How to force java server to accept only tls 1.2 and reject tls 1.0 and tls 1.1 connections

29
votes

I have a HTTPS web service running on Java 7. I need to make changes so that this service only accepts TLS1.2 connection and reject SSL3, TLS1.0 and TLS1.1.

I have added the following Java parameter so that TLS1.2 is the highest priority.

-Dhttps.protocols=TLSv1.2

but it also accepts the TLS1.0 connections from Java clients. If the client is also running with above Java parameter, the connection is TLS1.2 but if the client is running without this parameter, the connections is TLS1.0.

I did some play around the java.security file in jdk/jre/lib/security folder.

I currently have following disabled algorithms:

jdk.certpath.disabledAlgorithms= MD2, MD4, MD5, SHA224, DSA, EC keySize < 256, RSA keySize < 2048, SHA1 keysize < 224
jdk.tls.disabledAlgorithms=DSA, DHE, EC keySize < 256, RSA keySize < 2048, SHA1 keysize < 224

I am using Java 7 update 79. I am not inclined towards intercepting each connection and checking the TLS version.

My server certificate is 2048 bit generated with MD5 with RSA algorithm.

If the disabled algorithm list has RSA in place of RSA keySize < 2048, I get the SSLHandShakeError with error message:

no cipher suites in common.

My test program is running the HTTP server from following URL: http://www.herongyang.com/JDK/HTTPS-HttpsEchoer-Better-HTTPS-Server.html

Please help how to make java accept only TLS1.2 connections.

3
javasecuritysslhttps
does SSLContext.getInstance("TLSv1.2") work? – user5266804
@user5266804 No, it does not. The SSLContext.getInstance method basically takes either SSL or TLS as an argument. I'll bet that under the covers, the Sun provider doesn't even care what string you pass in: you always get "the TLS engine" provided by JSSE. – Christopher Schultz

3 Answers

44
votes

I found a solution for this. I set the

jdk.tls.disabledAlgorithms= SSLv2Hello, SSLv3, TLSv1, TLSv1.1

in the file jre/lib/security/java.security on the server.

After setting this, server only accepts the TLS1.2 connection and reject lower security protocol versions.

3
votes

I have also done the same changes in "/java/jdk1.7.0_79/jre/lib/security"-java.security file but some of clients are still able to call my services with SSL protocol.

----Changes jdk.tls.disabledAlgorithms=SSL,SSLv2,SSLv3, TLSv1, TLSv1.1,MD5, SSLv3, DSA, RSA keySize < 2048

2
votes

Just a small remark;

In the question you stated that you generated a 2048 size certificate with MD5. But in the cert path alg you disabled MD5 so this normally should not work. Secondly Server certificates generated with a MD5 hash are banned from modern browsers such as Internet Explorer 10/Edge.

I would like to advice you to generate your Server certificate at least with a SHA256 or < hash.