Summary
-------

Disable DTLS 1.0.

Problem
-------

DTLS 1.0 has weakened over time and lacks support for stronger cipher suites. DTLS 1.0 correlates with version 1.1 of TLS which has already been [disabled by default](https://bugs.openjdk.org/browse/JDK-8202343) in JDK 16. The IETF has deprecated this version of DTLS (along with TLS 1.0 and 1.1) in [RFC 8996](https://www.rfc-editor.org/rfc/rfc8996.html).

Solution
--------

Disable DTLS 1.0 by default, by adding "DTLSv1.0" to the `jdk.tls.disabledAlgorithms` security property in the `java.security` configuration file. This will cause attempts to use DTLSv1.0 to fail with an `SSLHandshakeException`. Users can, at their own risk, re-enable the version by removing "DTLSv1.0" from the `jdk.tls.disabledAlgorithms` security property.

Specification
-------------
Change to the `java.security` file:
```
- jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, RC4, DES, MD5withRSA, \
-     DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL
+ jdk.tls.disabledAlgorithms=SSLv3, TLSv1, TLSv1.1, DTLSv1.0, RC4, DES, \
+     MD5withRSA, DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL
```