(Node.js) Create JPK VAT metadata XML

Demonstrates how to create the JPK VAT metadata XML (InitUpload) that will be signed using XADES.

Install Chilkat for Node.js and Electron using npm at Chilkat npm packages for Node.js Chilkat npm packages for Electron on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    // First build an InitUpload XML template

    // Use this online tool to generate the code from the sample XML below: 
    // Generate Code to Create XML

    // <InitUpload xmlns="http://e-dokumenty.mf.gov.pl">
    //     <DocumentType>JPK</DocumentType>
    //     <Version>01.02.01.20160617</Version>
    //     <EncryptionKey algorithm="RSA" encoding="Base64" mode="ECB" padding="PKCS#1">F9EhKFec...uWqAWUIg==</EncryptionKey>
    //     <DocumentList>
    //         <Document>
    //             <FormCode schemaVersion="1-1" systemCode="JPK_VAT (3)">JPK_VAT</FormCode>
    //             <FileName>JPK_VAT_3_v1-1_20181201.xml</FileName>
    //             <ContentLength>8736</ContentLength>
    //             <HashValue algorithm="SHA-256" encoding="Base64">JFDI1pItwh6dj/Xe1uts/x61qnjZ4DLHpkZMhmf1oKQ=</HashValue>
    //             <FileSignatureList filesNumber="1">
    //                 <Packaging>
    //                     <SplitZip mode="zip" type="split"/>
    //                 </Packaging>
    //                 <Encryption>
    //                     <AES block="16" mode="CBC" padding="PKCS#7" size="256">
    //                         <IV bytes="16" encoding="Base64">z64oN9zXHt1+S3XACRSCYw==</IV>
    //                     </AES>
    //                 </Encryption>
    //                 <FileSignature>
    //                     <OrdinalNumber>1</OrdinalNumber>
    //                     <FileName>JPK_VAT_3_v1-1_20181201-000.xml.zip.aes</FileName>
    //                     <ContentLength>16</ContentLength>
    //                     <HashValue algorithm="MD5" encoding="Base64">5NX0q1935fvMjLFV7E1yDw==</HashValue>
    //                 </FileSignature>
    //             </FileSignatureList>
    //         </Document>
    //     </DocumentList>
    // </InitUpload>

    var success;
    var xml = new chilkat.Xml();
    xml.Tag = "InitUpload";
    xml.AddAttribute("xmlns","http://e-dokumenty.mf.gov.pl");
    xml.UpdateChildContent("DocumentType","JPK");
    xml.UpdateChildContent("Version","01.02.01.20160617");
    xml.UpdateAttrAt("EncryptionKey",true,"algorithm","RSA");
    xml.UpdateAttrAt("EncryptionKey",true,"encoding","Base64");
    xml.UpdateAttrAt("EncryptionKey",true,"mode","ECB");
    xml.UpdateAttrAt("EncryptionKey",true,"padding","PKCS#1");
    xml.UpdateChildContent("EncryptionKey","TO BE DETERMINED");
    xml.UpdateAttrAt("DocumentList|Document|FormCode",true,"schemaVersion","1-1");
    xml.UpdateAttrAt("DocumentList|Document|FormCode",true,"systemCode","JPK_VAT (3)");
    xml.UpdateChildContent("DocumentList|Document|FormCode","JPK_VAT");
    xml.UpdateChildContent("DocumentList|Document|FileName","JPK_VAT_3_v1-1_20181201.xml");
    xml.UpdateChildContent("DocumentList|Document|ContentLength","9999");
    xml.UpdateAttrAt("DocumentList|Document|HashValue",true,"algorithm","SHA-256");
    xml.UpdateAttrAt("DocumentList|Document|HashValue",true,"encoding","Base64");
    xml.UpdateChildContent("DocumentList|Document|HashValue","TO BE DETERMINED");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList",true,"filesNumber","1");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Packaging|SplitZip",true,"mode","zip");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Packaging|SplitZip",true,"type","split");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",true,"block","16");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",true,"mode","CBC");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",true,"padding","PKCS#7");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",true,"size","256");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES|IV",true,"bytes","16");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES|IV",true,"encoding","Base64");
    xml.UpdateChildContent("DocumentList|Document|FileSignatureList|Encryption|AES|IV","TO BE DETERMINED");
    xml.UpdateChildContent("DocumentList|Document|FileSignatureList|FileSignature|OrdinalNumber","1");
    xml.UpdateChildContent("DocumentList|Document|FileSignatureList|FileSignature|FileName","JPK_VAT_3_v1-1_20181201-000.xml.zip.aes");
    xml.UpdateChildContent("DocumentList|Document|FileSignatureList|FileSignature|ContentLength","9999");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|FileSignature|HashValue",true,"algorithm","MD5");
    xml.UpdateAttrAt("DocumentList|Document|FileSignatureList|FileSignature|HashValue",true,"encoding","Base64");
    xml.UpdateChildContent("DocumentList|Document|FileSignatureList|FileSignature|HashValue","TO BE DETERMINED");

    // ------------------------------------------------------------
    // Step 1: Load our JPK_VAT XML and update the DocumentList|Document|HashValue
    // and DocumentList|Document|ContentLength
    var bdXml = new chilkat.BinData();
    success = bdXml.LoadFile("qa_data/xml_dsig/jpk_vat/JPK_VAT_3_v1-1_20181201-000.xml");
    if (success !== true) {
        console.log("Failed to load XML file.");
        return;
    }

    xml.UpdateChildContentInt("DocumentList|Document|ContentLength",bdXml.NumBytes);

    var crypt = new chilkat.Crypt2();
    crypt.HashAlgorithm = "sha256";
    crypt.EncodingMode = "base64";
    xml.UpdateChildContent("DocumentList|Document|HashValue",crypt.HashBdENC(bdXml));

    // ------------------------------------------------------------
    // Step 2: Create a Zip archive containing the XML.
    var zip = new chilkat.Zip();
    // The filename we pass here doesn't matter because we won't actually be creating a .zip file.
    zip.NewZip("anything.zip");
    // e: ZipEntry
    var e = zip.AppendBd("JPK_VAT_3_v1-1_20181201-000.xml",bdXml);

    // Write the .zip file to a BinData object.
    var bdZip = new chilkat.BinData();
    zip.WriteBd(bdZip);

    // ------------------------------------------------------------
    // Step 3: Generate a random 256-bit AES key (32-bytes)
    var prng = new chilkat.Prng();
    var bdAesKey = new chilkat.BinData();
    prng.GenRandomBd(32,bdAesKey);
    var ivBytes = prng.GenRandom(16,"base64");

    // Store the IV (base64 string) in the XML.
    xml.UpdateChildContent("DocumentList|Document|FileSignatureList|Encryption|AES|IV",ivBytes);

    // ------------------------------------------------------------
    // Step 4: AES encrypt our zip archive (the contents of bdZip)
    crypt.CipherMode = "cbc";
    crypt.KeyLength = 256;
    crypt.CryptAlgorithm = "aes";
    crypt.PaddingScheme = 0;
    crypt.SetEncodedIV(ivBytes,"base64");
    crypt.SetEncodedKey(bdAesKey.GetEncoded("base64"),"base64");
    // AES by definition has a block size of 16.
    crypt.EncryptBd(bdZip);

    // bdZip now contains the AES encrypted data. 
    // Note: This is NOT the same as a zip where the contents are AES encrypted.
    // In that case, we have an unencrypted zip structure with AES encrypted files within.
    // In our case, the entire zip file image is encrypted.

    // Save the bdZip to a file.  This is what will get sent to e-dokumenty.mf.gov.pl
    success = bdZip.WriteFile("qa_output/JPK_VAT_3_v1-1_20181201-000.xml.zip.aes");
    xml.UpdateChildContentInt("DocumentList|Document|FileSignatureList|FileSignature|ContentLength",bdZip.NumBytes);

    // ------------------------------------------------------------
    // Step 4: RSA Encrypt the AES key using the public key certificate provided by the Ministry of Finance
    var cert = new chilkat.Cert();
    success = cert.LoadFromFile("qa_data/pem/mf_public_rsa.pem");
    if (success !== true) {
        console.log(cert.LastErrorText);
        return;
    }

    // pubKey: PublicKey
    var pubKey = cert.ExportPublicKey();
    var rsa = new chilkat.Rsa();
    rsa.ImportPublicKeyObj(pubKey);

    rsa.EncodingMode = "base64";
    rsa.LittleEndian = false;
    // in-place RSA encrypt the contents of bdAesKey.
    rsa.EncryptBd(bdAesKey,false);
    xml.UpdateChildContent("EncryptionKey",bdAesKey.GetEncoded("base64"));

    // Step 5: We forgot to get the MD5 hash of the AES encrypted zip.
    // (I'm assuming we need the MD5 of the encrypted zip as opposed to the MD5 of the pre-encrypted zip..)
    crypt.HashAlgorithm = "md5";
    xml.UpdateChildContent("DocumentList|Document|FileSignatureList|FileSignature|HashValue",crypt.HashBdENC(bdZip));

    // At this point, the XML is prepared and the AES encrypted image of the zip file is written
    // to a file (and also in bdZip).
    var finalXml = xml.GetXml();
    console.log(finalXml);

    xml.SaveXml("qa_output/jpk_vat.xml");

    console.log("Finished.");

}

chilkatExample();