Patching vs. Detouring

[Viano]

Hi,

I was looking at Apoc's code (WhiteMagic) and I am wondering what the hell is patching and what is the difference to detouring? I found this class PatcherManager and it has almost the same methods as DetourManager, these are Apply and Remove and they basically replace some original addresses with your own.

/// <summary>
        /// Removes this Patch from memory. (Reverts the bytes back to their originals.)
        /// </summary>
        /// <returns></returns>
        public bool Remove()
        {
            if (_win32.WriteBytes(_address, _originalBytes) == _originalBytes.Length)
            {
                IsApplied = false;
                return true;
            }
            return false;
        }

        /// <summary>
        /// Applies this Patch to memory. (Writes new bytes to memory)
        /// </summary>
        /// <returns></returns>
        public bool Apply()
        {
            if (_win32.WriteBytes(_address, _patchBytes) == _patchBytes.Length)
            {
                IsApplied = true;
                return true;
            }
            return false;
        }

http://www.mmowned.com/forums/wow-me...ml#post1680184

[Kryso]

Patch is supposed to "patch" any bytes in memory

Detour is for "redirecting" function calls and calling the original one

[GliderPro]

A detour uses a patch to redirect functions.

[nitrogrlie]

A detour is essentially a patch ( as you write bytes to jmp to your detour in the original function ). The main difference is that usually when you 'patch' you are changing the instructions executed (usually to skip some code path or modify a return value). When you 'detour' you tend to not change the original code directly as you still execute it, you just also do additional work surrounding that functions (aka prologue/epilogue).

[WannaBeProgrammer]

A detour is essentially a patch ( as you write bytes to jmp to your detour in the original function ). The main difference is that usually when you 'patch' you are changing the instructions executed (usually to skip some code path or modify a return value). When you 'detour' you tend to not change the original code directly as you still execute it, you just also do additional work surrounding that functions (aka prologue/epilogue).

Just a noobish question, what does prologue/epilogue mean?( I Googled it btw nothing refing to what you talking about)

[Apoc]

You didn't even bother to search what prologue/epilogue mean? Pick up a dictionary. It's not even a technical term...

[nitrogrlie]

Just a noobish question, what does prologue/epilogue mean?( I Googled it btw nothing refing to what you talking about)

AKA prolog/epilog

The Rootkit Arsenal: Escape and ... - Google Books

If your scroll up to page 350, it will show you a graphical representation of what they are...