Determination of valid input sequences for an unknown binary program

One or more non-transitory computer readable media that include instructions that when executed by one or more processors perform operations to determine valid input sequence for an unknown stateful binary program, the operations comprising:

• obtain an unknown stateful binary program including the first state and a second state;
• obtain inputs for the unknown stateful binary program;
• determine that the inputs are valid for a first state of the unknown stateful binary program, for each of the inputs the determining including:
• execute the unknown stateful binary program in the first state without a transition to the second state with one of the inputs as input to the unknown stateful binary program in the first state;
• determine a number of instructions executed during the execution of the unknown stateful binary program with the one of the inputs as input;
• and
• compare the number of executed instructions to a threshold number of instructions;
• after determining that the inputs are valid, obtain an input sequence for the unknown stateful binary program, the input sequence including a subset of two or more of the inputs determined to be valid;
• obtain a memory address range for each of one or more variables in the unknown stateful binary program;
• execute an instrumented version of the unknown stateful binary program with the input sequence as an input to the instrumented version of the unknown stateful binary program, wherein the executing of the instrumented version of the unknown stateful binary program with the input sequence as the input causes the unknown stateful binary program to enter a second state and the executing of the instrumented version of the unknown stateful binary program with ewer than the subset of inputs as the input does not cause the unknown stateful binary program to enter the second state;
• record one or more memory addresses accessed during the execution of the instrumented version of the unknown stateful binary program;
• and
• determine that the unknown stateful binary program accepts the input sequence as valid based on one or more of the one or more recorded memory addresses corresponding to the memory address range of one or more of the variables in the unknown stateful binary program.