(.NET Core C#) Alliance Access LAU Sign Message (XML Signature using HMAC-SHA-256)

Demonstrates how to sign XML according to the requirements for Alliance Access LAU (Local Authentication) using HMAC-SHA-256.

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

// We begin with this message:

// <?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:SwGbl="urn:swift:snl:ns.SwGbl" xmlns:SwInt="urn:swift:snl:ns:SwInt" xmlns:SwSec="url:swift:snl:ns.SwSec">
//     <Saa:Revision>2.0.7</Saa:Revision>
//     <Saa:Header>
//         <Saa:Message>
// 			<test>blah blah</test>
//         </Saa:Message>
//     </Saa:Header>
//     <Saa:Body>...</Saa:Body>
//     <Saa:LAU>
//     </Saa:LAU>
// </Saa:DataPDU>

// And we want so sign to create this as the result:
// The signed XML we'll create will not be indented and pretty-printed like this.
// Instead, we'll use the "CompactSignedXml" behavior to produce compact single-line 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:SwGbl="urn:swift:snl:ns.SwGbl" xmlns:SwInt="urn:swift:snl:ns:SwInt" xmlns:SwSec="url:swift:snl:ns.SwSec">
//     <Saa:Revision>2.0.7</Saa:Revision>
//     <Saa:Header>
//         <Saa:Message>
// 			<test>blah blah</test>
//         </Saa:Message>
//     </Saa:Header>
//     <Saa:Body>...</Saa:Body>
//     <Saa:LAU>
//         <ds:Signature xmlns:ds="http://www.w3.org/2000/09/xmldsig#">
//             <ds:SignedInfo>
//                 <ds:CanonicalizationMethod Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
//                 <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#hmac-sha256"/>
//                 <ds:Reference URI="">
//                     <ds:Transforms>
//                         <ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/>
//                         <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
//                     </ds:Transforms>
//                     <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
//                     <ds:DigestValue>Y7oScHnYOUQvni/TSzZbDec+HR+mWIFH149GXpwj1Ws=</ds:DigestValue>
//                 </ds:Reference>
//             </ds:SignedInfo>
//             <ds:SignatureValue>6ynF/FcwbPsHrtlj3h2agJigdnvpbO6hOzKSRGzqkw0=</ds:SignatureValue>
//         </ds:Signature>
//     </Saa:LAU>
// </Saa:DataPDU>

bool success = true;

// Create the XML to be signed...

// (The XML does not need to be created this way.  It can be loaded from a file or a string.)
// Also, use this online tool to generate code from sample XML: 
// Generate Code to Create XML

Chilkat.Xml xmlToSign = new Chilkat.Xml();
xmlToSign.Tag = "Saa:DataPDU";
xmlToSign.AddAttribute("xmlns:Saa","urn:swift:saa:xsd:saa.2.0");
xmlToSign.AddAttribute("xmlns:Sw","urn:swift:snl:ns.Sw");
xmlToSign.AddAttribute("xmlns:SwGbl","urn:swift:snl:ns.SwGbl");
xmlToSign.AddAttribute("xmlns:SwInt","urn:swift:snl:ns:SwInt");
xmlToSign.AddAttribute("xmlns:SwSec","url:swift:snl:ns.SwSec");
xmlToSign.UpdateChildContent("Saa:Revision","2.0.7");
xmlToSign.UpdateChildContent("Saa:Header|Saa:Message|test","blah blah");
xmlToSign.UpdateChildContent("Saa:Body","...");
xmlToSign.UpdateChildContent("Saa:LAU","");

Chilkat.XmlDSigGen gen = new Chilkat.XmlDSigGen();

gen.SigLocation = "Saa:DataPDU|Saa:LAU";
gen.SigLocationMod = 0;
gen.SigNamespacePrefix = "ds";
gen.SigNamespaceUri = "http://www.w3.org/2000/09/xmldsig#";
gen.SignedInfoCanonAlg = "EXCL_C14N";
gen.SignedInfoDigestMethod = "sha256";

// You may alternatively choose "IndentedSignature" instead of "CompactSignedXml"
gen.Behaviors = "CompactSignedXml";

gen.AddSameDocRef("","sha256","EXCL_C14N","","");

// Specify the HMAC key.
// For example, if the HMAC key is to be the us-ascii bytes of the string "secret",
// the HMAC key can be set in any of the following ways (and also more ways not shown here..)
gen.SetHmacKey("secret","ascii");
// or
gen.SetHmacKey("c2VjcmV0","base64");
// or
gen.SetHmacKey("736563726574","hex");

// Sign the XML..
Chilkat.StringBuilder sbXml = new Chilkat.StringBuilder();
xmlToSign.GetXmlSb(sbXml);
success = gen.CreateXmlDSigSb(sbXml);
if (success != true) {
    Debug.WriteLine(gen.LastErrorText);
    return;
}

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

// Show the signed XML.
Debug.WriteLine(sbXml.GetAsString());