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tpm2_policycountertimer(1)  General Commands Manual tpm2_policycountertimer(1)

NAME
       tpm2_policycountertimer(1) - Enables policy authorization by evaluating
       the  comparison	operation  on  the  TPM	 parameters time, clock, reset
       count, restart count and	TPM clock safe flag.

SYNOPSIS
       tpm2_policycountertimer [OPTIONS] [ARGUMENT]

DESCRIPTION
       tpm2_policycountertimer(1) - Enables policy authorization by evaluating
       the comparison operation	on  the	 TPM  parameters  time,	 clock,	 reset
       count, restart count and	TPM clock safe flag.  If time/clock, it	is in-
       put  as	milliseconds value.  The parameter and the value is given as a
       command line argument as	below:

	      tpm2_policycountertimer -S session.ctx safe
	      tpm2_policycountertimer -S session.ctx clock=<N ms>
	      tpm2_policycountertimer -S session.ctx time=<N ms>
	      tpm2_policycountertimer -S session.ctx resets=<N>
	      tpm2_policycountertimer -S session.ctx restarts=<N>

       By default comparison tests for equality	and also by default  it	 tests
       for time.

OPTIONS
       • -L, --policy=FILE:

	 File to save the policy digest.

       • -S, --session=FILE:

	 The  policy  session  file  generated via the -S option to tpm2_star-
	 tauthsession or saved off of a	previous tool run.

       • -eq

	 if value of current time in the TPM = value of	specified input	time.

       • -neq

       if value	of current time	in the TPM != value of specified input time.

       • -sgt

       if signed value of current time in the TPM > signed value of  specified
       input time.

       • -ugt

       if unsigned value of current time in the	TPM > unsigned value of	speci-
       fied input time.

       • -slt

       if  signed value	of current time	in the TPM < signed value of specified
       input time.

       • -ult

       if unsigned value of current time in the	TPM < unsigned value of	speci-
       fied input time.

       • -sge

       if signed value of current time in the TPM >= signed value of specified
       input time.

       • -uge

       if unsigned value of current time in the	TPM >= unsigned	value of spec-
       ified input time.

       • -sle

       if signed value of current time in the TPM <= unsigned value of	speci-
       fied input time.

       • -ule

       if unsigned value of current time in the	TPM <= unsigned	value of spec-
       ified input time.

       • -bs

	 if  all bits set in value of current time in the TPM are set in value
	 of specified input time.

       • -bc

	 if all	bits set in value of current time in the TPM are clear in val-
	 ue of specified input time.

       • --cphash=FILE

	 File path to record the hash of the command parameters.  This is com-
	 monly termed as cpHash.  NOTE:	When this option is selected, The tool
	 will not actually execute the command,	it simply returns a cpHash.

   References
COMMON OPTIONS
       This collection of options are common to	many programs and provide  in-
       formation 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  re-
	 quested,  the	tool  will  provide errors from	man on stderr.	If the
	 "no-man" option if specified, or the manpager fails,  the  short  op-
	 tions 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.   in-
	 formation 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 vari-
       able.

       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  simula-
	 tor.

       • 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  respective-
       ly.

   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	 indi-
       cate 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 li-
       brary 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="de-
	 vice:/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_TC-
	 TI="mssim:host=localhost,port=2321"

       • abrmd:	 For  the abrmd	TCTI, the configuration	string format is a se-
	 ries 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.ex-
	 ample.FooBar:

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

	 Specify the default (abrmd) tcti and a	config string of bus_type=ses-
	 sion:

		\--tcti:bus_type=session

	 NOTE:	abrmd  and tabrmd are synonymous.  the various known TCTI mod-
	 ules.

EXAMPLES
       Create a	sealing	object with an authorization policy that evaluates on-
       ly for first minute of TPM restart.

   Create the policy and the sealing object
	      tpm2_startauthsession -S session.ctx

	      tpm2_policycountertimer -S session.ctx -L	policy.countertimer --ult 60000

	      tpm2_flushcontext	session.ctx

	      tpm2_createprimary -C o -c prim.ctx -Q

	      echo "SUPERSECRET" | \
	      tpm2_create -Q -u	key.pub	-r key.priv -i-	-C prim.ctx \
	      -L policy.countertimer -a	"fixedtpm|fixedparent" -c key.ctx

   Unsealing should work in the	first minute after TPM restart
	      tpm2_startauthsession -S session.ctx --policy-session

	      tpm2_policycountertimer -S session.ctx --ult 60000

	      tpm2_unseal -c key.ctx -p	session:session.ctx

	      tpm2_flushcontext	session.ctx

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_startauthses-
       sion(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/listin-
       fo/tpm2)

tpm2-tools					    tpm2_policycountertimer(1)

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