knf approximation

1 files changed, 56 insertions, 44 deletions

diff --git a/lib/libcrypto/ec/ecp_nistputil.c b/lib/libcrypto/ec/ecp_nistputil.c
index c8140c807fb..0312fb16add 100644
--- a/lib/libcrypto/ec/ecp_nistputil.c
+++ b/lib/libcrypto/ec/ecp_nistputil.c
@@ -41,16 +41,17 @@
  * 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))
-	{
+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;
 
 #define tmp_felem(I) (&((char *)tmp_felems)[(I) * felem_size])
@@ -62,50 +63,59 @@ void ec_GFp_nistp_points_make_affine_internal(size_t num, void *point_array,
 		felem_assign(tmp_felem(0), Z(0));
 	else
 		felem_one(tmp_felem(0));
-	for (i = 1; i < (int)num; i++)
-		{
+	for (i = 1; i < (int) num; i++) {
 		if (!felem_is_zero(Z(i)))
-			felem_mul(tmp_felem(i), tmp_felem(i-1), 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_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--)
-		{
+	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)
+			/*
+			 * 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) */
+			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_assign(tmp_felem(num), tmp_felem(0));	/* 1/Z(0) */
 
-		if (!felem_is_zero(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));
+				/*
+				 * 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) */
+			/*
+			 * 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
-			{
+		} else {
 			if (i > 0)
-				/* For next iteration, replace tmp_felem(i-1) by its inverse */
-				felem_assign(tmp_felem(i-1), tmp_felem(i));
-			}
+				/*
+				 * 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
@@ -180,18 +190,20 @@ 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)
-	{
+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 */
+	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;
-	}
+}
 #else
-static void *dummy=&dummy;
+static void *dummy = &dummy;
 #endif