Re: [tpm2] NVRAM_write, BUFFER_SIZE is 0

[Duncan.Palmer at data61.csiro.au]

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Thanks for updating the patch with a default size William. Sorry, I hadn't the time to do it yet...


Duncan Palmer
Senior Software Engineer | Autonomous Systems
Data61 | CSIRO

E duncan.palmer(a)csiro.au

Queensland Centre for Advanced Technologies (QCAT),

1 Technology Court, Pullenvale QLD, 4069

www.data61.csiro.au<http://my.csiro.au/Business-Units/Operations/Communication/CSIRO-Branding/Data61-Branding/www.data61.csiro.au>


CSIRO's Digital Productivity business unit and NICTA have joined forces to create digital powerhouse Data61

________________________________
From: Ian Oliver <ian.justin.oliver(a)gmail.com>
Sent: 26 April 2018 03:02
To: Roberts, William C
Cc: Palmer, Duncan (Data61, Pullenvale); tpm2(a)lists.01.org
Subject: Re: [tpm2] NVRAM_write, BUFFER_SIZE is 0

Actually some TPMs aren't reporting this value as part of the properties (tpm2_getcap -c properties-fixed IIRC) so it gets interpreted as 0.

Can you also confirm the maximum size of an NV_RAM area, or is it always bounded by MAX_NV_BUFFER_SIZE  ?

t.

Ian

On 25 April 2018 at 19:29, Roberts, William C <william.c.roberts(a)intel.com<mailto:william.c.roberts(a)intel.com>> wrote:
I have heard of this bug before but never encountered it. I looked at the PR:
https://github.com/tpm2-software/tpm2-tools/pull/1002

I heard as well that setting the buffer to something smaller than MAX size and that 512 bytes is recommended.
Someone actually polled the vendors to find out what buffer size is always a safe bet, and 512 was it.

> -----Original Message-----
> From: tpm2 [mailto:tpm2-bounces(a)lists.01.org<mailto:tpm2-bounces(a)lists.01.org>] On Behalf Of Ian Oliver
> Sent: Tuesday, April 24, 2018 7:48 AM
> To: Duncan.Palmer(a)data61.csiro.au<mailto:Duncan.Palmer(a)data61.csiro.au>
> Cc: tpm2(a)lists.01.org<mailto:tpm2(a)lists.01.org>
> Subject: Re: [tpm2] NVRAM_write, BUFFER_SIZE is 0
>
> Thanks,
>
>
> We are seeing the same issue on the TPMs in our Intel NUCs .. Infineon 9655s ?
> Need to check tomorrow
>
>
> t.
>
>
> Ian
>
>
> On 24 April 2018 at 15:51, <Duncan.Palmer(a)data61.csiro.au<mailto:Duncan.Palmer(a)data61.csiro.au>
> <mailto:Duncan.Palmer(a)data61.csiro.au<mailto:Duncan.Palmer(a)data61.csiro.au>> > wrote:
>
>
>       Done. I hadn't submitted a pull request before as I was unsure whether
> this issue was related to the TPM I'm using (which doesn't seem commonly
> used), or more generally applicable.
>
>       Duncan Palmer
>       Senior Software Engineer | Autonomous Systems
>       Data61 | CSIRO
>       E duncan.palmer(a)csiro.au
>       Queensland Centre for Advanced Technologies (QCAT),
>       1 Technology Court, Pullenvale QLD, 4069
>       www.data61.csiro.au<http://www.data61.csiro.au> <http://www.data61.csiro.au>
>
>       CSIRO's Digital Productivity business unit and NICTA have joined forces to
> create digital powerhouse Data61
>
>       ________________________________________
>       From: Tadeusz Struk <tadeusz.struk(a)intel.com<mailto:tadeusz.struk(a)intel.com>
> <mailto:tadeusz.struk(a)intel.com<mailto:tadeusz.struk(a)intel.com>> >
>       Sent: 19 April 2018 04:17
>       To: Palmer, Duncan (Data61, Pullenvale); ian.justin.oliver(a)gmail.com<mailto:ian.justin.oliver(a)gmail.com>
> <mailto:ian.justin.oliver(a)gmail.com<mailto:ian.justin.oliver(a)gmail.com>> ; tpm2(a)lists.01.org<mailto:tpm2(a)lists.01.org>
> <mailto:tpm2(a)lists.01.org<mailto:tpm2(a)lists.01.org>>
>       Subject: Re: [tpm2] NVRAM_write, BUFFER_SIZE is 0
>
>
>       On 04/17/2018 03:24 PM, Duncan.Palmer(a)data61.csiro.au<mailto:Duncan.Palmer(a)data61.csiro.au>
> <mailto:Duncan.Palmer(a)data61.csiro.au<mailto:Duncan.Palmer(a)data61.csiro.au>>  wrote:
>       > We see the same behaviour on an Intel NUC5i7. I haven't looked at the
> capabilities reported by the TPM device on that platform. The attached patch
> (setting max_data_size = MAX_NV_BUFFER_SIZE when max_data_size is
> reported as 0), sorts the problem out.
>       >
>
>       Hi Duncan,
>       Could you please send a Pull Request with your fix to the tools repo.
>
>       Thanks,
>       --
>       Tadeusz
>
>
>
>
>
>
> --
>
> Dr. Ian Oliver
> ===============================
>
> Privacy Engineering:  via Amazon <http://www.amazon.co.uk/dp/1497569710>
> Twitter: @i_j_oliver



--
Dr. Ian Oliver
===============================
Privacy Engineering:  via Amazon<http://www.amazon.co.uk/dp/1497569710>
Twitter: @i_j_oliver

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