javax.net.ssl.SSLException: Certificate doesn't match any of the subject alternative names

Question

I recently added LetsEncrypt certificates to my server and my java applet is having problems connecting using TLS.

My applet uses Apache HttpClient.

My web s

Answer 1

Following Yurri's comment, it solved my problem by adding NoopHostnameVerifier.INSTANCE while initialising SSLConnectionSocketFactory :

import org.apache.http.HttpHost;
import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustSelfSignedStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.TrustStrategy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.stereotype.Component;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.RestTemplate;

import java.net.Proxy;
import java.nio.charset.StandardCharsets;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;

import javax.net.ssl.SSLContext;

/**
 * Provide basic Utils for getting HttpHeader and making REST api calls.
 * 
 */
@Component
public class HttpUtil {

    private static final Logger LOG = LoggerFactory.getLogger(HttpUtil.class);

    /**
     * The default implementation to get basic headers.
     * @return HttpHeaders.
     */
    public HttpHeaders getHttpHeaders(String userAgent, String host) {
        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(MediaType.APPLICATION_JSON);
        headers.set(HttpHeaders.ACCEPT_CHARSET, StandardCharsets.UTF_8.name());
        headers.set(HttpHeaders.USER_AGENT, userAgent);
        LOG.info("host=" + host);
        if (null != host) {
            headers.set(HttpHeaders.HOST, host);
        }

        return headers;
    }

    /**
     * Default implementation to get RestTemplate
     * @return
     */
     public RestTemplate getRestTemplate(String proxyHost, int proxyPort)
        throws KeyStoreException, NoSuchAlgorithmException, KeyManagementException {

    TrustStrategy acceptingTrustStrategy = new TrustSelfSignedStrategy();

    SSLContext sslContext = org.apache.http.ssl.SSLContexts.custom().loadTrustMaterial(null, acceptingTrustStrategy)
            .build();

    SSLConnectionSocketFactory csf = new SSLConnectionSocketFactory(sslContext, NoopHostnameVerifier.INSTANCE);

    CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(csf).build();

    HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
    if (null != proxyHost && proxyPort > 0) {
        LOG.info("PROXY CONFIGURED | proxyHost=" + proxyHost + " | proxyPort=" + proxyPort);
        HttpHost proxy = new HttpHost(proxyHost, proxyPort, Proxy.Type.HTTP.name());
        httpClient = HttpClients.custom().setSSLSocketFactory(csf)
                .setRoutePlanner(new DefaultProxyRoutePlanner(proxy)).build();
    }
    requestFactory.setHttpClient(httpClient);
    RestTemplate restTemplate = new RestTemplate(requestFactory);
    return restTemplate;
}

    /**
     * Make a rest api call
     * @return ResponseEntity
     */
    public ResponseEntity getApiResponse(HttpMethod httpMethod, final String URL, final String userAgent,
            String proxyHost, int proxyPort, String host) throws HttpClientErrorException {
        ResponseEntity response = null;
        HttpEntity httpEntity = new HttpEntity<>(getHttpHeaders(userAgent, host));
        try {
            if (null != httpMethod && null != URL) {
                RestTemplate request = null;
                try {
                    request = getRestTemplate(proxyHost, proxyPort);
                    response = request.exchange(URL, httpMethod, httpEntity, String.class);
                } catch (KeyManagementException | KeyStoreException | NoSuchAlgorithmException e) {
                    LOG.error("Error creating Rest Template", e);
                }
            }
        } catch (HttpClientErrorException ex) {
            LOG.error("Method = " + httpMethod.toString() + "Request URL = " + URL);
            LOG.error("Headers =" + getHttpHeaders(userAgent, host));
            LOG.error("Response Status = " + ex.getStatusText());
            LOG.error("Response Body = " + ex.getResponseBodyAsString());
            throw ex;
        }
        return response;
    }
}