Android 4.4 以下，OkHttp访问Https报错，设置了sslSocketFactory仍无效的解决方法

背景

Android 4.4 及以下，使用 OkHttp 发送 Https 请求，报以下错误：

    javax.net.ssl.SSLHandshakeException: javax.net.ssl.SSLProtocolException: SSL handshake aborted: ssl=0x6b712c90: Failure in SSL library, usually a protocol error
    error:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure (external/openssl/ssl/s23_clnt.c:741 0x68111cd4:0x00000000)
        at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:448)
        at okhttp3.internal.connection.RealConnection.connectTls(RealConnection.java:302)
        at okhttp3.internal.connection.RealConnection.establishProtocol(RealConnection.java:270)
        at okhttp3.internal.connection.RealConnection.connect(RealConnection.java:162)
        at okhttp3.internal.connection.StreamAllocation.findConnection(StreamAllocation.java:257)
        at okhttp3.internal.connection.StreamAllocation.findHealthyConnection(StreamAllocation.java:135)
        at okhttp3.internal.connection.StreamAllocation.newStream(StreamAllocation.java:114)
        at okhttp3.internal.connection.ConnectInterceptor.intercept(ConnectInterceptor.java:42)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
        at okhttp3.internal.cache.CacheInterceptor.intercept(CacheInterceptor.java:93)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
        at okhttp3.internal.http.BridgeInterceptor.intercept(BridgeInterceptor.java:93)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
        at okhttp3.internal.http.RetryAndFollowUpInterceptor.intercept(RetryAndFollowUpInterceptor.java:126)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:147)
        at okhttp3.internal.http.RealInterceptorChain.proceed(RealInterceptorChain.java:121)
        at okhttp3.RealCall.getResponseWithInterceptorChain(RealCall.java:200)
        at okhttp3.RealCall$AsyncCall.execute(RealCall.java:147)
        at okhttp3.internal.NamedRunnable.run(NamedRunnable.java:32)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
        at java.lang.Thread.run(Thread.java:841)
     Caused by: javax.net.ssl.SSLProtocolException: SSL handshake aborted: ssl=0x6b712c90: Failure in SSL library, usually a protocol error
    error:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure (external/openssl/ssl/s23_clnt.c:741 0x68111cd4:0x00000000)
        at com.android.org.conscrypt.NativeCrypto.SSL_do_handshake(Native Method)
        at com.android.org.conscrypt.OpenSSLSocketImpl.startHandshake(OpenSSLSocketImpl.java:405)
        	... 23 more

一、确保OkHttp的Https配置正确

首先配制好 sslSocketFactory 和 hostnameVerifier：

import android.annotation.SuppressLint
import java.net.InetAddress
import java.net.Socket
import java.security.cert.CertificateException
import java.security.cert.X509Certificate
import javax.net.ssl.SSLContext
import javax.net.ssl.SSLSocket
import javax.net.ssl.SSLSocketFactory
import javax.net.ssl.TrustManager
import javax.net.ssl.X509TrustManager

class MySSLSocketFactory(tm: TrustManager = TrustAllTrustManager()) : SSLSocketFactory() {
    var internalSSLSocketFactory: SSLSocketFactory
    var context: SSLContext = SSLContext.getInstance("TLSv1.1")

    init {
        context.init(null, arrayOf(tm), null)
        internalSSLSocketFactory = context.socketFactory
    }


    override fun getDefaultCipherSuites(): Array<String> {
        return internalSSLSocketFactory.defaultCipherSuites
    }

    override fun createSocket(s: Socket?, host: String?, port: Int, autoClose: Boolean): Socket {
        val sslSocket = context.socketFactory?.createSocket(s, host, port, autoClose) as SSLSocket
        sslSocket.enabledProtocols = arrayOf("TLSv1.2", "TLSv1.1")
        return sslSocket
    }

    override fun getSupportedCipherSuites(): Array<String> {
        return internalSSLSocketFactory.supportedCipherSuites
    }

    override fun createSocket(host: String?, port: Int): Socket {
        val sslSocket = context.socketFactory?.createSocket(host, port) as SSLSocket
        sslSocket.enabledProtocols = arrayOf("TLSv1.2", "TLSv1.1")
        return sslSocket
    }

    override fun createSocket(host: String?, port: Int, localHost: InetAddress?, localPort: Int): Socket {
        val sslSocket = context.socketFactory?.createSocket(host, port, localHost, localPort) as SSLSocket
        sslSocket.enabledProtocols = arrayOf("TLSv1.2", "TLSv1.1")
        return sslSocket
    }

    override fun createSocket(host: InetAddress?, port: Int): Socket {
        val sslSocket = context.socketFactory?.createSocket(host, port) as SSLSocket
        sslSocket.enabledProtocols = arrayOf("TLSv1.2", "TLSv1.1")
        return sslSocket
    }

    override fun createSocket(address: InetAddress?, port: Int, localAddress: InetAddress?, localPort: Int): Socket {
        val sslSocket = context.socketFactory?.createSocket(address, port, localAddress, localPort) as SSLSocket
        sslSocket.enabledProtocols = arrayOf("TLSv1.2", "TLSv1.1")
        return sslSocket
    }

    @SuppressLint("CustomX509TrustManager", "TrustAllX509TrustManager")
    class TrustAllTrustManager : X509TrustManager {
        @Throws(CertificateException::class)
        override fun checkClientTrusted(chain: Array<X509Certificate>, authType: String) {
        }

        @Throws(CertificateException::class)
        override fun checkServerTrusted(chain: Array<X509Certificate>, authType: String) {
        }

        override fun getAcceptedIssuers(): Array<X509Certificate> {
            return arrayOf()
        }
    }
}

public class SSLSocketClient {
    //获取这个SSLSocketFactory
    public static SSLSocketFactory getSSLSocketFactory() {
        try {
            SSLContext sslContext = SSLContext.getInstance("SSL");
            sslContext.init(null, getTrustManager(), new SecureRandom());
            return sslContext.getSocketFactory();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }

    //获取TrustManager
    private static TrustManager[] getTrustManager() {
        return new TrustManager[]{new X509TrustManager() {
            @Override
            public void checkClientTrusted(X509Certificate[] chain, String authType) {
            }

            @Override
            public void checkServerTrusted(X509Certificate[] chain, String authType) {
            }

            @Override
            public X509Certificate[] getAcceptedIssuers() {
                return new X509Certificate[0];
            }
        }};
    }

    //获取HostnameVerifier
    public static HostnameVerifier getHostnameVerifier() {
        HostnameVerifier hostnameVerifier = new HostnameVerifier() {
            @Override
            public boolean verify(String s, SSLSession sslSession) {
                return true;
            }
        };
        return hostnameVerifier;
    }
}

在OkHttp中使用：

    val tm = TrustAllTrustManager()
    val client = OkHttpClient.Builder()
        .sslSocketFactory(
            MySSLSocketFactory(tm), tm
        )
        .hostnameVerifier(SSLSocketClient.getHostnameVerifier())
        .build()
    val request = Request.Builder().url(url).build()
    client.newCall(request).enqueue(object : Callback {
        override fun onFailure(call: Call, e: IOException) {
            Log.w(TAG, "onFailure: ", e)
            onResult(Log.getStackTraceString(e))
        }

        override fun onResponse(call: Call, response: Response) {
            val result = response.body()?.string()
            onResult(result)
        }
    })

二、仍然报错的解决方案

如果通过以上的配置，仍然报 Failure in SSL library, usually a protocol error 的错，可能的原因是 OkHttp 使用了本机不支持的 TLS 协议或者加密算法。
有以下解决方案：

方法1：降级OkHttp

将 OkHttp 降级到 3.9.0，即可正常请求。
根据 OkHttp 的官方文档：

The configuration of each spec changes with each OkHttp release. This is annoying: upgrading your OkHttp library can break connectivity to certain web servers! But it’s a necessary annoyance because the TLS ecosystem is dynamic and staying up to date is necessary to stay secure. See OkHttp’s TLS Configuration History to track these changes.
每个 OkHttp 发布版本的规范配置都会发生变化。这很令人困扰：升级 OkHttp 库可能会导致与某些 Web 服务器的连接中断！但这是一个必要的困扰，因为 TLS 生态系统是动态的，并且保持更新是保持安全性所必需的。请查看 OkHttp 的 TLS 配置历史记录以跟踪这些变化。

方法2：配置ConnectionSpec

在 OkHttpClient 创建的过程中，添加 ConnectionSpec 的配置，如下：

    // ConnectionSpec的配置
    val spec = ConnectionSpec.Builder(ConnectionSpec.COMPATIBLE_TLS)
        .tlsVersions(TlsVersion.TLS_1_2, TlsVersion.TLS_1_1, TlsVersion.TLS_1_0)
        .cipherSuites(
            CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
            CipherSuite.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
            CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
            CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
        )
        .build()

    val tm = TrustAllTrustManager()
    val client = OkHttpClient.Builder()
        // CLEARTEXT：允许明文传输；MODERN_TLS：支持绝大多数场景，OkHttp的默认配置
        .connectionSpecs(listOf(ConnectionSpec.CLEARTEXT, ConnectionSpec.MODERN_TLS, spec))
        .sslSocketFactory(
            MySSLSocketFactory(tm), tm
        )
        .hostnameVerifier(SSLSocketClient.getHostnameVerifier())
        .build()
    val request = Request.Builder().url(url).build()
    client.newCall(request).enqueue(object : Callback {
        override fun onFailure(call: Call, e: IOException) {
            Log.w(TAG, "onFailure: ", e)
            onResult(Log.getStackTraceString(e))
        }

        override fun onResponse(call: Call, response: Response) {
            val result = response.body()?.string()
            onResult(result)
        }
    })

注意，以上代码中的tlsVersions 和cipherSuites 分别配置了 OkHttp 使用的 TLS 协议版本和加密算法。使用以下代码可以获取本机支持的加密算法，并生成对应的 ConnectionSpec：

    /**
     * Android 4 使用的连接参数
     */
    private static ConnectionSpec compatibleConnectionSpec() {
        // 获取系统支持的加密算法
        SSLSocketFactory factory = (SSLSocketFactory) SSLSocketFactory.getDefault();
        String[] defaultCipherSuites = factory.getDefaultCipherSuites();
        Log.v(TAG, "compatibleConnectionSpec: defaultCipherSuites = " + Arrays.toString(defaultCipherSuites));
        ConnectionSpec.Builder builder = new ConnectionSpec.Builder(ConnectionSpec.COMPATIBLE_TLS)
                .tlsVersions(TlsVersion.TLS_1_2, TlsVersion.TLS_1_1, TlsVersion.TLS_1_0);
        if (defaultCipherSuites != null && defaultCipherSuites.length > 0) {
            builder.cipherSuites(defaultCipherSuites);
        } else {
            CipherSuite[] supportedCipherSuitesApi19 = new CipherSuite[]{
                    CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
                    CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
                    CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
                    CipherSuite.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
                    CipherSuite.TLS_RSA_WITH_AES_256_CBC_SHA,
                    CipherSuite.TLS_EMPTY_RENEGOTIATION_INFO_SCSV
            };
            builder.cipherSuites(supportedCipherSuitesApi19);
        }
        return builder.build();
    }

方法3：使用HttpsUrlConnection

使用HttpsUrlConnection 替代 OkHttp：

    private fun useHttpUrlConnection() {
        thread {
            try {
                val conn = URL(url).openConnection() as HttpsURLConnection
                conn.connectTimeout = 10000
                conn.readTimeout = 10000
                conn.requestMethod = "GET"
                conn.sslSocketFactory = MySSLSocketFactory()
                conn.connect()
                Log.i(TAG, "useHttpUrlConnection: ${conn.responseCode}")
                val text = conn.inputStream.bufferedReader().readText()
                runOnUiThread {
                    onResult(text)
                }
            } catch (e: Exception) {
                onResult(Log.getStackTraceString(e))
                return@thread
            }
        }
    }

转至：https://blog.csdn.net/zengsidou/article/details/136456509