JDK 8u161 Release Notes

Java™ SE Development Kit 8, Update 161 (JDK 8u161)

January 16, 2018

The full version string for this update release is 1.8.0_161-b12 (where "b" means "build"). The version number is 8u161.

IANA Data 2017c

JDK 8u161 contains IANA time zone data version 2017c. For more information, refer to Timezone Data Versions in the JRE Software.

Security Baselines

The security baselines for the Java Runtime Environment (JRE) at the time of the release of JDK 8u161 are specified in the following table:

JRE Family Version JRE Security Baseline (Full Version String)
8 1.8.0_161-b12
7 1.7.0_171-b11
6 1.6.0_181-b10

JRE Expiration Date

The JRE expires whenever a new release with security vulnerability fixes becomes available. Critical patch updates, which contain security vulnerability fixes, are announced one year in advance on Critical Patch Updates, Security Alerts and Third Party Bulletin. This JRE (version 8u161) will expire with the release of the next critical patch update scheduled for April 17, 2018.

For systems unable to reach the Oracle Servers, a secondary mechanism expires this JRE (version 8u161) on May 17, 2018. After either condition is met (new release becoming available or expiration date reached), the JRE will provide additional warnings and reminders to users to update to the newer version. For more information, see JRE Expiration Date.

New Features


Added TLS session hash and extended master secret extension support

Support has been added for the TLS session hash and extended master secret extension (RFC 7627) in JDK JSSE provider. Note that in general, server certificate change is restricted if endpoint identification is not enabled and the previous handshake is a session-resumption abbreviated initial handshake, unless the identities represented by both certificates can be regarded as the same. However, if the extension is enabled or negotiated, the server certificate changing restriction is not necessary and will be discarded accordingly. In case of compatibility issues, an application may disable negotiation of this extension by setting the System Property jdk.tls.useExtendedMasterSecret to false in the JDK. By setting the System Property jdk.tls.allowLegacyResumption to false, an application can reject abbreviated handshaking when the session hash and extended master secret extension is not negotiated. By setting the System Property jdk.tls.allowLegacyMasterSecret to false, an application can reject connections that do not support the session hash and extended master secret extension.

See JDK-8148421


Support DHE sizes up to 8192-bits and DSA sizes up to 3072-bits

Enhance the JDK security providers to support 3072-bit DiffieHellman and DSA parameters generation, pre-computed DiffieHellman parameters up to 8192 bits and pre-computed DSA parameters up to 3072 bits.

See JDK-8072452


Add additional IDL stub type checks to org.omg.CORBA.ORBstring_to_object method

Applications that either explicitly or implicitly call org.omg.CORBA.ORB.string_to_object, and wish to ensure the integrity of the IDL stub type involved in the ORB::string_to_object call flow, should specify additional IDL stub type checking. This is an "opt in" feature and is not enabled by default.

To take advantage of the additional type checking, the list of valid IDL interface class names of IDL stub classes is configured by one of the following:

  • Specifying the security property com.sun.CORBA.ORBIorTypeCheckRegistryFilter located in the file conf/security/ in Java SE 9 or in jre/lib/security/ in Java SE 8 and earlier.
  • Specifying the system property com.sun.CORBA.ORBIorTypeCheckRegistryFilter with the list of classes. If the system property is set, its value overrides the corresponding property defined in the configuration.

If the com.sun.CORBA.ORBIorTypeCheckRegistryFilter property is not set, the type checking is only performed against a set of class names of the IDL interface types corresponding to the built-in IDL stub classes.

JDK-8160104 (not public)



RSA public key validation

In 8u161, the RSA implementation in the SunRsaSign provider will reject any RSA public key that has an exponent that is not in the valid range as defined by PKCS#1 version 2.2. This change will affect JSSE connections as well as applications built on JCE.

JDK-8174756 (not public)


Restrict Diffie-Hellman keys less than 1024 bits

Diffie-Hellman keys less than 1024 bits are considered too weak to use in practice and should be restricted by default in SSL/TLS/DTLS connections. Accordingly, Diffie-Hellman keys less than 1024 bits have been disabled by default by adding "DH keySize < 1024" to the "jdk.tls.disabledAlgorithms" security property in the file. Although it is not recommended, administrators can update the security property ("jdk.tls.disabledAlgorithms") and permit smaller key sizes (for example, by setting "DH keySize < 768").

JDK-8148108 (not public)


Provider default key size is updated

This change updates the JDK providers to use 2048 bits as the default key size for DSA instead of 1024 bits when applications have not explicitly initialized the and objects with a key size.

If compatibility issues arise, existing applications can set the system property introduced in JDK-8181048 with the algorithm and its desired default key size.

JDK-8178466 (not public)


Stricter key generation

The generateSecret(String) method has been mostly disabled in the javax.crypto.KeyAgreement services of the SunJCE and SunPKCS11 providers. Invoking this method for these providers will result in a NoSuchAlgorithmException for most algorithm string arguments. The previous behavior of this method can be re-enabled by setting the value of the jdk.crypto.KeyAgreement.legacyKDF system property to true (case insensitive). Re-enabling this method by setting this system property is not recommended.

Prior to this change, the following code could be used to produce secret keys for AES using Diffie-Hellman:

KeyAgreement ka = KeyAgreement.getInstance("DiffieHellman");



SecretKey sk = ka.generateSecret("AES");

The issue with this code is that it is unspecified how the provider should derive a secret key from the output of the Diffie-Hellman operation. There are several options for how this key derivation function can work, and each of these options has different security properties. For example, the key derivation function may bind the secret key to some information about the context or the parties involved in the key agreement. Without a clear specification of the behavior of this method, there is a risk that the key derivation function will not have some security property that is expected by the client.

To address this risk, the generateSecret(String) method of KeyAgreement was mostly disabled in the DiffieHellman services, and code like the example above will now result in a Clients still may use the no-argument generateSecret method to obtain the raw Diffie-Hellman output, which can be used with an appropriate key derivation function to produce a secret key.

Existing applications that use the generateSecret(String) method of this service will need to be modified. Here are a few options:

A) Implement the key derivation function from an appropriate standard. For example, NIST SP 800-56Ar2[1] section 5.8 describes how to derive keys from Diffie-Hellman output.

B) Implement the following simple key derivation function:

  1. Call KeyAgreement.generateSecret() to get the shared secret as a byte array
  2. Hash the byte array produced in step 1 using SHA-256
  3. Pass the byte array produced in step 2 into the constructor of SecretKeySpec. This constructor also

requires the standard name of the secret-key algorithm (e.g. "AES")

This is a simple key derivation function that may provide adequate security in a typical application. Developers should note that this method provides no protection against the reuse of key agreement output in different contexts, so it is not appropriate for all applications. Also, some additional effort may be required to enforce key size restrictions like the ones in Table 2 of NIST SP 800-57pt1r4[2].

C) Set the jdk.crypto.KeyAgreement.legacyKDF system property to "true". This will restore the previous behavior of this KeyAgreement service. This solution should only be used as a last resort if the application code cannot be modified, or if the application must interoperate with a system that cannot be modified. The "legacy" key derivation function and its security are unspecified.

JDK-8185292 (not public)


Unlimited cryptography enabled by default

The JDK uses the Java Cryptography Extension (JCE) Jurisdiction Policy files to configure cryptographic algorithm restrictions. Previously, the Policy files in the JDK placed limits on various algorithms. This release ships with both the limited and unlimited jurisdiction policy files, with unlimited being the default. The behavior can be controlled via the new 'crypto.policy' Security property found in the /lib/ file. Please refer to that file for more information on this property.

See JDK-8170157


The RMI Registry filter is relaxed to allow binding arrays of any type

The RMI Registry built-in serial filter is modified to check only the array size and not the component type. The maximum array size is increased to 1,000,000. The override filter can be used to decrease the limit. Array sizes greater than the maxarray limit will be rejected and otherwise will be allowed. The file contains more information about the sun.rmi.registry.registryFilter property and it will be updated in the conf/security/ configuration file to better describe the default behavior and how to override it.

See JDK-8185346


Disable exportable cipher suites

To improve the strength of SSL/TLS connections, exportable cipher suites have been disabled in SSL/TLS connections in the JDK by the jdk.tls.disabledAlgorithms Security Property.

See JDK-8163237


Disable JARs signed with DSA keys less than 1024 bits

DSA keys less than 1024 bits have been added to the jdk.jar.disabledAlgorithms Security property in the file. This property contains a list of disabled algorithms and key sizes for signed JAR files. If a signed JAR file uses a disabled algorithm or key size less than the minimum length, signature verification operations will ignore the signature and treat the JAR as if it were unsigned. This can potentially occur in the following types of applications that use signed JAR files:

  1. Applets or Web Start Applications
  2. Standalone or Server Applications run with a SecurityManager enabled and that are configured with a policy file that grants permissions based on the code signer(s) of the JAR file.

Running jarsigner -verify -verbose on a JAR file signed with a weak algorithm or key will print more information about the disabled algorithm or key.

For example, to check a JAR file named test.jar, use this command: jarsigner -verify -verbose test.jar

If the file in this example was signed with a weak key such as 512 bit DSA, this output would be seen:

- Signed by "CN=weak_signer"
Digest algorithm: SHA1 
Signature algorithm: SHA1withDSA, 512-bit key (weak)  

To address the issue, the JAR file will need to be re-signed with a stronger key size. Alternatively, the restrictions can be reverted by removing the applicable weak algorithms or key sizes from the jdk.jar.disabledAlgorithms security property; however, this option is not recommended. Before re-signing affected JARs, the existing signature(s) should be removed from the JAR file. This can be done with the zip utility, as follows:

zip -d test.jar 'META-INF/*.SF' 'META-INF/*.RSA' 'META-INF/*.DSA'

Periodically check the Oracle JRE and JDK Cryptographic Roadmap at for planned restrictions to signed JARs and other security components.

JDK-8185909 (not public)


JMX Connections need deserialization filters

New public attributes, RMIConnectorServer.CREDENTIALS_FILTER_PATTERN and RMIConnectorServer.SERIAL_FILTER_PATTERN have been added to With these new attributes, users can specify the deserialization filter pattern strings to be used while making a RMIServer.newClient() remote call and while sending deserializing parameters over RMI to server respectively.

The user can also provide a filter pattern string to the default agent via As a result, a new attribute is added to

Existing attribute RMIConnectorServer.CREDENTIAL_TYPES is superseded by RMIConnectorServer.CREDENTIALS_FILTER_PATTERN and has been removed.

JDK-8159377 (not public)


JDK Transform, Validation and XPath use the system-default parser

Java SE 9 changes the JDK's Transform, Validation and XPath implementations to use the JDK's system-default parser even when a third party parser is on the classpath. In order to override the JDK system-default parser, applications need to explicitly set the new System property jdk.xml.overrideDefaultParser.

  1. Support through the API

    The overrideDefaultParser property is supported by the following APIs:

    1. TransformerFactory::setFeature
    2. SchemaFactory::setFeature
    3. Validator::setFeature
    4. XPathFactory::setFeature
  2. Support as a System property
  3. The overrideDefaultParser property can be set through the System.setProperty.

  4. Support as a JAXP system property
  5. The overrideDefaultParser property can be set in the JAXP configuration file

  6. Scope and order

The overrideDefaultParser property follows the same rule as other JDK JAXP properties in that a setting of a narrower scope takes preference over that of a wider scope. A setting through the API overrides the System property which in turn overrides that in the file.

JDK-8186080 (not public)


Bug Fixes

This release contains fixes for security vulnerabilities described in the Oracle Critical Patch Update.

# BugId Component Subcomponent Summary
1 JDK-8079595 client‑libs java.awt Resizing dialog which is JWindow parent makes JVM crash
2 JDK-8184016 client‑libs java.swing Text in native popup is not always updated with Sogou IME
3 JDK-8035105 core‑libs javax.naming DNS provider cleanups
4 JDK-8185661 deploy webstart JNLP files won't launch from IE11 on Windows 10 Creators Update
5 JDK-8186344 deploy webstart 64 bit java install not setting jnlp associate if lower 32bit versions exist
6 JDK-8157548 hotspot runtime JVM crashes sometimes while starting
7 JDK-8191607 install install undo 8189805: 64 and 32 bit RPMS must co‑exist
8 JDK-8178728 security‑libs Check the AlgorithmParameters in algorithm constraints
9 JDK-8184673 security‑libs Fix compatibility issue in AlgorithmChecker for 3rd party JCE providers
10 JDK-8072452 security‑libs javax.crypto Support DHE sizes up to 8192‑bits and DSA sizes up to 3072‑bits
11 JDK-8170157 security‑libs javax.crypto Enable unlimited cryptographic policy by default in Oracle JDK builds
12 JDK-8156502 security‑libs Use short name of
13 JDK-8193683 security‑libs Increase the number of clones in the CloneableDigest
14 JDK-8159240 xml jaxb XSOM parser incorrectly processes type names with whitespaces