Ubuntu Manpage: tpm2_getekcertificate(1) - Retrieve the Endorsement key Certificate.

NAME

       tpm2_getekcertificate(1) - Retrieve the Endorsement key Certificate.

SYNOPSIS

       tpm2_getekcertificate [OPTIONS] [ARGUMENT]

DESCRIPTION

       tpm2_getekcertificate(1)  -  Retrieve the endorsement key certificate.  The certificate is
       present either on  the  TCG  specified  TPM  NV  indices  OR  on  the  TPM  manufacturer’s
       endorsement  certificate  hosting  server.   Following  are  the  conditions dictating the
       certificate location lookup.

       1. NV-Index:

           Default search location when ARGUMENT is not specified.

       2. Intel-EK-certificate-server:

           Search location  when  EK  certificate  could  not  be  found  in  the  NV  index  AND
           tpmEPSgenerated bit is CLEAR AND manufacturer is INTC.

       3. Intel-EK-Re-certification-server:

           Search  location  when  EK  certificate  could  not  be  found  in  the  NV  index AND
           tpmEPSgenerated bit is SET AND manufacturer is INTC.

           Note:

           In this operation information is provided regarding additional software to be  run  as
           part of the re-provisioning/ re-certification service.

           After  re-provisioning/  recertification  process  is complete, EK certificates can be
           read from the NV indexes by running another instance of tpm2_getekcertificate.

       4. Generic or other EK-certificate-server:

           Search location when ARGUMENT specifies the EK certificate web hosting address.

OPTIONS

• -o, --ek-certificate=FILE or STDOUT:

The file to save the Endorsement key certificate. When EK certificates are found in the
TPM NV indices, this option can be specified additional times to save the RSA and ECC EK
certificates in order. The tool will warn if additional EK certificates are found on
the TPM NV indices and only a single output file is specified. If the option isn’t
specified all the EK certificates retrieved either from the manufacturer web hosting or
from the TPM NV indices, are output to stdout.

• -X, --allow-unverified:

Specifies to attempt connecting with the TPM manufacturer provisioning server without
verifying server certificate. This option is irrelevant when EK certificates are found
on the TPM NV indices.

WARNING: This option should be used only on platforms with older CA certificates.

• -u, --ek-public=FILE:

Specifies the file path for the endorsement key public portion in tss format.

• -x, --offline:

This flags the tool to operate in an offline mode. In that the certificates can be
retrieved for supplied EK public that do not belong to the platform the tool is run on.
Useful in factory provisioning of multiple platforms that are not individually connected
to the Internet. In such a scenario a single Internet facing provisioning server can
utilize this tool in this mode. This forces the tool to not look for the EK
certificates on the NV indices.

• –raw:

This flags the tool to output the EK certificate as is received from the source: NV/
Web-Hosting.

• -E, --encoding=ENCODING:

Specifies the encoding format to use explicitly. Normally, the default method is the
one used by Intel unless an AMD fTPM is detected, in which case the AMD-specific
encoding is used. Use `a' for AMD and `i' for Intel.

• ARGUMENT the command line argument specifies the URL address for the EK certificate
portal. This forces the tool to not look for the EK certificates on the NV indices.

References

COMMON OPTIONS

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

• -h, --help=[man|no-man]: Display the tools manpage. By default, it attempts to invoke
the manpager for the tool, however, on failure will output a short tool summary. This
is the same behavior if the “man” option argument is specified, however if explicit
“man” is requested, the tool will provide errors from man on stderr. If the “no-man”
option if specified, or the manpager fails, the short options will be output to stdout.

To successfully use the manpages feature 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. Defining the environment
TPM2TOOLS_ENABLE_ERRATA is equivalent.

• -R, --autoflush: Enable autoflush for transient objects created by the command. If a
parent object is loaded from a context file also the transient parent object will be
flushed. Autoflush can also be activated if the environment variable
TPM2TOOLS_AUTOFLUSH is is set to yes or true. information many users may expect.

TCTI Configuration

The TCTI or “Transmission Interface” is the communication mechanism with the TPM. TCTIs
can be changed for communication with TPMs across different mediums.

To control the TCTI, the tools respect:

1. The command line option -T or --tcti

2. The environment variable: TPM2TOOLS_TCTI.

Note: The command line option always overrides the environment variable.

The current known TCTIs are:

• tabrmd - The resource manager, called tabrmd
(https://github.com/tpm2-software/tpm2-abrmd). Note that tabrmd and abrmd as a tcti
name are synonymous.

• mssim - Typically used for communicating to the TPM software simulator.

• device - Used when talking directly to a TPM device file.

• none - Do not initalize a connection with the TPM. Some tools allow for off-tpm options
and thus support not using a TCTI. Tools that do not support it will error when
attempted to be used without a TCTI connection. Does not support ANY options and MUST
BE presented as the exact text of “none”.

The arguments to either the command line option or the environment variable are in the
form:

<tcti-name>:<tcti-option-config>

Specifying an empty string for either the <tcti-name> or <tcti-option-config> results in
the default being used for that portion respectively.

TCTI Defaults
When a TCTI is not specified, the default TCTI is searched for using dlopen(3) semantics.
The tools will search for tabrmd, device and mssim TCTIs IN THAT ORDER and USE THE FIRST
ONE FOUND. You can query what TCTI will be chosen as the default by using the -v option
to print the version information. The “default-tcti” key-value pair will indicate which
of the aforementioned TCTIs is the default.

Custom TCTIs
Any TCTI that implements the dynamic TCTI interface can be loaded. The tools internally
use dlopen(3), and the raw tcti-name value is used for the lookup. Thus, this could be a
path to the shared library, or a library name as understood by dlopen(3) semantics.

TCTI OPTIONS

This collection of options are used to configure the various known TCTI modules available:

• device: For the device TCTI, the TPM character device file for use by the device TCTI
can be specified. The default is /dev/tpm0.

Example: -T device:/dev/tpm0 or export TPM2TOOLS_TCTI=“device:/dev/tpm0”

• mssim: For the mssim TCTI, the domain name or IP address and port number used by the
simulator can be specified. The default are 127.0.0.1 and 2321.

Example: -T mssim:host=localhost,port=2321 or export
TPM2TOOLS_TCTI=“mssim:host=localhost,port=2321”

• abrmd: For the abrmd TCTI, the configuration string format is a series of simple key
value pairs separated by a `,' character. Each key and value string are separated by a
`=' character.

• TCTI abrmd supports two keys:

1. `bus_name' : The name of the tabrmd service on the bus (a string).

2. `bus_type' : The type of the dbus instance (a string) limited to `session' and
`system'.

Specify the tabrmd tcti name and a config string of bus_name=com.example.FooBar:

\--tcti=tabrmd:bus_name=com.example.FooBar

Specify the default (abrmd) tcti and a config string of bus_type=session:

\--tcti:bus_type=session

NOTE: abrmd and tabrmd are synonymous. the various known TCTI modules.

NOTES

       When the verbose option is specified, additional curl debugging information is provided by
       setting  the  curl mode verbose, see <https://curl.haxx.se/libcurl/c/CURLOPT_VERBOSE.html>
       for more information.

EXAMPLES

   Retrieve EK certificate from TPM manufacturer backend by supplying EK public.
              tpm2_createek -G rsa -u ek.pub -c key.ctx

              tpm2_getekcertificate -X -o ECcert.bin -u ek.pub \
              https://tpm.manufacturer.com/ekcertserver/

   Retrieve EK certificate from Intel backend if certificate not found on NV.
              tpm2_createek -G rsa -u ek.pub -c key.ctx

              tpm2_getekcertificate -X -o ECcert.bin -u ek.pub

   Retrieve EK certificate from Intel backend for an offline platform.
              tpm2_getekcertificate -X -x -o ECcert.bin -u ek.pub

   Retrieve EK certificate from TPM NV indices only, fail otherwise.
              tpm2_getekcertificate -o ECcert.bin

   Retrieve multiple EK certificates from TPM NV indices only, fail otherwise.
              tpm2_getekcertificate -o RSA_EK_cert.bin -o ECC_EK_cert.bin

Returns

       Tools can return any of the following codes:

       • 0 - Success.

       • 1 - General non-specific error.

       • 2 - Options handling error.

       • 3 - Authentication error.

       • 4 - TCTI related error.

       • 5 - Non supported scheme.  Applicable to tpm2_testparams.

BUGS

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

HELP

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