--- a/libtommath/bn_mp_reduce_2k_l.c	Sat Jun 24 17:50:50 2017 +0800
+++ b/libtommath/bn_mp_reduce_2k_l.c	Sat Jun 24 22:37:14 2017 +0800
@@ -1,4 +1,4 @@
-#include <tommath.h>
+#include <tommath_private.h>
 #ifdef BN_MP_REDUCE_2K_L_C
 /* LibTomMath, multiple-precision integer library -- Tom St Denis
  *
@@ -12,10 +12,10 @@
  * The library is free for all purposes without any express
  * guarantee it works.
  *
- * Tom St Denis, [email protected], http://math.libtomcrypt.com
+ * Tom St Denis, [email protected], http://libtom.org
  */
 
-/* reduces a modulo n where n is of the form 2**p - d 
+/* reduces a modulo n where n is of the form 2**p - d
    This differs from reduce_2k since "d" can be larger
    than a single digit.
 */
@@ -23,33 +23,35 @@
 {
    mp_int q;
    int    p, res;
-   
+
    if ((res = mp_init(&q)) != MP_OKAY) {
       return res;
    }
-   
-   p = mp_count_bits(n);    
+
+   p = mp_count_bits(n);
 top:
    /* q = a/2**p, a = a mod 2**p */
    if ((res = mp_div_2d(a, p, &q, a)) != MP_OKAY) {
       goto ERR;
    }
-   
+
    /* q = q * d */
-   if ((res = mp_mul(&q, d, &q)) != MP_OKAY) { 
+   if ((res = mp_mul(&q, d, &q)) != MP_OKAY) {
       goto ERR;
    }
-   
+
    /* a = a + q */
    if ((res = s_mp_add(a, &q, a)) != MP_OKAY) {
       goto ERR;
    }
-   
+
    if (mp_cmp_mag(a, n) != MP_LT) {
-      s_mp_sub(a, n, a);
+      if ((res = s_mp_sub(a, n, a)) != MP_OKAY) {
+         goto ERR;
+      }
       goto top;
    }
-   
+
 ERR:
    mp_clear(&q);
    return res;
@@ -57,6 +59,6 @@
 
 #endif
 
-/* $Source: /cvs/libtom/libtommath/bn_mp_reduce_2k_l.c,v $ */
-/* $Revision: 1.3 $ */
-/* $Date: 2006/03/31 14:18:44 $ */
+/* $Source$ */
+/* $Revision$ */
+/* $Date$ */