(DataFlex) Verify HMAC XML Digital Signature

Demonstrates how to validate an XML digital signature signed with an HMAC key.

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

Use ChilkatAx-win32.pkg

Procedure Test
    String sUrl
    Handle hoHttp
    Variant vSbXml
    Handle hoSbXml
    Boolean iSuccess
    Handle hoVerifier
    Boolean iBVerified
    String sTemp1

    // 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..

    Move "https://www.chilkatsoft.com/exampleData/hmacSigned.xml" To sUrl
    Get Create (RefClass(cComChilkatHttp)) To hoHttp
    If (Not(IsComObjectCreated(hoHttp))) Begin
        Send CreateComObject of hoHttp
    End
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSbXml
    If (Not(IsComObjectCreated(hoSbXml))) Begin
        Send CreateComObject of hoSbXml
    End
    Get pvComObject of hoSbXml to vSbXml
    Get ComQuickGetSb Of hoHttp sUrl vSbXml To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoHttp To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    Get Create (RefClass(cComChilkatXmlDSig)) To hoVerifier
    If (Not(IsComObjectCreated(hoVerifier))) Begin
        Send CreateComObject of hoVerifier
    End

    // Load the XML containing the signature to be verified.
    Get pvComObject of hoSbXml to vSbXml
    Get ComLoadSignatureSb Of hoVerifier vSbXml To iSuccess
    If (iSuccess <> True) Begin
        Get ComLastErrorText Of hoVerifier To sTemp1
        Showln sTemp1
        Procedure_Return
    End

    // 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..)
    Get ComSetHmacKey Of hoVerifier "secret" "ascii" To iSuccess
    // or
    Get ComSetHmacKey Of hoVerifier "c2VjcmV0" "base64" To iSuccess
    // or
    Get ComSetHmacKey Of hoVerifier "736563726574" "hex" To iSuccess

    // Verify the signature
    Get ComVerifySignature Of hoVerifier True To iBVerified
    Showln "Signature verified = " iBVerified


End_Procedure