diff options
Diffstat (limited to 'crypto/ec/curve448/curve448.c')
| -rw-r--r-- | crypto/ec/curve448/curve448.c | 25 |
1 files changed, 15 insertions, 10 deletions
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) */ } |