Re: [PATCH] KEYS: trusted: fix -Wvarags warning

From: Denis Kenzior
Date: Fri Oct 12 2018 - 08:29:59 EST

Hi Nick,

@@ -123,7 +123,7 @@ static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
unsigned int keylen, unsigned char *h1,
- unsigned char *h2, unsigned char h3, ...)
+ unsigned char h2, unsigned char *h3, ...)
unsigned char paramdigest[SHA1_DIGEST_SIZE];
struct sdesc *sdesc;

So my concern here is that this actually breaks the natural argument order compared to what the specification uses. This in turn requires one to perform some mental gymnastics and I'm not sure that this is such a good idea. Refer to for details.

Note that H3 is really the 'continueAuthSession' variable which is a bool. In the above specification BOOL has a size of 1, and TSS_authhmac already assigns a h3 to 'c' which is used for the actual hashing.

So can't we simply use 'bool' or uint32 as the type for h3 instead of re-ordering everything?