APIS should have security options enabled by default– for example, having best practice cipher suites enabled by default (something that changes over time) while disabling out-of-favor cipher suites by default. When interface stability is also a design requirement, an interface can meet both goals by providing off-by-default options that produce stable behavior, such as
Noncompliant Code Example
If the caller of this API in this noncompliant example doesn't understand what the options mean, they will pass 0 or
TLS_DEFAULT_OPTIONS and get a connection vulnerable to man-in-the-middle attacks and using old versions of TLS.
If the caller of this API doesn't understand the options and passes 0 or
TLS_DEFAULT_OPTIONS they will get certificate validation with only the current version of TLS enabled.