If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)

Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

Patching a DLL file - x86 Assembler

nobodythere · 2006-07-31 17:55:05

I'm trying to patch a DLL in windows, jump from a function to my code, and jump back. I need to pass strings to a function before calling it, such as PUSH addressofstring CALL function The addressofstring will be a relative virtual address, so say the base address is FF000000, I could put it at offset 1000 for example and…

Options

31-07-2006 6:55pm

#1

nobodythere

Closed Accounts Posts: 2,349 ✭✭✭

Join Date: November 2001

Posts: 2049

I'm trying to patch a DLL in windows, jump from a function to my code, and jump back. I need to pass strings to a function before calling it, such as

PUSH addressofstring
CALL function

The addressofstring will be a relative virtual address, so say the base address is FF000000, I could put it at offset 1000 for example and it would be PUSH FF001000. My question is, what if the program doesn't get its preferred address. If it was in the EXE it wouldn't be a problem because they're always loaded first, but with DLLs the base address could be relocated. Would this pose a problem if it happened?

Will I have to go arse deep in PE format and modify the reloc tables etc Cos that's not something I'd be looking forward to!

0