Re: [PATCH] crypto: gcm - restrict assoclen for rfc4543
From: Iuliana Prodan
Date: Thu Jul 18 2019 - 10:56:43 EST
On 7/18/2019 5:46 PM, Herbert Xu wrote:
> On Thu, Jul 18, 2019 at 05:43:04PM +0300, Iuliana Prodan wrote:
>> Based on seqiv, IPsec ESP and rfc4543/rfc4106 the assoclen can be 16 or
>> 20 bytes.
>> >From esp4/esp6, assoclen is sizeof IP Header. This includes spi, seq_no
>> and extended seq_no, that is 8 or 12 bytes.
>> In seqiv, to asscolen is added the IV size (8 bytes).
>> Therefore, the assoclen, for rfc4543, should be restricted to 16 or 20
>> bytes, as for rfc4106.
>> Signed-off-by: Iuliana Prodan <iuliana.prodan@xxxxxxx>
> Why does this matter? Is it for the fuzz test?
Yes, this is for fuzz testing.
The generic implementation for rfc4543 considers any assoclen valid,
which is not correct.