Could not parse certificate: java.io.IOException: Empty input X509Certificate

Question

I am getting the error given below when parsing the signature. Anybody has idea why the error is showing?

Note that:

1. Using the same certificate I signed my own XML and verified which is working fine. That mean there is no issue with certificate.

2. Client provided signed document not able to validate.

Errors:

Exception in thread "main" javax.xml.crypto.MarshalException: Cannot create X509Certificate
at org.jcp.xml.dsig.internal.dom.DOMX509Data.unmarshalX509Certificate(DOMX509Data.java:225)
at org.jcp.xml.dsig.internal.dom.DOMX509Data.<init>(DOMX509Data.java:116)
at org.jcp.xml.dsig.internal.dom.DOMKeyInfo.<init>(DOMKeyInfo.java:116)
at org.jcp.xml.dsig.internal.dom.DOMXMLSignature.<init>(DOMXMLSignature.java:150)
at org.jcp.xml.dsig.internal.dom.DOMXMLSignatureFactory.unmarshal(DOMXMLSignatureFactory.java:173)
at org.jcp.xml.dsig.internal.dom.DOMXMLSignatureFactory.unmarshalXMLSignature(DOMXMLSignatureFactory.java:137)
at com.signing.ValidateSignedXML.main(ValidateSignedXML.java:126)
Caused by: java.security.cert.CertificateException: Could not parse certificate: java.io.IOException: Empty input
at sun.security.provider.X509Factory.engineGenerateCertificate(X509Factory.java:104)
at java.security.cert.CertificateFactory.generateCertificate(CertificateFactory.java:339)
at org.jcp.xml.dsig.internal.dom.DOMX509Data.unmarshalX509Certificate(DOMX509Data.java:223)
... 6 more
Caused by: java.io.IOException: Empty input
at sun.security.provider.X509Factory.engineGenerateCertificate(X509Factory.java:101)

Adding the code here for reference

package com.signing;

import java.io.FileInputStream;
import java.security.KeyStore;
import java.security.cert.X509Certificate;
import java.util.Iterator;

import javax.xml.crypto.dsig.Reference;
import javax.xml.crypto.dsig.XMLSignature;
import javax.xml.crypto.dsig.XMLSignatureFactory;
import javax.xml.crypto.dsig.dom.DOMValidateContext;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class ValidateSignedXML {

    /**
     * @param args
     * @throws Exception 
     */
/**
     * @param args
     * @throws Exception 
     */
    public static void main(String[] args) throws Exception {
        // TODO Auto-generated method stub

        // Load the KeyStore and get the signing key and certificate.
        KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
        ks.load(new FileInputStream("C:\\Program Files\\Java\\jre1.8.0_31\\bin\\newstore8.jks"), "changeit7".toCharArray());


        KeyStore.PrivateKeyEntry keyEntry =
            (KeyStore.PrivateKeyEntry) ks.getEntry
                ("newkey8", new KeyStore.PasswordProtection("changeit7".toCharArray()));
        X509Certificate cert = (X509Certificate) keyEntry.getCertificate();
        XMLSignatureFactory fac = XMLSignatureFactory.getInstance("DOM");


        //Load the signed document.
        DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
        dbf.setNamespaceAware(true);
        Document doc = dbf.newDocumentBuilder().parse
            (new FileInputStream("C:\\src\\com\\signing\\signed.xml"));


        // Find Signature element.
        NodeList nl =
            doc.getElementsByTagNameNS(XMLSignature.XMLNS, "Signature");
        if (nl.getLength() == 0) {
            throw new Exception("Cannot find Signature element");
        }else{
            /*System.out.println("---- Start of Print Tag ----\n");
            for(int k=0;k<nl.getLength();k++){
                 printTags((Node)nl.item(k));
             }
            System.out.println("---- End of Print Tag ----\n");*/
        }

        // Create a DOMValidateContext and specify a KeySelector
        // and document context.
        DOMValidateContext valContext = new DOMValidateContext
            (new X509KeySelector(), nl.item(0));

        // Unmarshal the XMLSignature.
        XMLSignature signatures = fac.unmarshalXMLSignature(valContext);

        // Validate the XMLSignature.
        boolean coreValidity = signatures.validate(valContext);

        System.out.println("Signature Validate :"+coreValidity);

        // Check core validation status.
        if (coreValidity == false) {
            String validateError;
            validateError = "Signature core validation status:false";
            boolean sv = signatures.getSignatureValue().validate(valContext);
            validateError = validateError + " | Signature validation status:" + sv;
            if (sv == false || true) {
                validateError = validateError + " | References: ";
                // Check the validation status of each Reference.
                Iterator g = signatures.getSignedInfo().getReferences().iterator();
                for (int j = 0; g.hasNext(); j++) {

                    Reference r = (Reference) g.next();
                    boolean refValid = r.validate(valContext);
                    validateError = validateError + "{ref[" + r.getURI() + "] validity status: " + refValid + "}";
                }
            }
            throw new Exception(validateError);
        } else {
            System.out.println("Signature passed core validation");
        }

    }

}

Answer 1

It's been a while since this post but I came here looking for this issue. In my case, the key was that the certificate was in a Base64-String.getBytes[] instead of a DECODED-Base64-String.getBytes[].

Hope it helps someone :)