The code style on this makes my eyes bleed. It was a long time since I saw anyone do "if () single statement; else { block of statements }"

Making the first thing a block doesn't add any lines and makes it less brittle, and makes future diffs better

And they do some weird alignment of assignments, and for some reason carry on adding extra spaces for some assignments even when they're alone in a block?

And they go out of their way to do pointer arithmetic rather than array operations that are more readable

And the code is essentially sscanf(str, "%%%2x", &value) plus some checks, so why not write that instead?

Also what kind of psycho uses CppStyleFunctionNames() in C?