(PureBasic) 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 PureBasic Module Download Chilkat PureBasic Module

IncludeFile "CkStringBuilder.pb"
IncludeFile "CkXmlDSigGen.pb"

Procedure ChilkatExample()

    ; 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.
    sbXml.i = CkStringBuilder::ckCreate()
    If sbXml.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    success.i = CkStringBuilder::ckLoadFile(sbXml,"c:/someDir/fileToSign.xml","utf-8")
    If success = 0
        Debug "Failed to load XML file."
        CkStringBuilder::ckDispose(sbXml)
        ProcedureReturn
    EndIf

    ; We need to add a "LAU" XML element just before the "</Saa:DataPDU>"
    numReplaced.i = CkStringBuilder::ckReplace(sbXml,"</Saa:DataPDU>","<LAU xmlns=" + Chr(34) + "urn:swift:saa:xsd:saa.2.0" + Chr(34) + "></LAU></Saa:DataPDU>")

    gen.i = CkXmlDSigGen::ckCreate()
    If gen.i = 0
        Debug "Failed to create object."
        ProcedureReturn
    EndIf

    CkXmlDSigGen::setCkSigLocation(gen, "Saa:DataPDU|LAU")
    CkXmlDSigGen::setCkSigLocationMod(gen, 0)
    CkXmlDSigGen::setCkSigNamespacePrefix(gen, "ds")
    CkXmlDSigGen::setCkSigNamespaceUri(gen, "http://www.w3.org/2000/09/xmldsig#")
    CkXmlDSigGen::setCkSignedInfoCanonAlg(gen, "EXCL_C14N")
    CkXmlDSigGen::setCkSignedInfoDigestMethod(gen, "sha256")
    CkXmlDSigGen::setCkBehaviors(gen, "CompactSignedXml")

    ; Sign the entire document.
    CkXmlDSigGen::ckAddSameDocRef(gen,"","sha256","EXCL_C14N","","")

    ; Set our HMAC key
    CkXmlDSigGen::ckSetHmacKey(gen,"Abcdef0123456789Abcdef0123456789","ascii")

    ; Sign the XML:
    success = CkXmlDSigGen::ckCreateXmlDSigSb(gen,sbXml)
    If success = 0
        Debug CkXmlDSigGen::ckLastErrorText(gen)
        CkStringBuilder::ckDispose(sbXml)
        CkXmlDSigGen::ckDispose(gen)
        ProcedureReturn
    EndIf

    ; Examine the signed XML
    Debug CkStringBuilder::ckGetAsString(sbXml)

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


    CkStringBuilder::ckDispose(sbXml)
    CkXmlDSigGen::ckDispose(gen)


    ProcedureReturn
EndProcedure