[Opensrf-commits] r1809 - trunk/src/libopensrf (scottmk)

[svn at svn.open-ils.org]

Author: scottmk
Date: 2009-10-08 14:26:37 -0400 (Thu, 08 Oct 2009)
New Revision: 1809

Modified:
   trunk/src/libopensrf/utils.c
Log:
Fix a bug in md5sum() (which only affected code compiled
with debugging turned on).

md5sum() builds an md5 message digest in a buffer.  Originally
it used memset() to initialize the buffer with binary zeroes.
At some point the call to memset() was replaced with the
osrf_clearbuf() macro.  When compiled in debugging mode,
osrf_clearbuf() fills the buffer with exclamation points;
otherwise it reverts to the original memset().

In this case the use of osrf_clearbuf is inappropriate, because
we use strcat() to build the message digest, two bytes at a
time.  We don't need to use memset(), but the first byte needs
to be initialized to a nul byte so that strcat() will work as
intended.  Hence:

1. Remove the call to osrf_clearbuf().

2. Put a nul byte at the beginning of the buffer.

Also, I made the buffer smaller.  There's no reason for it
to be 256 bytes long.

M    src/libopensrf/utils.c


Modified: trunk/src/libopensrf/utils.c
===================================================================
--- trunk/src/libopensrf/utils.c	2009-10-05 18:53:02 UTC (rev 1808)
+++ trunk/src/libopensrf/utils.c	2009-10-08 18:26:37 UTC (rev 1809)
@@ -728,8 +728,8 @@
 	MD5_stop (&ctx, digest);
 
 	char buf[16];
-	char final[256];
-	osrf_clearbuf(final, sizeof(final));
+	char final[ 1 + 2 * sizeof( digest ) ];
+	final[0] = '\0';
 
 	for ( i=0 ; i<16 ; i++ ) {
 		snprintf(buf, sizeof(buf), "%02x", digest[i]);