RFR: 8349583: Add mechanism to disable signature schemes based on their TLS scope [v3]

[Artur Barashev]

On Mon, 24 Feb 2025 17:34:42 GMT, Artur Barashev <abarashev at openjdk.org> wrote:

>> src/java.base/share/classes/sun/security/ssl/SignatureScheme.java line 223:
>> 
>>> 221:     // Handshake signature scope
>>> 222:     public static final Set<SSLCryptoScope> HANDSHAKE_SCOPE =
>>> 223:             Collections.unmodifiableSet(EnumSet.of(SSLCryptoScope.HANDSHAKE));
>> 
>> I think you get the same with `Set.of(SSLCryptoScope.HANDSHAKE)`
>
> Yes, looks that way. I just re-used the collections type that was used before in this code. Actually `Set.of` utilizes stricter `ImmutableCollections` as opposed to current `UnmodifiableCollection`.

On the 2nd thought: `Set.of` was introduced in 2015, so it's not available in Java 8, this might be a problem when backporting this code.
@seanjmullan what are your thoughts about this?

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PR Review Comment: https://git.openjdk.org/jdk/pull/23681#discussion_r1968189436