Subject: Re: [PATCH 5/7] esp6: Switch to new AEAD interface

From: Stephan Mueller <[email-masked]>
Date: Tue, 26 May 2015 10:15:37 +0200

Am Dienstag, 26. Mai 2015, 15:57:59 schrieb Herbert Xu:

Hi Herbert,

>On Tue, May 26, 2015 at 09:56:17AM +0200, Stephan Mueller wrote:
>> Actually, I mean the real in-kernel crypto API: the IKE daemon would set up
>> the SA via XFRM where the rfc4106(gcm(aes)) cipher is set, is it not? So,
>> user space is responsible to set the right IPSEC cipher.
>> 
>> As that user space cipher name is now changed, user space would need to be
>> aware of that modification, would it not?
>
>No the change was done in a backwards compatible way.  So if you
>allocate rfc4106(gcm(aes)) and use the givencrypt interface (not
>encrypt) then you still get the old behaviour.

I fully understand that. But the current patch set that we discuss modifies 
the IPSEC implementation of esp_ouput to use the new interface. Therefore, to 
use rfc4106(gcm(aes)) *with* the IV generator (i.e. to get the old removed 
givcrypt logic), the AEAD cipher handle must be allocated with 
seqniv(rfc4106(gcm(aes))), would it not?

Therfore, I would assume that user space has to use the new cipher name when 
setting up IPSEC that uses the new interface.

Ciao
Stephan