On Thu, 17 Apr 2025 21:35:36 GMT, Valerie Peng <[email protected]> wrote:
>> This PR removes the internal JSSE HKDF impl and changes to use the KDF API
>> for the HKDF support from JCA/JCE providers.
>>
>> This is just code refactoring. Known-answer regression test for the internal
>> JSSE HKDF impl is removed as the test vectors are already covered by the
>> HKDF impl in SunJCE provider.
>>
>> Thanks in advance for the review~
>
> Valerie Peng has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Undo the special workaround for JSSE in PKCS11 HKDF impl.
src/java.base/share/classes/sun/security/ssl/KAKeyDerivation.java line 131:
> 129:
> 130: // derive handshake secret
> 131: return hkdf.deriveKey(type, HKDFParameterSpec.ofExtract()
The line above may fail because the `hkdf` object has been used once on line
121 with zero-valued salt and IKM, which selected the software-based HKDF from
SunJCE. At this point, however, `sharedSecret` is the result of ECDH and may be
non-extractable if produced by an HSM, making it incompatible with the SunJCE
implementation. To avoid this issue, get a new `hkdf` by calling `hkdf =
KDF.getInstance(hashAlg.hkdfAlgorithm)` before this line.
src/java.base/share/classes/sun/security/ssl/PreSharedKeyExtension.java line
851:
> 849: return hkdf.deriveKey("TlsBinderKey",
> 850: HKDFParameterSpec.expandOnly(earlySecret, hkdfInfo,
> 851: hashAlg.hashLength));
Is it possible to combine the 2 `deriveKey` calls above into a single
Extract-Then-Expand call? Then you don't need to clean up `earlySecret`.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/24393#discussion_r2060472356
PR Review Comment: https://git.openjdk.org/jdk/pull/24393#discussion_r2060479191
