Summary

This is a CSR based off the parent CSR (JDK-8364386). The changes themselves are JDK implementation specific. I propose an edit to the specification section compared to that used in JDK 26. i.e.

• Update the java.security doc with same verbiage as that found in JDK 26 patch.
• NO updates to the various javax.crypto, java.security javadoc edits made to JDK 26. The text refers to the "The JDK Reference Implementation" and I don't believe it's required for Update Releases. A release note will describe the changes being made.

Everything below is identical to JDK 26 CSR with exception of specification section.

Introduce a new security property "jdk.crypto.disabledAlgorithms" for disabling algorithms for JCE/JCA cryptographic services. For now, this property only supports Cipher, KeyStore, MessageDigest, and Signature services. This security property can be overridden by a system property of the same name if applications need to re-enable algorithms.

Problem

As time goes by and algorithms become legacy, there are no mechanisms to stop or detect their use. With this new security property, once set, requests made to the supported service classes, i.e. Cipher, KeyStore, MessageDigest, and Signature, matching the disabled algorithm will be rejected with exception.

Solution

Add a security property "jdk.crypto.disabledAlgorithms" (overridable by a system property of the same name) whose value has the following syntax: "DisabledService {, DisabledService}"

Each "DisabledService" component has the format of "Service.AlgorithmName" where "Service" is one of Cipher, KeyStore, MessageDigest, or Signature (more services may be added later) and "AlgorithmName" is the standard algorithm name of the disabled service. See the Java Security Standard Algorithm Names Specification for information about Standard Algorithm Names. Matching is performed using a case-insensitive exact matching rule. For the Cipher service, its algorithm is the transformation string. If the property value contains entries with invalid syntax or unsupported services at the time of checking, an ExceptionInInitializerError with a cause of IllegalArgumentException will be thrown.

Note: This property is currently used by the JDK Reference implementation. It is not guaranteed to be examined and used by other implementations.

Specification

1. document the security property "jdk.crypto.disabledAlgorithms" in the java.security file. See patch below.

2. A release note will accompany this enhancement. Any necessary security docs updates willl be made also.

+#
+# Algorithm restrictions for Java Crypto API services
+#
+# In some environments, certain algorithms may be undesirable for certain
+# cryptographic services. For example, "MD2" is generally no longer considered
+# to be a secure hash algorithm.  This section describes the mechanism for
+# disabling algorithms at the JCA/JCE level based on service name and algorithm
+# name.
+#
+# If a system property of the same name is also specified, it supersedes the
+# security property value defined here.
+#
+# The syntax of the disabled services string is described as follows:
+#       "DisabledService {, DisabledService}"
+#
+#   DisabledService:
+#       Service.AlgorithmName
+#
+# Service:  (one of the following, more services may be added later)
+#     Cipher | KeyStore | MessageDigest | Signature
+#
+#   AlgorithmName:
+#       (see below)
+#
+# The "AlgorithmName" is the standard algorithm name of the disabled
+# service. See the Java Security Standard Algorithm Names Specification
+# for information about Standard Algorithm Names.  Matching is
+# performed using a case-insensitive exact matching rule. For Cipher service,
+# its algorithm is the transformation string.
+#
+# Note: If the property value contains entries with invalid syntax or
+# unsupported services at the time of checking, an ExceptionInInitializerError
+# with a cause of IllegalArgumentException will be thrown.
+#
+# Note: The restriction is applied in the various getInstance(...) methods
+# of the supported Service classes, i.e. Cipher, KeyStore, MessageDigest,
+# and Signature.
+#
+# Note: This property is currently used by the JDK Reference implementation.
+# It is not guaranteed to be examined and used by other implementations.
+#
+# Example:
+#   jdk.crypto.disabledAlgorithms=Cipher.RSA/ECB/PKCS1Padding, MessageDigest.MD2