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Topic created on: September 7, 2009 00:57 CDT by fundoo .

I was analysing a program that uses GetPrivateProfileStringA API to read key value from an ini file. When I tried to debug, I didnt find any calls going into kernel32.dll:CreateFileA or kernel32.dll:ReadFile.

Can someone help me to understand how GetPrivateProfileStringA API gets the desired values?

Regards,
fundoo

dennis		September 7, 2009 02:40.24 CDT
hi, the GetPrivateProfileString() function doesn't need a file handle to be passed to, it just opens the file itself (check last param of the API function, first push in the disassembly respectively: http://msdn.microsoft.com/en-us/library/ms724353(VS.85).aspx) If you were looking for how CreateFile() works internally, you might want to have a look at its callchains (https://www.openrce.org/reference_library/win32_call_chains/XPSP2/KERNEL32/GetPrivateProfileStringA) or disassemble it yourself. If you disassemble it yourself, you can see the function calling: BaseDllReadWriteIniFile() -> BaseDllReadWriteIniFileOnDisk() -> BaseDllOpenIniFileOnDisk() -> NtOpenFile() and NtReadFile()

fundoo		September 7, 2009 03:32.00 CDT
hi Dennis, Thanks for your quick reply. Actually while debugging it, I could find CrateFile getting called for the ini file. Another question why cant I see BaseDllReadWriteIniFile, BaseDllReadWriteIniFileOnDisk etc. in my kernel32.dll? :-(

dennis		September 7, 2009 13:30.54 CDT
hi, you probably haven't loaded any symbols for kernel32.dll if you can't see BaseDllReadWriteIniFile() and the like. But putting a breakpoint on NtOpenFile() could do the trick if you're debugging the application.

fundoo		September 7, 2009 22:07.05 CDT
Thanks a lot for your inputs. It really helped.

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