---
name: "tpm_updatepcrhash"
section: "8"
platform: "linux"
package: "tpm-quote-tools"
version: "1.0.4-1+b3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/tpm_updatepcrhash"
---

# tpm\_updatepcrhash(8)

update a PCR composite hash

## NAME

tpm\_updatepcrhash - update a PCR composite hash

## SYNOPSIS

**tpm\_updatepcrhash** \[**-hv**\] OLD-HASH-FILE PCR-VALUE-FILE NEW\_HASH-FILE\

## DESCRIPTION

This program updates the PCR composite hash in file OLD-HASH-FILE to produce the file NEW-HASH-FILE. The new composite hash is computed from the data in the file PCR-VALUE-FILE, which contains a list of PCR index=value pairs.  The format of this file as the same as PCR value file generated by **tpm\_getpcrhash.**

- \-h

  Display command usage info.

- \-v

  Display command version info.

## SEE ALSO

[**tpm\_quote\_tools**(8)](/tpm_quote_tools/8.md), [**tpm\_mkaik**(8)](/tpm_mkaik/8.md), [**tpm\_getpcrhash**(8)](/tpm_getpcrhash/8.md), [**tpm\_getquote**(8)](/tpm_getquote/8.md)