Re: [PATCH 5/5] Add arc4random() etc. from OpenBSD 5.8

[Craig Howland <howland at LGSInnovations dot com>]

On 03/18/2016 06:49 AM, Sebastian Huber wrote:
> ...
> diff --git a/newlib/libc/stdlib/chacha_private.h b/newlib/libc/stdlib/chacha_private.h
> new file mode 100644
> index 0000000..b48c981
> --- /dev/null
> +++ b/newlib/libc/stdlib/chacha_private.h
> @@ -0,0 +1,224 @@
> +/*
> +...
> +#include <stdint.h>
> +
> +typedef uint8_t u8;
> +typedef uint32_t u32;
> +
> +typedef struct
> +{
> +  u32 input[16]; /* could be compressed */
> +} chacha_ctx;
> +
> +#define U8C(v) (v##U)
> +#define U32C(v) (v##U)
Not good, as may or may not match what is defined in stdint.h, and can be 
inaccurate, for example if long is needed for 32 bits. However, they are only 
used in the 2 lines below, so just get rid of these two defines.  
(Realistically, I would expect it to still provide the correct results, but it 
is definitely an error in usage.)

> +
> +#define U8V(v) ((u8)(v) & U8C(0xFF))
> +#define U32V(v) ((u32)(v) & U32C(0xFFFFFFFF))
#define U8V(v) ((u8)(v) & UINT8_C(0xFF))
#define U32V(v) ((u32)(v) & UINT32_C(0xFFFFFFFF))
(For that matter, the '& mask' is not needed, as the cast does it.)