(VBScript) Swift Alliance LAU XML Signature

Calculating the LAU for Swift Alliance File Act XML using HMAC SHA256. (The XML signature, also referred to as Local Authentication (LAU), is computed using the algorithm HMAC based on SHA-256.)

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

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

' We begin with the following XML:

' <?xml version="1.0" encoding="UTF-8"?>
' <Saa:DataPDU xmlns:Saa="urn:swift:saa:xsd:saa.2.0" xmlns:Sw="urn:swift:snl:ns.Sw" xmlns:SwInt="urn:swift:snl:ns.SwInt" xmlns:SwGbl="urn:swift:snl:ns.SwGbl" xmlns:SwSec="urn:swift:snl:ns.SwSec">
'     <Saa:Revision>2.0.6</Saa:Revision>
'     <Saa:Header>
'         <Saa:Message>
'             <Saa:SenderReference>Ref760FA1234</Saa:SenderReference>
'             <Saa:MessageIdentifier>tsrv.fin.mt7xx.gteesstandbys</Saa:MessageIdentifier>
'             <Saa:Format>File</Saa:Format>
'             <Saa:SubFormat>Input</Saa:SubFormat>
'             <Saa:Sender>
'                 <Saa:DN>cn=su8,o=ptsqgbbb,o=swift</Saa:DN>
'                 <Saa:FullName>
'                     <Saa:X1>PTSQGBBBXXX</Saa:X1>
'                 </Saa:FullName>
'             </Saa:Sender>
'             <Saa:Receiver>
'                 <Saa:DN>cn=abc,ou=saa,o=xxx,o=swift</Saa:DN>
'                 <Saa:FullName>
'                     <Saa:X1>PTSXXXXXXXX</Saa:X1>
'                     <Saa:X2>saa</Saa:X2>
'                 </Saa:FullName>
'             </Saa:Receiver>
'             <Saa:InterfaceInfo>
'                 <Saa:UserReference>CRE...</Saa:UserReference>
'                 <Saa:MessageCreator>ApplicationInterface</Saa:MessageCreator>
'                 <Saa:MessageContext>Original</Saa:MessageContext>
'                 <Saa:MessageNature>Financial</Saa:MessageNature>
'             </Saa:InterfaceInfo>
'             <Saa:NetworkInfo>
'                 <Saa:Priority>Normal</Saa:Priority>
'                 <Saa:IsPossibleDuplicate>true</Saa:IsPossibleDuplicate>
'                 <Saa:Service>swift.corp.fast!x</Saa:Service>
'                 <Saa:Network>Application</Saa:Network>
'                 <Saa:SessionNr>0080</Saa:SessionNr>
'                 <Saa:SeqNr>000001</Saa:SeqNr>
'                 <Saa:SWIFTNetNetworkInfo>
'                     <Saa:RequestType>tsrv.fin.mt7xx.gteesstandbys</Saa:RequestType>
'                     <Saa:Reference>2f949999-d32e-49eb-9999-9a819b9b9c0d</Saa:Reference>
'                     <Saa:FileInfo>SwCompression=Zip</Saa:FileInfo>
'                 </Saa:SWIFTNetNetworkInfo>
'             </Saa:NetworkInfo>
'             <Saa:SecurityInfo>
'                 <Saa:SWIFTNetSecurityInfo>
'                     <Saa:FileDigestAlgorithm>SHA-256</Saa:FileDigestAlgorithm>
'                     <Saa:FileDigestValue>9tnnjIgsowPSU+ehm8Rb0J5TvZIvhCYnySzFkpur1aw=</Saa:FileDigestValue>
'                 </Saa:SWIFTNetSecurityInfo>
'             </Saa:SecurityInfo>
'             <Saa:FileLogicalName>Payload.ZIP</Saa:FileLogicalName>
'             <Saa:ExpiryDateTime>20210712074808</Saa:ExpiryDateTime>
'         </Saa:Message>
'     </Saa:Header>
'     <Saa:Body>Payload.ZIP</Saa:Body>
' </Saa:DataPDU>

' Load the XML file to be signed.
' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.StringBuilder")
set sbXml = CreateObject("Chilkat.StringBuilder")
success = sbXml.LoadFile("c:/someDir/fileToSign.xml","utf-8")
If (success = 0) Then
    outFile.WriteLine("Failed to load XML file.")
    WScript.Quit
End If

' We need to add a "LAU" XML element just before the "</Saa:DataPDU>"
numReplaced = sbXml.Replace("</Saa:DataPDU>","<LAU xmlns=""urn:swift:saa:xsd:saa.2.0""></LAU></Saa:DataPDU>")

' For versions of Chilkat < 10.0.0, use CreateObject("Chilkat_9_5_0.XmlDSigGen")
set gen = CreateObject("Chilkat.XmlDSigGen")
gen.SigLocation = "Saa:DataPDU|LAU"
gen.SigLocationMod = 0
gen.SigNamespacePrefix = "ds"
gen.SigNamespaceUri = "http://www.w3.org/2000/09/xmldsig#"
gen.SignedInfoCanonAlg = "EXCL_C14N"
gen.SignedInfoDigestMethod = "sha256"
gen.Behaviors = "CompactSignedXml"

' Sign the entire document.
success = gen.AddSameDocRef("","sha256","EXCL_C14N","","")

' Set our HMAC key
success = gen.SetHmacKey("Abcdef0123456789Abcdef0123456789","ascii")

' Sign the XML:
success = gen.CreateXmlDSigSb(sbXml)
If (success = 0) Then
    outFile.WriteLine(gen.LastErrorText)
    WScript.Quit
End If

' Examine the signed XML
outFile.WriteLine(sbXml.GetAsString())

' Save the signed XML to a file.
success = sbXml.WriteFile("c:/someDir/signedFile.xml","utf-8",0)

outFile.Close