Bug 27506 - Inconsistent error for AES-CTR's "get key length" operation

[mwatson2]

Bug 27506:

AES-CTR throws a DataError in its "get key length" operation if the length is not one of {128, 192, 256}.

Whereas the other AES algorithms throw an OperationError in this case.

I suggest using OperationError for AES-CTR to match the others.

[mwatson2]

@jimsch wrote:

I agree that this should be made consistent. However I believe that DataError would be the correct error returned in this case. The data provided is incorrect.

I believe we are using DataError for the cases where encoded key import data (raw, ASN.1 or JWK) is in error and we are using OperationError for anything where the directly supplied parameters are in error.

Get key length is used by deriveKey to peek the length of the desired derived key, so it does not process encoded key import data, only directly provided parameters.

So, I think OperationError is correct.

[jimsch]

I can live with this

[mwatson2]

PR #112

[engelke]

The PR looks good to me.