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.
JDK 8u161 contains IANA time zone data version 2017c. For more information, refer to Timezone Data Versions in the JRE Software.
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)
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.
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
false in the JDK. By setting the System Property
false, an application can reject abbreviated handshaking when the session hash and extended master secret extension is not negotiated. By setting the System Property
false, an application can reject connections that do not support the session hash and extended master secret extension.
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.
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/java.security in Java SE 9 or in
jre/lib/security/java.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
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.
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.
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 java.security 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").
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
java.security.AlgorithmParameterGenerator objects with a key size.
If compatibility issues arise, existing applications can set the system property
jdk.security.defaultKeySize introduced in JDK-8181048 with the algorithm and its desired default key size.
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 java.security.NoSuchAlgorithmException. 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 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.
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.
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/java.security file. Please refer to that file for more information on this property.
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
java.security file contains more information about the
sun.rmi.registry.registryFilter property and it will be updated in the
conf/security/java.security configuration file to better describe the default behavior and how to override it.
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.
DSA keys less than 1024 bits have been added to the
jdk.jar.disabledAlgorithms Security property in the java.security 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:
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 http://java.com/cryptoroadmap for planned restrictions to signed JARs and other security components.
New public attributes,
RMIConnectorServer.SERIAL_FILTER_PATTERN have been added to
RMIConnectorServer.java. 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 management.properties. As a result, a new attribute is added to management.properties.
RMIConnectorServer.CREDENTIAL_TYPES is superseded by
RMIConnectorServer.CREDENTIALS_FILTER_PATTERN and has been removed.
Java SE 9 changes the JDK's
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
overrideDefaultParserproperty is supported by the following APIs:
overrideDefaultParserproperty can be set through the System.setProperty.
overrideDefaultParserproperty can be set in the JAXP configuration file
overrideDefaultParserproperty 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
This release contains fixes for security vulnerabilities described in the Oracle Critical Patch Update. For a more complete list of the bug fixes included in this release, see the JDK 8u161 Bug Fixes page.