Dlelegating X509TrustManager #X509TrustManager #JavaCryptoGraphy

DelegatingX509TrustManager.java

package com.example.composedtruststores;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.security.KeyManagementException;
import java.security.KeyStore;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.TrustManagerFactory;
import javax.net.ssl.X509TrustManager;

public class DelegatingX509TrustManager implements X509TrustManager {
    private final X509TrustManager[] x509TrustManagers;

    public DelegatingX509TrustManager(X509TrustManager... x509TrustManagers) {
        this.x509TrustManagers = x509TrustManagers;
    }

    @Override
    public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        for (X509TrustManager x509TrustManager : x509TrustManagers) {
            x509TrustManager.checkClientTrusted(chain, authType);
        }
    }

    @Override
    public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
        for (X509TrustManager x509TrustManager : x509TrustManagers) {
            x509TrustManager.checkServerTrusted(chain, authType);
        }

    }

    @Override
    public X509Certificate[] getAcceptedIssuers() {
        List<X509Certificate> x509CertificatesList = new LinkedList<>();
        for (X509TrustManager x509TrustManager : x509TrustManagers) {
            x509CertificatesList.addAll(Arrays.asList(x509TrustManager.getAcceptedIssuers()));
        }
        return x509CertificatesList.toArray(new X509Certificate[0]);
    }

    public SSLContext getSSLContext() throws NoSuchAlgorithmException, KeyManagementException {
        return getSSLContext("TLS");
    }

    public SSLContext getSSLContext(String protocol) throws NoSuchAlgorithmException, KeyManagementException {
        SSLContext sslContext = SSLContext.getInstance(protocol);
        sslContext.init(null, new TrustManager[] { this }, null);
        return sslContext;
    }

    public static X509TrustManager getTrustManager(String trustStore, String trustStorePassword)
            throws FileNotFoundException, KeyStoreException, IOException, NoSuchAlgorithmException,
            CertificateException {
        // Adapt to load your keystore
        try (FileInputStream myKeys = new FileInputStream(trustStore)) {
            KeyStore myTrustStore = KeyStore.getInstance("jks");
            myTrustStore.load(myKeys, trustStorePassword.toCharArray());
            return getTrustManagerFromKeyStore(myTrustStore);
        }
    }

    public static X509TrustManager getDefaultTrustManager(KeyStore keyStore)
        throws NoSuchAlgorithmException, KeyStoreException {
        return getTrustManagerFromKeyStore(null);
    }

    private static X509TrustManager getTrustManagerFromKeyStore(KeyStore keyStore)
        throws NoSuchAlgorithmException, KeyStoreException {
        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init(keyStore); // If keyStore is null, tmf will be initialized with the default trust store

        for (TrustManager tm : tmf.getTrustManagers()) {
            if (tm instanceof X509TrustManager) {
                return (X509TrustManager) tm;
            }
        }
        return null;
    }

}