HttpClient with SSL
Overview
This article will show how to configure the Apache HttpClient 4 with “Accept All” SSL support. The goal is simple – consume HTTPS URLs which do not have valid certificates.
The SSLPeerUnverifiedException
@Test(expected = SSLPeerUnverifiedException.class)
public void whenHttpsUrlIsConsumed_thenException()
throws ClientProtocolException, IOException {
CloseableHttpClient httpClient = HttpClients.createDefault();
String urlOverHttps = "https://localhost:8082/httpclient-simple";
HttpGet getMethod = new HttpGet(urlOverHttps);
HttpResponse response = httpClient.execute(getMethod);
assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
}
The javax.net.ssl.SSLPeerUnverifiedException
exception occurs whenever a valid chain of trust couldn’t be established for the URL.
Configure SSL – Accept All (HttpClient < 4.3)
@Test
public final void givenAcceptingAllCertificates_whenHttpsUrlIsConsumed_thenOk()
throws GeneralSecurityException {
HttpComponentsClientHttpRequestFactory requestFactory = new HttpComponentsClientHttpRequestFactory();
CloseableHttpClient httpClient = (CloseableHttpClient) requestFactory.getHttpClient();
TrustStrategy acceptingTrustStrategy = (cert, authType) -> true;
SSLSocketFactory sf = new SSLSocketFactory(acceptingTrustStrategy, ALLOW_ALL_HOSTNAME_VERIFIER);
httpClient.getConnectionManager().getSchemeRegistry().register(new Scheme("https", 8443, sf));
ResponseEntity<String> response = new RestTemplate(requestFactory).
exchange(urlOverHttps, HttpMethod.GET, null, String.class);
assertThat(response.getStatusCode().value(), equalTo(200));
}
With the new TrustStrategy
now overriding the standard certificate verification process (which should consult a configured trust manager)
Configure SSL – Accept All (HttpClient 4.4 and Above)
@Test
public final void givenAcceptingAllCertificates_whenHttpsUrlIsConsumed_thenOk()
throws GeneralSecurityException {
TrustStrategy acceptingTrustStrategy = (cert, authType) -> true;
SSLContext sslContext = SSLContexts.custom().loadTrustMaterial(null, acceptingTrustStrategy).build();
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext,
NoopHostnameVerifier.INSTANCE);
Registry<ConnectionSocketFactory> socketFactoryRegistry =
RegistryBuilder.<ConnectionSocketFactory> create()
.register("https", sslsf)
.register("http", new PlainConnectionSocketFactory())
.build();
BasicHttpClientConnectionManager connectionManager =
new BasicHttpClientConnectionManager(socketFactoryRegistry);
CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(sslsf)
.setConnectionManager(connectionManager).build();
HttpComponentsClientHttpRequestFactory requestFactory =
new HttpComponentsClientHttpRequestFactory(httpClient);
ResponseEntity<String> response = new RestTemplate(requestFactory)
.exchange(urlOverHttps, HttpMethod.GET, null, String.class);
assertThat(response.getStatusCode().value(), equalTo(200));
}
The Spring RestTemplate with SSL (HttpClient < 4.3)
Now that we have seen how to configure a raw HttpClient with SSL support, let’s take a look at a higher level client – the Spring RestTemplate
.
With no SSL configured, the following test fails as expected:
@Test(expected = ResourceAccessException.class)
public void whenHttpsUrlIsConsumed_thenException() {
String urlOverHttps = "https://localhost:8443/httpclient-simple/api/bars/1";
ResponseEntity<String> response
= new RestTemplate().exchange(urlOverHttps, HttpMethod.GET, null, String.class);
assertThat(response.getStatusCode().value(), equalTo(200));
}
So let’s configure SSL:
@Test
public void givenAcceptingAllCertificates_whenHttpsUrlIsConsumed_thenException()
throws GeneralSecurityException {
HttpComponentsClientHttpRequestFactory requestFactory
= new HttpComponentsClientHttpRequestFactory();
DefaultHttpClient httpClient
= (DefaultHttpClient) requestFactory.getHttpClient();
TrustStrategy acceptingTrustStrategy = (cert, authType) -> true
SSLSocketFactory sf = new SSLSocketFactory(
acceptingTrustStrategy, ALLOW_ALL_HOSTNAME_VERIFIER);
httpClient.getConnectionManager().getSchemeRegistry()
.register(new Scheme("https", 8443, sf));
String urlOverHttps = "https://localhost:8443/httpclient-simple/api/bars/1";
ResponseEntity<String> response = new RestTemplate(requestFactory).
exchange(urlOverHttps, HttpMethod.GET, null, String.class);
assertThat(response.getStatusCode().value(), equalTo(200));
}
The Spring RestTemplate with SSL (HttpClient 4.4)
@Test
public void givenAcceptingAllCertificatesUsing4_4_whenUsingRestTemplate_thenCorrect()
throws ClientProtocolException, IOException {
CloseableHttpClient httpClient
= HttpClients.custom()
.setSSLHostnameVerifier(new NoopHostnameVerifier())
.build();
HttpComponentsClientHttpRequestFactory requestFactory
= new HttpComponentsClientHttpRequestFactory();
requestFactory.setHttpClient(httpClient);
ResponseEntity<String> response
= new RestTemplate(requestFactory).exchange(
urlOverHttps, HttpMethod.GET, null, String.class);
assertThat(response.getStatusCode().value(), equalTo(200));
}
Results
HttpClientSslTest