Re: [PATCH 2/3] gpg-interface: provide access to the payload

From: Jeff King <peff@peff.net>
Date: Jun 13, 2014, 10:34 UTC
Message-ID: <20140613103419.GA14066@sigill.intra.peff.net>
In-Reply-To: <539AC7FC.8040707@drmicha.warpmail.net>

On Fri, Jun 13, 2014 at 11:44:28AM +0200, Michael J Gruber wrote:

> > Perhaps this is a sign that we need a "signature_check_clear()" helper?
> 
> ... or simply switch to language which has (or can overload) free for an
> object :)

I hear somebody has reimplemented git in pure javascript. ;P

> Do we have prior art for such helpers so that the new one would be
> analogous?

I was thinking of credential_clear, string_list_clear, etc. Literally just:

  void signature_check_clear(struct signature_check *s)
  {
	free(s->gpg_output);
	free(s->gpg_status);
	free(s->signer);
	free(s->key);
  }

Your first commit fixed a leak on gpg_status. Did it also need to handle the "key" field there?

For some structs, we'd also do:

	memset(s, 0, sizeof(*s));

to get us back to a usable, initialized state so the struct can be reused. However, check_commit_signature doesn't care if the struct is initialized or not (i.e., there is no initialized state). Doing so does help detect use-after-free conditions, though.

-Peff