[systemd-devel] [PATCH] cryptsetup: Do not warn If the key is /dev/*random

[Lennart Poettering]

On Mon, 02.02.15 12:06, Cristian Rodríguez (crrodriguez at opensuse.org) wrote:

> Using /dev/urandom as a key is valid for swap, do not
> warn if this devices are world readable.
> ---
>  src/cryptsetup/cryptsetup.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c
> index e6b37ac..38930ae 100644
> --- a/src/cryptsetup/cryptsetup.c
> +++ b/src/cryptsetup/cryptsetup.c
> @@ -624,8 +624,10 @@ int main(int argc, char *argv[]) {
>  
>                          /* Ideally we'd do this on the open fd, but since this is just a
>                           * warning it's OK to do this in two steps. */
> -                        if (stat(key_file, &st) >= 0 && (st.st_mode & 0005))
> -                                log_warning("Key file %s is world-readable. This is not a good idea!", key_file);
> +                        if (stat(key_file, &st) >= 0 && (st.st_mode & 0005)) {
> +                                if(!STR_IN_SET(key_file, "/dev/urandom", "/dev/random", "/dev/hw_random"))
> +                                    log_warning("Key file %s is world-readable. This is not a good idea!", key_file);
> +                        }

I'd prefer if we'd change the check instead to only apply to
S_ISREG() files. This way we wouldn't have to list all RNG device
nodes.

Lennart

-- 
Lennart Poettering, Red Hat