RFR: 8368073: PKCS11 HKDF can't use byte array IKM in FIPS mode

[Valerie Peng]

On Mon, 22 Sep 2025 23:57:20 GMT, Valerie Peng <valeriep at openjdk.org> wrote:

>> Enable HDKF to work with providers that do not allow secret keys to be created from arbitrary data.
>> 
>> This permits the TLS 1.3 handshake to complete with SunPKCS11 provider backed by NSS in FIPS mode.
>> 
>> I added a TLS 1.3 test case to an existing test. The new test passes with the HKDF changes, fails without them. Other tier1-3 tests continue to pass.
>
> src/jdk.crypto.cryptoki/share/classes/sun/security/pkcs11/P11HKDF.java line 268:
> 
>> 266:     }
>> 267: 
>> 268:     private long convertKeyToData(byte[] keyBytes) {
> 
> Check `keyBytes` being non-null?

Consider using `SecretKey` argument instead of `byte[]` so it's clear that `keyBytes` is entirely internal, then add a `finally` block to the `try` block to erase the key encoding, i.e. 

+        } finally {
+            Arrays.fill(keyBytes, (byte)0);
+        }

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PR Review Comment: https://git.openjdk.org/jdk/pull/27384#discussion_r2370671871