On Fri, Oct 07, 2016 at 02:33:13PM -0500, Brent Cook wrote:
>
> > On Oct 7, 2016, at 12:18 PM, Ted Unangst <[email protected]> wrote:
> >
> > Kinichiro Inoguchi wrote:
> >> I think this 16 bytes string assignment has boundary issue.
> >>
> >> static const char sigma[16] = "expand 32-byte k";
> >>
> >> I found this when I tried to build libressl-portable with MSVC on Windows.
> >
> > another broken compiler? the above line is perfectly valid C.
> >
>
> Technically, that's a 17-byte string being assigned to a 16-byte character
> array, including the NULL. I believe there is a way to get GCC to warn about
> this as well.
Nah, there is a special rule that says you can init an x byte array
with a x length string. The 0 byte is discarded in that case,
See section 6.7.8 Example 8 of the C99 standard.
-Otto
>
> This is a simpler change:
>
> diff --git a/src/lib/libc/crypt/chacha_private.h
> b/src/lib/libc/crypt/chacha_private.h
> index b720d93..a08509c 100644
> --- a/src/lib/libc/crypt/chacha_private.h
> +++ b/src/lib/libc/crypt/chacha_private.h
> @@ -48,8 +48,8 @@ typedef struct
> a = PLUS(a,b); d = ROTATE(XOR(d,a), 8); \
> c = PLUS(c,d); b = ROTATE(XOR(b,c), 7);
>
> -static const char sigma[16] = "expand 32-byte k";
> -static const char tau[16] = "expand 16-byte k";
> +static const char sigma[] = "expand 32-byte k";
> +static const char tau[] = "expand 16-byte k";
>
> static void
> chacha_keysetup(chacha_ctx *x,const u8 *k,u32 kbits,u32 ivbits)
