(VB.NET) Create JPK VAT metadata XML

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

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

' 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>

Dim success As Boolean
Dim xml As 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
Dim bdXml As New Chilkat.BinData
success = bdXml.LoadFile("qa_data/xml_dsig/jpk_vat/JPK_VAT_3_v1-1_20181201-000.xml")
If (success <> True) Then
    Debug.WriteLine("Failed to load XML file.")
    Exit Sub
End If


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

Dim crypt As 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.
Dim zip As 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")
Dim e As Chilkat.ZipEntry = zip.AppendBd("JPK_VAT_3_v1-1_20181201-000.xml",bdXml)

' Write the .zip file to a BinData object.
Dim bdZip As New Chilkat.BinData
zip.WriteBd(bdZip)

' ------------------------------------------------------------
' Step 3: Generate a random 256-bit AES key (32-bytes)
Dim prng As New Chilkat.Prng
Dim bdAesKey As New Chilkat.BinData
prng.GenRandomBd(32,bdAesKey)
Dim ivBytes As String = 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
Dim cert As New Chilkat.Cert
success = cert.LoadFromFile("qa_data/pem/mf_public_rsa.pem")
If (success <> True) Then
    Debug.WriteLine(cert.LastErrorText)
    Exit Sub
End If

Dim pubKey As Chilkat.PublicKey = cert.ExportPublicKey()
Dim rsa As 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).
Dim finalXml As String = xml.GetXml()
Debug.WriteLine(finalXml)

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

Debug.WriteLine("Finished.")