From: Xi Wang <xi.wang@gmail.com>
Date: Mon, 22 Oct 2012 20:09:46 +0000 (-0400)
Subject: Fix incorrect loop condition in egg_hkdf_perform()
X-Git-Tag: upstream/0.13~26
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=275d314d5706e412c346fe85027b888cf7d99f76;p=platform%2Fupstream%2Flibsecret.git

Fix incorrect loop condition in egg_hkdf_perform()

This does not cause a change in behavior (as evidenced by tests,
at least on linux when built with gcc) but is more correct code,
and less likely to be miscompiled.

The condition (i < 256) in the following loop is always false since i
is of type guchar, which is at most 255.

	guchar i;
	...
	for (i = 1; i < 256; ++i) { ... }

This patch changes i to a larger type gint.

Also in the loop we have:

	gcry_md_write (md2, &i, 1);

change it to use gcry_md_putc().
---

diff --git a/egg/egg-hkdf.c b/egg/egg-hkdf.c
index e79b9d4..bc2919a 100644
--- a/egg/egg-hkdf.c
+++ b/egg/egg-hkdf.c
@@ -39,7 +39,7 @@ egg_hkdf_perform (const gchar *hash_algo, gconstpointer input, gsize n_input,
 	gpointer buffer = NULL;
 	gcry_md_hd_t md1, md2;
 	guint hash_len;
-	guchar i;
+	gint i;
 	gint flags, algo;
 	gsize step, n_buffer;
 	guchar *at;
@@ -89,7 +89,7 @@ egg_hkdf_perform (const gchar *hash_algo, gconstpointer input, gsize n_input,
 		gcry_md_reset (md2);
 		gcry_md_write (md2, buffer, n_buffer);
 		gcry_md_write (md2, info, n_info);
-		gcry_md_write (md2, &i, 1);
+		gcry_md_putc (md2, i);
 
 		n_buffer = hash_len;
 		memcpy (buffer, gcry_md_read (md2, algo), n_buffer);