Messages in this thread | | | Subject | Re: [Linux-ima-devel] [PATCH v2 4/5] keys, trusted: modify arguments of tpm_pcr_extend() | From | Roberto Sassu <> | Date | Tue, 30 May 2017 15:41:13 +0200 |
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On 5/30/2017 2:06 PM, Mimi Zohar wrote: > On Tue, 2017-05-30 at 09:36 +0200, Roberto Sassu wrote: >> On 5/30/2017 5:35 AM, Mimi Zohar wrote: >>> On Fri, 2017-05-05 at 16:21 +0200, Roberto Sassu wrote: >>>> pcrlock() has been modified to pass the correct arguments >>>> to tpm_pcr_extend(): the pointer of a tpm2_digest structure containing >>>> a random value generated by tpm_get_random() and the size of the array (1). >>> >>> If the number of arguments is wrong, that means the patch that >>> introduced the change is not bi-sect safe. (This comment is >>> applicable to patch 5/5 too.) >> >> Jarkko (the TPM driver maintainer) asked me to not introduce >> a new function to pass multiple digests, but to modify >> the parameters of tpm_pcr_extend(). > > Since struct tpm2_digest is a static size, shouldn't we be able to > compute the number of digests?
The length of 'hash' is not passed to tpm_pcr_extend().
The only way to avoid changing the number of parameters would be to pass a buffer whose format is the same of the event log format defined by TCG:
<algo count> <algo1 ID> <digest1> ... <algoN ID> <digestN>
Roberto
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