Section: General Commands Manual (1)
Updated: SEPTEMBER 2017
tpm2_certify(1) - prove that an object is loaded in the tpm.
tpm2_certify(1) proves that an object with a specific
NAME is loaded in the TPM.
By certifying that the object is loaded, the TPM warrants that a public
area with a given NAME is self-consistent and associated with
a valid sensitive area.
If a relying party has a public area that has the same NAME as
a NAME certified with this command, then the values in that
public area are correct.
The object may be any object that is loaded with TPM2_Load() or
An object that only has its public area loaded cannot be certified.
These options control the ceritifcation:
-H, -obj-handle=OBJECT_HANDLE: The
handle of the object to be certified.
-C, -obj-context=FILE: Use
FILE for providing the object context.
-k, -key-handle=KEY_HANDLE: Handle of
the key used to sign the attestation structure.
-c, -key-context=KEY_CONTEXT: Filename
of the key context used to sign the attestation structure.
-P, -pwdo=OBJECT_PASSWORD: Use
OBJECT_PASSWORD for providing an authorization value for the
object specified in OBJECT_HANDLE.
Passwords should follow the "password formatting standards, see
-K, -pwdk=KEY_PASSWORD: Use
KEY_PASSWORD for providing an authorization value for the key
specified in KEY_HANDLE.
Follows the same formatting guidelines as the object handle password or
-a, -attest-file=ATTEST_FILE: Output
file name for the attestation data.
-s, -sig-file=SIG_FILE: Output file
name for the signature data.
Format selection for the signature output file.
See section "Signature Format Specifiers".
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
Useful if an errata fixup needs to be applied to commands sent to the
# 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
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
The current known TCTIs are:
tabrmd - The new resource manager, called
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.
This collection of options are used to configure the varous TCTI modules
They override any environment variables.
Select the TCTI used for communication with the next component down the
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
For the device TCTI, the TPM device file for use by the device TCTI can
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
Passwords are interpreted in two forms, string and hex-string.
A string password is not interpreted, and is directly used for
A hex-string, is converted from a hexidecimal form into a byte array
form, thus allowing passwords with non-printable and/or terminal
By default passwords are assumed to be in the string form.
Password form is specified with special prefix values, they are:
str: - Used to indicate it is a raw string.
Useful for escaping a password that starts with the "hex:"
hex: - Used when specifying a password in hex string format.
Signature Format Specifiers
Format selection for the signature output file.
tss (the default) will output a binary blob according to the
TPM 2.0 specification and any potential compiler padding.
The option plain will output the plain signature data as
defined by the used cryptographic algorithm.
tpm2_certify -H 0x81010002 -k 0x81010001 -P 0x0011 -K 0x00FF -g 0x00B -a <fileName> -s <fileName>
tpm2_certify -C obj.context -c key.context -P 0x0011 -K 0x00FF -g 0x00B -a <fileName> -s <fileName>
tpm2_certify -H 0x81010002 -k 0x81010001 -P 0011 -K 00FF -X -g 0x00B -a <fileName> -s <fileName>
0 on success or 1 on failure.
Github Issues (https://github.com/01org/tpm2-tools/issues)
See the Mailing List (https://lists.01.org/mailman/listinfo/tpm2)