RELEASE NOTES: JDK 11.0.17

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.

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.

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signer and the Timestamp Authority, and any CRLs or OCSP responses that are used to verify if those certificates have been revoked.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.

Upgrade the Default PKCS12 MAC Algorithm

The default MAC algorithm used in a PKCS #12 keystore has been updated. The new algorithm is based on SHA-256 and is stronger than the old one based on SHA-1. See the security properties starting with keystore.pkcs12 in the java.security file for detailed information.

The new SHA-256 based MAC algorithms were introduced in the 11.0.12, 8u301, and 7u311 JDK versions. Keystores created using this newer, stronger, MAC algorithm cannot be opened in JDK versions earlier than 11.0.12, 8u301, and 7u311. A 'java.security.NoSuchAlgorithmException' exception will be thrown in such circumstances.

For compatibility, use the keystore.pkcs12.legacy system property, which will revert the algorithms to use the older, weaker algorithms. There is no value defined for this 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

JDK Flight Recorder Event for Deserialization

A new JDK Flight Recorder (JFR) event has been added to monitor deserialization of objects. When JFR is enabled and the JFR configuration includes deserialization events, JFR will emit an event whenever the running program attempts to deserialize an object. The deserialization event is named java/deserialization, and it is disabled by default. The deserialization event contains information that is used by the serialization filter mechanism. Additionally, if a filter is enabled, the JFR event indicates whether the filter accepted or rejected deserialization of the object.

The new Deserialization Event captures:

• Whether a serialization filter is configured or not.
• The serialization filter status, if one is configured.
• The class of the object being deserialized.
• The number of array elements when deserializing an array.
• The current graph depth.
• The current number of object references.
• The current number of bytes in the stream that have been consumed.
• The exception type and message, if thrown by the serialization filter.

Refer to Context-Specific Deserialization Filter and Serialization Filtering Guide for details.

JDK Flight Recorder Event for Deserialization

It is now possible to monitor deserialization of objects using JDK Flight Recorder (JFR). When JFR is enabled and the JFR configuration includes deserialization events, JFR will emit an event whenever the running program attempts to deserialize an object. The deserialization event is named jdk.Deserialization, and it is disabled by default. The deserialization event contains information that is used by the serialization filter mechanism; see the ObjectInputFilter specification. Additionally, if a filter is enabled, the JFR event indicates whether the filter accepted or rejected deserialization of the object. For further information about how to use the JFR deserialization event, see the article Monitoring Deserialization to Improve Application Security. For reference information about using and configuring JFR, see the JFR Runtime Guide and JFR Command Reference sections of the JDK Mission Control documentation.

JDK Flight Recorder Event for Deserialization

It is now possible to monitor deserialization of objects using JDK Flight Recorder (JFR). When JFR is enabled and the JFR configuration includes deserialization events, JFR will emit an event whenever the running program attempts to deserialize an object. The deserialization event is named jdk.Deserialization, and it is disabled by default. The deserialization event contains information that is used by the serialization filter mechanism; see the ObjectInputFilter specification. Additionally, if a filter is enabled, the JFR event indicates whether the filter accepted or rejected deserialization of the object. For further information about how to use the JFR deserialization event, see the article Monitoring Deserialization to Improve Application Security. For reference information about using and configuring JFR, see the JFR Runtime Guide and JFR Command Reference sections of the JDK Mission Control documentation.

Deprecate 3DES and RC4 in Kerberos

The des3-hmac-sha1 and rc4-hmac Kerberos encryption types (etypes) are now deprecated and disabled by default. Users can set allow_weak_crypto = true in the krb5.conf configuration file to re-enable them (along with other weak etypes including des-cbc-crc and des-cbc-md5) at their own risk. To disable a subset of the weak etypes, users can list preferred etypes explicitly in any of the default_tkt_enctypes, default_tgs_enctypes, or permitted_enctypes settings.