1. An apparatus, comprising: a memory storing (i) a plurality of functions and (ii) a mapping of locations of the plurality of functions in the memory; a processor configured to: generate a callback to a security function of the plurality of functions, wherein the callback is a function call for the security function to execute, in response to the callback, determine a location in the memory of the security function using the mapping, and execute the security function upon branching to the location of the security function in the memory according to the mapping.