Sample code for 30+ languages & platforms
AutoIt

Extract SignatureValue from Signed XML

See more XML Digital Signatures Examples

Demonstrates how to extract the signature value from signed XML.

Chilkat AutoIt Downloads

AutoIt
Local $bSuccess = False

;  This example will work with the following signed XML, which as been reformatted for readability.

;  <?xml version="1.0" encoding="utf-8"?>
;  <SOAP-ENV:Envelope xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/">
;      <SOAP-ENV:Header>
;          <wsse:Security xmlns:wsse="http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" SOAP-ENV:mustUnderstand="1">
;              <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#">
;                          <InclusiveNamespaces xmlns="http://www.w3.org/2001/10/xml-exc-c14n#" PrefixList="wsse SOAP-ENV"/>
;                      </ds:CanonicalizationMethod>
;                      <ds:SignatureMethod Algorithm="http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"/>
;                      <ds:Reference URI="#Body">
;                          <ds:Transforms>
;                              <ds:Transform Algorithm="http://www.w3.org/2001/10/xml-exc-c14n#"/>
;                          </ds:Transforms>
;                          <ds:DigestMethod Algorithm="http://www.w3.org/2001/04/xmlenc#sha256"/>
;                          <ds:DigestValue>OwgHPZNfDkXnZsjpfzXqAcT3RV3HzmTsEy2bP44FJ0M=</ds:DigestValue>
;                      </ds:Reference>
;                  </ds:SignedInfo>
;                  <ds:SignatureValue>C+7FWngU....DJFBcdg==</ds:SignatureValue>
;                  <ds:KeyInfo>
;                      <ds:KeyValue>
;                          <ds:RSAKeyValue>
;                              <ds:Modulus>sXeRhM55P13.....NAcibRw==</ds:Modulus>
;                              <ds:Exponent>AQAB</ds:Exponent>
;                          </ds:RSAKeyValue>
;                      </ds:KeyValue>
;                  </ds:KeyInfo>
;              </ds:Signature>
;          </wsse:Security>
;      </SOAP-ENV:Header>
;      <SOAP-ENV:Body xmlns:SOAP-SEC="http://schemas.xmlsoap.org/soap/security/2000-12" SOAP-SEC:id="Body">
;          <z:FooBar xmlns:z="http://example.com"/>
;      </SOAP-ENV:Body>
;  </SOAP-ENV:Envelope>

;  -----------------------------------------------------------------------------------------
;  There are a number of ways we can get the contents of the  <ds:SignatureValue>...</ds:SignatureValue>

Local $sFilePath = "qa_data/xml_dsig_testing/sample_to_show_how_to_extract_sig.xml"

;  If you know there will only be a single SignatureValue in the XML, you don't need to parse XML.
;  Just do quick and simple string search..
;  For example:
$oSb = ObjCreate("Chilkat.StringBuilder")
$bSuccess = $oSb.LoadFile($sFilePath,"utf-8")
If ($bSuccess = False) Then
    ConsoleWrite("Failed to load file." & @CRLF)
    Exit
EndIf

Local $sBase64Sig = $oSb.GetBetween("SignatureValue>","</")
ConsoleWrite("base64Sig = " & $sBase64Sig & @CRLF)

;  -----------------------------------------------------------------------------------------
;  If the XML might contain multiple signatures, but the signatures will always be located in the 
;  same place, then you can (beforehand) copy a sample signed XML into Chilkat's online tool
;  at Generate Parsing Code from XML
;  to get the path to the SignatureValue.  For example, the line of code generated for the SignatureValue
;  for the above XML is:
;  string ds_SignatureValue = xml.GetChildContent("SOAP-ENV:Header|wsse:Security|ds:Signature|ds:SignatureValue");

;  So you can simply use that path..
$oXml = ObjCreate("Chilkat.Xml")
$bSuccess = $oXml.LoadXmlFile($sFilePath)
;  Assume success..

$sBase64Sig = $oXml.GetChildContent("SOAP-ENV:Header|wsse:Security|ds:Signature|ds:SignatureValue")
ConsoleWrite("base64Sig = " & $sBase64Sig & @CRLF)

;  -----------------------------------------------------------------------------------------
;  Or perhaps you don't know where the signature is located in the XML.
;  You can search for the tag..
Local $oXSigVal = $oXml.SearchForTag($oXml,"*:SignatureValue")
If ($oXml.LastMethodSuccess = True) Then
    ConsoleWrite("base64Sig = " & $oXSigVal.Content & @CRLF)

Else
    ConsoleWrite("No SignatureValue found." & @CRLF)
EndIf