Re: [PATCH 2/3] mkimage: fit: handle FDT_ERR_NOSPACE when ciphering

On Thu, Jul 30, 2020 at 1:02 AM Philippe REYNES philippe.reynes@softathome.com wrote:

Hi Patrick

...

From: Patrick Oppenlander patrick.oppenlander@gmail.com

This meant that the order of operations had to change. If we replace the data property first then fail to add the data-size-unciphered property the data will be ciphered again when retrying.

This patch is good, but I disagree with the comment. It is not mandatory to change the order of operation because when signing/ciphering we always start from "fresh" file.

This "trick" is done in the function fit_handle_file(...)

Just before the loop, the tmpfile is rename in bakfile

    sprintf(bakfile, "%s%s", tmpfile, ".bak");
    rename(tmpfile, bakfile);

And in the loop, the first operation is to copy bakfile to tmpfile:

    for (size_inc = 0; size_inc < 64 * 1024; size_inc += 1024) {
            if (copyfile(bakfile, tmpfile) < 0) {
                    printf("Can't copy %s to %s\n", bakfile, tmpfile);
                    ret = -EIO;
                    break;
            }
            ret = fit_add_file_data(params, size_inc, tmpfile);
            if (!ret || ret != -ENOSPC)
                    break;
    }

So I think that we always cipher with unciphered data.

Hi Philip,

I don't think that is the case if you use "mkimage -F". The input can already be ciphered.

Patrick