Hello guys, this is my first post, so don't be harsh if I do something stupid.

Well, the reason why I'm posting here is because I need to find a method to alter the stream itself, not just the buffer I send to a variable with "file.Read(".

For example, lets say i have a file whose bytes are as follows:
05 FF 3E 23 80 BD

As I'm using MFC I'd use 'file.Open' to open the file, and 'file.Read' to send the stream above to a buffer (char *) variable.

What I want to do is to change the stream to something else before I use the Read function so that it will be something different when I read the stream whilst still keeping the file untouched.

The reason I need this is for encryption purposes, and because I dont want to create a temporary file on the computer.

By the way, I don't want just to send the stream to the buffer and then process it, I want to change the stream itself.

Any help is appreciated.
Regards, Gabriel.

What do you mean you want to change the stream to something else? What do you want to change it to?

Lets say we had the above file "05 FF 3E 23 80 BD"

I wanted to use my decription algorythm that would change it to something like:
BF 46 E6 AF 08 99

Before I used the Read function however not changing the actual file. (I already have the decryption algorythm)

Now how in the world do you expect to decrypt a file without reading it?? Just read the file, decrypt it and save it in memory. I don't see why you need a temp file to do that.

Because the .read function is used several times later (more than 100) and I didn't want to change that because I would have to convert char[4] to int for exemple.. something that the function does by itself.

converting char[4] to int is simple assignment int x = *(int *)buffer; , assuming that buffer contains the binary representation of the int.