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Date:   Thu, 20 May 2021 19:39:33 +0300
From:   Jarkko Sakkinen <jarkko@kernel.org>
To:     amirmizi6@gmail.com
Cc:     Eyal.Cohen@nuvoton.com, peterhuewe@gmx.de, jgg@ziepe.ca,
        linux-kernel@vger.kernel.org, linux-integrity@vger.kernel.org,
        Dan.Morav@nuvoton.com, oren.tanami@nuvoton.com,
        shmulik.hager@nuvoton.com, amir.mizinski@nuvoton.com
Subject: Re: [PATCH v2] tpm2: add longer timeout for verify signature command
Message-ID: <YKaQxV4wzZ/UYrdu@kernel.org>
References: <20210519140059.85919-1-amirmizi6@gmail.com>
 <20210519140059.85919-2-amirmizi6@gmail.com>
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On Wed, May 19, 2021 at 05:00:59PM +0300, amirmizi6@gmail.com wrote:
> From: Amir Mizinski <amirmizi6@gmail.com>
> 
> While running a TPM2_CC_VERIFY_SIGNATURE(0x177) operation with RSA 3070-bit

The hexcode for the TPM command is absoulutely irrelevant detail.

AFAIK, 3070-bit does not exist. It's 3072-bit.

> keys the TPM driver fails with the following error:

Empty line here.

> "kernel: [ 2416.187522] tpm tpm0: Operation Timed out"
> 
> Since a) the TPM PC Client specification does not specify a number for

Remove "a)".
> verify signature operation timeout, and b) the duration of

Remove "b)".

> TPM2_CC_VERIFY_SIGNATURE with RSA 3070-bit keys exceeds the current timeout
> of TPM_LONG (2 seconds), it is preferable to pick the longest timeout
> possible.

Empty line here.

> Therefore, set the duration for TPM2_CC_VERIFY_SIGNATUE to TPM_LONG_LONG
> (5 minutes).
> 
Add here:

Link: https://trustedcomputinggroup.org/resource/pc-client-specific-platform-firmware-profile-specification/

> Signed-off-by: Amir Mizinski <amirmizi6@gmail.com>


> ---
>  drivers/char/tpm/tpm2-cmd.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 7603295..e71154b 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -87,7 +87,7 @@ static u8 tpm2_ordinal_duration_index(u32 ordinal)
>  		return TPM_MEDIUM;
>  
>  	case TPM2_CC_VERIFY_SIGNATURE:        /* 177 */
> -		return TPM_LONG;
> +		return TPM_LONG_LONG;
>  
>  	case TPM2_CC_PCR_EXTEND:              /* 182 */
>  		return TPM_MEDIUM;
> -- 
> 2.7.4
> 
> 

/Jarkko