From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephan =?ISO-8859-1?Q?M=FCller?= <smueller@chronox.de>
Subject: Re: What should be the algo priority
Date: Tue, 04 Apr 2017 14:37:02 +0200
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To: Harsh Jain <harshjain.prof@gmail.com>
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Am Dienstag, 4. April 2017, 09:53:17 CEST schrieb Harsh Jain:

Hi Harsh,

> Hi,
> 
> Do we have any guidelines documented to decide what should be the
> algorithm priority. Specially for authenc implementation.Most of the
> drivers have fixed priority for all algos. Problem comes in when we
> have cbc(aes), hmac(sha1) and authenc(cbc(aes),hmac(sha1))
> implementation in driver. Base authenc driver gets more precedence
> because of higher priority(enc->base.cra_priority * 10 +
> auth_base->cra_priority;)
> 
> What should be the priority of
> cbc(aes),
> hmac(sha1)
> authenc(cbc(aes),hmac(sha1))

There is no general rule about the actual numbers. But commonly, the prios are 
set such that the prios of C implementations < ASM implementations < hardware 
accelerators. The idea is to give users the fastest implementation there is 
for his particular system.

Ciao
Stephan