Re: [PATCH v2 1/3] crypto: drbg - fix drbg_generate return val check

[Stephan Mueller <smueller@chronox.de>]

Am Samstag, 18. April 2015, 16:42:20 schrieb Stephan Mueller:

Hi Stephan,

> The drbg_generate returns 0 in success case. That means that
> drbg_generate_long will always only generate drbg_max_request_bytes at
> most. Longer requests will be truncated to drbg_max_request_bytes.
> 
> Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
> Signed-off-by: Stephan Mueller <smueller@chronox.de>
> ---
>  crypto/drbg.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/crypto/drbg.c b/crypto/drbg.c
> index b69409c..74f7c1e 100644
> --- a/crypto/drbg.c
> +++ b/crypto/drbg.c
> @@ -1450,7 +1450,7 @@ static int drbg_generate_long(struct drbg_state *drbg,
> slice = ((buflen - len) / drbg_max_request_bytes(drbg));
>  		chunk = slice ? drbg_max_request_bytes(drbg) : (buflen - len);
>  		tmplen = drbg_generate(drbg, buf + len, chunk, addtl);
> -		if (0 >= tmplen)
> +		if (0 > tmplen)

Please disregard this patch :-(

I need to update that one further -- my preliminary tests worked but more 
extensive tests showed that the patch is wrong.

>  			return tmplen;
>  		len += tmplen;
>  	} while (slice > 0 && (len < buflen));


-- 
Ciao
Stephan