Exception in thread "main" javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

[rpgottipati]

Issue Summary

Windows 10 build : 1909 (OS Build 183636.2158)

Exception in thread "main" javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

Steps to Reproduce

1. JDK 1.8.0_241
   java version "1.8.0_241"
   Java(TM) SE Runtime Environment (build 1.8.0_241-b07)
   Java HotSpot(TM) 64-Bit Server VM (build 25.241-b07, mixed mode)

2. https://confluence.atlassian.com/kb/files/779355358/779355357/1/1441897666313/SSLPoke.class

3.java SSLPoke api.sendgrid.com 443
sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:450)
at sun.security.validator.PKIXValidator.engineValidate(PKIXValidator.java:317)
at sun.security.validator.Validator.validate(Validator.java:262)
at sun.security.ssl.X509TrustManagerImpl.validate(X509TrustManagerImpl.java:330)
at sun.security.ssl.X509TrustManagerImpl.checkTrusted(X509TrustManagerImpl.java:227)
at sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(X509TrustManagerImpl.java:132)
at sun.security.ssl.ClientHandshaker.serverCertificate(ClientHandshaker.java:1622)
at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:223)
at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1037)
at sun.security.ssl.Handshaker.process_record(Handshaker.java:965)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1064)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1367)
at sun.security.ssl.SSLSocketImpl.writeRecord(SSLSocketImpl.java:750)
at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:123)
at sun.security.ssl.AppOutputStream.write(AppOutputStream.java:138)
at SSLPoke.main(SSLPoke.java:31)
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at sun.security.provider.certpath.SunCertPathBuilder.build(SunCertPathBuilder.java:141)
at sun.security.provider.certpath.SunCertPathBuilder.engineBuild(SunCertPathBuilder.java:126)
at java.security.cert.CertPathBuilder.build(CertPathBuilder.java:280)
at sun.security.validator.PKIXValidator.doBuild(PKIXValidator.java:445)
... 15 more

4. add the cert to keystore

keytool -import -alias api_sendgrid -keystore "C:\Java\jdk1.8.0_241\jre\lib\security\cacerts" -file C:\temp\api_v3.cer

5. tried
   java -Djavax.net.ssl.trustStore=C:\Java\jdk1.8.0_241\jre\lib\security\cacerts SSLPoke api.sendgrid.com 443

got the same error as above

Code Snippet

public class Example 
{
  public static void main(String[] args) throws IOException 
  {
	  
	// Create a trust manager that does not validate certificate chains
      TrustManager[] trustAllCerts = new TrustManager[] {new X509TrustManager() {
          public java.security.cert.X509Certificate[] getAcceptedIssuers() {
              return null;
          }
			public void checkClientTrusted(java.security.cert.X509Certificate[] arg0, String arg1)
					throws CertificateException {
				
			}
			public void checkServerTrusted(java.security.cert.X509Certificate[] arg0, String arg1)
					throws CertificateException {
				
			}
      }
      };

      // Install the all-trusting trust manager
      SSLContext sc = null;
	try {
		sc = SSLContext.getInstance("SSL");
	} catch (NoSuchAlgorithmException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
      try {
		sc.init(null, trustAllCerts, new java.security.SecureRandom());
	} catch (KeyManagementException e) {
		// TODO Auto-generated catch block
		e.printStackTrace();
	}
      HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());

      // Create all-trusting host name verifier
      HostnameVerifier allHostsValid = new HostnameVerifier() {
          public boolean verify(String hostname, SSLSession session) {
              return true;
          }
      };

      // Install the all-trusting host verifier
      HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid);
	  
    Email from = new Email("[email protected]");
    String subject = "Sending with SendGrid is Fun";
    Email to = new Email("[email protected]");
    Content content = new Content("text/plain", "and easy to do anywhere, even with Java");
    Mail mail = new Mail(from, subject, to, content);

    SendGrid sg = new SendGrid("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");
    Request request = new Request();
    try {
      request.setMethod(Method.POST);
      request.setEndpoint("mail/send");
      request.setBody(mail.build());
      Response response = sg.api(request);
      System.out.println(response.getStatusCode());
      System.out.println(response.getBody());
      System.out.println(response.getHeaders());
    } catch (IOException ex) {
      throw ex;
    }
  }
}

Exception/Log

Exception in thread "main" javax.net.ssl.SSLHandshakeException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
at java.base/sun.security.ssl.Alert.createSSLException(Alert.java:131)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:369)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:312)
at java.base/sun.security.ssl.TransportContext.fatal(TransportContext.java:307)
at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.checkServerCerts(CertificateMessage.java:1356)
at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.onConsumeCertificate(CertificateMessage.java:1231)
at java.base/sun.security.ssl.CertificateMessage$T13CertificateConsumer.consume(CertificateMessage.java:1174)
at java.base/sun.security.ssl.SSLHandshake.consume(SSLHandshake.java:392)
at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:478)
at java.base/sun.security.ssl.HandshakeContext.dispatch(HandshakeContext.java:456)
at java.base/sun.security.ssl.TransportContext.dispatch(TransportContext.java:199)
at java.base/sun.security.ssl.SSLTransport.decode(SSLTransport.java:171)
at java.base/sun.security.ssl.SSLSocketImpl.decode(SSLSocketImpl.java:1369

### Technical details:
* sendgrid-java version: 4.0.1
* java version:1.8.0_241