RELEASE NOTES: JDK openjdk8u352

Enable TLSv1.3 by Default on JDK 8 for Client Roles

The TLSv1.3 implementation is now enabled by default for client roles in 8u341. It has been enabled by default for server roles since 8u261. You can find more details in the Additional Information section of the Oracle JRE and JDK Cryptographic Roadmap.

Note that TLS 1.3 is not directly compatible with previous versions. Enabling it on the client may introduce compatibility issues on either the server or the client side. Here are some more details on potential compatibility issues that you should be aware of:

• TLS 1.3 uses a half-close policy, while TLS 1.2 and prior versions use a duplex-close policy. For applications that depend on the duplex-close policy, there may be compatibility issues when upgrading to TLS 1.3.

• The signaturealgorithmscert extension requires that pre-defined signature algorithms are used for certificate authentication. In practice, however, an application may use non-supported signature algorithms.

• The DSA signature algorithm is not supported in TLS 1.3. If a server is configured to only use DSA certificates, it cannot upgrade to TLS 1.3.

• The supported cipher suites for TLS 1.3 are not the same as TLS 1.2 and prior versions. If an application hard-codes cipher suites which are no longer supported, it may not be able to use TLS 1.3 without modifying the application code, for example TLSAES128GCMSHA256 (1.3 and later) versus TLSECDHERSAWITHAES128CBC_SHA (1.2 and earlier).

• The TLS 1.3 session resumption and key update behaviors are different from TLS 1.2 and prior versions. The compatibility should be minimal, but it could be a risk if an application depends on the handshake details of the TLS protocols.

• TLS 1.3 requires that the implementation support new cryptographic algorithms which previous versions of TLS did not, such as RSASSA-PSS. If your application is configured to use 3rd party JCE provider(s) which do not support the required algorithms, you may get handshake failures.

Update Timezone Data to 2022c

This version includes changes from 2022b that merged multiple regions that have the same timestamp data post-1970 into a single time zone database. All time zone IDs remain the same but the merged time zones will point to a shared zone database.

As a result, pre-1970 data may not be compatible with earlier JDK versions. The affected zones are `Antarctica/Vostok, Asia/Brunei, Asia/Kuala_Lumpur, Atlantic/Reykjavik, Europe/Amsterdam, Europe/Copenhagen, Europe/Luxembourg, Europe/Monaco, Europe/Oslo, Europe/Stockholm, Indian/Christmas, Indian/Cocos, Indian/Kerguelen, Indian/Mahe, Indian/Reunion, Pacific/Chuuk, Pacific/Funafuti, Pacific/Majuro, Pacific/Pohnpei, Pacific/Wake, Pacific/Wallis, Arctic/Longyearbyen, Atlantic/Jan_Mayen, Iceland, Pacific/Ponape, Pacific/Truk, and Pacific/Yap`.

For more details, refer to the announcement of 2022b

Phantom references are automatically cleared as soft and weak references

This enhancement changes phantom references to be automatically cleared by the garbage collector as soft and weak references.

An object becomes phantom reachable after it has been finalized. This change may cause the phantom reachable objects to be GC'ed earlier - previously the referent is kept alive until PhantomReference objects are GC'ed or cleared by the application. This potential behavioral change might only impact existing code that would depend on PhantomReference being enqueued rather than when the referent be freed from the heap.

System Property for Java SE Specification Maintenance Version

The java.specification.maintenance.version system property is defined to indicate the maintenance release number of the Java SE specification being implemented by the JDK. If the implemented specification has not undergone a maintenance release, the value of system property is not set.

java.lang.ref.Reference Does Not Support Cloning

java.lang.ref.Reference::clone method always throws CloneNotSupportedException. Reference objects cannot be meaningfully cloned. To create a new Reference object, call the constructor to create a Reference object with the same referent and reference queue instead.

java.lang.ref.Reference.enqueue method clears the reference object before enqueuing

java.lang.ref.Reference.enqueue method clears the reference object before it is added to the registered queue. When the enqueue method is called, the reference object is cleared and get() method will return null in JDK 9.

Typically when a reference object is enqueued, it is expected that the reference object is cleared explicitly via the clear method to avoid memory leak because its referent is no longer referenced. In other words the get method is expected not to be called in common cases once the enqueuemethod is called. In the case when the get method from an enqueued reference object and existing code attempts to access members of the referent, NullPointerException may be thrown. Such code will need to be updated.