Ubuntu Manpage: tpm2_policyduplicationselect(1) - Restricts duplication to a specific new parent.

NAME

       tpm2_policyduplicationselect(1) - Restricts duplication to a specific new parent.

SYNOPSIS

       tpm2_policyduplicationselect [OPTIONS]

DESCRIPTION

       tpm2_policyduplicationselect(1) - Restricts duplication to a specific new parent.

OPTIONS

       • -S, --session=FILE:

         The policy session file generated via the -S option to tpm2_startauthsession(1).

       • -n, --object-name=FILE:

         Input name file of the object to be duplicated.

       • -N, --parent-name=FILE:

         Input name file of the new parent.

       • -L, --policy=FILE:

         File to save the policy digest.

       • --include-object:

         If exists, the object name will be included in the value in policy digest.

   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.

EXAMPLES

   Setup a duplication role policy to restricted new parent
   Create source parent and destination(or new) parent
              tpm2_createprimary -C n -g sha256 -G rsa -c dst_n.ctx -Q
              tpm2_createprimary -C o -g sha256 -G rsa -c src_o.ctx -Q

   Create the restricted parent policy
              tpm2_readpublic -c dst_n.ctx -n dst_n.name -Q
              tpm2_startauthsession -S session.ctx
              tpm2_policyduplicationselect -S session.ctx  -N dst_n.name \
              -L policydupselect.dat -Q
              tpm2_flushcontext session.ctx
              rm session.ctx

   Create the object to be duplicated using the policy
              tpm2_create -C src_o.ctx -g sha256 -G rsa -r dupkey.priv -u dupkey.pub \
              -L policydupselect.dat  -a "sensitivedataorigin|sign|decrypt" -c dupkey.ctx -Q
              tpm2_readpublic -c dupkey.ctx -n dupkey.name -Q

   Satisfy the policy and duplicate the object
              tpm2_startauthsession -S session.ctx --policy-session
              tpm2_policyduplicationselect -S session.ctx  -N dst_n.name -n dupkey.name -Q
              tpm2_duplicate -C dst_n.ctx -c dupkey.ctx -G null -p session:session.ctx \
              -r new_dupkey.priv -s dupseed.dat
              tpm2_flushcontext  session.ctx
              rm session.ctx

NOTES

       • This   command   usually   cooperates   with  tpm2_duplicate(1),  so  referring  to  the  man  page  of
         tpm2_duplicate(1) is recommended.

       • This command will set the policy session’s command code to TPM_CC_Duplicate which  enables  duplication
         role of the policy.

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.

Limitations

       It  expects  a  session  to  be  already established via tpm2_startauthsession(1) and requires one of the
       following:

       • direct device access

       • extended session support with tpm2-abrmd.

       Without it, most resource managers will not save session state between command invocations.

BUGS

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

HELP

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