RFR: 8360463: Ambiguity in Cipher.getInstance() specification between NoSuchAlgorithmException and NoSuchPaddingException [v8]

[Valerie Peng]

On Thu, 18 Sep 2025 00:06:01 GMT, Valerie Peng <valeriep at openjdk.org> wrote:

>> This PR is for clarifying the `NoSuchAlgorithmException` and `NoSuchPaddingException` for the `Cipher.getInstance(String transformation, Provider provider)` and `Cipher.getInstance(String transformation, String provider)` methods.
>> 
>> As stated in `javax.crypto.CipherSpi` class, provider has the flexibility to register their implementations through various sub-transformations. As a result, depending on how the providers register the implementation, it may lead to `NoSuchAlgorithmException` or `NoSuchPaddingException`. For example, the provider A registers to support "AES/CBC/PKCS5Padding" vs provider B registers to support "AES" (but would only accept "CBC" and "PKCS5Padding" as the valid input for setting mode and padding). Calling `Cipher.getInstance(...)` with "AES/CBC/NoPadding" against provider A and B would lead to `NoSuchAlgorithmException` and `NoSuchPaddingException`. This javadoc update hope to make it clear.
>> 
>> Thanks in advance for the review~
>> Valerie
>
> Valerie Peng has updated the pull request incrementally with one additional commit since the last revision:
> 
>   updated the checkTransformation() method w/ specific provider and
>   exception per Sean's suggestion

Release Note is filed @ https://bugs.openjdk.org/browse/JDK-8367577
Thanks in advance for review~

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PR Comment: https://git.openjdk.org/jdk/pull/26489#issuecomment-3305067363