Automic Application Manager V9 Client: Run with Java 9

My team uses Automic AM v9.1.0 (v9.1.0_28363_28431), which is configured with Java 6 and Java 7 by default. It also works in Java 8. However, if you run it with Java 9, you will encounter network error with the followings in detail:

javax.net.ssl.SSLHandshakeException: DHPublicKey does not comply to algorithm constraints
 at java.base/sun.security.ssl.DHCrypt.checkConstraints(DHCrypt.java:237)
 at java.base/sun.security.ssl.ClientHandshaker.serverKeyExchange(ClientHandshaker.java:837)
 at java.base/sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:320)

The reason you see this error is Java 9 requires DH key size must be larger than 1024, and the version of v9.1.0 must use DHPublicKey shorter than 1024. Check /usr/java/default/conf/security/java.security.

jdk.tls.disabledAlgorithms=SSLv3, RC4, MD5withRSA, DH keySize < 1024, \
    EC keySize < 224

If you update the file as below, you can run the client with Java 9.

jdk.tls.disabledAlgorithms=SSLv3, RC4, MD5withRSA, DH keySize < 768, \
    EC keySize < 224

The reason I want to run AM using Java 9 because Java 9 have a better support for GDK and I can get sharp font on HiDPI screen like MacBook Pro with Retina Display.

• You can run $JAVA_HOME/bin/javaws -J-Dawt.useSystemAAFontSettings=lcd http://am_host/am_engine/Client.jnlp to get better fonts with smooth edge.
• Set environment variable GDK_SCALE=2 to make the client window large on a HiDPI display.

Because this method needs to change java.security, it will be applied to every application using the Java 9 deployment, and may be a security issue. I’m running AM in a docker container, there is no such a problem, because the Java with this change is only for AM.

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