From: Harsh Jain Subject: Who will copy the AAD data to dest. buffer Date: Fri, 2 Sep 2016 20:05:04 +0530 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 To: Herbert Xu , linux-crypto@vger.kernel.org, Stephan Mueller Return-path: Received: from mail-oi0-f43.google.com ([209.85.218.43]:35623 "EHLO mail-oi0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753332AbcIBOfF (ORCPT ); Fri, 2 Sep 2016 10:35:05 -0400 Received: by mail-oi0-f43.google.com with SMTP id p186so128450316oia.2 for ; Fri, 02 Sep 2016 07:35:05 -0700 (PDT) Sender: linux-crypto-owner@vger.kernel.org List-ID: Hi Herbert, Is copy of AAD data to destination buffer when dst != src is mandatory requirements for crypto drivers or we can skip this copy. Actually I am bit confused, In following link Stephen had mentioned caller will memcpy the AAD to destination buffer but authenc.c also copies the AAD to dest. buffer. http://www.chronox.de/libkcapi/html/ch02s02.html Secondly When AAD data remains unchanged in AEAD encryption/decryption operations. Why we copy the same data to destination buffer? Thanks & Regards Harsh Jain