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

If you use HttpClient 4.4 then you need to specify host verifier (NoopHostnameVerifier) to allow accepting certificates from different hosts:

SSLConnectionSocketFactory scsf = SSLConnectionSocketFactory(
     SSLContexts.custom().loadTrustMaterial(null, new TrustSelfSignedStrategy()).build(), 
        NoopHostnameVerifier.INSTANCE)
httpclient = HttpClients.custom().setSSLSocketFactory(scsf).build()