Merge branch 'feature/timing_resist' into develop

bn_mp_expt_d.c

@@ -15,41 +15,12 @@
  * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
  */
 
-/* calculate c = a**b  using a square-multiply algorithm */
+/* wrapper function for mp_expt_d_ex() */
 int mp_expt_d (mp_int * a, mp_digit b, mp_int * c)
 {
-  int     res;
+  return mp_expt_d_ex(a, b, c, 0);
-  mp_int  g;
-
-  if ((res = mp_init_copy (&g, a)) != MP_OKAY) {
-    return res;
-  }
-
-  /* set initial result */
-  mp_set (c, 1);
-
-  while (b > 0) {
-    /* if the bit is set multiply */
-    if (b & 1) {
-      if ((res = mp_mul (c, &g, c)) != MP_OKAY) {
-        mp_clear (&g);
-        return res;
-      }
-    }
-
-    /* square */
-    if (b > 1 && (res = mp_sqr (&g, &g)) != MP_OKAY) {
-      mp_clear (&g);
-      return res;
-    }
-
-    /* shift to next bit */
-    b >>= 1;
-  }
-
-  mp_clear (&g);
-  return MP_OKAY;
 }
+
 #endif
 
 /* $Source$ */

bn_mp_expt_d_ex.c

@@ -0,0 +1,81 @@
+#include <tommath.h>
+#ifdef BN_MP_EXPT_D_EX_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
+ */
+
+/* calculate c = a**b  using a square-multiply algorithm */
+int mp_expt_d_ex (mp_int * a, mp_digit b, mp_int * c, int fast)
+{
+  int     res;
+  unsigned int x;
+
+  mp_int  g;
+
+  if ((res = mp_init_copy (&g, a)) != MP_OKAY) {
+    return res;
+  }
+
+  /* set initial result */
+  mp_set (c, 1);
+
+  if (fast) {
+    while (b > 0) {
+      /* if the bit is set multiply */
+      if (b & 1) {
+        if ((res = mp_mul (c, &g, c)) != MP_OKAY) {
+          mp_clear (&g);
+          return res;
+        }
+      }
+
+      /* square */
+      if (b > 1 && (res = mp_sqr (&g, &g)) != MP_OKAY) {
+        mp_clear (&g);
+        return res;
+      }
+
+      /* shift to next bit */
+      b >>= 1;
+    }
+  }
+  else {
+    for (x = 0; x < DIGIT_BIT; x++) {
+      /* square */
+      if ((res = mp_sqr (c, c)) != MP_OKAY) {
+        mp_clear (&g);
+        return res;
+      }
+
+      /* if the bit is set multiply */
+      if ((b & (mp_digit) (((mp_digit)1) << (DIGIT_BIT - 1))) != 0) {
+        if ((res = mp_mul (c, &g, c)) != MP_OKAY) {
+           mp_clear (&g);
+           return res;
+        }
+      }
+
+      /* shift to next bit */
+      b <<= 1;
+    }
+    } /* if ... else */
+
+    mp_clear (&g);
+  return MP_OKAY;
+}
+#endif
+
+/* $Source$ */
+/* $Revision$ */
+/* $Date$ */

bn_mp_n_root.c

@@ -15,116 +15,14 @@
  * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
  */
 
-/* find the n'th root of an integer 
+/* wrapper function for mp_n_root_ex()
- *
+ * computes c = (a)**(1/b) such that (c)**b <= a and (c+1)**b > a
- * Result found such that (c)**b <= a and (c+1)**b > a 
- *
- * This algorithm uses Newton's approximation 
- * x[i+1] = x[i] - f(x[i])/f'(x[i]) 
- * which will find the root in log(N) time where 
- * each step involves a fair bit.  This is not meant to 
- * find huge roots [square and cube, etc].
  */
 int mp_n_root (mp_int * a, mp_digit b, mp_int * c)
 {
-  mp_int  t1, t2, t3;
+  return mp_n_root_ex(a, b, c, 0);
-  int     res, neg;
-
-  /* input must be positive if b is even */
-  if ((b & 1) == 0 && a->sign == MP_NEG) {
-    return MP_VAL;
-  }
-
-  if ((res = mp_init (&t1)) != MP_OKAY) {
-    return res;
-  }
-
-  if ((res = mp_init (&t2)) != MP_OKAY) {
-    goto LBL_T1;
-  }
-
-  if ((res = mp_init (&t3)) != MP_OKAY) {
-    goto LBL_T2;
-  }
-
-  /* if a is negative fudge the sign but keep track */
-  neg     = a->sign;
-  a->sign = MP_ZPOS;
-
-  /* t2 = 2 */
-  mp_set (&t2, 2);
-
-  do {
-    /* t1 = t2 */
-    if ((res = mp_copy (&t2, &t1)) != MP_OKAY) {
-      goto LBL_T3;
-    }
-
-    /* t2 = t1 - ((t1**b - a) / (b * t1**(b-1))) */
-    
-    /* t3 = t1**(b-1) */
-    if ((res = mp_expt_d (&t1, b - 1, &t3)) != MP_OKAY) {   
-      goto LBL_T3;
-    }
-
-    /* numerator */
-    /* t2 = t1**b */
-    if ((res = mp_mul (&t3, &t1, &t2)) != MP_OKAY) {    
-      goto LBL_T3;
-    }
-
-    /* t2 = t1**b - a */
-    if ((res = mp_sub (&t2, a, &t2)) != MP_OKAY) {  
-      goto LBL_T3;
-    }
-
-    /* denominator */
-    /* t3 = t1**(b-1) * b  */
-    if ((res = mp_mul_d (&t3, b, &t3)) != MP_OKAY) {    
-      goto LBL_T3;
-    }
-
-    /* t3 = (t1**b - a)/(b * t1**(b-1)) */
-    if ((res = mp_div (&t2, &t3, &t3, NULL)) != MP_OKAY) {  
-      goto LBL_T3;
-    }
-
-    if ((res = mp_sub (&t1, &t3, &t2)) != MP_OKAY) {
-      goto LBL_T3;
-    }
-  }  while (mp_cmp (&t1, &t2) != MP_EQ);
-
-  /* result can be off by a few so check */
-  for (;;) {
-    if ((res = mp_expt_d (&t1, b, &t2)) != MP_OKAY) {
-      goto LBL_T3;
-    }
-
-    if (mp_cmp (&t2, a) == MP_GT) {
-      if ((res = mp_sub_d (&t1, 1, &t1)) != MP_OKAY) {
-         goto LBL_T3;
-      }
-    } else {
-      break;
-    }
-  }
-
-  /* reset the sign of a first */
-  a->sign = neg;
-
-  /* set the result */
-  mp_exch (&t1, c);
-
-  /* set the sign of the result */
-  c->sign = neg;
-
-  res = MP_OKAY;
-
-LBL_T3:mp_clear (&t3);
-LBL_T2:mp_clear (&t2);
-LBL_T1:mp_clear (&t1);
-  return res;
 }
+
 #endif
 
 /* $Source$ */

bn_mp_n_root_ex.c

@@ -0,0 +1,132 @@
+#include <tommath.h>
+#ifdef BN_MP_N_ROOT_EX_C
+/* LibTomMath, multiple-precision integer library -- Tom St Denis
+ *
+ * LibTomMath is a library that provides multiple-precision
+ * integer arithmetic as well as number theoretic functionality.
+ *
+ * The library was designed directly after the MPI library by
+ * Michael Fromberger but has been written from scratch with
+ * additional optimizations in place.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ *
+ * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
+ */
+
+/* find the n'th root of an integer
+ *
+ * Result found such that (c)**b <= a and (c+1)**b > a
+ *
+ * This algorithm uses Newton's approximation
+ * x[i+1] = x[i] - f(x[i])/f'(x[i])
+ * which will find the root in log(N) time where
+ * each step involves a fair bit.  This is not meant to
+ * find huge roots [square and cube, etc].
+ */
+int mp_n_root_ex (mp_int * a, mp_digit b, mp_int * c, int fast)
+{
+  mp_int  t1, t2, t3;
+  int     res, neg;
+
+  /* input must be positive if b is even */
+  if ((b & 1) == 0 && a->sign == MP_NEG) {
+    return MP_VAL;
+  }
+
+  if ((res = mp_init (&t1)) != MP_OKAY) {
+    return res;
+  }
+
+  if ((res = mp_init (&t2)) != MP_OKAY) {
+    goto LBL_T1;
+  }
+
+  if ((res = mp_init (&t3)) != MP_OKAY) {
+    goto LBL_T2;
+  }
+
+  /* if a is negative fudge the sign but keep track */
+  neg     = a->sign;
+  a->sign = MP_ZPOS;
+
+  /* t2 = 2 */
+  mp_set (&t2, 2);
+
+  do {
+    /* t1 = t2 */
+    if ((res = mp_copy (&t2, &t1)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+
+    /* t2 = t1 - ((t1**b - a) / (b * t1**(b-1))) */
+
+    /* t3 = t1**(b-1) */
+    if ((res = mp_expt_d_ex (&t1, b - 1, &t3, fast)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+
+    /* numerator */
+    /* t2 = t1**b */
+    if ((res = mp_mul (&t3, &t1, &t2)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+
+    /* t2 = t1**b - a */
+    if ((res = mp_sub (&t2, a, &t2)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+
+    /* denominator */
+    /* t3 = t1**(b-1) * b  */
+    if ((res = mp_mul_d (&t3, b, &t3)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+
+    /* t3 = (t1**b - a)/(b * t1**(b-1)) */
+    if ((res = mp_div (&t2, &t3, &t3, NULL)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+
+    if ((res = mp_sub (&t1, &t3, &t2)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+  }  while (mp_cmp (&t1, &t2) != MP_EQ);
+
+  /* result can be off by a few so check */
+  for (;;) {
+    if ((res = mp_expt_d_ex (&t1, b, &t2, fast)) != MP_OKAY) {
+      goto LBL_T3;
+    }
+
+    if (mp_cmp (&t2, a) == MP_GT) {
+      if ((res = mp_sub_d (&t1, 1, &t1)) != MP_OKAY) {
+         goto LBL_T3;
+      }
+    } else {
+      break;
+    }
+  }
+
+  /* reset the sign of a first */
+  a->sign = neg;
+
+  /* set the result */
+  mp_exch (&t1, c);
+
+  /* set the sign of the result */
+  c->sign = neg;
+
+  res = MP_OKAY;
+
+LBL_T3:mp_clear (&t3);
+LBL_T2:mp_clear (&t2);
+LBL_T1:mp_clear (&t1);
+  return res;
+}
+#endif
+
+/* $Source$ */
+/* $Revision$ */
+/* $Date$ */

demo/demo.c

@@ -179,8 +179,13 @@ printf("compare no compare!\n"); return EXIT_FAILURE; }
 	 printf("\nmp_sqrt() error!");
 	 return EXIT_FAILURE;
       }
-      mp_n_root(&a, 2, &a);
+      mp_n_root_ex(&a, 2, &c, 0);
-      if (mp_cmp_mag(&b, &a) != MP_EQ) {
+      mp_n_root_ex(&a, 2, &d, 1);
+      if (mp_cmp_mag(&c, &d) != MP_EQ) {
+	 printf("\nmp_n_root_ex() bad result!");
+	 return EXIT_FAILURE;
+      }
+      if (mp_cmp_mag(&b, &c) != MP_EQ) {
 	 printf("mp_sqrt() bad result!\n");
 	 return 1;
       }

makefile

@@ -96,7 +96,7 @@ bn_mp_init_multi.o bn_mp_clear_multi.o bn_mp_exteuclid.o bn_mp_toradix_n.o \
 bn_mp_prime_random_ex.o bn_mp_get_int.o bn_mp_sqrt.o bn_mp_is_square.o bn_mp_init_set.o \
 bn_mp_init_set_int.o bn_mp_invmod_slow.o bn_mp_prime_rabin_miller_trials.o \
 bn_mp_to_signed_bin_n.o bn_mp_to_unsigned_bin_n.o bn_mp_import.o bn_mp_export.o \
-bn_mp_balance_mul.o
+bn_mp_balance_mul.o bn_mp_expt_d_ex.o bn_mp_n_root_ex.o
 
 $(LIBNAME):  $(OBJECTS)
 	$(AR) $(ARFLAGS) $@ $(OBJECTS)

tommath.h

@@ -364,6 +364,7 @@ int mp_div_3(mp_int *a, mp_int *c, mp_digit *d);
 
 /* c = a**b */
 int mp_expt_d(mp_int *a, mp_digit b, mp_int *c);
+int mp_expt_d_ex (mp_int * a, mp_digit b, mp_int * c, int fast);
 
 /* c = a mod b, 0 <= c < b  */
 int mp_mod_d(mp_int *a, mp_digit b, mp_digit *c);
@@ -399,6 +400,7 @@ int mp_lcm(mp_int *a, mp_int *b, mp_int *c);
  * returns error if a < 0 and b is even
  */
 int mp_n_root(mp_int *a, mp_digit b, mp_int *c);
+int mp_n_root_ex (mp_int * a, mp_digit b, mp_int * c, int fast);
 
 /* special sqrt algo */
 int mp_sqrt(mp_int *arg, mp_int *ret);

tommath_class.h

@@ -41,6 +41,7 @@
 #define BN_MP_EXCH_C
 #define BN_MP_EXPORT_C
 #define BN_MP_EXPT_D_C
+#define BN_MP_EXPT_D_EX_C
 #define BN_MP_EXPTMOD_C
 #define BN_MP_EXPTMOD_FAST_C
 #define BN_MP_EXTEUCLID_C
@@ -76,6 +77,7 @@
 #define BN_MP_MUL_D_C
 #define BN_MP_MULMOD_C
 #define BN_MP_N_ROOT_C
+#define BN_MP_N_ROOT_EX_C
 #define BN_MP_NEG_C
 #define BN_MP_OR_C
 #define BN_MP_PRIME_FERMAT_C
@@ -333,6 +335,10 @@
 #endif
 
 #if defined(BN_MP_EXPT_D_C)
+   #define BN_MP_EXPT_D_EX_C
+#endif
+
+#if defined(BN_MP_EXPT_D_EX_C)
    #define BN_MP_INIT_COPY_C
    #define BN_MP_SET_C
    #define BN_MP_MUL_C
@@ -609,10 +615,14 @@
 #endif
 
 #if defined(BN_MP_N_ROOT_C)
+   #define BN_MP_N_ROOT_EX_C
+#endif
+
+#if defined(BN_MP_N_ROOT_EX_C)
    #define BN_MP_INIT_C
    #define BN_MP_SET_C
    #define BN_MP_COPY_C
-   #define BN_MP_EXPT_D_C
+   #define BN_MP_EXPT_D_EX_C
    #define BN_MP_MUL_C
    #define BN_MP_SUB_C
    #define BN_MP_MUL_D_C
@@ -1018,7 +1028,3 @@
 #else
 #define LTM_LAST
 #endif
-
-/* $Source$ */
-/* $Revision$ */
-/* $Date$ */