(Perl) Create JPK VAT metadata XML

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

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# 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 = chilkat::CkXml->new();
$xml->put_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",1,"algorithm","RSA");
$xml->UpdateAttrAt("EncryptionKey",1,"encoding","Base64");
$xml->UpdateAttrAt("EncryptionKey",1,"mode","ECB");
$xml->UpdateAttrAt("EncryptionKey",1,"padding","PKCS#1");
$xml->UpdateChildContent("EncryptionKey","TO BE DETERMINED");
$xml->UpdateAttrAt("DocumentList|Document|FormCode",1,"schemaVersion","1-1");
$xml->UpdateAttrAt("DocumentList|Document|FormCode",1,"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",1,"algorithm","SHA-256");
$xml->UpdateAttrAt("DocumentList|Document|HashValue",1,"encoding","Base64");
$xml->UpdateChildContent("DocumentList|Document|HashValue","TO BE DETERMINED");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList",1,"filesNumber","1");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Packaging|SplitZip",1,"mode","zip");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Packaging|SplitZip",1,"type","split");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",1,"block","16");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",1,"mode","CBC");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",1,"padding","PKCS#7");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES",1,"size","256");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES|IV",1,"bytes","16");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|Encryption|AES|IV",1,"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",1,"algorithm","MD5");
$xml->UpdateAttrAt("DocumentList|Document|FileSignatureList|FileSignature|HashValue",1,"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
$bdXml = chilkat::CkBinData->new();
$success = $bdXml->LoadFile("qa_data/xml_dsig/jpk_vat/JPK_VAT_3_v1-1_20181201-000.xml");
if ($success != 1) {
    print "Failed to load XML file." . "\r\n";
    exit;
}

$xml->UpdateChildContentInt("DocumentList|Document|ContentLength",$bdXml->get_NumBytes());

$crypt = chilkat::CkCrypt2->new();
$crypt->put_HashAlgorithm("sha256");
$crypt->put_EncodingMode("base64");
$xml->UpdateChildContent("DocumentList|Document|HashValue",$crypt->hashBdENC($bdXml));

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

# Write the .zip file to a BinData object.
$bdZip = chilkat::CkBinData->new();
$zip->WriteBd($bdZip);

# ------------------------------------------------------------
# Step 3: Generate a random 256-bit AES key (32-bytes)
$prng = chilkat::CkPrng->new();
$bdAesKey = chilkat::CkBinData->new();
$prng->GenRandomBd(32,$bdAesKey);
$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->put_CipherMode("cbc");
$crypt->put_KeyLength(256);
$crypt->put_CryptAlgorithm("aes");
$crypt->put_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->get_NumBytes());

# ------------------------------------------------------------
# Step 4: RSA Encrypt the AES key using the public key certificate provided by the Ministry of Finance
$cert = chilkat::CkCert->new();
$success = $cert->LoadFromFile("qa_data/pem/mf_public_rsa.pem");
if ($success != 1) {
    print $cert->lastErrorText() . "\r\n";
    exit;
}

# pubKey is a PublicKey
$pubKey = $cert->ExportPublicKey();
$rsa = chilkat::CkRsa->new();
$rsa->ImportPublicKeyObj($pubKey);

$rsa->put_EncodingMode("base64");
$rsa->put_LittleEndian(0);
# in-place RSA encrypt the contents of bdAesKey.
$rsa->EncryptBd($bdAesKey,0);
$xml->UpdateChildContent("EncryptionKey",$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->put_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).
$finalXml = $xml->getXml();
print $finalXml . "\r\n";

$xml->SaveXml("qa_output/jpk_vat.xml");

print "Finished." . "\r\n";