MQTT Paho Android 支持SSL/TLS(亲测有效)

登录时支持ssl的交互

这是调测登录界面设计

代码中对ssl/tls的支持

使用MqttAndroidClient配置mqtt客户端请求时，不加密及加密方式连接存在以下几点差异：

url及端口差异

 val uri: String = if (tlsConnection) {"ssl://$host:$port"} else {"tcp://$host:$port"}

支持tls时，url前缀是ssl:
普通mqtt连接时候，前缀是tcp

端口差异：
tcp请求时，默认端口1883
ssl请求时，默认端口是8883

socketFactory配置项

笔者项目中只支持单向验证，即客户端验证服务端，所以需要在客户端加载服务端证书用于ssl连接

 if(connection.isSSL == 1){//单项验证，客户端验证服务端，onenet提供的.pem证书，需要用keytool转成java支持的bks、或者jks等connOpts.socketFactory = connection.client.getSSLSocketFactory(context.assets.open("MQTTS-certificate.bks"), "12345678")connOpts.isHttpsHostnameVerificationEnabled = falseconnOpts.setSSLHostnameVerifier { _, _ -> true  }}

说明：

java中不支持pem证书加载，所以需要使用keytool工具将pem格式证书转成java/android支持的bks或者jks等

 keytool -importcert -v -trustcacerts -file ./MQTTS-certificate.pem -alias ca -keystore ./mqtt.bks -storetype BKS -provider org.bouncycastle.jce.provider.BouncyCastleProvider -providerpath ./bcprov-ext-jdk18on-176.jar

bcprov-ext-jdk18on-176.jar需要从以下地址下载
https://www.bouncycastle.org/latest_releases.html

证书中会涉及域名验证，如果证书中缺少这个字段，那么运行时候会报下面错误
MqttException (0) - javax.net.ssl.SSLHandshakeException: No subjectAltNames on the certificate match
解决办法是跳过域名及host验证的流程

connOpts.isHttpsHostnameVerificationEnabled = false
connOpts.setSSLHostnameVerifier { _, _ -> true  }

client.getSSLSocketFactory实现

下面我们看看MqttAndroidClient创建sslSocketFactory的具体实现代码。

//info.mqtt.android.service.MqttAndroidClient/*** Get the SSLSocketFactory using SSL key store and password* A convenience method, which will help user to create a SSLSocketFactory* object** @param keyStore the SSL key store which is generated by some SSL key tool,* such as keytool in Java JDK* @param password the password of the key store which is set when the key store* is generated* @return SSLSocketFactory used to connect to the server with SSL* authentication* @throws MqttSecurityException if there was any error when getting the SSLSocketFactory*/@Throws(MqttSecurityException::class)fun getSSLSocketFactory(keyStore: InputStream?, password: String): SSLSocketFactory {return try {val sslSockFactory: SSLSocketFactoryval ts: KeyStore = KeyStore.getInstance("BKS")ts.load(keyStore, password.toCharArray())val tmf = TrustManagerFactory.getInstance("X509")tmf.init(ts)val tm = tmf.trustManagersval ctx: SSLContext = SSLContext.getInstance("TLSv1")ctx.init(null, tm, null)sslSockFactory = ctx.socketFactorysslSockFactory} catch (e: KeyStoreException) {throw MqttSecurityException(e)} catch (e: CertificateException) {throw MqttSecurityException(e)} catch (e: IOException) {throw MqttSecurityException(e)} catch (e: NoSuchAlgorithmException) {throw MqttSecurityException(e)} catch (e: KeyManagementException) {throw MqttSecurityException(e)}}