(Visual Basic 6.0) 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

' 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.
Dim sbXml As New ChilkatStringBuilder
Dim success As Long
success = sbXml.LoadFile("c:/someDir/fileToSign.xml","utf-8")
If (success = 0) Then
    Debug.Print "Failed to load XML file."
    Exit Sub
End If

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

Dim gen As New ChilkatXmlDSigGen
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
    Debug.Print gen.LastErrorText
    Exit Sub
End If

' Examine the signed XML
Debug.Print sbXml.GetAsString()

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