Description: The function ENGINE_get_ssl_client_cert_function is deprecated and needs to either be removed entirely or made private to the openssl library.

Actions:

1. Determine if ENGINE_get_ssl_client_cert_function is public to the openssl library.

2. If (1) is public, determine if other internal library functions need it

3. If (2) is true, migrate the function so that it is prototyped in a private header rather than a public header

4. If (1) is true, update the 4.0 migration guide to add this function with an explanation regarding what APIs should be used to replace it.

• Public API removed
• Documentation updated