Abstract: Disclosed herein are systems, methods, and computer-readable storage media for obfuscating by a common function. A system configured to practice the method identifies a set of functions in source code, generates a transformed set of functions by transforming each function of the set of functions to accept a uniform set of arguments and return a uniform type, and merges the transformed set of functions into a single recursive function. The single recursive function can allocate memory in the heap. The stack can contain a pointer to the allocated memory in the heap. The single recursive function can include instructions for creating and explicitly managing a virtual stack in the heap. The virtual stack can emulate what would happen to the real stack if one of the set of functions was called. The system can further compile the source code including the single recursive function.

Abstract: Disclosed herein are systems, methods, and computer readable-media for obfuscating code. The method includes extracting a conditional statement from a computer program, creating a function equivalent to the conditional statement, creating a pointer that points to the function, storing the pointer in an array of pointers, replacing the conditional statement with a call to the function using the pointer at an index in the array, and during runtime of the computer program, dynamically calculating the index corresponding to the pointer in the array. In one aspect, a subset of instructions is extracted from a path associated with the conditional statement and the subset of instructions is placed in the function to evaluate the conditional statement. In another aspect, the conditional statement is replaced with a call to a select function that (1) calculates the index into the array, (2) retrieves the function pointer from the array using the index, and (3) calls the function using the function pointer.

Abstract: Disclosed herein are systems, methods, and computer readable-media for obfuscating array contents in a first array, the method comprising dividing the first array into a plurality of secondary arrays having a combined total size equal to or greater than the first array, expanding each respective array in the plurality of the secondary arrays by a respective multiple M to generate a plurality of expanded arrays, and arranging data elements within each of the plurality of expanded arrays such that a data element located at an index I in a respective secondary array is located at an index I*M, wherein M is the respective multiple M in an associated expanded array, wherein data in the first array is obfuscated in the plurality of expanded arrays. One aspect further splits one or more of the secondary arrays by dividing individual data elements in a plurality of sub-arrays. The split sub-arrays may contain more data elements than the respective secondary array.

Abstract: Disclosed herein are systems, methods, and computer readable-media for obfuscating code through conditional expansion obfuscation. The method includes identifying a conditional expression in a computer program, identifying a sequence of conditional expressions that is semantically equivalent to the conditional expression, and replacing the conditional expression with the semantically equivalent sequence of conditional expressions. One option replaces each like conditional expression in the computer program with a diverse set of sequences of semantically equivalent conditional expressions. A second option rearranges computer instructions that are to be processed after the sequence of conditional expression is evaluated so that a portion of the instructions is performed before the entire sequence of conditional expressions is evaluated. A third option performs conditional expansion obfuscation of a conditional statement in combination with branch extraction obfuscation.

Abstract: Disclosed herein are systems, computer-implemented methods, and computer-readable storage media for obfuscating a function call. The method receives a computer program having an annotated function and determines prolog instructions for setting up a stack frame of the annotated function and epilog instructions for tearing down the stack frame. The method places a first portion of the prolog instructions in the computer program preceding a jump to the annotated function and a second portion of the prolog instructions at a beginning of the annotated function. The method places a first portion of the epilog instructions at an end of the annotated function and a second portion of the epilog instructions in the computer program after the jump. Executing the first and second portions of the prolog instructions together sets up the stack frame. Executing the first and the second portions of the epilog instructions together tears down the stack frame.

Abstract: Disclosed herein are methods, systems, and computer-readable storage media for annotation driven integrity program verification. The method includes distributing verification calls configured to verify a function across call paths leading to the function in source code, generating a binary from the source code having placeholders associated with the verification calls, and filling each placeholder in the binary with verification data or reference checksums. Alternatively, the method includes receiving source code having a verification call, replacing the verification call with one or more equivalent verification calls distributed over a call path, replacing each verification call with a checksum function generating placeholders while compiling, generating a binary based on the placeholders, and filling each placeholder in the binary with reference checksums. The system includes a processor and a module controlling the processor to perform the methods.

Abstract: Disclosed herein are systems, computer-implemented methods, and computer-readable storage media for call path enforcement. The method includes tracking, during run-time, a run-time call order for a series of function calls in a software program, and when executing a protected function call during run-time, allowing or causing proper execution of a protected function call only if the run-time call order matches a predetermined order. The predetermined order can be an expected run-time call order based on a programmed order of function calls in the software program. The method can include maintaining an evolving value associated with the run-time call order and calling the protected function by passing the evolving value and function parameters corrupted based on the evolving value. The protected function uncorrupts the corrupted parameters based on the passed evolving value and an expected predetermined call order. A buffer containing the uncorrupted parameters can replace the corrupted parameters.

Abstract: Disclosed herein are systems, methods, and computer-readable storage media for obfuscating by a common function. A system configured to practice the method identifies a set of functions in source code, generates a transformed set of functions by transforming each function of the set of functions to accept a uniform set of arguments and return a uniform type, and merges the transformed set of functions into a single recursive function. The single recursive function can allocate memory in the heap. The stack can contain a pointer to the allocated memory in the heap. The single recursive function can include instructions for creating and explicitly managing a virtual stack in the heap. The virtual stack can emulate what would happen to the real stack if one of the set of functions was called. The system can further compile the source code including the single recursive function.

Abstract: Disclosed herein are methods, systems, and computer-readable storage media for annotation driven integrity program verification. The method includes distributing verification calls configured to verify a function across call paths leading to the function in source code, generating a binary from the source code having placeholders associated with the verification calls, and filling each placeholder in the binary with verification data or reference checksums. Alternatively, the method includes receiving source code having a verification call, replacing the verification call with one or more equivalent verification calls distributed over a call path, replacing each verification call with a checksum function generating placeholders while compiling, generating a binary based on the placeholders, and filling each placeholder in the binary with reference checksums. The system includes a processor and a module controlling the processor to perform the methods.

Abstract: Disclosed herein are systems, computer-implemented methods, and computer-readable storage media for call path enforcement. The method includes tracking, during run-time, a run-time call order for a series of function calls in a software program, and when executing a protected function call during run-time, allowing or causing proper execution of a protected function call only if the run-time call order matches a predetermined order. The predetermined order can be an expected run-time call order based on a programmed order of function calls in the software program. The method can include maintaining an evolving value associated with the run-time call order and calling the protected function by passing the evolving value and function parameters corrupted based on the evolving value. The protected function uncorrupts the corrupted parameters based on the passed evolving value and an expected predetermined call order. A buffer containing the uncorrupted parameters can replace the corrupted parameters.

Abstract: Disclosed herein are systems, computer-implemented methods, and computer-readable storage media for obfuscating a function call. The method receives a computer program having an annotated function and determines prolog instructions for setting up a stack frame of the annotated function and epilog instructions for tearing down the stack frame. The method places a first portion of the prolog instructions in the computer program preceding a jump to the annotated function and a second portion of the prolog instructions at a beginning of the annotated function. The method places a first portion of the epilog instructions at an end of the annotated function and a second portion of the epilog instructions in the computer program after the jump. Executing the first and second portions of the prolog instructions together sets up the stack frame. Executing the first and the second portions of the epilog instructions together tears down the stack frame.

Abstract: Disclosed herein are systems, methods, and computer readable-media for obfuscating code through conditional expansion obfuscation. The method includes identifying a conditional expression in a computer program, identifying a sequence of conditional expressions that is semantically equivalent to the conditional expression, and replacing the conditional expression with the semantically equivalent sequence of conditional expressions. One option replaces each like conditional expression in the computer program with a diverse set of sequences of semantically equivalent conditional expressions. A second option rearranges computer instructions that are to be processed after the sequence of conditional expression is evaluated so that a portion of the instructions is performed before the entire sequence of conditional expressions is evaluated. A third option performs conditional expansion obfuscation of a conditional statement in combination with branch extraction obfuscation.

Abstract: Disclosed herein are systems, methods, and computer readable-media for obfuscating code. The method includes extracting a conditional statement from a computer program, creating a function equivalent to the conditional statement, creating a pointer that points to the function, storing the pointer in an array of pointers, replacing the conditional statement with a call to the function using the pointer at an index in the array, and during runtime of the computer program, dynamically calculating the index corresponding to the pointer in the array. In one aspect, a subset of instructions is extracted from a path associated with the conditional statement and the subset of instructions is placed in the function to evaluate the conditional statement. In another aspect, the conditional statement is replaced with a call to a select function that (1) calculates the index into the array, (2) retrieves the function pointer from the array using the index, and (3) calls the function using the function pointer.

Abstract: Disclosed herein are systems, methods, and computer readable-media for obfuscating array contents in a first array, the method comprising dividing the first array into a plurality of secondary arrays having a combined total size equal to or greater than the first array, expanding each respective array in the plurality of the secondary arrays by a respective multiple M to generate a plurality of expanded arrays, and arranging data elements within each of the plurality of expanded arrays such that a data element located at an index I in a respective secondary array is located at an index I*M, wherein M is the respective multiple M in an associated expanded array, wherein data in the first array is obfuscated in the plurality of expanded arrays. One aspect further splits one or more of the secondary arrays by dividing individual data elements in a plurality of sub-arrays. The split sub-arrays may contain more data elements than the respective secondary array.