tpm_manager: use per-operation sessions

Use per-operation sessions in tpm_manager for nvram access
authorizxation.

Before this change, tpm_manager started a global trunks_session_
when it launched, and later used that session to access nvram
spaces when owner password was required (e.g. to delete a space).
TPM Resume flushes sessions, so after suspend that global session
handle became invalid.

BUG=chromium:689582
BUG=chrome-os-partner:58786
TEST=On first login, initiate suspend:
     powerd_dbus_suspend --wakeup_timeout=10
     Then attempt setting FWMP flags:
     cryptohome --action=set_firmware_management_parameters --flags=8
     That operation should succeed.

Change-Id: I8903841e5f8e211ab59b43c1dc21d89e55b12ca1
Reviewed-on: https://chromium-review.googlesource.com/438782
Commit-Ready: Andrey Pronin <apronin@chromium.org>
Tested-by: Andrey Pronin <apronin@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
1 file changed