Re: [PATCH] crypto: aesni: add setkey for driver-gcm-aes-aesni

From: Stephan Mueller
Date: Mon Jan 19 2015 - 22:35:52 EST


Am Dienstag, 20. Januar 2015, 14:17:04 schrieb Herbert Xu:

Hi Herbert,

>On Sun, Jan 18, 2015 at 11:56:03PM +0100, Stephan Mueller wrote:
>> The cipher registered as __driver-gcm-aes-aesni is never intended
>> to be used directly by any caller. Instead it is a service mechanism
>> to rfc4106-gcm-aesni.
>>
>> The kernel crypto API unconditionally calls the registered setkey
>> function. In case a caller erroneously uses __driver-gcm-aes-aesni a
>> call to crypto_aead_setkey will cause a NULL pointer dereference
>> without this patch.
>>
>> CC: Tadeusz Struk <tadeusz.struk@xxxxxxxxx>
>> Signed-off-by: Stephan Mueller <smueller@xxxxxxxxxx>
>
>Rather than adding a bogus setkey function, please fix this mess
>properly by moving the top-level setkey function into the __driver
>one where it should be. Compare with how we handle it in the
>ablk_helper which is pretty much the same thing.

That is a good suggestion. And the modification is quite limited as the
existing rfc4106_set_key could be used for the __driver with only slight
modifications.

In that case, however, we should apply the same to rfc4106_set_authsize.

This in turn would then turn the __driver implementation into a full GCM
implementation. That would mean that we should rename it from __driver
into gcm(aes) / gcm-aesni.
>
>Thanks,


Ciao
Stephan
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