% tpm2_pcrextend(1) tpm2-tools | General Commands Manual


tpm2_pcrextend(1) - Extends a PCR.


tpm2_pcrextend [OPTIONS] PCR_DIGEST_SPEC


tpm2_pcrextend(1) - Extends the pcrs with values indicated by PCR_DIGEST_SPEC.

A PCR_DIGEST_SPEC is defined as follows:

  • A numerical PCR identifier.
  • A colon followed by the algorithm hash specification.

The algorithm hash specification is as follows: * The algorithm friendly name or raw numerical. * An equals sign. * The hex hash value.

Example Digest Specification


Note: Multiple specifications of PCR and hash are allowed. Multiple hashes cause the PCR to be extended with both hashes. Multiple same PCR values cause the PCR to be extended multiple times. Extension is done in order from left to right as specified. At most 5 hash extensions per PCR entry are supported. This is to keep the parser simple.


This tool accepts no tool specific options.

common options

common tcti options

PCR bank specifiers


Extend PCR 4's SHA1 bank with a hash

tpm2_pcrextend 4:sha1=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15

Extend PCR 4's SHA1 and SHA256 banks with hashes

tpm2_pcrextend 4:sha1=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15,sha256=b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c

Extend PCR 4's SHA1 and PCR 7's SHA256 bank with hashes

tpm2_pcrextend 4:sha1=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15 7:sha256=b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c