(Delphi DLL) Create JPK VAT metadata XML

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

Note: This example requires Chilkat v11.0.0 or greater.

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, PublicKey, Zip, Prng, BinData, Rsa, Cert, Xml, Crypt2;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
xml: HCkXml;
bdXml: HCkBinData;
crypt: HCkCrypt2;
zip: HCkZip;
bdZip: HCkBinData;
prng: HCkPrng;
bdAesKey: HCkBinData;
ivBytes: PWideChar;
cert: HCkCert;
pubKey: HCkPublicKey;
rsa: HCkRsa;
finalXml: PWideChar;

begin
success := False;

// 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>

xml := CkXml_Create();
CkXml_putTag(xml,'InitUpload');
CkXml_AddAttribute(xml,'xmlns','http://e-dokumenty.mf.gov.pl');
CkXml_UpdateChildContent(xml,'DocumentType','JPK');
CkXml_UpdateChildContent(xml,'Version','01.02.01.20160617');
CkXml_UpdateAttrAt(xml,'EncryptionKey',True,'algorithm','RSA');
CkXml_UpdateAttrAt(xml,'EncryptionKey',True,'encoding','Base64');
CkXml_UpdateAttrAt(xml,'EncryptionKey',True,'mode','ECB');
CkXml_UpdateAttrAt(xml,'EncryptionKey',True,'padding','PKCS#1');
CkXml_UpdateChildContent(xml,'EncryptionKey','TO BE DETERMINED');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FormCode',True,'schemaVersion','1-1');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FormCode',True,'systemCode','JPK_VAT (3)');
CkXml_UpdateChildContent(xml,'DocumentList|Document|FormCode','JPK_VAT');
CkXml_UpdateChildContent(xml,'DocumentList|Document|FileName','JPK_VAT_3_v1-1_20181201.xml');
CkXml_UpdateChildContent(xml,'DocumentList|Document|ContentLength','9999');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|HashValue',True,'algorithm','SHA-256');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|HashValue',True,'encoding','Base64');
CkXml_UpdateChildContent(xml,'DocumentList|Document|HashValue','TO BE DETERMINED');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList',True,'filesNumber','1');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Packaging|SplitZip',True,'mode','zip');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Packaging|SplitZip',True,'type','split');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Encryption|AES',True,'block','16');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Encryption|AES',True,'mode','CBC');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Encryption|AES',True,'padding','PKCS#7');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Encryption|AES',True,'size','256');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Encryption|AES|IV',True,'bytes','16');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|Encryption|AES|IV',True,'encoding','Base64');
CkXml_UpdateChildContent(xml,'DocumentList|Document|FileSignatureList|Encryption|AES|IV','TO BE DETERMINED');
CkXml_UpdateChildContent(xml,'DocumentList|Document|FileSignatureList|FileSignature|OrdinalNumber','1');
CkXml_UpdateChildContent(xml,'DocumentList|Document|FileSignatureList|FileSignature|FileName','JPK_VAT_3_v1-1_20181201-000.xml.zip.aes');
CkXml_UpdateChildContent(xml,'DocumentList|Document|FileSignatureList|FileSignature|ContentLength','9999');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|FileSignature|HashValue',True,'algorithm','MD5');
CkXml_UpdateAttrAt(xml,'DocumentList|Document|FileSignatureList|FileSignature|HashValue',True,'encoding','Base64');
CkXml_UpdateChildContent(xml,'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
bdXml := CkBinData_Create();
success := CkBinData_LoadFile(bdXml,'qa_data/xml_dsig/jpk_vat/JPK_VAT_3_v1-1_20181201-000.xml');
if (success <> True) then
  begin
    Memo1.Lines.Add('Failed to load XML file.');
    Exit;
  end;

CkXml_UpdateChildContentInt(xml,'DocumentList|Document|ContentLength',CkBinData_getNumBytes(bdXml));

crypt := CkCrypt2_Create();
CkCrypt2_putHashAlgorithm(crypt,'sha256');
CkCrypt2_putEncodingMode(crypt,'base64');
CkXml_UpdateChildContent(xml,'DocumentList|Document|HashValue',CkCrypt2__hashBdENC(crypt,bdXml));

// ------------------------------------------------------------
// Step 2: Create a Zip archive containing the XML.
zip := CkZip_Create();
// The filename we pass here doesn't matter because we won't actually be creating a .zip file.
CkZip_NewZip(zip,'anything.zip');
CkZip_AddBd(zip,'JPK_VAT_3_v1-1_20181201-000.xml',bdXml);
// Write the .zip file to a BinData object.
bdZip := CkBinData_Create();
CkZip_WriteBd(zip,bdZip);

// ------------------------------------------------------------
// Step 3: Generate a random 256-bit AES key (32-bytes)
prng := CkPrng_Create();
bdAesKey := CkBinData_Create();
CkPrng_GenRandomBd(prng,32,bdAesKey);
ivBytes := CkPrng__genRandom(prng,16,'base64');

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

// ------------------------------------------------------------
// Step 4: AES encrypt our zip archive (the contents of bdZip)
CkCrypt2_putCipherMode(crypt,'cbc');
CkCrypt2_putKeyLength(crypt,256);
CkCrypt2_putCryptAlgorithm(crypt,'aes');
CkCrypt2_putPaddingScheme(crypt,0);
CkCrypt2_SetEncodedIV(crypt,ivBytes,'base64');
CkCrypt2_SetEncodedKey(crypt,CkBinData__getEncoded(bdAesKey,'base64'),'base64');
// AES by definition has a block size of 16.
CkCrypt2_EncryptBd(crypt,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 := CkBinData_WriteFile(bdZip,'qa_output/JPK_VAT_3_v1-1_20181201-000.xml.zip.aes');
CkXml_UpdateChildContentInt(xml,'DocumentList|Document|FileSignatureList|FileSignature|ContentLength',CkBinData_getNumBytes(bdZip));

// ------------------------------------------------------------
// Step 4: RSA Encrypt the AES key using the public key certificate provided by the Ministry of Finance
cert := CkCert_Create();
success := CkCert_LoadFromFile(cert,'qa_data/pem/mf_public_rsa.pem');
if (success = False) then
  begin
    Memo1.Lines.Add(CkCert__lastErrorText(cert));
    Exit;
  end;

pubKey := CkPublicKey_Create();
CkCert_GetPublicKey(cert,pubKey);

rsa := CkRsa_Create();
CkRsa_UsePublicKey(rsa,pubKey);

CkRsa_putEncodingMode(rsa,'base64');
CkRsa_putLittleEndian(rsa,False);
// in-place RSA encrypt the contents of bdAesKey.
CkRsa_EncryptBd(rsa,bdAesKey,False);
CkXml_UpdateChildContent(xml,'EncryptionKey',CkBinData__getEncoded(bdAesKey,'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..)
CkCrypt2_putHashAlgorithm(crypt,'md5');
CkXml_UpdateChildContent(xml,'DocumentList|Document|FileSignatureList|FileSignature|HashValue',CkCrypt2__hashBdENC(crypt,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).
finalXml := CkXml__getXml(xml);
Memo1.Lines.Add(finalXml);

CkXml_SaveXml(xml,'qa_output/jpk_vat.xml');

Memo1.Lines.Add('Finished.');

CkXml_Dispose(xml);
CkBinData_Dispose(bdXml);
CkCrypt2_Dispose(crypt);
CkZip_Dispose(zip);
CkBinData_Dispose(bdZip);
CkPrng_Dispose(prng);
CkBinData_Dispose(bdAesKey);
CkCert_Dispose(cert);
CkPublicKey_Dispose(pubKey);
CkRsa_Dispose(rsa);

end;