Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v7 2/7] tpm: tpm_tis: Add verify_data_integrity handle toy
 tpm_tis_phy_ops
To:     Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc:     Eyal.Cohen@nuvoton.com, oshrialkoby85@gmail.com,
        alexander.steffen@infineon.com, robh+dt@kernel.org,
        mark.rutland@arm.com, peterhuewe@gmx.de, jgg@ziepe.ca,
        arnd@arndb.de, gregkh@linuxfoundation.org, benoit.houyere@st.com,
        eajames@linux.ibm.com, joel@jms.id.au, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org,
        oshri.alkoby@nuvoton.com, tmaimon77@gmail.com, gcwilson@us.ibm.com,
        kgoldman@us.ibm.com, Dan.Morav@nuvoton.com,
        oren.tanami@nuvoton.com, shmulik.hager@nuvoton.com,
        amir.mizinski@nuvoton.com,
        Christophe Ricard <christophe-h.ricard@st.com>
References: <20200427124931.115697-1-amirmizi6@gmail.com>
 <20200427124931.115697-3-amirmizi6@gmail.com>
 <20200429053456.GE8452@linux.intel.com>
From:   Amir Mizinski <amirmizi6@gmail.com>
Message-ID: <d0eec29a-20f5-1187-f0c3-c564879d7878@gmail.com>
Date:   Thu, 30 Apr 2020 10:19:09 +0000
User-Agent: Mozilla/5.0 (X11; Linux armv7l; rv:68.0) Gecko/20100101
 Thunderbird/68.7.0
MIME-Version: 1.0
In-Reply-To: <20200429053456.GE8452@linux.intel.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk


On 2020-04-29 05:34, Jarkko Sakkinen wrote:
> On Mon, Apr 27, 2020 at 03:49:26PM +0300, amirmizi6@gmail.com wrote:
>> +    bool (*verify_data_integrity)(struct tpm_tis_data *data, const u8 *buf,
>> +                      size_t len);
>
> Why can't the i2c driver verify this in the end of read_bytes()?
>

The TPM calculates the checksum of the entire command data at the end
of command transmission or the checksum of the entire response data at the
end of response transmission.
read_bytes is not necessarily called at the end of response transmission. Same for write_bytes.

> /Jarkko