(Unicode C++) Signed Zip as Base64 with XAdES-BES

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:

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

This example will also show the reverse:

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

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#include <CkStringBuilderW.h>
#include <CkZipW.h>
#include <CkZipEntryW.h>
#include <CkBinDataW.h>
#include <CkXmlDSigGenW.h>
#include <CkXmlW.h>
#include <CkCertW.h>
#include <CkXmlDSigW.h>

void ChilkatSample(void)
    {
    // 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).
    CkStringBuilderW sbXmlToZip;
    bool success = sbXmlToZip.LoadFile(L"qa_data/xml/PIT-11Z.xml",L"utf-8");
    if (success != true) {
        wprintf(L"Failed to load the XML to be zipped.\n");
        return;
    }

    CkZipW zip;

    // Initialize the zip object. No file is created in this call.
    // It should always return true.
    success = zip.NewZip(L"PIT-11Z.zip");

    // Add the XML to be zipped.
    CkZipEntryW *entry = zip.AppendString(L"PIT-11Z.xml",sbXmlToZip.getAsString());
    delete entry;

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

    CkXmlDSigGenW gen;

    gen.put_SigLocation(L"");
    gen.put_SigLocationMod(0);

    gen.put_SigId(L"Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19");
    gen.put_SigNamespacePrefix(L"ds");
    gen.put_SigNamespaceUri(L"http://www.w3.org/2000/09/xmldsig#");
    gen.put_SigValueId(L"SignatureValue_2a8df7f8-b958-40cc-83f6-edb53b837347_52");
    gen.put_SignedInfoId(L"SignedInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_41");
    gen.put_SignedInfoCanonAlg(L"C14N");
    gen.put_SignedInfoDigestMethod(L"sha1");

    // Set the KeyInfoId before adding references..
    gen.put_KeyInfoId(L"KeyInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_24");

    // Create an Object to be added to the Signature.
    CkXmlW object1;
    object1.put_Tag(L"xades:QualifyingProperties");
    object1.AddAttribute(L"xmlns:xades",L"http://uri.etsi.org/01903/v1.3.2#");
    object1.AddAttribute(L"Id",L"QualifyingProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_43");
    object1.AddAttribute(L"Target",L"#Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19");
    object1.UpdateAttrAt(L"xades:SignedProperties",true,L"Id",L"SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e");
    object1.UpdateAttrAt(L"xades:SignedProperties|xades:SignedSignatureProperties",true,L"Id",L"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(L"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningTime",L"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(L"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestMethod",true,L"Algorithm",L"http://www.w3.org/2000/09/xmldsig#sha1");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestValue",L"TO BE GENERATED BY CHILKAT");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:IssuerSerialV2",L"TO BE GENERATED BY CHILKAT");
    object1.UpdateAttrAt(L"xades:SignedProperties|xades:SignedDataObjectProperties",true,L"Id",L"SignedDataObjectProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4b");
    object1.UpdateAttrAt(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat",true,L"ObjectReference",L"#Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:Description",L"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(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier",true,L"Qualifier",L"OIDAsURI");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier",L"http://www.certum.pl/OIDAsURI/signedFile/1.2.616.1.113527.3.1.1.3.1");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Description",L"Opis formatu dokumentu oraz jego pelna nazwa");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:DocumentationReferences|xades:DocumentationReference",L"http://www.certum.pl/OIDAsURI/signedFile.pdf");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:MimeType",L"application/zip");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:CommitmentTypeId|xades:Identifier",L"http://uri.etsi.org/01903/v1.2.2#ProofOfApproval");
    object1.UpdateChildContent(L"xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:AllSignedDataObjects",L"");
    object1.UpdateAttrAt(L"xades:UnsignedProperties",true,L"Id",L"UnsignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_55");

    // Emit XML in compact (single-line) format to avoid whitespace problems.
    object1.put_EmitCompact(true);
    gen.AddObject(L"",object1.getXml(),L"",L"");

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

    // -------- Reference 1 --------
    gen.AddObjectRef(L"Object1_2a8df7f8-b958-40cc-83f6-edb53b837347",L"sha1",L"C14N_WithComments",L"",L"");
    gen.SetRefIdAttr(L"Object1_2a8df7f8-b958-40cc-83f6-edb53b837347",L"Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27");

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

    // Provide a certificate + private key. (PFX password is test123)
    CkCertW cert;
    success = cert.LoadPfxFile(L"qa_data/pfx/cert_test123.pfx",L"test123");
    if (success != true) {
        wprintf(L"%s\n",cert.lastErrorText());
        return;
    }

    gen.SetX509Cert(cert,true);

    gen.put_KeyInfoType(L"X509Data");
    gen.put_X509Type(L"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.
    CkStringBuilderW sbXml;

    // 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.put_Behaviors(L"AttributeSortingBug,CompactSignedXml");

    // Sign the XML...
    success = gen.CreateXmlDSigSb(sbXml);
    if (success != true) {
        wprintf(L"%s\n",gen.lastErrorText());
        return;
    }

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

    // Save the signed XML to a file.
    success = sbXml.WriteFile(L"qa_output/signedXml.xml",L"utf-8",false);

    wprintf(L"%s\n",sbXml.getAsString());

    // ----------------------------------------
    // Verify the signature we just produced...
    CkXmlDSigW verifier;
    success = verifier.LoadSignatureSb(sbXml);
    if (success != true) {
        wprintf(L"%s\n",verifier.lastErrorText());
        return;
    }

    bool verified = verifier.VerifySignature(true);
    if (verified != true) {
        wprintf(L"%s\n",verifier.lastErrorText());
        return;
    }

    wprintf(L"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.
    CkXmlW 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.)
    const wchar_t *strZipBase64 = xml.getChildContent(L"ds:Object[1]");

    bdZip.Clear();
    bdZip.AppendEncoded(strZipBase64,L"base64");
    if (bdZip.get_NumBytes() == 0) {
        wprintf(L"Something went wrong.. we dont' have any data..\n");
        return;
    }

    success = zip.OpenBd(bdZip);
    if (success != true) {
        wprintf(L"%s\n",zip.lastErrorText());
        return;
    }

    // Get the 1st file in the zip, which should be the PIT-11Z.xml
    entry = zip.GetEntryByIndex(0);
    if (zip.get_LastMethodSuccess() != true) {
        wprintf(L"Zip contains no files...\n");
        return;
    }

    // Get the XML:
    const wchar_t *origXml = entry->unzipToString(0,L"utf-8");
    wprintf(L"Original XML extracted from base64 zip:\n");
    wprintf(L"%s\n",origXml);

    delete entry;
    }