Commit 9fd3c858 authored by Matt Caswell's avatar Matt Caswell
Browse files

Remove a strict aliasing issue with pre-computed curve448 constants 



Reviewed-by: default avatarBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/5105)
parent 68b20c00

crypto/ec/curve448/curve448.c

+2 −24
Original line number Original line Diff line number Diff line
@@ -19,10 +19,6 @@ 




#define COFACTOR 4

#define COFACTOR 4





/* Comb config: number of combs, n, t, s. */

#define COMBS_N 5

#define COMBS_T 5

#define COMBS_S 18

#define C448_WNAF_FIXED_TABLE_BITS 5

#define C448_WNAF_FIXED_TABLE_BITS 5

#define C448_WNAF_VAR_TABLE_BITS 3

#define C448_WNAF_VAR_TABLE_BITS 3
@@ -40,23 +36,7 @@ static const curve448_scalar_t precomputed_scalarmul_adjustment = { 




#define WBITS C448_WORD_BITS   /* NB this may be different from ARCH_WORD_BITS */

#define WBITS C448_WORD_BITS   /* NB this may be different from ARCH_WORD_BITS */





/* Projective Niels coordinates */

extern const struct curve448_precomputed_s *curve448_precomputed_base;

typedef struct {

    gf a, b, c;

} niels_s, niels_t[1];

typedef struct {

    niels_t n;

    gf z;

} VECTOR_ALIGNED pniels_t[1];



/* Precomputed base */

struct curve448_precomputed_s {

    niels_t table[COMBS_N << (COMBS_T - 1)];

};



extern const gf curve448_precomputed_base_as_fe[];

const curve448_precomputed_s *curve448_precomputed_base =

    (const curve448_precomputed_s *)&curve448_precomputed_base_as_fe;





/* Inverse. */

/* Inverse. */

static void gf_invert(gf y, const gf x, int assert_nonzero)

static void gf_invert(gf y, const gf x, int assert_nonzero)
@@ -642,9 +622,7 @@ static void prepare_wnaf_table(pniels_t * output, 
    OPENSSL_cleanse(twop, sizeof(twop));

    OPENSSL_cleanse(twop, sizeof(twop));

}

}





extern const gf curve448_precomputed_wnaf_as_fe[];

extern const niels_t *curve448_wnaf_base;

static const niels_t *curve448_wnaf_base =

    (const niels_t *)curve448_precomputed_wnaf_as_fe;





void curve448_base_double_scalarmul_non_secret(curve448_point_t combo,

void curve448_base_double_scalarmul_non_secret(curve448_point_t combo,

                                               const curve448_scalar_t scalar1,

                                               const curve448_scalar_t scalar1,

crypto/ec/curve448/curve448_tables.c

+458 −340

File changed.

Preview size limit exceeded, changes collapsed.

crypto/ec/curve448/point_448.h

+18 −0
Original line number Original line Diff line number Diff line
@@ -16,6 +16,24 @@ 
# include "curve448utils.h"

# include "curve448utils.h"

# include "field.h"

# include "field.h"





/* Comb config: number of combs, n, t, s. */

#define COMBS_N 5

#define COMBS_T 5

#define COMBS_S 18



/* Projective Niels coordinates */

typedef struct {

    gf a, b, c;

} niels_s, niels_t[1];

typedef struct {

    niels_t n;

    gf z;

} VECTOR_ALIGNED pniels_t[1];



/* Precomputed base */

struct curve448_precomputed_s {

    niels_t table[COMBS_N << (COMBS_T - 1)];

};





# define C448_SCALAR_LIMBS ((446-1)/C448_WORD_BITS+1)

# define C448_SCALAR_LIMBS ((446-1)/C448_WORD_BITS+1)