javax.net.ssl.SSLException: Could not generate DH keypair

[Roedy Green]

javax.net.ssl.SSLException: Could not generate DH keypair

I am getting this exception on one website doing a simple GET.
https://cdburnerxp.se/en/home

I can access with a browser, no trouble.

There is a ton of material on this exception, but it all says is was a
bug back the days of Java 1.6 and it has been fixed.

I tried installing all the Comodo root certs both in Windows and
cacerts.

It is not doing redirection.

The root cert is PositiveSSL CA 2

TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256, 128 bit keys

I refreshed the unlimited strength policy files.
see http://mindprod.com/jgloss/unlimitedstrength.html
for how.


Still no joy

 

[Roedy Green]

javax.net.ssl.SSLException: Could not generate DH keypair

the webmaster gave me one more clue.

"Since apache 2.4.7, mod_ssl handles DH parameters according to RFC
3526, the server sends a 2048 bit DH key"

How big a key does Java support when "unlimited strength" is
installed.

 

[Roedy Green]

Still no joy

I have a clue.

jdk.tls.ephemeralDHKeySize system property is reputed to expand from
1024 to 2048 bit SSL.