Thread: CreateFile problems

Hi, CreateFile always return INVALID_HANDLE_VALUE. I run program into MyDocuments directory, and on C drive. What am i doing wrong?

Code:

printf("Enter path:\n");
    
    scanf("%s", &szPath);


    HANDLE hFile = CreateFile(szPath, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ |
        FILE_SHARE_WRITE, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);


    if (hFile == INVALID_HANDLE_VALUE)
    {
        printf("Error hFile!\n");
        std::cout << GetLastError();
        return 0;
    }

Output:
Error hFile!
5

What is the exact path you are entering? (If there are any spaces in the path, your "scanf()" will not be sufficient.)

Is the file supposed to already exist?

Code:

OPEN_EXISTING

Opens a file or device, only if it exists.
If the specified file or device does not exist, the function fails and the last-error code is set to ERROR_FILE_NOT_FOUND (2).

https://msdn.microsoft.com/en-us/lib...(v=vs.85).aspx

Why are you using C functions (printf/scanf) in a C++ program?

I have two files in one folder, so i enter only filename, without full path.

Then what is the name of the file?

You should post the simplest program that demonstrates the problem.

This looks suspicious:

Code:

scanf("%s", &szPath);

What type is "szPath"?

char szPath[256];
The file i've try to open is ollydbg.exe

And you're not getting any warnings from your compiler with that "scanf()" call?

Output:
Error hFile!
5

According to MSDN, a value of 5 indicates "access denied".

The OllyDbg software seems to be used sometimes for questionable practices. What exactly is your goal with this program?

I use _CRT_SECURE_NO_WARNINGS.
I think problem is not in scanf function, because i tried CreateFile(argc[1]) and there was the same problem

any ideas?

I gave strong hints about a problem with your "scanf()" call - whether or not it's related to the problem, it should still be looked into.

I also gave a link that tells you what an error code of 5 stands for. A quick search with the appropriate terms yields plenty of results. Do some research, try to solve the problem, and if you're still stuck, post with an update (including what you've done since and how it didn't work).

If Matticus won't spell it out for you (cuz he wants you to do a little work yourself) I will. This...

scanf("%s", &szPath);

...is quite poor. Your C/C++ fundamentals are failing you. I expect you are coding in Windows as seen by the Hungarian Notation, which is fine (Oh! CreateFile() too!). Anyway, I expect you have something like so...

char szPath[256];

That's fine. In C/C++ syntax the name of an array without the brackets, i.e.,

szPath

...is a pointer to the first byte of the array, i.e., its base address. So your scanf function call needs to lose the '&' symbol.

Why in the world would you want to open OllyDebug.exe for writting???