Undefined behavior in mbedtls_platform_zeroize()

[Patater]

Description

Calling memset() with a non-NULL buffer argument is undefined in C. mbedtls_platform_zeroize() can end up calling memset() directly (via a function pointer). It might be good to make mbedtls_platform_zeroize() have defined behavior when the buffer argument in NULL and size is 0.

Issue request type

[ ] Question
[ ] Enhancement
[x] Bug

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/IOTCRYPT-672