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

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

diff --git a/userapps/opensource/sshd/libtommath/bn_mp_montgomery_calc_normalization.c b/userapps/opensource/sshd/libtommath/bn_mp_montgomery_calc_normalization.c
index a1ff2cd..e2efc34 100755 (executable)
--- a/userapps/opensource/sshd/libtommath/bn_mp_montgomery_calc_normalization.c
+++ b/userapps/opensource/sshd/libtommath/bn_mp_montgomery_calc_normalization.c
@@ -1,9 +1,11 @@
+#include <tommath.h>
+#ifdef BN_MP_MONTGOMERY_CALC_NORMALIZATION_C

 /* LibTomMath, multiple-precision integer library -- Tom St Denis
  *
 /* 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.
  *
  * 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.
  *
  * Michael Fromberger but has been written from scratch with
  * additional optimizations in place.
  *


@@ -12,31 +14,30 @@
  *
  * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
  */
  *
  * Tom St Denis, tomstdenis@iahu.ca, http://math.libtomcrypt.org
  */

-#include <tommath.h>

 
 

-/* calculates a = B^n mod b for Montgomery reduction
- * Where B is the base [e.g. 2^DIGIT_BIT].
- * B^n mod b is computed by first computing
- * A = B^(n-1) which doesn't require a reduction but a simple OR.
- * then C = A * B = B^n is computed by performing upto DIGIT_BIT
+/*

  * shifts with subtractions when the result is greater than b.
  *
  * The method is slightly modified to shift B unconditionally upto just under
  * the leading bit of b.  This saves alot of multiple precision shifting.
  */
  * shifts with subtractions when the result is greater than b.
  *
  * The method is slightly modified to shift B unconditionally upto just under
  * the leading bit of b.  This saves alot of multiple precision shifting.
  */

-int
-mp_montgomery_calc_normalization (mp_int * a, mp_int * b)
+int mp_montgomery_calc_normalization (mp_int * a, mp_int * b)

 {
   int     x, bits, res;
 
   /* how many bits of last digit does b use */
   bits = mp_count_bits (b) % DIGIT_BIT;
 
 {
   int     x, bits, res;
 
   /* how many bits of last digit does b use */
   bits = mp_count_bits (b) % DIGIT_BIT;
 

-  /* compute A = B^(n-1) * 2^(bits-1) */
-  if ((res = mp_2expt (a, (b->used - 1) * DIGIT_BIT + bits - 1)) != MP_OKAY) {
-    return res;
+  if (b->used > 1) {
+     if ((res = mp_2expt (a, (b->used - 1) * DIGIT_BIT + bits - 1)) != MP_OKAY) {
+        return res;
+     }
+  } else {
+     mp_set(a, 1);
+     bits = 1;

   }
 
   }
 

+

   /* now compute C = A * B mod b */
   for (x = bits - 1; x < (int)DIGIT_BIT; x++) {
     if ((res = mp_mul_2 (a, a)) != MP_OKAY) {
   /* now compute C = A * B mod b */
   for (x = bits - 1; x < (int)DIGIT_BIT; x++) {
     if ((res = mp_mul_2 (a, a)) != MP_OKAY) {


@@ -51,3 +52,4 @@ mp_montgomery_calc_normalization (mp_int * a, mp_int * b)
 
   return MP_OKAY;
 }
 
   return MP_OKAY;
 }

+#endif