add ECDSA_size to ec_asn1.c
[openssl.git] / crypto / ec / ecp_nistputil.c
index 6280a432935ef601c6b12b5f3eabd9a9e56f4b5f..8ba2a25e9380132282f302f3c7472ae76f9075d6 100644 (file)
  *  limitations under the License.
  */
 
-#ifdef EC_NISTP_64_GCC_128
+#include <openssl/opensslconf.h>
+#ifndef OPENSSL_NO_EC_NISTP_64_GCC_128
 
 /*
  * Common utility functions for ecp_nistp224.c, ecp_nistp256.c, ecp_nistp521.c.
  */
 
-#include <stddef.h>
-#include "ec_lcl.h"
+# include <stddef.h>
+# include "ec_lcl.h"
 
-/* Convert an array of points into affine coordinates.
- * (If the point at infinity is found (Z = 0), it remains unchanged.)
- * This function is essentially an equivalent to EC_POINTs_make_affine(), but
- * works with the internal representation of points as used by ecp_nistp###.c
- * rather than with (BIGNUM-based) EC_POINT data structures.
- *
- * point_array is the input/output buffer ('num' points in projective form,
- * i.e. three coordinates each), based on an internal representation of
- * field elements of size 'felem_size'.
- *
- * tmp_felems needs to point to a temporary array of 'num'+1 field elements
- * for storage of intermediate values.
+/*
+ * Convert an array of points into affine coordinates. (If the point at
+ * infinity is found (Z = 0), it remains unchanged.) This function is
+ * essentially an equivalent to EC_POINTs_make_affine(), but works with the
+ * internal representation of points as used by ecp_nistp###.c rather than
+ * with (BIGNUM-based) EC_POINT data structures. point_array is the
+ * input/output buffer ('num' points in projective form, i.e. three
+ * coordinates each), based on an internal representation of field elements
+ * of size 'felem_size'. tmp_felems needs to point to a temporary array of
+ * 'num'+1 field elements for storage of intermediate values.
  */
 void ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array,
-       size_t felem_size, void *tmp_felems,
-       void (*felem_one)(void *out),
-       int (*felem_is_zero)(const void *in),
-       void (*felem_assign)(void *out, const void *in),
-       void (*felem_square)(void *out, const void *in),
-       void (*felem_mul)(void *out, const void *in1, const void *in2),
-       void (*felem_inv)(void *out, const void *in),
-       void (*felem_contract)(void *out, const void *in))
-       {
-       int i = 0;
+                                              size_t felem_size,
+                                              void *tmp_felems,
+                                              void (*felem_one) (void *out),
+                                              int (*felem_is_zero) (const void
+                                                                    *in),
+                                              void (*felem_assign) (void *out,
+                                                                    const void
+                                                                    *in),
+                                              void (*felem_square) (void *out,
+                                                                    const void
+                                                                    *in),
+                                              void (*felem_mul) (void *out,
+                                                                 const void
+                                                                 *in1,
+                                                                 const void
+                                                                 *in2),
+                                              void (*felem_inv) (void *out,
+                                                                 const void
+                                                                 *in),
+                                              void (*felem_contract) (void
+                                                                      *out,
+                                                                      const
+                                                                      void
+                                                                      *in))
+{
+    int i = 0;
 
-#define tmp_felem(I) (&((char *)tmp_felems)[(I) * felem_size])
-#define X(I) (&((char *)point_array)[3*(I) * felem_size])
-#define Y(I) (&((char *)point_array)[(3*(I) + 1) * felem_size])
-#define Z(I) (&((char *)point_array)[(3*(I) + 2) * felem_size])
+# define tmp_felem(I) (&((char *)tmp_felems)[(I) * felem_size])
+# define X(I) (&((char *)point_array)[3*(I) * felem_size])
+# define Y(I) (&((char *)point_array)[(3*(I) + 1) * felem_size])
+# define Z(I) (&((char *)point_array)[(3*(I) + 2) * felem_size])
 
-       if (!felem_is_zero(Z(0)))
-               felem_assign(tmp_felem(0), Z(0));
-       else
-               felem_one(tmp_felem(0));
-       for (i = 1; i < (int)num; i++)
-               {
-               if (!felem_is_zero(Z(i)))
-                       felem_mul(tmp_felem(i), tmp_felem(i-1), Z(i));
-               else
-                       felem_assign(tmp_felem(i), tmp_felem(i-1));
-               }
-       /* Now each tmp_felem(i) is the product of Z(0) .. Z(i), skipping any zero-valued factors:
-        * if Z(i) = 0, we essentially pretend that Z(i) = 1 */
+    if (!felem_is_zero(Z(0)))
+        felem_assign(tmp_felem(0), Z(0));
+    else
+        felem_one(tmp_felem(0));
+    for (i = 1; i < (int)num; i++) {
+        if (!felem_is_zero(Z(i)))
+            felem_mul(tmp_felem(i), tmp_felem(i - 1), Z(i));
+        else
+            felem_assign(tmp_felem(i), tmp_felem(i - 1));
+    }
+    /*
+     * Now each tmp_felem(i) is the product of Z(0) .. Z(i), skipping any
+     * zero-valued factors: if Z(i) = 0, we essentially pretend that Z(i) = 1
+     */
 
-       felem_inv(tmp_felem(num-1), tmp_felem(num-1));
-       for (i = num - 1; i >= 0; i--)
-               {
-               if (i > 0)
-                       /* tmp_felem(i-1) is the product of Z(0) .. Z(i-1),
-                        * tmp_felem(i) is the inverse of the product of Z(0) .. Z(i)
-                        */
-                       felem_mul(tmp_felem(num), tmp_felem(i-1), tmp_felem(i)); /* 1/Z(i) */
-               else
-                       felem_assign(tmp_felem(num), tmp_felem(0)); /* 1/Z(0) */
+    felem_inv(tmp_felem(num - 1), tmp_felem(num - 1));
+    for (i = num - 1; i >= 0; i--) {
+        if (i > 0)
+            /*
+             * tmp_felem(i-1) is the product of Z(0) .. Z(i-1), tmp_felem(i)
+             * is the inverse of the product of Z(0) .. Z(i)
+             */
+            /* 1/Z(i) */
+            felem_mul(tmp_felem(num), tmp_felem(i - 1), tmp_felem(i));
+        else
+            felem_assign(tmp_felem(num), tmp_felem(0)); /* 1/Z(0) */
 
-               if (!felem_is_zero(Z(i)))
-                       {
-                       if (i > 0)
-                               /* For next iteration, replace tmp_felem(i-1) by its inverse */
-                               felem_mul(tmp_felem(i-1), tmp_felem(i), Z(i));
+        if (!felem_is_zero(Z(i))) {
+            if (i > 0)
+                /*
+                 * For next iteration, replace tmp_felem(i-1) by its inverse
+                 */
+                felem_mul(tmp_felem(i - 1), tmp_felem(i), Z(i));
 
-                       /* Convert point (X, Y, Z) into affine form (X/(Z^2), Y/(Z^3), 1) */
-                       felem_square(Z(i), tmp_felem(num)); /* 1/(Z^2) */
-                       felem_mul(X(i), X(i), Z(i)); /* X/(Z^2) */
-                       felem_mul(Z(i), Z(i), tmp_felem(num)); /* 1/(Z^3) */
-                       felem_mul(Y(i), Y(i), Z(i)); /* Y/(Z^3) */
-                       felem_contract(X(i), X(i));
-                       felem_contract(Y(i), Y(i));
-                       felem_one(Z(i));
-                       }
-               else
-                       {
-                       if (i > 0)
-                               /* For next iteration, replace tmp_felem(i-1) by its inverse */
-                               felem_assign(tmp_felem(i-1), tmp_felem(i));
-                       }
-               }
-       }
+            /*
+             * Convert point (X, Y, Z) into affine form (X/(Z^2), Y/(Z^3), 1)
+             */
+            felem_square(Z(i), tmp_felem(num)); /* 1/(Z^2) */
+            felem_mul(X(i), X(i), Z(i)); /* X/(Z^2) */
+            felem_mul(Z(i), Z(i), tmp_felem(num)); /* 1/(Z^3) */
+            felem_mul(Y(i), Y(i), Z(i)); /* Y/(Z^3) */
+            felem_contract(X(i), X(i));
+            felem_contract(Y(i), Y(i));
+            felem_one(Z(i));
+        } else {
+            if (i > 0)
+                /*
+                 * For next iteration, replace tmp_felem(i-1) by its inverse
+                 */
+                felem_assign(tmp_felem(i - 1), tmp_felem(i));
+        }
+    }
+}
 
-/*
+/*-
  * This function looks at 5+1 scalar bits (5 current, 1 adjacent less
  * significant bit), and recodes them into a signed digit for use in fast point
  * multiplication: the use of signed rather than unsigned digits means that
@@ -179,18 +199,20 @@ void ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array,
  * has to be b_4 b_3 b_2 b_1 b_0 0.
  *
  */
-void ec_GFp_nistp_recode_scalar_bits(unsigned char *sign, unsigned char *digit, unsigned char in)
-       {
-       unsigned char s, d;
+void ec_GFp_nistp_recode_scalar_bits(unsigned char *sign,
+                                     unsigned char *digit, unsigned char in)
+{
+    unsigned char s, d;
 
-       s = ~((in >> 5) - 1); /* sets all bits to MSB(in), 'in' seen as 6-bit value */
-       d = (1 << 6) - in - 1;
-       d = (d & s) | (in & ~s);
-       d = (d >> 1) + (d & 1);
+    s = ~((in >> 5) - 1);       /* sets all bits to MSB(in), 'in' seen as
+                                 * 6-bit value */
+    d = (1 << 6) - in - 1;
+    d = (d & s) | (in & ~s);
+    d = (d >> 1) + (d & 1);
 
-       *sign = s & 1;
-       *digit = d;
-       }
+    *sign = s & 1;
+    *digit = d;
+}
 #else
-static void *dummy=&dummy;
+static void *dummy = &dummy;
 #endif