Method of enforcing control flow integrity in a monolithic binary using static analysis

1. A method of enforcing control flow integrity (CFI) for a monolithic binary using static analysis, the method comprising:

performing, by at least one processor, operations to enforce the CFI while protecting essential functions and maintaining a behavior and a performance of the monolithic binary, the operations including:

marking some evaluated functions as core functions by a chosen heuristic or empirically;

generating a binary call graph;

when the generated binary call graph is incomplete, then:

creating a call graph from static analysis;

setting a privilege 2 for functions with incomplete estimation;

setting an ad hoc privilege for specific functions; and

generating a policy;

merging all function nodes of core functions as a node of highest privilege (set 0);

merging all leaf functions in one node without privilege (set n);

merging all nodes without privilege that reach functions of privilege i and setting the merged node privilege to i+1;

checking whether there is a node without privilege besides a trivial function; and

based on a result of the checking:

in a positive case, returning to merging all nodes without privilege and setting the merged node privilege to i+1; and

in a negative case, setting the privilege of trivial functions as i+2,

wherein the privilege of each function is put before an entry point of each function.