Obfuscate

Compile-time string literal obfuscation library for C++14.

Whats the problem?

When plain text string literals are used in C++ programs, they will be compiled as-is into the resultant binary. This causes them to be incredibly easy to find. One can simply open up the binary file in a text editor to see all of the embedded string literals in plain view. A special utility called strings actually exists which can be used to search binary files for plain text strings.

What does this library do?

This header-only library seeks to make it much much more difficult for embedded string literals in binary files to be found by encrypting them at compile-time, forcing the compiler to store the encrypted string literal instead of the plain text version. This will then be decrypted at runtime to be utilised within the program.

How do I use this library?

By simply wrapping your string literal "My String" with AY_OBFUSCATE("My String") it will be encrypted at compile time and stored in an ay::obfuscated_data object which you can manipulate at runtime. For convenience it is also implicitly convertable to a char*.

For example, the following program will not store the string "Hello World" in plain text anywhere in the compiled executable.

int main()
{
  std::cout << AY_OBFUSCATE("Hello World") << std::endl;
  return 0;
}

Binary file size overhead

This does come at a small cost. In a very simple program, which only prints out strings the following binary file bloat exists.

Config	Plain string literals	Obfuscated strings	Bloat
Release	9216	9728	512 (5.6%)
Debug	37376	48640	11264 (30.1%)

This output is generated by running calculate_bloat.py