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Lua 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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Lua 
local chilkat = require("chilkat")

-- 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).
local sbXmlToZip = chilkat.StringBuilder.new()
local success = sbXmlToZip:load_file("qa_data/xml/PIT-11Z.xml", "utf-8")
if not success then
    print("Failed to load the XML to be zipped.")
    return
end

local zip = chilkat.Zip.new()

-- Initialize the zip object. No file is created in this call.
-- It should always return true.
success = zip:new_zip("PIT-11Z.zip")

-- Add the XML to be zipped.
zip:add_sb("PIT-11Z.xml", sbXmlToZip, "utf-8")

-- Write the zip to a BinData object.
local bdZip = chilkat.BinData.new()
zip:write_bd(bdZip)
-- The contents of the bdZip will be retrieved in base64 format when needed below..

local gen = chilkat.XmlDSigGen.new()

gen.sig_location = ""
gen.sig_location_mod = 0

gen.sig_id = "Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19"
gen.sig_namespace_prefix = "ds"
gen.sig_namespace_uri = "http://www.w3.org/2000/09/xmldsig#"
gen.sig_value_id = "SignatureValue_2a8df7f8-b958-40cc-83f6-edb53b837347_52"
gen.signed_info_id = "SignedInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_41"
gen.signed_info_canon_alg = "C14N"
gen.signed_info_digest_method = "sha1"

-- Set the KeyInfoId before adding references..
gen.key_info_id = "KeyInfo_2a8df7f8-b958-40cc-83f6-edb53b837347_24"

-- Create an Object to be added to the Signature.
local object1 = chilkat.Xml.new()
object1.tag = "xades:QualifyingProperties"
object1:add_attribute("xmlns:xades", "http://uri.etsi.org/01903/v1.3.2#")
object1:add_attribute("Id", "QualifyingProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_43")
object1:add_attribute("Target", "#Signature_2a8df7f8-b958-40cc-83f6-edb53b837347_19")
object1:update_attr_at("xades:SignedProperties", true, "Id", "SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e")
object1:update_attr_at("xades:SignedProperties|xades:SignedSignatureProperties", true, "Id", "SignedSignatureProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_0a")
-- Chilkat will replace the strings "TO BE GENERATED BY CHILKAT" with actual values when the signature is created.
object1:update_child_content("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:update_attr_at("xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestMethod", true, "Algorithm", "http://www.w3.org/2000/09/xmldsig#sha1")
object1:update_child_content("xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:CertDigest|ds:DigestValue", "TO BE GENERATED BY CHILKAT")
object1:update_child_content("xades:SignedProperties|xades:SignedSignatureProperties|xades:SigningCertificateV2|xades:Cert|xades:IssuerSerialV2", "TO BE GENERATED BY CHILKAT")
object1:update_attr_at("xades:SignedProperties|xades:SignedDataObjectProperties", true, "Id", "SignedDataObjectProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4b")
object1:update_attr_at("xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat", true, "ObjectReference", "#Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27")
object1:update_child_content("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:update_attr_at("xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Identifier", true, "Qualifier", "OIDAsURI")
object1:update_child_content("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:update_child_content("xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:Description", "Opis formatu dokumentu oraz jego pelna nazwa")
object1:update_child_content("xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:ObjectIdentifier|xades:DocumentationReferences|xades:DocumentationReference", "http://www.certum.pl/OIDAsURI/signedFile.pdf")
object1:update_child_content("xades:SignedProperties|xades:SignedDataObjectProperties|xades:DataObjectFormat|xades:MimeType", "application/zip")
object1:update_child_content("xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:CommitmentTypeId|xades:Identifier", "http://uri.etsi.org/01903/v1.2.2#ProofOfApproval")
object1:update_child_content("xades:SignedProperties|xades:SignedDataObjectProperties|xades:CommitmentTypeIndication|xades:AllSignedDataObjects", "")
object1:update_attr_at("xades:UnsignedProperties", true, "Id", "UnsignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_55")

-- Emit XML in compact (single-line) format to avoid whitespace problems.
object1.emit_compact = true
gen:add_object("", object1:get_xml(), "", "")

-- Create an Object to be added to the Signature.
-- This is where we add the base64 representation of the PIT-11Z.zip
gen:add_object("Object1_2a8df7f8-b958-40cc-83f6-edb53b837347", bdZip:get_encoded("base64"), "", "http://www.w3.org/2000/09/xmldsig#base64")

-- -------- Reference 1 --------
gen:add_object_ref("Object1_2a8df7f8-b958-40cc-83f6-edb53b837347", "sha1", "C14N_WithComments", "", "")
gen:set_ref_id_attr("Object1_2a8df7f8-b958-40cc-83f6-edb53b837347", "Reference1_2a8df7f8-b958-40cc-83f6-edb53b837347_27")

-- -------- Reference 2 --------
gen:add_object_ref("SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e", "sha1", "", "", "http://uri.etsi.org/01903#SignedProperties")
gen:set_ref_id_attr("SignedProperties_2a8df7f8-b958-40cc-83f6-edb53b837347_4e", "SignedProperties-Reference_2a8df7f8-b958-40cc-83f6-edb53b837347_28")

-- Provide a certificate + private key. (PFX password is test123)
local cert = chilkat.Cert.new()
success = cert:load_pfx_file("qa_data/pfx/cert_test123.pfx", "test123")
if not success then
    print(cert.last_error_text)
    return
end

gen:set_x509_cert(cert, true)

gen.key_info_type = "X509Data"
gen.x509_type = "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.
local sbXml = chilkat.StringBuilder.new()

-- 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.behaviors = "AttributeSortingBug,CompactSignedXml"

-- Sign the XML...
success = gen:create_xml_dsig_sb(sbXml)
if not success then
    print(gen.last_error_text)
    return
end

-- -----------------------------------------------

-- Save the signed XML to a file.
success = sbXml:write_file("qa_output/signedXml.xml", "utf-8", false)

print(sbXml:get_as_string())

-- ----------------------------------------
-- Verify the signature we just produced...
local verifier = chilkat.XmlDSig.new()
success = verifier:load_signature_sb(sbXml)
if not success then
    print(verifier.last_error_text)
    return
end

local verified = verifier:verify_signature(true)
if not verified then
    print(verifier.last_error_text)
    return
end

print("This signature was successfully verified.")

-- ------------------------------------
-- Finally, let's extract the .zip from the signed XML, and then unzip the original PIT-11Z.xml from the in-memory zip.
local xml = chilkat.Xml.new()
xml:load_sb(sbXml, true)

-- 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.)
local strZipBase64 = xml:get_child_content("ds:Object[1]")

bdZip:clear()
bdZip:append_encoded(strZipBase64, "base64")
if bdZip.num_bytes == 0 then
    print("Something went wrong.. we dont' have any data..")
    return
end

success = zip:open_bd(bdZip)
if not success then
    print(zip.last_error_text)
    return
end

-- Get the 1st file in the zip, which should be the PIT-11Z.xml
local entry = chilkat.ZipEntry.new()
success = zip:entry_at(0, entry)
if not success then
    print("Zip contains no files...")
    return
end

-- Get the XML:
local origXml = entry:unzip_to_string(0, "utf-8")
print("Original XML extracted from base64 zip:")
print(origXml)