package io.emqx.mqtt;

import org.bouncycastle.jce.provider.BouncyCastleProvider;
import org.bouncycastle.openssl.PEMKeyPair;
import org.bouncycastle.openssl.PEMParser;
import org.bouncycastle.openssl.jcajce.JcaPEMKeyConverter;

import java.io.BufferedInputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.security.KeyPair;
import java.security.KeyStore;
import java.security.Security;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManagerFactory;

public class SSLUtils {

    public static SSLSocketFactory getSingleSocketFactory(InputStream caCrtFileInputStream) throws Exception {
        Security.addProvider(new BouncyCastleProvider());
        X509Certificate caCert = null;

        BufferedInputStream bis = new BufferedInputStream(caCrtFileInputStream);
        CertificateFactory cf = CertificateFactory.getInstance("X.509");

        while (bis.available() > 0) {
            caCert = (X509Certificate) cf.generateCertificate(bis);
        }
        KeyStore caKs = KeyStore.getInstance(KeyStore.getDefaultType());
        caKs.load(null, null);
        caKs.setCertificateEntry("cert-certificate", caCert);
        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init(caKs);
        SSLContext sslContext = SSLContext.getInstance("TLSv1.2");
        sslContext.init(null, tmf.getTrustManagers(), null);
        return sslContext.getSocketFactory();
    }


    public static SSLSocketFactory getSocketFactory(InputStream caCrtFile, InputStream crtFile, InputStream keyFile,
                                                    String password) throws Exception {
        Security.addProvider(new BouncyCastleProvider());

        // load CA certificate
        X509Certificate caCert = null;

        BufferedInputStream bis = new BufferedInputStream(caCrtFile);
        CertificateFactory cf = CertificateFactory.getInstance("X.509");

        while (bis.available() > 0) {
            caCert = (X509Certificate) cf.generateCertificate(bis);
        }

        // load client certificate
        bis = new BufferedInputStream(crtFile);
        X509Certificate cert = null;
        while (bis.available() > 0) {
            cert = (X509Certificate) cf.generateCertificate(bis);
        }

        // load client private cert
        PEMParser pemParser = new PEMParser(new InputStreamReader(keyFile));
        Object object = pemParser.readObject();
        JcaPEMKeyConverter converter = new JcaPEMKeyConverter().setProvider("BC");
        KeyPair key = converter.getKeyPair((PEMKeyPair) object);

        KeyStore caKs = KeyStore.getInstance(KeyStore.getDefaultType());
        caKs.load(null, null);
        caKs.setCertificateEntry("cert-certificate", caCert);
        TrustManagerFactory tmf = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
        tmf.init(caKs);

        KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());
        ks.load(null, null);
        ks.setCertificateEntry("certificate", cert);
        ks.setKeyEntry("private-cert", key.getPrivate(), password.toCharArray(),
                new java.security.cert.Certificate[]{cert});
        KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
        kmf.init(ks, password.toCharArray());

        SSLContext context = SSLContext.getInstance("TLSv1.2");
        context.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);

        return context.getSocketFactory();
    }
}
