From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753944AbbLIMTf (ORCPT ); Wed, 9 Dec 2015 07:19:35 -0500 Received: from helcar.hengli.com.au ([209.40.204.226]:33896 "EHLO helcar.hengli.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750904AbbLIMTc (ORCPT ); Wed, 9 Dec 2015 07:19:32 -0500 Date: Wed, 9 Dec 2015 20:18:58 +0800 From: Herbert Xu To: "Jason A. Donenfeld" Cc: davem@davemloft.net, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, Netdev , martin@strongswan.org, stable@vger.kernel.org Subject: Re: [PATCH 1/2] blkcipher: Copy iv from desc even for 0-len walks Message-ID: <20151209121858.GC27962@gondor.apana.org.au> References: <1449366698-2422-1-git-send-email-Jason@zx2c4.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1449366698-2422-1-git-send-email-Jason@zx2c4.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 06, 2015 at 02:51:37AM +0100, Jason A. Donenfeld wrote: > Some ciphers actually support encrypting zero length plaintexts. For > example, many AEAD modes support this. The resulting ciphertext for > those winds up being only the authentication tag, which is a result of > the key, the iv, the additional data, and the fact that the plaintext > had zero length. The blkcipher constructors won't copy the IV to the > right place, however, when using a zero length input, resulting in > some significant problems when ciphers call their initialization > routines, only to find that the ->iv parameter is uninitialized. One > such example of this would be using chacha20poly1305 with a zero length > input, which then calls chacha20, which calls the key setup routine, > which eventually OOPSes due to the uninitialized ->iv member. > > Signed-off-by: Jason A. Donenfeld > Cc: Applied to crypto. -- Email: Herbert Xu Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt