Sample code for 30+ languages & platforms
C#

Create XML Digital Signature using HMAC Key

See more XML Digital Signatures Examples

Demonstrates how to create an XML digital signature using an HMAC key.

Chilkat C# Downloads

C#
bool success = false;

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

//  Signs the following XML using an HMAC key.

//  <?xml version="1.0" encoding="UTF-8" standalone="no"?>
//  <collection Id="root">
//  	<album>
//  		<title>Questions, unanswered</title>
//  		<artist>Steve and the flubberblubs</artist>
//  		<year>1989</year>
//  		<t:tracks xmlns:t="http://test.xades4j/tracks">
//  			<t:song length="4:05" tracknumber="1">
//  				<t:title>What do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:31</t:lastplayed>
//  			</t:song>
//  			<t:song length="3:45" tracknumber="2">
//  				<t:title>Who do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:35</t:lastplayed>
//  			</t:song>
//  			<t:song length="5:14" tracknumber="3">
//  				<t:title>When do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:39</t:lastplayed>
//  			</t:song>
//  			<t:song length="4:19" tracknumber="4">
//  				<t:title>Do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:44</t:lastplayed>
//  			</t:song>
//  		</t:tracks>
//  	</album>
//  </collection>
//  

//  The above XML is available at https://www.chilkatsoft.com/exampleData/flubberblub.xml
//  Fetch the XML and then sign it..

string url = "https://www.chilkatsoft.com/exampleData/flubberblub.xml";
Chilkat.Http http = new Chilkat.Http();
Chilkat.StringBuilder sbXml = new Chilkat.StringBuilder();
success = http.QuickGetSb(url,sbXml);
if (success != true) {
    Debug.WriteLine(http.LastErrorText);
    return;
}

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

//  The Signature will be inserted under the "collection" element.
xmlSigGen.SigLocation = "collection";

//  Sign everything in <collection Id="root"> ... </collection>
xmlSigGen.AddSameDocRef("root","sha256","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..)
xmlSigGen.SetHmacKey("secret","ascii");
//  or
xmlSigGen.SetHmacKey("c2VjcmV0","base64");
//  or
xmlSigGen.SetHmacKey("736563726574","hex");

//  Sign the XML..
success = xmlSigGen.CreateXmlDSigSb(sbXml);
if (success != true) {
    Debug.WriteLine(xmlSigGen.LastErrorText);
    return;
}

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

//  The output is:
//  
//  <?xml version="1.0" encoding="UTF-8" standalone="no"?>
//  <collection Id="root">
//  	<album>
//  		<title>Questions, unanswered</title>
//  		<artist>Steve and the flubberblubs</artist>
//  		<year>1989</year>
//  		<t:tracks xmlns:t="http://test.xades4j/tracks">
//  			<t:song length="4:05" tracknumber="1">
//  				<t:title>What do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:31</t:lastplayed>
//  			</t:song>
//  			<t:song length="3:45" tracknumber="2">
//  				<t:title>Who do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:35</t:lastplayed>
//  			</t:song>
//  			<t:song length="5:14" tracknumber="3">
//  				<t:title>When do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:39</t:lastplayed>
//  			</t:song>
//  			<t:song length="4:19" tracknumber="4">
//  				<t:title>Do you know?</t:title>
//  				<t:artist>Steve and the flubberblubs</t:artist>
//  				<t:lastplayed>2006-10-17-08:44</t:lastplayed>
//  			</t:song>
//  		</t:tracks>
//  	</album>
//  <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="#root"><ds:Transforms><ds:Transform Algorithm="http://www.w3.org/2000/09/xmldsig#enveloped-signature"/></ds:Transforms><ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/><ds:DigestValue>rD/g8soqKz8EiPUBhEWfcQacS0ta4ULHX3dKMEH6ZoQ=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>R8dXP95VRYJBfL6d0Peogybdk27+R+JIfX8jnVu0NOI=</ds:SignatureValue></ds:Signature></collection>
//