Update changelog with the new public API
Changes
- * The mbedcrypto library includes new a source code module constant_time.c,
+ * The mbedcrypto library includes a new source code module constant_time.c,
containing various functions meant to resist timing side channel attacks.
This module does not have a separate configuration option, and functions
from this module will be included in the build as required. Currently
- the interface of this module is private and may change at any time.
+ most of the interface of this module is private and may change at any
+ time.
+
+Features
+ * Add new API mbedtls_ct_memcmp for constant time buffer comparison.
