How to determine available hash functions programmatically (2 replies)

Due to some distributions (eg; CentOS) of MySQL where the distributed version number may not accurately reflect the internal functionality (eg; distributed version 5.1 may contain newer functionality from source version 5.5), I need a way to programmatically query/show the available HASH functions within any given MySQL executable. Somewhere between 5.1.xx and 5.5, SHA2 was added, but I cannot rely on documentation alone.

I could attempt to call a particular HASH function and deal with the errors, if any, but that is a messy approach at best.

Note: this has nothing to do with "password hash".