SAMLResponse使对象未初始化以进行签名或验证

Question

我获得了生成SAML的证书。这是我到目前为止所做的，但我在org.apache.xml.security.signature.XMLSignatureException: object not initialized for signature or verification时收到Signer.signObject(singature)错误 如果我注释掉这一行并尝试获得SAMLResponse但是没有SignatureValue和DigestValue。但我当然需要它们 有任何想法吗？

（另外我只有证书中的publicKey（），因为这不是由我生成的。如果这首先是正确的，请告诉我。我没有在SO中找到任何相关的回答问题所以张贴在这里。）

        doSmthMethod() { 
     signature = getSignature(); // See below
     assertion.setSignature(signature);

    try 
    {

    Configuration.getMarshallerFactory().getMarshaller(assertion).marshall(assertion);
    Signer.signObject(signature);  //**Errors out Here**
    } catch (MarshallingException e) {
        logger.log(Level.SEVERE,"Marshalling Exception:" + e);          
    } catch (SignatureException e) {
        logger.log(Level.SEVERE,"Signature Exception:"+e);  

    }
    }
    ...
    ...
    ...
    ...
    ...

    public static Signature getSignature() {

    Credential signingCredential = getCredential(); // See below

    Signature signature = null;
    try {
        DefaultBootstrap.bootstrap();
    } catch (ConfigurationException e) {
        e.printStackTrace();
    }       

    signature = (Signature) Configuration.getBuilderFactory()
            .getBuilder(Signature.DEFAULT_ELEMENT_NAME)
            .buildObject(Signature.DEFAULT_ELEMENT_NAME);
    signature.setSignatureAlgorithm(SignatureConstants.ALGO_ID_SIGNATURE_RSA_SHA1);
    signature.setSigningCredential(signingCredential);

    SecurityConfiguration secConfig = Configuration.getGlobalSecurityConfiguration();   
    //Added below for Keyinfo
            KeyInfo keyInfo = null;/*   (KeyInfo)Configuration.getBuilderFactory()
            .getBuilder(Signature.DEFAULT_ELEMENT_NAME)
            .buildObject(Signature.DEFAULT_ELEMENT_NAME);*/
            NamedKeyInfoGeneratorManager namedKeyInfoGeneratorManager = secConfig.getKeyInfoGeneratorManager(); 
            KeyInfoGeneratorManager keyInfoGeneratorManager = namedKeyInfoGeneratorManager.getDefaultManager(); 
            KeyInfoGeneratorFactory keyInfoGeneratorFactory = keyInfoGeneratorManager.getFactory(signingCredential); 
            KeyInfoGenerator keyInfoGenerator = keyInfoGeneratorFactory.newInstance(); 
            try{
            try {
                keyInfo = keyInfoGenerator.generate(signingCredential);
            } catch (org.opensaml.xml.security.SecurityException e) {
                logger.log(Level.SEVERE,"Exception while creating keyInfo:: "+ e);
            }
            }catch (SecurityException e) {
            logger.log(Level.SEVERE,"Exception occured: "+e);
            } 
            signature.setKeyInfo(keyInfo);
    try {
        logger.log(Level.INFO,"Prepating signature params...");
        System.out.println("In getSignature.....before preparingSignatureParams");
        SecurityHelper.prepareSignatureParams(signature, signingCredential, secConfig, null);
        System.out.println(" After preparing params");
    } catch (SecurityException e) {
        logger.log(Level.SEVERE,"Failed to prepareSignature:: "+ e);
        System.out.println(" *******Got securirytExcption");
        e.printStackTrace();
    } catch (org.opensaml.xml.security.SecurityException e) {
        logger.log(Level.SEVERE,"Failed to prepareSignature:: "+ e);
        System.out.println(" *******Got openSaml securirytExcption");
        e.printStackTrace();
    }
    catch(Exception e)
    {
        System.out.println(" *******Got Exception in SelfSignassertion");
        e.printStackTrace();
    }
    return signature;
}

private static Credential getCredential()
{

        InputStream inStream = new FileInputStream("C:\\samplecert.cer");
        CertificateFactory cf = CertificateFactory.getInstance("X.509");

        X509Certificate cert=    (X509Certificate)cf.generateCertificate(inStream);
        BasicX509Credential credential = new BasicX509Credential();

        credential.setEntityCertificate(cert);
        credential.setPublicKey(cert.getPublicKey());
        return credential;
}