RFR: 8244336: Restrict algorithms at JCE layer

[Sean Mullan]

On Fri, 18 Jul 2025 01:44:33 GMT, Valerie Peng <valeriep at openjdk.org> wrote:

> This enhancement introduces a new security property "jdk.crypto.disabledAlgorithms" which can be leveraged to disable algorithms for JCE/JCA crypto services. For now, only Cipher, KeyStore, MessageDigest, and Signature services support this new security property. The support can be expanded later to cover more services if needed. Note that this security property is meant to disable algorithms irrespective of providers. If the algorithm is found to be disabled, it will be rejected before reaching out to provider(s) for the corresponding implementation(s).
> 
> A few implementation notes:
> 1) The specified security property value is lazily loaded and all changes after it's been loaded are ignored. Invalid entries, e.g. wrong syntax, are ignored and removed. The algorithm name check is case-insensitive. If a disabled algorithm is known to has an object identifier (oid) by JDK, this oid and its aliases is also added to the disabled services.
> 2) The algorithm name checking impl is based on the sun.security.util.AlgorithmConstraints class, but without the decomposing and different constraints.
> 3) The hardwiring of NONEwithRSA signature to RSA/ECB/PKCS1Padding cipher in java.security.Signature class is removed. Instead, this is moved to the provider level, i.e. SunJCE and SunPKCS11 provider are changed to claim the NONEwithRSA signature support. Disabling one will not affect the other. 
> 
> CSR will be filed once the review is wrapping up.
> 
> Thanks~
> Valerie

Some initial comments.

src/java.base/share/classes/javax/crypto/Cipher.java line 526:

> 524:      * on the transformation defaults used by JDK providers.
> 525:      * </li>
> 526:      * <li>the {@code jdk.crypto.disabledAlgorithms}

Missing "The JDK Reference Implementation additionally uses".

src/java.base/share/classes/javax/crypto/Cipher.java line 702:

> 700:      * on the transformation defaults used by JDK providers.
> 701:      *
> 702:      * @implNote

You also need a similar implNote for `getInstance(String, String)`.

src/java.base/share/classes/javax/crypto/Cipher.java line 706:

> 704:      * the {@code jdk.crypto.disabledAlgorithms}
> 705:      * {@link Security#getProperty(String) Security} property to determine
> 706:      * if the specified keystore type is allowed.

s/keystore type/algorithm/

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PR Review: https://git.openjdk.org/jdk/pull/26377#pullrequestreview-3053183717
PR Review Comment: https://git.openjdk.org/jdk/pull/26377#discussion_r2229514609
PR Review Comment: https://git.openjdk.org/jdk/pull/26377#discussion_r2229532938
PR Review Comment: https://git.openjdk.org/jdk/pull/26377#discussion_r2229513661