NAME

       TPMLIB_SetState  - Set the TPM's volatile, permanent, or save state

       TPMLIB_GetState  - Get the TPM's volatile, permanent, or save state

LIBRARY

       TPM library (libtpms, -ltpms)

SYNOPSIS

       #include <libtpms/tpm_library.h>

       TPM_RESULT TPMLIB_SetState(enum TPMLIB_StateType st,
                                  const unsigned char *buffer, uint32_t buflen);

       TPM_RESULT TPMLIB_GetState(enum TPMLIB_StateType st,
                                  unsigned char **buffer, uint32_t *buflen);

DESCRIPTION

       The TPMLIB_SetState() function allows a user to set either one of the state blobs of the
       TPM. The passed state blob is tested for whether it can be accepted and a TPM error code
       is returned in case it cannot be accepted. In case of acceptance, the state blob will be
       passed to the TPM upon TPM_MainInit(). Setting a state blob hides a file that may contain
       the same type of blob and would be read otherwise.  It is required to call this function
       with a NULL pointer for the buffer parameter to hide a state blob in a file.

       It is only possible to set the state blobs after TPMLIB_ChooseTPMVersion() has been
       called. All state blobs are cleared when a different version of TPM is chosen using
       TPMLIB_ChooseTPMVersion or when a call to TPMLIB_SetState() fails because a state blob
       could not be accepted.

       The order in which state blobs are set is important. The first state blob has to be the
       one representing the TPM's permanent state. Only after that either the volatile or save
       state blobs can be set.

       The TPMLIB_GetState() function allows a user to get the current state of the TPM.  For as
       long as the TPM has not been started, this function either returns the state blob
       previously set with TPMLIB_SetState() or the state is read from a file.  Once the TPM has
       been start the state of the running TPM is returned.

       The TPMLIB_STATE_SAVE_STATE (save state) type of TPM state can be set with this function.
       The same state blob will be returned until TPM_Startup(ST_STATE) has been called, after
       which an empty blob will be returned. This blob can also only be read after
       TPM_SaveState() has been sent to the TPM.

SEE ALSO

       TPMLIB_ChooseTPMVersion(3), TPMLIB_MainInit(3), TPMLIB_Terminate(3)