possible rijndael bug

[Hajimu UMEMOTO]

Hi,

>>>>> On Wed, 17 Sep 2003 01:09:24 -0700
>>>>> vlm at netli.com (Lev Walkin) said:

> I saw it during working on next KAME merge into 5-CURRENT.
> KAME/NetBSD uses assert() here like:
> 
> 	assert(padLen > 0 && padLen <= 16);
> 
> Since FreeBSD doesn't have assert() in kernel, this line was changed
> to:
> 
> 	if (padLen > 0 && padLen <= 16)
> 		return BAD_CIPHER_STATE;
> 
> for KAME/FreeBSD.  Since if expression is true, the assert() macro
> does nothing, the expression seems wrong, and it should be:
> 
> 	if (padLen <= 0 || padLen > 16)
> 		return BAD_CIPHER_STATE;
> 
> as you pointed out.


vlm> Absolutely NOT.

vlm> According to RFC1423 and FIPS81, the padding length may be somewhere
vlm> in between 1 to 16 bytes, which translated into

vlm> 	if(padLen < 0 || padLen >= 16)

vlm> for this particular code.

Ah, yes.  Then, `assert(padLen > 0 && padLen <= 16)'; should be wrong.

Sincerely,

--
Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume at mahoroba.org  ume at bisd.hitachi.co.jp  ume@{,jp.}FreeBSD.org
http://www.imasy.org/~ume/