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Zig 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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Zig 
const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // 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).
    const sb_xml_to_zip = try chilkat.StringBuilder.init();
    defer sb_xml_to_zip.deinit();
    sb_xml_to_zip.loadFile("qa_data/xml/PIT-11Z.xml", "utf-8") catch {
        std.debug.print("Failed to load the XML to be zipped.\n", .{});
        return;
    };

    const zip = try chilkat.Zip.init();
    defer zip.deinit();

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

    // Add the XML to be zipped.
    zip.addSb("PIT-11Z.xml", sb_xml_to_zip, "utf-8") catch {};

    // Write the zip to a BinData object.
    const bd_zip = try chilkat.BinData.init();
    defer bd_zip.deinit();
    zip.writeBd(bd_zip) catch {};
    // The contents of the bdZip will be retrieved in base64 format when needed below..

    const gen = try chilkat.XmlDSigGen.init();
    defer gen.deinit();

    gen.setSigLocation("");
    gen.setSigLocationMod(0);

    gen.setSigId("Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19");
    gen.setSigNamespacePrefix("ds");
    gen.setSigNamespaceUri("http://www.w3.org/2000/09/xmldsig#");
    gen.setSigValueId("SignatureValue_2a8df7f8-b958-40cc-83f6-edb53b837347_52");
    gen.setSignedInfoId("SignedInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_41");
    gen.setSignedInfoCanonAlg("C14N");
    gen.setSignedInfoDigestMethod("sha1");

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

    // Create an Object to be added to the Signature.
    const object1 = try chilkat.Xml.init();
    defer object1.deinit();
    object1.setTag("xades:QualifyingProperties");
    object1.addAttribute("xmlns:xades", "http://uri.etsi.org/01903/v1.3.2#") catch {};
    object1.addAttribute("Id", "QualifyingProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_43") catch {};
    object1.addAttribute("Target", "#Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19") catch {};
    object1.updateAttrAt("xades:SignedProperties", true, "Id", "SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e") catch {};
    object1.updateAttrAt("xades:SignedProperties|xades:SignedSignatureProperties", true, "Id", "SignedSignatureProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_0a") catch {};
    // 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") catch {};
    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") catch {};
    object1.updateAttrAt("xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat", true, "ObjectReference", "#Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27") catch {};
    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="PIT-11Z.zip"");
    object1.updateAttrAt("xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier", true, "Qualifier", "OIDAsURI") catch {};
    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") catch {};

    // Emit XML in compact (single-line) format to avoid whitespace problems.
    object1.setEmitCompact(true);
    gen.addObject("", try object1.getXml(alloc), "", "") catch {};

    // 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", try bd_zip.getEncoded(alloc, "base64"), "", "http://www.w3.org/2000/09/xmldsig#base64") catch {};

    // -------- Reference 1 --------
    gen.addObjectRef("Object1_2a8df7f8-b958-40cc-83f6-edb53b837347", "sha1", "C14N_WithComments", "", "") catch {};
    gen.setRefIdAttr("Object1_2a8df7f8-b958-40cc-83f6-edb53b837347", "Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27") catch {};

    // -------- Reference 2 --------
    gen.addObjectRef("SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e", "sha1", "", "", "http://uri.etsi.org/01903#SignedProperties") catch {};
    gen.setRefIdAttr("SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e", "SignedProperties-Reference_2a8df7f8-b958-40cc-83f6-edb53b837347_28") catch {};

    // Provide a certificate + private key. (PFX password is test123)
    const cert = try chilkat.Cert.init();
    defer cert.deinit();
    cert.loadPfxFile("qa_data/pfx/cert_test123.pfx", "test123") catch {
        std.debug.print("{s}\n", .{try cert.getLastErrorText(alloc)});
        return;
    };

    gen.setX509Cert(cert, true) catch {};

    gen.setKeyInfoType("X509Data");
    gen.setX509Type("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.
    const sb_xml = try chilkat.StringBuilder.init();
    defer sb_xml.deinit();

    // 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.setBehaviors("AttributeSortingBug,CompactSignedXml");

    // Sign the XML...
    gen.createXmlDSigSb(sb_xml) catch {
        std.debug.print("{s}\n", .{try gen.getLastErrorText(alloc)});
        return;
    };

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

    // Save the signed XML to a file.
    try sb_xml.writeFile("qa_output/signedXml.xml", "utf-8", false);

    std.debug.print("{s}\n", .{try sb_xml.getAsString(alloc)});

    // ----------------------------------------
    // Verify the signature we just produced...
    const verifier = try chilkat.XmlDSig.init();
    defer verifier.deinit();
    verifier.loadSignatureSb(sb_xml) catch {
        std.debug.print("{s}\n", .{try verifier.getLastErrorText(alloc)});
        return;
    };

    verifier.verifySignature(true) catch {
        std.debug.print("{s}\n", .{try verifier.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("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.
    const xml = try chilkat.Xml.init();
    defer xml.deinit();
    xml.loadSb(sb_xml, true) catch {};

    // 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 str_zip_base64 = try xml.getChildContent(alloc, "ds:Object[1]");

    bd_zip.clear() catch {};
    bd_zip.appendEncoded(str_zip_base64, "base64") catch {};
    if (bd_zip.getNumBytes() == 0) {
        std.debug.print("Something went wrong.. we dont' have any data..\n", .{});
        return;
    }

    zip.openBd(bd_zip) catch {
        std.debug.print("{s}\n", .{try zip.getLastErrorText(alloc)});
        return;
    };

    // Get the 1st file in the zip, which should be the PIT-11Z.xml
    const entry = try chilkat.ZipEntry.init();
    defer entry.deinit();
    zip.entryAt(0, entry) catch {
        std.debug.print("Zip contains no files...\n", .{});
        return;
    };

    // Get the XML:
    const orig_xml = try entry.unzipToString(alloc, 0, "utf-8");
    std.debug.print("Original XML extracted from base64 zip:\n", .{});
    std.debug.print("{s}\n", .{orig_xml});
}