www.usr.com/support/gpl/USR9107_release.1.4.tar.gz

[bcm963xx.git] / userapps / opensource / sshd / libtommath / bn_mp_grow.c

diff --git a/userapps/opensource/sshd/libtommath/bn_mp_grow.c b/userapps/opensource/sshd/libtommath/bn_mp_grow.c
index 2a8249c..12a78a8 100755 (executable)
--- a/userapps/opensource/sshd/libtommath/bn_mp_grow.c
+++ b/userapps/opensource/sshd/libtommath/bn_mp_grow.c
@@ -1,9 +1,11 @@
+#include <tommath.h>
+#ifdef BN_MP_GROW_C
 /* LibTomMath, multiple-precision integer library -- Tom St Denis
  *
- * LibTomMath is library that provides for multiple-precision
+ * LibTomMath is a library that provides multiple-precision
  * integer arithmetic as well as number theoretic functionality.
  *
- * The library is designed directly after the MPI library by
+ * The library was designed directly after the MPI library by
  * Michael Fromberger but has been written from scratch with
  * additional optimizations in place.
  *
@@ -12,24 +14,33 @@
  *
  * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
  */
-#include <tommath.h>
 
 /* grow as required */
-int
-mp_grow (mp_int * a, int size)
+int mp_grow (mp_int * a, int size)
 {
   int     i;
+  mp_digit *tmp;
 
   /* if the alloc size is smaller alloc more ram */
   if (a->alloc < size) {
     /* ensure there are always at least MP_PREC digits extra on top */
-    size += (MP_PREC * 2) - (size & (MP_PREC - 1));     
+    size += (MP_PREC * 2) - (size % MP_PREC);
 
-    a->dp = OPT_CAST realloc (a->dp, sizeof (mp_digit) * size);
-    if (a->dp == NULL) {
+    /* reallocate the array a->dp
+     *
+     * We store the return in a temporary variable
+     * in case the operation failed we don't want
+     * to overwrite the dp member of a.
+     */
+    tmp = OPT_CAST(mp_digit) XREALLOC (a->dp, sizeof (mp_digit) * size);
+    if (tmp == NULL) {
+      /* reallocation failed but "a" is still valid [can be freed] */
       return MP_MEM;
     }
 
+    /* reallocation succeeded so set a->dp */
+    a->dp = tmp;
+
     /* zero excess digits */
     i        = a->alloc;
     a->alloc = size;
@@ -39,3 +50,4 @@ mp_grow (mp_int * a, int size)
   }
   return MP_OKAY;
 }
+#endif