Java

Decrypt a govtalk.gov.uk SOAP GovTalkMessage

See more Encryption Examples

Demonstrates how to decrypt the content contained in the XML of a GovTalkMessage SOAP response. Chilkat2 Java

import com.chilkatsoft.chilkat2.BinData;
import com.chilkatsoft.chilkat2.Cert;
import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.Crypt2;
import com.chilkatsoft.chilkat2.Xml;

public class ChilkatExample {

    public static void main(String[] args) {
        // This example assumes the Chilkat API to have been previously unlocked.
        // See Global Unlock Sample for sample code.

        // The GovTalkMessage response looks something like this:

        // <?xml version="1.0" encoding="utf-8"?>
        // <GovTalkMessage xmlns="http://www.govtalk.gov.uk/CM/envelope">
        //   <EnvelopeVersion>3.1</EnvelopeVersion>
        //   <Header>
        //     <MessageDetails>
        //       <Class>CSSZ_DZDPN</Class>
        //       <Qualifier>request</Qualifier>
        //       <Function>submit</Function>
        //       <TransactionID />
        //       <AuditID />
        //       <CorrelationID>aaaaa</CorrelationID>
        //       <ResponseEndPoint PollInterval="0" />
        //       <Transformation>XML</Transformation>
        //       <GatewayTest />
        //       <GatewayTimestamp />
        //     </MessageDetails>
        //     <SenderDetails>
        //       <IDAuthentication>
        //         <SenderID />
        //         <Authentication>
        //           <Method>clear</Method>
        //           <Role />
        //           <Value />
        //         </Authentication>
        //       </IDAuthentication>
        //       <X509Certificate />
        //       <EmailAddress>somebody@example.com</EmailAddress>
        //     </SenderDetails>
        //   </Header>
        //   <GovTalkDetails>
        //     <Keys>
        //       <Key Type="vars">9999999999</Key>
        //     </Keys>
        //     <GatewayAdditions>
        //       <Source>VREP</Source>
        //     </GatewayAdditions>
        //   </GovTalkDetails>
        //   <Body>
        //     <Message xmlns="http://www.cssz.cz/XMLSchema/envelope" version="1.2" eType="DZDPN20">
        //       <Header>
        //         <Signature xmlns:dt="urn:schemas-microsoft-com:datatypes" dt:dt="bin.base64">MIIJ0A ... UMw=
        // </Signature>
        //         <Vendor productName="some product name" version="2019" />
        //       </Header>
        //       <Body xmlns:dt="urn:schemas-microsoft-com:datatypes" encrypted="yes" contentEncoding="gzip" dt:dt="bin.base64">MIIF2w ... N2vW</Body>
        //     </Message>
        //   </Body>
        // </GovTalkMessage>

        // We want to get the content of the Body and decrypt it.

        // First, let's get the content of the Body XML element, which is a base64 string starting with MIIF2w...

        Xml xml = new Xml();
        try {
            xml.loadXmlFile("qa_data/xml/govTalkMessageResponse.xml");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        String Body = xml.getChildContent("Body|Message|Body");
        System.out.println(Body);

        Cert cert = new Cert();
        try {
            cert.loadPfxFile("qa_data/pfx/govTalkMessage_aaa.pfx", "aaa");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        Crypt2 crypt = new Crypt2();
        crypt.setCryptAlgorithm("pki");
        try {
            crypt.setDecryptCert(cert);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        BinData bd = new BinData();
        // Append the bytes to bd.
        bd.appendEncoded(Body, "base64");

        // Decrypt in-place.
        try {
            crypt.decryptBd(bd);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // Save the decrypted data to a file.
        bd.writeFile("qa_output/out.dat");

        // If the decrypted data is non-text (binary) then we can examine it in an encoding, such as hex:
        System.out.println("Decrypted bytes as hex: " + bd.getEncoded("hex"));
    }
}