Question

I’m running this Java + SSL Tutorial, but I’m getting the following error.

main, handling exception: javax.net.ssl.SSLHandshakeException: Received fatal alert: certificate_unknown
javax.net.ssl.SSLHandshakeException: Received fatal alert: certificate_unknown
    at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Unknown Source)
    at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Unknown Source)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.recvAlert(Unknown Source)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(Unknown Source)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(Unknown Source)
    at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(Unknown Source)
    at com.sun.net.ssl.internal.ssl.AppInputStream.read(Unknown Source)
    at sun.nio.cs.StreamDecoder.readBytes(Unknown Source)
    at sun.nio.cs.StreamDecoder.implRead(Unknown Source)
    at sun.nio.cs.StreamDecoder.read(Unknown Source)
    at java.io.InputStreamReader.read(Unknown Source)
    at java.io.BufferedReader.fill(Unknown Source)
    at java.io.BufferedReader.readLine(Unknown Source)
    at java.io.BufferedReader.readLine(Unknown Source)
    at EchoServer.main(EchoServer.java:24)

The line in the code where the exception occurs is here:

        while ((string = bufferedreader.readLine()) != null) {

What am I doing wrong here? Have things changed since that example was written?

Answer 1

Probably you certificate is not valid (or not loaded) for some reason. Enabling the debug mode should help you to find more the problem

System.setProperty(“javax.net.debug”, “all”);

Also if you’re using self-sign certificates, take a look to: http://ctasada.blogspot.com.es/2010/11/httpclient-use-self-signed-certificates.html