(AutoIt) Verify XML Signature with External Data Reference

Demonstrates how to verify an XML digital signature where the data is external. In this case, the data is a JPG file.

This example requires Chilkat v9.5.0.69 or greater.

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

; 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"?>
; <abc>
;   <xyz>
;     <jpg>
;         <name>starfish.jpg</name>
;         <url>https://www.chilkatsoft.com/images/starfish.jpg</url>
;     <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#rsa-sha256"/><ds:Reference URI="https://www.chilkatsoft.com/images/starfish.jpg"><ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/><ds:DigestValue>AOU810yJV5Np/DnO29qpObqiTSTTCDvxGsX5ayiTYXI=</ds:DigestValue></ds:Reference></ds:SignedInfo><ds:SignatureValue>MbHOti6nOh9DJP/u7u1+a1u0wRYIGEdaAVk5ehxqeBhcR4qvGvCQ7wLxcfDuwFG2grSg43ANxDYngLqZTeFb5nCfywcuNBQI8FrNRVY5hkyv6kDW1BVN8ot9qPYX9oHxJp1e+nMszIiSxqHX3XDI7YnvFt/0CyeO5JaQQEzXzIwqqb8iUNcH/bJzR6CrTf1hGuQ5MPorG0bRwbYPPHHzipUqHBinK8VbHobnxL7GQHAhR8k9gDD35kZcMxf/74U7pGO19ZzTbdJW5S7q4bVVxvsuU3itTbhHI60pOE14ibrjZtIrPZLVUD3TQqIIF04TChW2NXdYOo3+ij4ZnP8x+g==</ds:SignatureValue><ds:KeyInfo><ds:KeyValue><ds:RSAKeyValue><ds:Modulus>sXeRhM55P13FbpNcXAMR3olbw2Wa6keZIHu5YTZYUBTlYWId+pNiwUz3zFIEo+0IfYR0H27ybIycQO+1IIzJofUFNMAL3tZps2OKPlsjuCPls6kXpXhv/gvhux8LrCtp4PcKWqJ6QVOZKChc7WAx40qFWzHi57ueqRTv3x0kESqGg/VjsqyTEvb55psJO2RsfhLT7+YVh3hImRM3RDaJdkTkPuOxeFyT6N7VXD09329sLuS3QkUbE9zEKDnz9X3d8dEQdJhSI9ba5fxl8R7fu8pB67ElfzFml96X1jLFtzy1pzOT5Fc4ROcaqlYckVzdBq9sxezm6MYmDBjNAcibRw==</ds:Modulus><ds:Exponent>AQAB</ds:Exponent></ds:RSAKeyValue></ds:KeyValue></ds:KeyInfo></ds:Signature></jpg>
;   </xyz>
; </abc>

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

Local $sUrl = "https://www.chilkatsoft.com/exampleData/xmlsig_external_jpg_reference.xml"
$oHttp = ObjCreate("Chilkat.Http")
$oSbXml = ObjCreate("Chilkat.StringBuilder")
Local $bSuccess = $oHttp.QuickGetSb($sUrl,$oSbXml)
If ($bSuccess <> True) Then
    ConsoleWrite($oHttp.LastErrorText & @CRLF)
    Exit
EndIf

$oVerifier = ObjCreate("Chilkat.XmlDSig")

; Load the XML containing the signatures to be verified.
; Note that this particular Signature already contains the RSA public key that will be used
; for verification.
$bSuccess = $oVerifier.LoadSignatureSb($oSbXml)
If ($bSuccess <> True) Then
    ConsoleWrite($oVerifier.LastErrorText & @CRLF)
    Exit
EndIf

; Get the Reference URI, which in this case is the URL to the binary data that was hashed.
; This fetchs the URI attribute value from:  <ds:Reference URI="https://www.chilkatsoft.com/images/starfish.jpg">
Local $sRefUri = $oVerifier.ReferenceUri(0)
If ($oVerifier.LastMethodSuccess <> True) Then
    ConsoleWrite("No reference URI found." & @CRLF)
    Exit
EndIf

; Download the JPG data to be verified.
$oJpgData = ObjCreate("Chilkat.BinData")
$bSuccess = $oHttp.QuickGetBd($sRefUri,$oJpgData)
If ($bSuccess <> True) Then
    ConsoleWrite($oHttp.LastErrorText & @CRLF)
    Exit
EndIf

; Provide the JPG data to the verifier
$oVerifier.SetRefDataBd(0,$oJpgData)

; Verify the signature
Local $bVerified = $oVerifier.VerifySignature(True)
ConsoleWrite("Signature verified = " & $bVerified & @CRLF)