OkHttpClient忽略https证书, PKIX path building failed：unable to find valid certification path to requeste

1.背景

近些年okhttpclient在后端开发中大放光彩，其高效、简介、逻辑清晰的特性吸引了大批后端开发人员，当满足的场景增多，问题也就随之而来，okhttpclient如何通过https认证就是一个常见的问题。

2.问题描述

接口url中使用https开头，使用okhttpclient发送请求，会报错，常见错误：

security.validator.ValidatorException: PKIX path building failed：unable to find valid certification path to requested target

3.解决方法： 

    （1）使用证书。我方是客户端，一般要去获取要访问的服务器的证书，并导入到我方客户端的jre_home的环境中即可生效。

a.浏览器保存，类似文件下载，直接另存到指定的位置即可，如下：

 

b.java代码生成证书,运行下面的代码：

import java.io.BufferedReader;  
import java.io.File;  
import java.io.FileInputStream;  
import java.io.FileOutputStream;  
import java.io.InputStream;  
import java.io.InputStreamReader;  
import java.io.OutputStream;  
import java.security.KeyStore;  
import java.security.MessageDigest;  
import java.security.cert.CertificateException;  
import java.security.cert.X509Certificate;  
  
import javax.net.ssl.SSLContext;  
import javax.net.ssl.SSLException;  
import javax.net.ssl.SSLSocket;  
import javax.net.ssl.SSLSocketFactory;  
import javax.net.ssl.TrustManager;  
import javax.net.ssl.TrustManagerFactory;  
import javax.net.ssl.X509TrustManager;  
  
public class InstallCert {  
  
    public static void main(String[] args) throws Exception {  
        String host;  
        int port;  
        char[] passphrase;  
        if ((args.length == 1) || (args.length == 2)) {  
            String[] c = args[0].split(":");  
            host = c[0];  
            port = (c.length == 1) ? 443 : Integer.parseInt(c[1]);  
            String p = (args.length == 1) ? "changeit" : args[1];  
            passphrase = p.toCharArray();  
        } else {  
            System.out  
                    .println("Usage: java InstallCert [:port] [passphrase]");  
            return;  
        }  
  
        File file = new File("jssecacerts");  
        if (file.isFile() == false) {  
            char SEP = File.separatorChar;  
            File dir = new File(System.getProperty("java.home") + SEP + "lib"  
                    + SEP + "security");  
            file = new File(dir, "jssecacerts");  
            if (file.isFile() == false) {  
                file = new File(dir, "cacerts");  
            }  
        }  
        System.out.println("Loading KeyStore " + file + "...");  
        InputStream in = new FileInputStream(file);  
        KeyStore ks = KeyStore.getInstance(KeyStore.getDefaultType());  
        ks.load(in, passphrase);  
        in.close();  
  
        SSLContext context = SSLContext.getInstance("TLS");  
        TrustManagerFactory tmf = TrustManagerFactory  
                .getInstance(TrustManagerFactory.getDefaultAlgorithm());  
        tmf.init(ks);  
        X509TrustManager defaultTrustManager = (X509TrustManager) tmf  
                .getTrustManagers()[0];  
        SavingTrustManager tm = new SavingTrustManager(defaultTrustManager);  
        context.init(null, new TrustManager[] { tm }, null);  
        SSLSocketFactory factory = context.getSocketFactory();  
  
        System.out  
                .println("Opening connection to " + host + ":" + port + "...");  
        SSLSocket socket = (SSLSocket) factory.createSocket(host, port);  
        socket.setSoTimeout(10000);  
        try {  
            System.out.println("Starting SSL handshake...");  
            socket.startHandshake();  
            socket.close();  
            System.out.println();  
            System.out.println("No errors, certificate is already trusted");  
        } catch (SSLException e) {  
            System.out.println();  
            e.printStackTrace(System.out);  
        }  
  
        X509Certificate[] chain = tm.chain;  
        if (chain == null) {  
            System.out.println("Could not obtain server certificate chain");  
            return;  
        }  
  
        BufferedReader reader = new BufferedReader(new InputStreamReader(  
                System.in));  
  
        System.out.println();  
        System.out.println("Server sent " + chain.length + " certificate(s):");  
        System.out.println();  
        MessageDigest sha1 = MessageDigest.getInstance("SHA1");  
        MessageDigest md5 = MessageDigest.getInstance("MD5");  
        for (int i = 0; i < chain.length; i++) {  
            X509Certificate cert = chain[i];  
            System.out.println(" " + (i + 1) + " Subject "  
                    + cert.getSubjectDN());  
            System.out.println("   Issuer  " + cert.getIssuerDN());  
            sha1.update(cert.getEncoded());  
            System.out.println("   sha1    " + toHexString(sha1.digest()));  
            md5.update(cert.getEncoded());  
            System.out.println("   md5     " + toHexString(md5.digest()));  
            System.out.println();  
        }  
  
        System.out  
                .println("Enter certificate to add to trusted keystore or 'q' to quit: [1]");  
        String line = reader.readLine().trim();  
        int k;  
        try {  
            k = (line.length() == 0) ? 0 : Integer.parseInt(line) - 1;  
        } catch (NumberFormatException e) {  
            System.out.println("KeyStore not changed");  
            return;  
        }  
  
        X509Certificate cert = chain[k];  
        String alias = host + "-" + (k + 1);  
        ks.setCertificateEntry(alias, cert);  
  
        OutputStream out = new FileOutputStream("jssecacerts");  
        ks.store(out, passphrase);  
        out.close();  
  
        System.out.println();  
        System.out.println(cert);  
        System.out.println();  
        System.out  
                .println("Added certificate to keystore 'jssecacerts' using alias '"  
                        + alias + "'");  
    }  
  
    private static final char[] HEXDIGITS = "0123456789abcdef".toCharArray();  
  
    private static String toHexString(byte[] bytes) {  
        StringBuilder sb = new StringBuilder(bytes.length * 3);  
        for (int b : bytes) {  
            b &= 0xff;  
            sb.append(HEXDIGITS[b >> 4]);  
            sb.append(HEXDIGITS[b & 15]);  
            sb.append(' ');  
        }  
        return sb.toString();  
    }  
  
    private static class SavingTrustManager implements X509TrustManager {  
  
        private final X509TrustManager tm;  
        private X509Certificate[] chain;  
  
        SavingTrustManager(X509TrustManager tm) {  
            this.tm = tm;  
        }  
  
        public X509Certificate[] getAcceptedIssuers() {  
            throw new UnsupportedOperationException();  
        }  
  
        public void checkClientTrusted(X509Certificate[] chain, String authType)  
                throws CertificateException {  
            throw new UnsupportedOperationException();  
        }  
  
        public void checkServerTrusted(X509Certificate[] chain, String authType)  
                throws CertificateException {  
            this.chain = chain;  
            tm.checkServerTrusted(chain, authType);  
        }  
    }  
  
}  
 

输入1，回车，然后会在当前的目录下产生一个名为“ssecacerts”的证书。

将证书拷贝到$JAVA_HOME/jre/lib/security目录下，或者通过以下方式：
a.System.setProperty("javax.net.ssl.trustStore", "你的jssecacerts证书路径");

b.shell窗口执行 sudo keytool -import -alias myfile.cer -keystore "/Library/Java/JavaVirtualMachines/jdk1.8.0_171.jdk/Contents/Home/jre/lib/security/cacerts" -file myfile.cer -trustcacerts

注意：因为是静态加载，所以要重新启动你的Web Server，证书才能生效

（2）获取服务器端的证书后，也可以不导入java的环境配置中，直接用代码读取证书，再配置到ssl工厂中，最后初始化到okhttpclient中发送请求即可，代码如下：

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.security.KeyStore;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.util.concurrent.TimeUnit;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManagerFactory;

import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

import org.apache.commons.lang.StringUtils;

import com.alibaba.fastjson.util.IOUtils;

public class OkHttpTool {

    public static final MediaType JSON_TYPE = MediaType.parse("application/json; charset=utf-8");
    public static final String AUTH_FILE_URL = "AUTH_FILE_URL";//配置的地址
    
    public static String post(String url, String json, String token) {
        String result = "";
        InputStream caInput =null;
        Response response =null;
        try {
            CertificateFactory cf = CertificateFactory.getInstance("X.509");
            caInput = new BufferedInputStream(new FileInputStream(AUTH_FILE_URL));
            Certificate ca = cf.generateCertificate(caInput);
            String keyStoreType = KeyStore.getDefaultType();
            KeyStore keyStore = KeyStore.getInstance(keyStoreType);
            keyStore.load(null, null);
            keyStore.setCertificateEntry("ca", ca);
            String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
            TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
            tmf.init(keyStore);
            SSLContext context = SSLContext.getInstance("TLS");
            context.init(null, tmf.getTrustManagers(), null);

            RequestBody body = RequestBody.create(JSON_TYPE, json);
            Request request = new Request.Builder().url(url).post(body)
                    .addHeader("clientId", "204")
                    .addHeader("Client-Type", "android")
                    .addHeader("Client-Version", "2.2.6")
                    .addHeader("plain-text-transfer", "true")
                    .addHeader("token", StringUtils.isBlank(token) ? "" : token).build();
            
            OkHttpClient client = new OkHttpClient.Builder()
            .sslSocketFactory(context.getSocketFactory())
            .connectTimeout(15, TimeUnit.SECONDS)
            .readTimeout(30, TimeUnit.SECONDS)
            .hostnameVerifier(new TrustAnyHostnameVerifier())
            .build();
            
            response = client.newCall(request).execute();
            if (response.isSuccessful()) {
                result = response.body().string();
            } else {
                throw new IOException("Unexpected code " + response);
            }
            caInput.close();
            response.close();
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            if(caInput!=null){
                IOUtils.close(caInput);
            }
            if(response!=null){
                IOUtils.close(response);
            }
        }
        return result;
    }
    
     private static class TrustAnyHostnameVerifier implements HostnameVerifier {
            public boolean verify(String hostname, SSLSession session) {
                return true;
            }
        }
}

    （3）代码中默认全部信任，也就是常说的忽略https认证，说白了就是自己构建一个x509认证，默认通过，再传到ssl配置工厂中，再用okhttpclient发送就不会报错了，代码如下：

import java.util.concurrent.TimeUnit;

import javax.net.ssl.HostnameVerifier;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSession;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

import okhttp3.OkHttpClient;

/*
*@Description: Okhttp工具类
*@Author: marx
*@Time: 2020年3月5日15:32:50
*/
public class OkHttpClientTool {
    /**
     * 获取OkHttpClient
     *
     * @return OkHttpClient
     */
    public static OkHttpClient getUnsafeOkHttpClient() {
        try {
            final TrustManager[] trustAllCerts = new TrustManager[]{
                    new X509TrustManager() {
                        @Override
                        public void checkClientTrusted(java.security.cert.X509Certificate[] chain, String authType) {
                        }

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

                        @Override
                        public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                            return new java.security.cert.X509Certificate[]{};
                        }
                    }
            };

            final SSLContext sslContext = SSLContext.getInstance("SSL");
            sslContext.init(null, trustAllCerts, new java.security.SecureRandom());
            final javax.net.ssl.SSLSocketFactory sslSocketFactory = sslContext.getSocketFactory();
            OkHttpClient.Builder builder = new OkHttpClient.Builder();
            // 过时方法，单构造参数方法过时，多传一个X509TrustManager就可以了
            //builder.sslSocketFactory(sslSocketFactory);
            builder.sslSocketFactory(sslSocketFactory, (X509TrustManager) trustAllCerts[0]);

            builder.hostnameVerifier(new HostnameVerifier() {
                @Override
                public boolean verify(String hostname, SSLSession session) {
                    return true;
                }
            });
            builder.connectTimeout(30, TimeUnit.SECONDS);
            return builder.build();
        } catch (Exception e) {
            throw new RuntimeException(e);
        }
    }
}