NAME

       tpm_clear - return the TPM to the default state (unowned, disabled, inactive)

SYNOPSIS

       tpm_clear [OPTION]

DESCRIPTION

       tpm_clear requests that the system's TPM perform a clear (via the TPM_OwnerClear API) wiping out all
       ownership information, in effect invalidaing all keys and data tied to the TPM, as well as disabling and
       deactivating the TPM.  This operation will prompt for the owner password.  The --force option relies on
       Phyiscal Presence to authorize the command (via the TPM_ForceClear API) skipping the owner password
       prompt.  The TPM OwnerClear API can be disabled until the current owner is cleared, requiring use of the
       --force with tpm_setclearable command.   The TPM_ForceClear API can be disabled for the current boot
       cycle with the tpm_setclearable command.  This command requires a reboot to complete the operation.

       -h, --help
              Display command usage info.

       -v, --version
              Display command version info.

       -l, --log [none|error|info|debug]
              Set logging level.

       -u, --unicode
              Use TSS UNICODE encoding for passwords to comply with applications using TSS popup boxes

       -f, --force
              Rely on Physical Presence for authorization; therefore, do not prompt for owner password.

       -z, --well-known
              Authenticate  using  20  bytes  of  zeros  as  owner password (the default TSS Well Known Secret),
              instead of prompting for an owner password.

SEE ALSO

       tpm_version(1), tpm_takeownership(8), tpm_setclearable(8), tpm_setactive(8), tpm_setenable(8), tcsd(8)

REPORTING BUGS

       Report bugs to <trousers-users@lists.sourceforge.net>

TPM Management                                     2005-05-05                                       tpm_clear(8)