tpm2_pcrextend

Section: General Commands Manual (1)
Updated: SEPTEMBER 2017
Page Index

NAME

tpm2_pcrextend(1) - Extends a PCR.

SYNOPSIS

tpm2_pcrextend [OPTIONS] [PCR_DIGEST_SPEC]

DESCRIPTION

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:


4:sha=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15

Note: that 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.

OPTIONS

This tool accepts no tool specific options.

COMMON OPTIONS

This collection of options are common to many programs and provide information that many users may expect.

•: -h, -help: Display the tools manpage. This requires the manpages to be installed or on MANPATH, See man(1) for more details.
•: -v, -version: Display version information for this tool, supported tctis and exit.
•: -V, -verbose: Increase the information that the tool prints to the console during its execution. When using this option the file and line number are printed.
•: -Q, -quiet: Silence normal tool output to stdout.
•: -Z, -enable-errata: Enable the application of errata fixups. Useful if an errata fixup needs to be applied to commands sent to the TPM. # TCTI ENVIRONMENT

This collection of environment variables that may be used to configure the various TCTI modules available.

The values passed through these variables can be overridden on a per-command basis using the available command line options, see the TCTI_OPTIONS section.

The variables respected depend on how the software was configured.

•

TPM2TOOLS_TCTI_NAME: Select the TCTI used for communication with the next component down the TSS stack. In most configurations this will be the TPM but it could be a simulator or proxy. The current known TCTIs are:

•: tabrmd - The new resource manager, called tabrmd (https://github.com/01org/tpm2-abrmd).
•: socket - Typically used with the old resource manager, or talking directly to a simulator.
•: device - Used when talking directly to a TPM device file.

•

TPM2TOOLS_DEVICE_FILE: When using the device TCTI, specify the TPM device file. The default is "/dev/tpm0".

: Note: Using the tpm directly requires the users to ensure that concurrent access does not occur and that they manage the tpm resources. These tasks are usually managed by a resource manager. Linux 4.12 and greater supports an in kernel resource manager at "/dev/tpmrm", typically "/dev/tpmrm0".

•

TPM2TOOLS_SOCKET_ADDRESS: When using the socket TCTI, specify the domain name or IP address used. The default is 127.0.0.1.

•

TPM2TOOLS_SOCKET_PORT: When using the socket TCTI, specify the port number used. The default is 2321.

TCTI OPTIONS

This collection of options are used to configure the varous TCTI modules available. They override any environment variables.

•

-T, -tcti=TCTI_NAME[:TCTI_OPTIONS]: Select the TCTI used for communication with the next component down the TSS stack. In most configurations this will be the resource manager: tabrmd (https://github.com/01org/tpm2-abrmd) Optionally, tcti specific options can appended to TCTI_NAME by appending a : to TCTI_NAME.

•: For the device TCTI, the TPM device file for use by the device TCTI can be specified. The default is /dev/tpm0. Example: -T device:/dev/tpm0
•: For the socket TCTI, the domain name or IP address and port number used by the socket can be specified. The default are 127.0.0.1 and 2321. Example: -T socket:127.0.0.1:2321
•: For the abrmd TCTI, it takes no options. Example: -T abrmd

EXAMPLES

Extend PCR 4's SHA1 bank with a hash:


tpm2_pcrextend 4:sha=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15

Extend PCR 4's SHA1 and SHA256 banks with hashes:


tpm2_pcrextend 4:sha=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15,sha256:b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c

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


tpm2_pcrextend 4:sha=f1d2d2f924e986ac86fdf7b36c94bcdf32beec15 7:sha256:b5bb9d8014a0f9b1d61e21e796d78dccdf1352f23cd32812f4850b878ae4944c

RETURNS

0 on success or 1 on failure.

BUGS

Github Issues (https://github.com/01org/tpm2-tools/issues)

HELP

See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)