Visual Basic 6.0
Verify HMAC XML Digital Signature

See more XML Digital Signatures Examples
Demonstrates how to validate an XML digital signature signed with an HMAC key.
Chilkat Visual Basic 6.0 Downloads

Visual Basic 6.0
Dim success As Long
success = 0

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

' The XML containing the Signature to be verified contains the following:

' <?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>

' The above XML is available at https://www.chilkatsoft.com/exampleData/hmacSigned.xml
' First fetch the XML..

Dim url As String
url = "https://www.chilkatsoft.com/exampleData/hmacSigned.xml"
Dim http As New ChilkatHttp
Dim sbXml As New ChilkatStringBuilder
success = http.QuickGetSb(url,sbXml)
If (success <> 1) Then
    Debug.Print http.LastErrorText
    Exit Sub
End If

Dim verifier As New ChilkatXmlDSig

' Load the XML containing the signature to be verified.
success = verifier.LoadSignatureSb(sbXml)
If (success <> 1) Then
    Debug.Print verifier.LastErrorText
    Exit Sub
End If

' Provide the HMAC key
' The HMAC key for this signature is the us-ascii bytes of the string "secret",
' It can be set in any of the following ways (and also more ways not shown here..)
success = verifier.SetHmacKey("secret","ascii")
' or
success = verifier.SetHmacKey("c2VjcmV0","base64")
' or
success = verifier.SetHmacKey("736563726574","hex")

' Verify the signature
Dim bVerified As Long
bVerified = verifier.VerifySignature(1)
Debug.Print "Signature verified = " & bVerified