[SeaBIOS] [PATCH v3 4/7] tpm: Extend tpm20_extend to support extending to multiple PCR banks

Kevin O'Connor kevin at koconnor.net
Wed Aug 10 19:22:19 CEST 2016


On Wed, Aug 10, 2016 at 11:17:30AM -0400, Kevin O'Connor wrote:
> How about the update below (which I'll squash into the appropriate
> patches).
> 
> -Kevin
> 
> 
> --- a/src/std/tcg.h
> +++ b/src/std/tcg.h
> @@ -518,6 +518,11 @@ struct tpm2_digest_values {
>      struct tpm2_digest_value digest[0];
>  } PACKED;
>  
> +// Each entry in the TPM log contains: a tpm_log_header, a variable
> +// length digest, a tpm_log_trailer, and a variable length event.  On
> +// TPM1.2 the digest is a SHA1 hash; on TPM2.0 the digest contains a
> +// tpm2_digest_values struct followed by a variable number of
> +// tpm2_digest_value structs.

Or slightly more detailed here:

// Each entry in the TPM log contains: a tpm_log_header, a variable
// length digest, a tpm_log_trailer, and a variable length event.  The
// 'digest' matches what is sent to the TPM hardware via the Extend
// command.  On TPM1.2 the digest is a SHA1 hash; on TPM2.0 the digest
// contains a tpm2_digest_values struct followed by a variable number
// of tpm2_digest_value structs (as specified by the hardware via the
// TPM2_CAP_PCRS request).

-Kevin



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