如何在 Java 中更改客户端 TLS 首选项？

我正在尝试向 Java 中的端点发出 POST 请求，当我尝试发送请求时，出现以下错误：

Caused by: javax.net.ssl.SSLHandshakeException: The server selected protocol version TLS10 is not accepted by client preferences [TLS13, TLS12]

这就是我到目前为止所拥有的

Map<Object, Object> data = new HashMap<>();
data.put("username","foo");
data.put("password","bar");

String url = "https://google.com";

HttpRequest request = HttpRequest.newBuilder()
     .POST(buildFormDataFromMap(data))
     .uri(URI.create(url))
     .build();

try{
     HttpResponse<String> response =  httpClient.send(request, 
          HttpResponse.BodyHandlers.ofString());
     System.out.println(response.statusCode());
     System.out.println(response.body());
} catch (Exception e){
     e.printStackTrace();
}

然后，当我运行代码时，发送请求/创建响应对象时会抛出错误。我的问题是，如果服务器的 TLS 首选项与客户端不同，我如何更改 Java 中的首选项，以便它仍然可以发出请求？

为了在 jdk 11 中解决这个问题，我必须创建一个 javax.net.ssl.SSLParameters 对象来启用“TLSv1”等：

SSLParameters sslParameters = new SSLParameters();
        sslParameters.setProtocols(new String[]{"TLSv1", "TLSv1.1", "TLSv1.2", "TLSv1.3"});

然后创建 HttpClient 并添加 sslParamters 对象：

HttpClient httpClient = HttpClient.newBuilder()
            .sslParameters(sslParameters)
            .build();

如果您还想禁用主机名验证，请在 HttpClient 初始化之前添加以下代码；

final Properties props = System.getProperties(); 
props.setProperty("jdk.internal.httpclient.disableHostnameVerification", Boolean.TRUE.toString());

您还可以添加新的 TrustManager 来信任所有证书（自签名）。 为此，请将以下代码添加到您的类中：

    TrustManager[] trustAllCerts = new TrustManager[] { 
        new X509TrustManager() {     
            public java.security.cert.X509Certificate[] getAcceptedIssuers() { 
                return new X509Certificate[0];
            } 
            public void checkClientTrusted( 
                java.security.cert.X509Certificate[] certs, String authType) {
                } 
            public void checkServerTrusted( 
                java.security.cert.X509Certificate[] certs, String authType) {
            }
        } 
    }; 

之后，您必须创建一个 SSLContext 对象并添加 TrustManger 对象：

SSLContext sslContext = SSLContext.getInstance("TLS");
        sslContext.init(null, trustAllCerts, new java.security.SecureRandom());

最后像这样改变 HttpClient 初始化：

httpClient = HttpClient.newBuilder()
            .sslContext(sslContext)
            .sslParameters(sslParameters)
            .build()

这是一个完整的类示例：

import java.net.http.HttpClient;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.X509Certificate;
import java.util.Properties;

import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLParameters;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;

public class HttpSSLClient {

    private SSLContext sslContext;
    private SSLParameters sslParameters;
    private HttpClient httpClient;

    public HttpSSLClient() throws KeyManagementException, NoSuchAlgorithmException {

        sslParameters = new SSLParameters();
        sslParameters.setProtocols(new String[]{"TLSv1", "TLSv1.1", "TLSv1.2", "TLSv1.3"});

        sslContext = SSLContext.getInstance("TLS");
        sslContext.init(null, trustAllCerts, new java.security.SecureRandom());

        final Properties props = System.getProperties(); 
        props.setProperty("jdk.internal.httpclient.disableHostnameVerification", Boolean.TRUE.toString());

        httpClient = HttpClient.newBuilder()
                .sslContext(sslContext)
                .sslParameters(sslParameters)
                .build();
    }

    public HttpClient getHttplClient() {
        return httpClient;
    }

    TrustManager[] trustAllCerts = new TrustManager[] { 
            new X509TrustManager() {     
                public java.security.cert.X509Certificate[] getAcceptedIssuers() { 
                    return new X509Certificate[0];
                } 
                public void checkClientTrusted( 
                    java.security.cert.X509Certificate[] certs, String authType) {
                    } 
                public void checkServerTrusted( 
                    java.security.cert.X509Certificate[] certs, String authType) {
                }
            } 
        }; 
}

您可以在调用 HttpRequest 时使用 getHttplClient() 函数。