RFR: JDK-6676643: Improve current C_GetAttributeValue native implementation

[Valerie Peng]

On Tue, 27 Apr 2021 04:31:42 GMT, Greg Rubin <github.com+829871+SalusaSecondus at openjdk.org> wrote:

>> Anyone can help review this somewhat trivial fix? The main change is inside src/jdk.crypto.cryptoki/share/native/libj2pkcs11/p11_objmgmt.c. This is to help better troubleshooting by reporting the type of unavailable attributes in PKCS11 exception message when C_GetAttributeValue(...) call failed. The java file changes are just cleanup for consolidating the CKR_* constants definition into PKCS11Exception class.
>> 
>> Thanks,
>> Valerie
>
> src/jdk.crypto.cryptoki/share/native/libj2pkcs11/p11_objmgmt.c line 252:
> 
>> 250: 
>> 251:     if (rv != CKR_OK) {
>> 252:         if (rv == CKR_ATTRIBUTE_SENSITIVE || rv == CKR_ATTRIBUTE_TYPE_INVALID) {
> 
> According to the PKCS#11v2.40 spec, `CKR_BUFFER_TOO_SMALL` should be handled in the same special ways as these too (in that it isn't a "true error").

For this particular call, the pValue field is null, it's meant to query the exact length of the specified attribute. Thus, CKR_BUFFER_TOO_SMALL should not be returned. 
Afterwards, we then allocate the buffer based on this queried result, so CKR_BUFFER_TOO_SMALL should also not occur.
So, based on the current API usage, CKR_BUFFER_TOO_SMALL should not happen.

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PR: https://git.openjdk.java.net/jdk/pull/3709