--- rsync-2.6.6/authenticate.c-orig     2006-03-06 11:10:23.000000000 +0100
+++ rsync-2.6.6/authenticate.c  2006-03-06 11:10:54.000000000 +0100
@@ -49,6 +49,9 @@
                }
                out[i] = b64[idx];
        }
+
+       while ((i % 4) > 0)
+               out[i++] = '=';
 }

 /* Generate a challenge buffer and return it base64-encoded. */