On Mon, 14 Apr 2025 19:01:45 GMT, Francisco Ferrari Bihurriet
<fferr...@openjdk.org> wrote:
>> As far as I understand it, `HmacSHA256` is blocked, but not
>> `PBEWithHmacSHA224AndAES_256`.
>>
>> ### `HmacSHA256`
>>
>> * Has an `HMACKeyInfo` entry with the following non-static fields:
>> * `KeyInfo.algo` = `"HmacSHA256"`
>> * `KeyInfo.keyType` = `CKK_GENERIC_SECRET`
>> * `KeyInfo.keyGenMech` = `CK_UNAVAILABLE_INFORMATION`
>> * `HMACKeyInfo.mech` = `CKM_SHA256_HMAC`
>> * `HMACKeyInfo.keyLen` = `256`
>>
>> Given `ki.keyType` is `CKK_GENERIC_SECRET` and `alg` is `HmacSHA256`, in
>> `P11HKDF::getDerivedKeyType` it will enter the first `case` but not the
>> `if`. So it will finally throw the expected exception:
>>
>>
>> InvalidAlgorithmParameterException("A key of algorithm 'HmacSHA256' is not
>> valid for derivation.")
>>
>>
>> ### `PBEWithHmacSHA224AndAES_256`
>>
>> * Has an `AESPBEKeyInfo` entry with the following non-static fields:
>> * `KeyInfo.algo` = `"PBEWithHmacSHA224AndAES_256"`
>> * `KeyInfo.keyType` = `CKK_AES`
>> * `KeyInfo.keyGenMech` = `CK_UNAVAILABLE_INFORMATION`
>> * `PBEKeyInfo.kdfMech` = `CKM_PKCS5_PBKD2`
>> * `PBEKeyInfo.prfMech` = `CKP_PKCS5_PBKD2_HMAC_SHA224`
>> * `PBEKeyInfo.keyLen` = `256`
>> * `PBEKeyInfo.extraAttrs` = `new CK_ATTRIBUTE[] {
>> CK_ATTRIBUTE.ENCRYPT_TRUE }`
>>
>> Given `ki.keyType` is `CKK_AES`, in `P11HKDF::getDerivedKeyType` it will
>> enter the first `case` and also the `if`, returning `CKK_AES`. Later, in
>> `P11KeyGenerator::checkKeySize(..., Token token)`,
>> `P11KeyGenerator::getSupportedRange` will return `null`, because
>> `ki.keyGenMech` is `CK_UNAVAILABLE_INFORMATION`. This will make
>> `P11KeyGenerator::checkKeySize(..., CK_MECHANISM_INFO range)` enter the
>> `default` case, and finally return the unmodified `keySize`. No exception is
>> thrown, unless I'm missing something.
>
> Also, we could save one of the `if` conditions by creating a separate `case`
> for `CKK_GENERIC_SECRET`:
>
>
> switch ((int) ki.keyType) {
> case (int) CKK_DES, (int) CKK_DES3, (int) CKK_AES, (int) CKK_RC4,
> (int) CKK_BLOWFISH, (int) CKK_CHACHA20 -> {
> return ki.keyType;
> }
> case (int) CKK_GENERIC_SECRET -> {
> if (alg.equalsIgnoreCase("Generic")) {
> return ki.keyType;
> }
> }
> // [...]
> }
>
>
> In my view, this is quicker to understand, what do you think?
Yes, I much prefer this idea of separate case for `CKK_GENERIC_SECRET`.
-------------
PR Review Comment: https://git.openjdk.org/jdk/pull/24526#discussion_r2047543388
