Re: [Trustedjava-support] Another problem when running tests

[Carolin L. <car...@un...>]

Hi Thomas,

thanks for the hint on how to use a clean setup. You were right. Now, I
am able to reproduce the problem using my C program. Perhaps it has to
do with the new version of the TPM emulator (I used version 0.3 before
installing jTSS).

Bye
Carolin

Thomas Winkler wrote:
> Hi Carolin,
>
>   
>> when I first clear the owner, using the clearOwner method of the TcITpm
>> class, a new owner can be set. But where does the wrapper store the
>> information whether a TPM has already been owned or not? I think, there
>> has to be a file on my HD. I thought, it has to be in the system.data
>> file in /var/tpm/, but deleting this file and reloading the module does
>> not help...
>>     
>
> Nor the wrapper nor the TSS stores if the TPM is already owned. The TPM
> itself knows if ownership is already taken or not. The file
> /usr/local/var/lib/tpm/system.data is the persistent system storage of
> the TrouSerS TSS.
> If you are using TPM emulator, there is another file representing the
> internal state of the TPM. It's default location is /var/tpm. The file
> name starts with tpm_emulator (the exact name depends on the version of
> the emulator you are using). Note that this file might not exist until
> you unload the emulator module. Upon unloading the emulator writes it's
> internal state to this file.
> So - if you want to start with a clean setup: Unload the emulator, make
> sure /var/tpm is empty and also delete the system.data file of TrouSerS
> (note that there also might be a ~/.trousers/user.data file from
> TrouSerS 0.2.7 onwards). Then load them emulator and start TrouSerS.
>
> The "Authentication failed" message you mentioned in your last mail is a
> known issue but the reasons for it are currently unclear. This seems to
> occur if the TSS/TPM is put under stress (i.e. it occasionally happens
> if you are running sequences with many TPM operations but it does not
> happen when executing them one by one). The problem has been reported to
> Kent Yoder (TrouSerS maintainer) and was confirmed by him. A solution is
> currently not known.
> I personally do not think that it is a problem of the jTSS wrapper
> because one can also trigger this behaviour when using TrouSerS with
> plain C test programs.
>
> Regards,
> Thomas Winkler
> IAIK, TU Graz, Austria
>
>
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