RFR: 8302017: Allocate BadPaddingException only if it will be thrown

[Valerie Peng]

On Wed, 12 Jul 2023 16:58:20 GMT, Xue-Lei Andrew Fan <xuelei at openjdk.org> wrote:

>> This change refactors the RSAPadding class to return an output record containing the status instead of relying on exception object to indicate a failure.
>> 
>> Thanks in advance for review~
>> Valerie
>
> src/java.base/share/classes/sun/security/rsa/RSASignature.java line 217:
> 
>> 215:             byte[] digest = getDigestValue();
>> 216:             byte[] decrypted = RSACore.rsa(sigBytes, publicKey);
>> 217:             RSAPadding.Output po = padding.unpad(decrypted);
> 
> In case you are already here, what if comparing the padded/encoded result, without use unpad() any longer? I meant to follow the spec as described in RFC8017#section-8.2.2: encode the `decryped` bytes and then compare the result with the `digest` bytes.

Ok, I can switch to this approach.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14839#discussion_r1261612766