Igor’s tip of the week #60: Type libraries

Type libraries are collections of high-level type information for selected platforms and compilers which can be used by IDA and the decompiler. A type library may contain: function prototypes, e.g.: void *__cdecl memcpy(void *, const void *Src, size_t Size); BOOL __stdcall EnumWindows(WNDENUMPROC lpEnumFunc, LPARAM lParam); typedefs, e.g.: typedef unsigned long DWORD; BOOL (__stdcall *WNDENUMPROC)(HWND, LPARAM); standard structure and enum definitions, e.g.: struct tagPOINT { LONG […]

Igor’s tip of the week #59: Automatic function arguments comments

You may have observed that IDA knows about standard APIs or library functions and adds automatic function comments for the arguments passed to them. For example, here’s a fragment of disassembly with commented arguments to Win32 APIs CreateFileW and ReadFile: This works well when functions are imported in a standard way and are known at load time. […]

Igor’s tip of the week #58: Keyboard modifiers

Today we’ll cover how keyboard modifiers (Ctr, Alt, Shift) can be used with some IDA actions to modify their behavior or provide additional functionality. Modifiers in shortcuts Obviously, some shortcuts already include modifiers as part of their key sequence, but some commonalities may be not immediately obvious. For example, the Search menu commands tend to use Alt-letter […]

Igor’s tip of the week #56: String literals in pseudocode

Strings in binaries are very useful for the reverse engineer: they often contain messages shown to the user, or sometimes even internal debugging information (function or variable names) and so having them displayed in the decompiled code is very helpful. However, sometimes you may see named variables in pseudocode even though the disassembly shows the string […]

Igor’s tip of the week #55: Using debug symbols

IDA supports many file formats, among them the main ones used on the three major operating systems: PE (Portable Executable) on Windows; ELF (Executable and Linkable Format) on Linux; Mach-O (Mach object) on macOS. Symbols and debugging information Symbols associate locations inside the file (e.g. addresses of functions or variables) with textual names (usually the names used in the original source […]

Igor’s tip of the week #54: Shifted pointers

Previously we briefly mentioned shifted pointers but without details. What are they? Shifted pointers is another custom extension to the C syntax. They are used by IDA and decompiler to represent a pointer to an object with some offset or adjustment (positive or negative). Let’s see how they work and several situations where they can […]

Igor’s tip of the week #51: Custom calling conventions

The Hex-Rays decompiler was originally created to deal with code produced by standard C compilers. In that world, everything is (mostly) nice and orderly: the calling conventions are known and standardized and the arguments are passed to function according to the ABI. However, the real life is not that simple: even in code coming […]

Igor’s tip of the week #50: Execution flow arrows

Although nowadays most IDA users probably use the graph view, the text view can still be useful in certain situations. In case you haven’t noticed, it has a UI element which can help you visualize code flow even without the full graph and even outside of functions (the graph view is available only for […]

Igor’s tip of the week #49: Navigation band

Navigation band, also sometimes called the navigator, or navbar, is the UI element shown by default at the top of IDA’s window, in the toolbar area. It shows the global overview of the program being analyzed and allows to see at a quick glance how well has the program been analyzed and what areas may need […]