ITS should call fsync

[gilles-peskine-arm]

Description

The PSA ITS implementation in Mbed Crypto was originally developed for testing. It modifies files atomically, so it's resilient to interruptions such as a process crash, but it does not call any disk synchronization primitives, so it is not resilient to an operating system crash.

PSA ITS should call a disk synchronization primitive that is configurable at build time. On Unix systems, it should call fsync on the file and on the containing directory.

Cc @paulhowardarm

Issue request type

[ ] Question
[x] Enhancement
[ ] Bug

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/IOTCRYPT-857

[adbridge]

Apologies, this was closed in error by the automated bot - re-opening.