DataFlex

Extract SignatureValue from Signed XML

See more XML Digital Signatures Examples

Demonstrates how to extract the signature value from signed XML. DataFlex

Use ChilkatAx-win32.pkg

Procedure Test
    Boolean iSuccess
    String sFilePath
    Handle hoSb
    String sBase64Sig
    Variant vXml
    Handle hoXml
    Variant vXSigVal
    Handle hoXSigVal
    String sTemp1
    Boolean bTemp1

    Move False To iSuccess

    // 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>

    Move "qa_data/xml_dsig_testing/sample_to_show_how_to_extract_sig.xml" To sFilePath

    // 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:
    Get Create (RefClass(cComChilkatStringBuilder)) To hoSb
    If (Not(IsComObjectCreated(hoSb))) Begin
        Send CreateComObject of hoSb
    End
    Get ComLoadFile Of hoSb sFilePath "utf-8" To iSuccess
    If (iSuccess = False) Begin
        Showln "Failed to load file."
        Procedure_Return
    End

    Get ComGetBetween Of hoSb "SignatureValue>" "</" To sBase64Sig
    Showln "base64Sig = " sBase64Sig

    // -----------------------------------------------------------------------------------------
    // 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..
    Get Create (RefClass(cComChilkatXml)) To hoXml
    If (Not(IsComObjectCreated(hoXml))) Begin
        Send CreateComObject of hoXml
    End
    Get ComLoadXmlFile Of hoXml sFilePath To iSuccess
    // Assume success..

    Get ComGetChildContent Of hoXml "SOAP-ENV:Header|wsse:Security|ds:Signature|ds:SignatureValue" To sBase64Sig
    Showln "base64Sig = " sBase64Sig

    // -----------------------------------------------------------------------------------------
    // Or perhaps you don't know where the signature is located in the XML.
    // You can search for the tag..
    Get pvComObject of hoXml to vXml
    Get ComSearchForTag Of hoXml vXml "*:SignatureValue" To vXSigVal
    If (IsComObject(vXSigVal)) Begin
        Get Create (RefClass(cComChilkatXml)) To hoXSigVal
        Set pvComObject Of hoXSigVal To vXSigVal
    End
    Get ComLastMethodSuccess Of hoXml To bTemp1
    If (bTemp1 = True) Begin
        Get ComContent Of hoXSigVal To sTemp1
        Showln "base64Sig = " sTemp1
        Send Destroy of hoXSigVal
    End
    Else Begin
        Showln "No SignatureValue found."
    End



End_Procedure