Java Security: Illegal key size or default parameters?

With Java 9, Java 8u161, Java 7u171 and Java 6u181 the limitation is now disabled by default. See issue in Java Bug Database.

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Beginning with Java 8u151 you can disable the limitation programmatically.

In older releases, JCE jurisdiction files had to be downloaded and installed separately to allow unlimited cryptography to be used by the JDK. The download and install steps are no longer necessary.

Instead you can now invoke the following line before first use of JCE classes (i.e. preferably right after application start):

Security.setProperty("crypto.policy", "unlimited");

Most likely you don't have the unlimited strength file installed now.

You may need to download this file:

Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 6

Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 7 Download

Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 8 Download (only required for versions before Java 8 u162)

Extract the jar files from the zip and save them in ${java.home}/jre/lib/security/.

The JRE/JDK/Java 8 jurisdiction files can be found here:

Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 8 Download

Like James said above:
Install the files in ${java.home}/jre/lib/security/.