przyjmujący w podpisie XAdES-BES formę zakodowaną base64.

The example demonstrates the following:

  1. Zip an XML file (PIT-11Z.xml is zipped to PIT-11Z.zip)
  2. Create XML to be signed, where the XML contains the base64 encoded content of the PIT-11Z.zip archive.
  3. XAdES-BES sign the XML containing the base64 zip.

This example will also show the reverse:

  1. Verify the signed XML.
  2. Extract the PIT-11z.zip from the signed XML.
  3. Unzip the PIT-11Z.zip to get the original PIT-11Z.xml

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<?php

use Chilkat2\BinData;
use Chilkat2\Cert;
use Chilkat2\StringBuilder;
use Chilkat2\Xml;
use Chilkat2\XmlDSig;
use Chilkat2\XmlDSigGen;
use Chilkat2\Zip;
use Chilkat2\ZipEntry;

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Zip the PIT-11Z.xml to create PIT-11Z.zip (not as a .zip file, but in-memory).
$sbXmlToZip = new StringBuilder();
try {
    $sbXmlToZip->LoadFile('qa_data/xml/PIT-11Z.xml', 'utf-8');
} catch (\Chilkat2\Exception $e) {
    echo "Failed to load the XML to be zipped.\n";
    exit;
}

$zip = new Zip();

// Initialize the zip object. No file is created in this call.
// It should always return true.
$zip->NewZip('PIT-11Z.zip');

// Add the XML to be zipped.
$zip->AddSb('PIT-11Z.xml', $sbXmlToZip, 'utf-8');

// Write the zip to a BinData object.
$bdZip = new BinData();
$zip->WriteBd($bdZip);
// The contents of the bdZip will be retrieved in base64 format when needed below..

$gen = new XmlDSigGen();

$gen->SigLocation = '';
$gen->SigLocationMod = 0;

$gen->SigId = 'Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19';
$gen->SigNamespacePrefix = 'ds';
$gen->SigNamespaceUri = 'http://www.w3.org/2000/09/xmldsig#';
$gen->SigValueId = 'SignatureValue_2a8df7f8-b958-40cc-83f6-edb53b837347_52';
$gen->SignedInfoId = 'SignedInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_41';
$gen->SignedInfoCanonAlg = 'C14N';
$gen->SignedInfoDigestMethod = 'sha1';

// Set the KeyInfoId before adding references..
$gen->KeyInfoId = 'KeyInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_24';

// Create an Object to be added to the Signature.
$object1 = new Xml();
$object1->Tag = 'xades:QualifyingProperties';
$object1->AddAttribute('xmlns:xades', 'http://uri.etsi.org/01903/v1.3.2#');
$object1->AddAttribute('Id', 'QualifyingProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_43');
$object1->AddAttribute('Target', '#Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19');
$object1->UpdateAttrAt('xades:SignedProperties', true, 'Id', 'SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e');
$object1->UpdateAttrAt('xades:SignedProperties|xades:SignedSignatureProperties', true, 'Id', 'SignedSignatureProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_0a');
// Chilkat will replace the strings "TO BE GENERATED BY CHILKAT" with actual values when the signature is created.
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningTime', 'TO BE GENERATED BY CHILKAT');
// Note: It may be that http://www.w3.org/2001/04/xmlenc#sha256 is needed in the following line instead of http://www.w3.org/2000/09/xmldsig#sha1
$object1->UpdateAttrAt('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestMethod', true, 'Algorithm', 'http://www.w3.org/2000/09/xmldsig#sha1');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestValue', 'TO BE GENERATED BY CHILKAT');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:IssuerSerialV2', 'TO BE GENERATED BY CHILKAT');
$object1->UpdateAttrAt('xades:SignedProperties|xades:SignedDataObjectProperties', true, 'Id', 'SignedDataObjectProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4b');
$object1->UpdateAttrAt('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat', true, 'ObjectReference', '#Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:Description', "MIME-Version: 1.0\r\nContent-Type: application/zip\r\nContent-Transfer-Encoding: binary\r\nContent-Disposition: filename=&quot;PIT-11Z.zip&quot;");
$object1->UpdateAttrAt('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier', true, 'Qualifier', 'OIDAsURI');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier', 'http://www.certum.pl/OIDAsURI/signedFile/1.2.616.1.113527.3.1.1.3.1');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Description', 'Opis formatu dokumentu oraz jego pelna nazwa');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:DocumentationReferences|xades:DocumentationReference', 'http://www.certum.pl/OIDAsURI/signedFile.pdf');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:MimeType', 'application/zip');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:CommitmentTypeId|xades:Identifier', 'http://uri.etsi.org/01903/v1.2.2#ProofOfApproval');
$object1->UpdateChildContent('xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:AllSignedDataObjects', '');
$object1->UpdateAttrAt('xades:UnsignedProperties', true, 'Id', 'UnsignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_55');

// Emit XML in compact (single-line) format to avoid whitespace problems.
$object1->EmitCompact = true;
$gen->AddObject('', $object1->GetXml(), '', '');

// Create an Object to be added to the Signature.
// This is where we add the base64 representation of the PIT-11Z.zip
$gen->AddObject('Object1_2a8df7f8-b958-40cc-83f6-edb53b837347', $bdZip->GetEncoded('base64'), '', 'http://www.w3.org/2000/09/xmldsig#base64');

// -------- Reference 1 --------
$gen->AddObjectRef('Object1_2a8df7f8-b958-40cc-83f6-edb53b837347', 'sha1', 'C14N_WithComments', '', '');
$gen->SetRefIdAttr('Object1_2a8df7f8-b958-40cc-83f6-edb53b837347', 'Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27');

// -------- Reference 2 --------
$gen->AddObjectRef('SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e', 'sha1', '', '', 'http://uri.etsi.org/01903#SignedProperties');
$gen->SetRefIdAttr('SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e', 'SignedProperties-Reference_2a8df7f8-b958-40cc-83f6-edb53b837347_28');

// Provide a certificate + private key. (PFX password is test123)
$cert = new Cert();
try {
    $cert->LoadPfxFile('qa_data/pfx/cert_test123.pfx', 'test123');

    $gen->SetX509Cert($cert, true);

    $gen->KeyInfoType = 'X509Data';
    $gen->X509Type = 'Certificate';

    // This will be an enveloping signature where the Signature element
    // is the XML document root, the signed data is contained within Object
    // tag(s) within the Signature.
    // Therefore, pass an empty sbXml to CreateXmlDsigSb.
    $sbXml = new StringBuilder();

    // The Polish government's XmlDSig implementation requires that we reproduce an attribute-sorting error.
    // (This is an error in the XML canonicalization that is not noticed when both the signature-creation code and signature-verification code use
    // the same XML canonicalization implementation w/ the bug.)
    $gen->Behaviors = 'AttributeSortingBug,CompactSignedXml';

    // Sign the XML...
    $gen->CreateXmlDSigSb($sbXml);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

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

// Save the signed XML to a file.
$sbXml->WriteFile('qa_output/signedXml.xml', 'utf-8', false);

echo $sbXml->GetAsString(), "\n";

// ----------------------------------------
// Verify the signature we just produced...
$verifier = new XmlDSig();
try {
    $verifier->LoadSignatureSb($sbXml);

    $verifier->VerifySignature(true);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo "This signature was successfully verified.\n";

// ------------------------------------
// Finally, let's extract the .zip from the signed XML, and then unzip the original PIT-11Z.xml from the in-memory zip.
$xml = new Xml();
$xml->LoadSb($sbXml, true);

// The base64 image of the PIT-11Z.zip is in the 2nd ds:Object child of the ds:Signature (the ds:Signature is the root element of the signed XML).
// (ds:Object[0] would be the 1st ds:Object child.  Index 1 is the 2nd ds:Object child.)
$strZipBase64 = $xml->GetChildContent('ds:Object[1]');

$bdZip->Clear();
$bdZip->AppendEncoded($strZipBase64, 'base64');
if ($bdZip->NumBytes == 0) {
    echo "Something went wrong.. we dont' have any data..\n";
    exit;
}

try {
    $zip->OpenBd($bdZip);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

// Get the 1st file in the zip, which should be the PIT-11Z.xml
$entry = new ZipEntry();
try {
    $zip->EntryAt(0, $entry);
} catch (\Chilkat2\Exception $e) {
    echo "Zip contains no files...\n";
    exit;
}

// Get the XML:
$origXml = $entry->UnzipToString(0, 'utf-8');
echo "Original XML extracted from base64 zip:\n";
echo $origXml, "\n";