如何使用自签名证书连接到Android（Paho客户端）中的Mqtt服务器？

Question

我在使用自签名证书连接到mqtt服务器时遇到问题。即时通讯使用Paho客户端，并想使用连接到html" target="_blank">服务器TLSv1.2。实际上，我成功连接了Android
API 20+，但此版本以下没有成功。

香港专业教育学院到目前为止做了什么：

1-创建了PKCS＃12密钥库，并将.crt文件放入密码并为其添加密码并将其保存（它将是.pfx文件）

2-将.pfx文件添加到android项目中资源的原始文件夹中

3-使用以下代码加载自签名证书：

connection = createConnection(mqttCallback);

MqttConnectOptions connOpts = optionsFromModel(connectionModel);

connOpts.setSocketFactory(getSSLSocketFactory(keyStoreInputStream, keyStorePassword));

connection.addConnectionOptions(connOpts);

而getSSLSocketFactory这是最重要的部分方法是：

    public SSLSocketFactory getSSLSocketFactory (InputStream keyStore, String password) throws MqttSecurityException {
    try{

        SSLContext ctx = null;
        SSLSocketFactory sslSockFactory=null;

        KeyStore ks;
        ks = KeyStore.getInstance("PKCS12");
        ks.load(keyStore, password.toCharArray());

        TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");
        tmf.init(ks);
        TrustManager[] tm = tmf.getTrustManagers();
        ctx = SSLContext.getInstance("TLS");
        ctx.init(null, tm, null);
        sslSockFactory = ctx.getSocketFactory();
        return sslSockFactory;

    } catch (KeyStoreException | CertificateException | IOException | NoSuchAlgorithmException | KeyManagementException e) {
        throw new MqttSecurityException(e);
    }
}

这可以完美运行，但在20以下的Android API中无法成功。

Answer 1

终于找到了解决办法。

根据此文档，Android API级别16（Android 4.1，Jelly
Bean）支持TLS 1.1和TLS 1.2。 但默认情况下， 直到API级别20+才 启用 （手表使用Android 4.4，Kitkat
Watch和手机5.0，Lollipop Android 5.0）。

因此，我们需要的是在代码中以图形方式启用它们。我们该怎么做？这里有解决此问题的方法，但是它只是解决了您要接受任何证书的情况下的问题。

我们需要做的是做同样的事情，但要使用我们自己的自签名证书。所以我们像下面这样
第一部分就像我之前所做的那样：（keyStoreInputStream是.pfx文件的输入流）

connection = createConnection(mqttCallback);

MqttConnectOptions connOpts = optionsFromModel(connectionModel);

connOpts.setSocketFactory(getSSLSocketFactory(keyStoreInputStream, keyStorePassword));

connection.addConnectionOptions(connOpts);

的getSSLSocketFactory方法改变为：

 public SSLSocketFactory getSSLSocketFactory (InputStream keyStore, String password) throws MqttSecurityException {
    try{

        SSLContext ctx = null;
        SSLSocketFactory sslSockFactory=null;

        KeyStore ks;
        ks = KeyStore.getInstance("PKCS12");
        ks.load(keyStore, password.toCharArray());

        TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");
        tmf.init(ks);
        TrustManager[] tm = tmf.getTrustManagers();
        ctx = SSLContext.getInstance("TLS");
        ctx.init(null, tm, null);

        if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
            sslSockFactory = new TLSSocketFactory(tm);
        } else {
            sslSockFactory = ctx.getSocketFactory();
        }
        return sslSockFactory;

    } catch (KeyStoreException | CertificateException | IOException | NoSuchAlgorithmException | KeyManagementException e) {
        throw new MqttSecurityException(e);
    }
}

与TLSSocketFactory类象下面这样：

import java.io.IOException;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;
import javax.net.ssl.TrustManager;


public class TLSSocketFactory extends SSLSocketFactory {

private SSLSocketFactory internalSSLSocketFactory;

public TLSSocketFactory(TrustManager[] trustManagers) throws KeyManagementException, NoSuchAlgorithmException {
    SSLContext context = SSLContext.getInstance("TLS");
    context.init(null, trustManagers, null);
    internalSSLSocketFactory = context.getSocketFactory();
}

@Override
public String[] getDefaultCipherSuites() {
    return internalSSLSocketFactory.getDefaultCipherSuites();
}

@Override
public String[] getSupportedCipherSuites() {
    return internalSSLSocketFactory.getSupportedCipherSuites();
}

@Override
public Socket createSocket() throws IOException {
    return enableTLSOnSocket(internalSSLSocketFactory.createSocket());
}

@Override
public Socket createSocket(Socket s, String host, int port, boolean autoClose) throws IOException {
    return enableTLSOnSocket(internalSSLSocketFactory.createSocket(s, host, port, autoClose));
}

@Override
public Socket createSocket(String host, int port) throws IOException, UnknownHostException {
    return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port));
}

@Override
public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException, UnknownHostException {
    return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port, localHost, localPort));
}

@Override
public Socket createSocket(InetAddress host, int port) throws IOException {
    return enableTLSOnSocket(internalSSLSocketFactory.createSocket(host, port));
}

@Override
public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException {
    return enableTLSOnSocket(internalSSLSocketFactory.createSocket(address, port, localAddress, localPort));
}

private Socket enableTLSOnSocket(Socket socket) {
    if(socket != null && (socket instanceof SSLSocket)) {
        ((SSLSocket)socket).setEnabledProtocols(new String[] {"TLSv1.2", "TLSv1.1"});
    }
    return socket;
}
}