diff -up silc-toolkit-1.1.5/lib/silcutil/silcutil.c.bufflow silc-toolkit-1.1.5/lib/silcutil/silcutil.c
--- silc-toolkit-1.1.5/lib/silcutil/silcutil.c.bufflow	2008-01-07 10:12:59.000000000 -0500
+++ silc-toolkit-1.1.5/lib/silcutil/silcutil.c	2008-01-07 10:17:25.000000000 -0500
@@ -468,19 +468,25 @@ SilcBool silc_hash_public_key_compare(vo
 char *silc_fingerprint(const unsigned char *data, SilcUInt32 data_len)
 {
   char fingerprint[64], *cp;
-  int i;
+  int i, maxlen = 64;
 
   memset(fingerprint, 0, sizeof(fingerprint));
   cp = fingerprint;
   for (i = 0; i < data_len; i++) {
-    silc_snprintf(cp, sizeof(fingerprint), "%02X", data[i]);
+    silc_snprintf(cp, maxlen, "%02X", data[i]);
     cp += 2;
+    maxlen = 64 - (cp - fingerprint);
 
-    if ((i + 1) % 2 == 0)
-      silc_snprintf(cp++, sizeof(fingerprint), " ");
+    if ((i + 1) % 2 == 0 && maxlen > 0)
+      silc_snprintf(cp++, maxlen, " ");
+    maxlen = 64 - (cp - fingerprint);
+
+    if ((i + 1) % 10 == 0 && maxlen > 0)
+      silc_snprintf(cp++, maxlen, " ");
+    maxlen = 64 - (cp - fingerprint);
 
-    if ((i + 1) % 10 == 0)
-      silc_snprintf(cp++, sizeof(fingerprint), " ");
+    if (maxlen <= 0)
+      break;
   }
   i--;
   if ((i + 1) % 2 == 0)