RELEASE NOTES: JDK 17.0.5

Make HttpURLConnection Default Keep Alive Timeout Configurable

Two system properties have been added which control the keep alive behavior of HttpURLConnection in the case where the server does not specify a keep alive time. Two properties are defined for controlling connections to servers and proxies separately. They are http.keepAlive.time.server and http.keepAlive.time.proxy respectively. More information about them can be found in Networking Properties.

Windows KeyStore Updated to Include Access to the Local Machine Location

The Windows KeyStore support in the SunMSCAPI provider has been expanded to include access to the local machine location. The new keystore types are:

• "Windows-MY-LOCALMACHINE"
• "Windows-ROOT-LOCALMACHINE"

The following keystore types were also added, allowing developers to make it clear they map to the current user:

• "Windows-MY-CURRENTUSER" (same as "Windows-MY")
• "Windows-ROOT-CURRENTUSER" (same as "Windows-ROOT")

CPU Shares Ignored When Computing Active Processor Count

Previous JDK releases used an incorrect interpretation of the Linux cgroups parameter "cpu.shares". This might cause the JVM to use fewer CPUs than available, leading to an under utilization of CPU resources when the JVM is used inside a container.

Starting from this JDK release, by default, the JVM no longer considers "cpu.shares" when deciding the number of threads to be used by the various thread pools. The -XX:+UseContainerCpuShares command-line option can be used to revert to the previous behavior. This option is deprecated and may be removed in a future JDK release.

Toolchain Upgrade to Visual Studio 2022

As part of ongoing maintenance, the JDK for Windows is built using the Microsoft Visual Studio 2022 toolchain starting with this release.

If you have issues with a Java application and if you have native or JNI libraries that are compiled with a different release of the compiler, then you must consider compatibility issues between the runtimes. Specifically, your environment is supported only if you follow the Microsoft guidelines when dealing with multiple runtimes. More information can be found in “C++ binary compatibility between Visual Studio versions”.

Disabled SHA-1 Signed JARs

JARs signed with SHA-1 algorithms are now restricted by default and treated as if they were unsigned. This applies to the algorithms used to digest, sign, and optionally timestamp the JAR. It also applies to the signature and digest algorithms of the certificates in the certificate chain of the code signer and the Timestamp Authority, and any CRLs or OCSP responses that are used to verify if those certificates have been revoked. These restrictions also apply to signed JCE providers.

To reduce the compatibility risk for JARs that have been previously timestamped, there is one exception to this policy:

• Any JAR signed with SHA-1 algorithms and timestamped prior to January 01, 2019 will not be restricted.

This exception may be removed in a future JDK release. To determine if your signed JARs are affected by this change, run jarsigner -verify -verbose -certs on the signed JAR, and look for instances of "SHA1" or "SHA-1" and "disabled" and a warning that the JAR will be treated as unsigned in the output.

For example:

``` - Signed by "CN="Signer"" Digest algorithm: SHA-1 (disabled) Signature algorithm: SHA1withRSA (disabled), 2048-bit key

WARNING: The jar will be treated as unsigned, because it is signed with a weak algorithm that is now disabled by the security property:

jdk.jar.disabledAlgorithms=MD2, MD5, RSA keySize < 1024, DSA keySize < 1024, SHA1 denyAfter 2019-01-01

```

JARs affected by these new restrictions should be replaced or re-signed with stronger algorithms.

Users can, at their own risk, remove these restrictions by modifying the java.security configuration file (or override it by using the java.security.properties system property) and removing "SHA1 usage SignedJAR & denyAfter 2019-01-01" from the jdk.certpath.disabledAlgorithms security property and "SHA1 denyAfter 2019-01-01" from the jdk.jar.disabledAlgorithms security property.

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