From: Matt Caswell <matt@openssl.org>
Date: Wed, 7 Feb 2018 17:03:14 +0000 (+0000)
Subject: Yet more style updates to the curve448 code
X-Git-Tag: OpenSSL_1_1_1-pre2~62
X-Git-Url: https://git.openssl.org/?p=openssl.git;a=commitdiff_plain;h=909c68ae7253a718993cf9d89412e4c9b403eb9b

Yet more style updates to the curve448 code

Reviewed-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/5105)
---

diff --git a/crypto/ec/curve448/curve448.c b/crypto/ec/curve448/curve448.c
index 1459976981..7c43a758f9 100644
--- a/crypto/ec/curve448/curve448.c
+++ b/crypto/ec/curve448/curve448.c
@@ -33,7 +33,7 @@ static const curve448_scalar_t precomputed_scalarmul_adjustment = {
     }
 };
 
-#define TWISTED_D ((EDWARDS_D)-1)
+#define TWISTED_D (EDWARDS_D - 1)
 
 #define WBITS C448_WORD_BITS   /* NB this may be different from ARCH_WORD_BITS */
 
@@ -385,7 +385,7 @@ c448_error_t x448_int(uint8_t out[X_PUBLIC_BYTES],
     mask_t swap = 0;
     mask_t nz;
 
-    ignore_result(gf_deserialize(x1, base, 1, 0));
+    (void)gf_deserialize(x1, base, 1, 0);
     gf_copy(x2, ONE);
     gf_copy(z2, ZERO);
     gf_copy(x3, x1);
@@ -409,25 +409,30 @@ c448_error_t x448_int(uint8_t out[X_PUBLIC_BYTES],
         gf_cond_swap(z2, z3, swap);
         swap = k_t;
 
-        gf_add_nr(t1, x2, z2);  /* A = x2 + z2 *//* 2+e */
-        gf_sub_nr(t2, x2, z2);  /* B = x2 - z2 *//* 3+e */
-        gf_sub_nr(z2, x3, z3);  /* D = x3 - z3 *//* 3+e */
+        /*
+         * The "_nr" below skips coefficient reduction. In the following
+         * comments, "2+e" is saying that the coefficients are at most 2+epsilon
+         * times the reduction limit.
+         */
+        gf_add_nr(t1, x2, z2);  /* A = x2 + z2 */ /* 2+e */
+        gf_sub_nr(t2, x2, z2);  /* B = x2 - z2 */ /* 3+e */
+        gf_sub_nr(z2, x3, z3);  /* D = x3 - z3 */ /* 3+e */
         gf_mul(x2, t1, z2);     /* DA */
-        gf_add_nr(z2, z3, x3);  /* C = x3 + z3 *//* 2+e */
+        gf_add_nr(z2, z3, x3);  /* C = x3 + z3 */ /* 2+e */
         gf_mul(x3, t2, z2);     /* CB */
-        gf_sub_nr(z3, x2, x3);  /* DA-CB *//* 3+e */
+        gf_sub_nr(z3, x2, x3);  /* DA-CB */ /* 3+e */
         gf_sqr(z2, z3);         /* (DA-CB)^2 */
         gf_mul(z3, x1, z2);     /* z3 = x1(DA-CB)^2 */
-        gf_add_nr(z2, x2, x3);  /* (DA+CB) *//* 2+e */
+        gf_add_nr(z2, x2, x3);  /* (DA+CB) */ /* 2+e */
         gf_sqr(x3, z2);         /* x3 = (DA+CB)^2 */
 
         gf_sqr(z2, t1);         /* AA = A^2 */
         gf_sqr(t1, t2);         /* BB = B^2 */
         gf_mul(x2, z2, t1);     /* x2 = AA*BB */
-        gf_sub_nr(t2, z2, t1);  /* E = AA-BB *//* 3+e */
+        gf_sub_nr(t2, z2, t1);  /* E = AA-BB */ /* 3+e */
 
         gf_mulw(t1, t2, -EDWARDS_D); /* E*-d = a24*E */
-        gf_add_nr(t1, t1, z2);  /* AA + a24*E *//* 2+e */
+        gf_add_nr(t1, t1, z2);  /* AA + a24*E */ /* 2+e */
         gf_mul(z2, t2, t1);     /* z2 = E(AA+a24*E) */
     }
 
diff --git a/crypto/ec/curve448/point_448.h b/crypto/ec/curve448/point_448.h
index 326718b305..219d9f7641 100644
--- a/crypto/ec/curve448/point_448.h
+++ b/crypto/ec/curve448/point_448.h
@@ -92,9 +92,8 @@ extern const niels_t *curve448_wnaf_base;
  * C448_FAILURE: The scalar was greater than the modulus, and has been reduced
  * modulo that modulus.
  */
-__owur c448_error_t curve448_scalar_decode(
-                            curve448_scalar_t out,
-                            const unsigned char ser[C448_SCALAR_BYTES]);
+c448_error_t curve448_scalar_decode(curve448_scalar_t out,
+                                    const unsigned char ser[C448_SCALAR_BYTES]);
 
 /*
  * Read a scalar from wire format or from bytes.  Reduces mod scalar prime.
diff --git a/crypto/ec/curve448/scalar.c b/crypto/ec/curve448/scalar.c
index f899ce2ae6..0f14bc4b98 100644
--- a/crypto/ec/curve448/scalar.c
+++ b/crypto/ec/curve448/scalar.c
@@ -39,7 +39,7 @@ static const curve448_scalar_t sc_p = {
 #define WBITS C448_WORD_BITS   /* NB this may be different from ARCH_WORD_BITS */
 
 const curve448_scalar_t curve448_scalar_one = {{{1}}};
-const curve448_scalar_t  curve448_scalar_zero = {{{0}}};
+const curve448_scalar_t curve448_scalar_zero = {{{0}}};
 
 /*
  * {extra,accum} - sub +? p
@@ -198,7 +198,7 @@ void curve448_scalar_decode_long(curve448_scalar_t s,
     while (i) {
         i -= C448_SCALAR_BYTES;
         sc_montmul(t1, t1, sc_r2);
-        ignore_result(curve448_scalar_decode(t2, ser + i));
+        (void)curve448_scalar_decode(t2, ser + i);
         curve448_scalar_add(t1, t1, t2);
     }
 
diff --git a/crypto/ec/curve448/word.h b/crypto/ec/curve448/word.h
index 179d70b853..6067404e65 100644
--- a/crypto/ec/curve448/word.h
+++ b/crypto/ec/curve448/word.h
@@ -101,9 +101,4 @@ static ossl_inline mask_t bool_to_mask(c448_bool_t m)
     return ret;
 }
 
-static ossl_inline void ignore_result(c448_bool_t boo)
-{
-    (void)boo;
-}
-
 #endif                          /* HEADER_WORD_H */