Received-SPF: pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Horia Geanta <horia.geanta@nxp.com>
To:     Iuliana Prodan <iuliana.prodan@nxp.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>
CC:     "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        dl-linux-imx <linux-imx@nxp.com>
Subject: Re: [PATCH v3] crypto: gcm - restrict assoclen for rfc4543
Thread-Topic: [PATCH v3] crypto: gcm - restrict assoclen for rfc4543
Thread-Index: AQHVRsZerF9ZNFVjE0av/0yPv9d+JA==
Date:   Tue, 30 Jul 2019 11:50:08 +0000
Message-ID: <VI1PR0402MB3485631639ADE29D91C4B6C298DC0@VI1PR0402MB3485.eurprd04.prod.outlook.com>
References: <1564484077-27727-1-git-send-email-iuliana.prodan@nxp.com>
Accept-Language: en-US
Content-Language: en-US
received-spf: None (protection.outlook.com: nxp.com does not designate
 permitted sender hosts)
Content-Type: text/plain; charset="iso-8859-2"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-MS-Exchange-CrossTenant-Network-Message-Id: f25c55da-1bd2-4b30-82a4-08d714e41213
X-MS-Exchange-CrossTenant-originalarrivaltime: 30 Jul 2019 11:50:08.3362
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: 686ea1d3-bc2b-4c6f-a92c-d99c5c301635
X-MS-Exchange-CrossTenant-mailboxtype: HOSTED
X-MS-Exchange-CrossTenant-userprincipalname: horia.geanta@nxp.com
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0402MB2735
Sender: linux-crypto-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-crypto.vger.kernel.org>
X-Mailing-List: linux-crypto@vger.kernel.org

On 7/30/2019 2:03 PM, Iuliana Prodan wrote:=0A=
> Based on seqiv, IPsec ESP and rfc4543/rfc4106 the assoclen can be 16 or=
=0A=
> 20 bytes.=0A=
> =0A=
> From esp4/esp6, assoclen is sizeof IP Header. This includes spi, seq_no=
=0A=
> and extended seq_no, that is 8 or 12 bytes.=0A=
> In seqiv, to asscolen is added the IV size (8 bytes).=0A=
> Therefore, the assoclen, for rfc4543, should be restricted to 16 or 20=0A=
> bytes, as for rfc4106.=0A=
> =0A=
> Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>=0A=
Reviewed-by: Horia Geant=E3 <horia.geanta@nxp.com>=0A=
=0A=
[...]=0A=
> diff --git a/crypto/gcm.c b/crypto/gcm.c=0A=
> index 2f3b50f..7eb5ced 100644=0A=
> --- a/crypto/gcm.c=0A=
> +++ b/crypto/gcm.c=0A=
> @@ -1034,11 +1034,23 @@ static int crypto_rfc4543_copy_src_to_dst(struct =
aead_request *req, bool enc)=0A=
>  =0A=
>  static int crypto_rfc4543_encrypt(struct aead_request *req)=0A=
>  {=0A=
> +	int err;=0A=
> +=0A=
> +	err =3D crypto_ipsec_check_assoclen(req->assoclen);=0A=
> +	if (err)=0A=
> +		return err;=0A=
> +=0A=
>  	return crypto_rfc4543_crypt(req, true);=0A=
>  }=0A=
Could as well be:=0A=
	return crypto_ipsec_check_assoclen(req->assoclen) ?:=0A=
	       crypto_rfc4543_crypt(req, true);=0A=
=0A=
The same for decryption.=0A=
=0A=
Horia=0A=