(Visual FoxPro) Create XML Digital Signature using HMAC Key

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

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

LOCAL lcUrl
LOCAL loHttp
LOCAL loSbXml
LOCAL lnSuccess
LOCAL loXmlSigGen

* 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..

lcUrl = "https://www.chilkatsoft.com/exampleData/flubberblub.xml"
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Http')
loHttp = CreateObject('Chilkat.Http')
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbXml = CreateObject('Chilkat.StringBuilder')
lnSuccess = loHttp.QuickGetSb(lcUrl,loSbXml)
IF (lnSuccess <> 1) THEN
    ? loHttp.LastErrorText
    RELEASE loHttp
    RELEASE loSbXml
    CANCEL
ENDIF

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.XmlDSigGen')
loXmlSigGen = CreateObject('Chilkat.XmlDSigGen')

* The Signature will be inserted under the "collection" element.
loXmlSigGen.SigLocation = "collection"

* Sign everything in <collection Id="root"> ... </collection>
loXmlSigGen.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..)
loXmlSigGen.SetHmacKey("secret","ascii")
* or
loXmlSigGen.SetHmacKey("c2VjcmV0","base64")
* or
loXmlSigGen.SetHmacKey("736563726574","hex")

* Sign the XML..
lnSuccess = loXmlSigGen.CreateXmlDSigSb(loSbXml)
IF (lnSuccess <> 1) THEN
    ? loXmlSigGen.LastErrorText
    RELEASE loHttp
    RELEASE loSbXml
    RELEASE loXmlSigGen
    CANCEL
ENDIF

* Examine the signed XML:
? loSbXml.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>
* 

RELEASE loHttp
RELEASE loSbXml
RELEASE loXmlSigGen