RFR: 8271566: DSA signature length value is not accurate in P11Signature [v3]

[Valerie Peng]

On Thu, 2 Dec 2021 21:31:52 GMT, Martin Balao <mbalao at openjdk.org> wrote:

>> As described in JDK-8271566 [1], this patch proposal is intended to fix a problem that arises when using DSA keys that have a 256-bits (or larger) G parameter for signatures (either signing or verifying). There were some incorrect assumptions and hard-coded length values in the code before. Please note that, for example, the tuple (2048, 256) for DSA is valid according to FIPS PUB 186-4.
>> 
>> Beyond the specific issues in signatures, I decided to provide a broader solution and enable key parameter retrieval for other key types (EC, DH) when possible. This is, when the key is not sensitive. One thing that I should note here is that token keys (those that have the CKA_TOKEN attribute equal to 'true') are considered sensitive in this regard, at least by the NSS Software Token implementation. I don't have access to other vendor implementations but if there is any concern, we can adjust the constraint to NSS-only. However, I'm not sure which use-case would require to get private keys out of a real token, weakening its security. I'd be more conservative here and not query the values if not sure that it will succeed.
>> 
>> No regressions found in jdk/sun/security/pkcs11. A new test added: LargerDSAKey.
>> 
>> --
>> [1] - https://bugs.openjdk.java.net/browse/JDK-8271566
>
> Martin Balao has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains six commits:
> 
>  - 8271566: DSA signature length value is not accurate in P11Signature (Webrev.02 based)
>  - Merge branch 'master' into JDK-8271566
>  - Revert 8271566: DSA signature length value is not accurate in P11Signature
>  - Revert P11Key static inner classes refactorings.
>  - P11Key static inner classes refactorings.
>  - 8271566: DSA signature length value is not accurate in P11Signature

src/jdk.crypto.cryptoki/share/classes/sun/security/pkcs11/P11Key.java line 126:

> 124:         boolean sensitive = false;
> 125:         boolean extractable = true;
> 126:         for (CK_ATTRIBUTE attr : attrs) {

Just noticed this: add a check for non-null attrs? If null, skip the for-loop.

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PR: https://git.openjdk.java.net/jdk/pull/4961