Softice breakpoint on a string?? [Archive] - RCE Messageboard's Regroupment

jerrydav

August 30th, 2001, 19:48

Hello!
I'm quite new in reversing and I have some problems trying to crack a dos program. I disassembled the program and I want Softice to break to a specific line or command saw in the disassembled program. For example, I want to break on : "cmp eax, 00000002". Is there a way to do that?? Of if I want to break when a specific string is written in memory like : 'test', how can I do that??

Jerry

qferret

August 30th, 2001, 20:10

Well....I've never played w/ SoftIce for DOS, but here are some pointers for Win32 proggies....some info may cross over ;-)

Quote:

jerrydav (08-30-2001 17:48):
Hello!
I'm quite new in reversing and I have some problems trying to crack a dos program. I disassembled the program and I want Softice to break to a specific line or command saw in the disassembled program. For example, I want to break on : "cmp eax, 00000002". Is there a way to do that??

nope....break on the address shown in the disassembly (make sure you have the selector right though)

Of if I want to break when a specific string is written in memory like : 'test', how can I do that??

First time through, search memory for the string using s 0 l ffffffff 'test' .....when you find where it's being stored, you can restart the program and set a BPM or BPX on the address to break when that address is read from or written to