diff options
Diffstat (limited to 'src/group.h')
| -rw-r--r-- | src/group.h | 106 |
1 files changed, 63 insertions, 43 deletions
diff --git a/src/group.h b/src/group.h index 0b08b3b991..ebfe1ca70c 100644 --- a/src/group.h +++ b/src/group.h @@ -12,110 +12,130 @@ /** A group element of the secp256k1 curve, in affine coordinates. */ typedef struct { - secp256k1_fe_t x; - secp256k1_fe_t y; + secp256k1_fe x; + secp256k1_fe y; int infinity; /* whether this represents the point at infinity */ -} secp256k1_ge_t; +} secp256k1_ge; #define SECP256K1_GE_CONST(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) {SECP256K1_FE_CONST((a),(b),(c),(d),(e),(f),(g),(h)), SECP256K1_FE_CONST((i),(j),(k),(l),(m),(n),(o),(p)), 0} #define SECP256K1_GE_CONST_INFINITY {SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), 1} /** A group element of the secp256k1 curve, in jacobian coordinates. */ typedef struct { - secp256k1_fe_t x; /* actual X: x/z^2 */ - secp256k1_fe_t y; /* actual Y: y/z^3 */ - secp256k1_fe_t z; + secp256k1_fe x; /* actual X: x/z^2 */ + secp256k1_fe y; /* actual Y: y/z^3 */ + secp256k1_fe z; int infinity; /* whether this represents the point at infinity */ -} secp256k1_gej_t; +} secp256k1_gej; #define SECP256K1_GEJ_CONST(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) {SECP256K1_FE_CONST((a),(b),(c),(d),(e),(f),(g),(h)), SECP256K1_FE_CONST((i),(j),(k),(l),(m),(n),(o),(p)), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 1), 0} #define SECP256K1_GEJ_CONST_INFINITY {SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), 1} typedef struct { - secp256k1_fe_storage_t x; - secp256k1_fe_storage_t y; -} secp256k1_ge_storage_t; + secp256k1_fe_storage x; + secp256k1_fe_storage y; +} secp256k1_ge_storage; #define SECP256K1_GE_STORAGE_CONST(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) {SECP256K1_FE_STORAGE_CONST((a),(b),(c),(d),(e),(f),(g),(h)), SECP256K1_FE_STORAGE_CONST((i),(j),(k),(l),(m),(n),(o),(p))} -/** Set a group element equal to the point at infinity */ -static void secp256k1_ge_set_infinity(secp256k1_ge_t *r); +#define SECP256K1_GE_STORAGE_CONST_GET(t) SECP256K1_FE_STORAGE_CONST_GET(t.x), SECP256K1_FE_STORAGE_CONST_GET(t.y) /** Set a group element equal to the point with given X and Y coordinates */ -static void secp256k1_ge_set_xy(secp256k1_ge_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y); +static void secp256k1_ge_set_xy(secp256k1_ge *r, const secp256k1_fe *x, const secp256k1_fe *y); + +/** Set a group element (affine) equal to the point with the given X coordinate + * and a Y coordinate that is a quadratic residue modulo p. The return value + * is true iff a coordinate with the given X coordinate exists. + */ +static int secp256k1_ge_set_xquad_var(secp256k1_ge *r, const secp256k1_fe *x); /** Set a group element (affine) equal to the point with the given X coordinate, and given oddness * for Y. Return value indicates whether the result is valid. */ -static int secp256k1_ge_set_xo_var(secp256k1_ge_t *r, const secp256k1_fe_t *x, int odd); +static int secp256k1_ge_set_xo_var(secp256k1_ge *r, const secp256k1_fe *x, int odd); /** Check whether a group element is the point at infinity. */ -static int secp256k1_ge_is_infinity(const secp256k1_ge_t *a); +static int secp256k1_ge_is_infinity(const secp256k1_ge *a); /** Check whether a group element is valid (i.e., on the curve). */ -static int secp256k1_ge_is_valid_var(const secp256k1_ge_t *a); +static int secp256k1_ge_is_valid_var(const secp256k1_ge *a); -static void secp256k1_ge_neg(secp256k1_ge_t *r, const secp256k1_ge_t *a); +static void secp256k1_ge_neg(secp256k1_ge *r, const secp256k1_ge *a); /** Set a group element equal to another which is given in jacobian coordinates */ -static void secp256k1_ge_set_gej(secp256k1_ge_t *r, secp256k1_gej_t *a); +static void secp256k1_ge_set_gej(secp256k1_ge *r, secp256k1_gej *a); /** Set a batch of group elements equal to the inputs given in jacobian coordinates */ -static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t *r, const secp256k1_gej_t *a); +static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_callback *cb); +/** Set a batch of group elements equal to the inputs given in jacobian + * coordinates (with known z-ratios). zr must contain the known z-ratios such + * that mul(a[i].z, zr[i+1]) == a[i+1].z. zr[0] is ignored. */ +static void secp256k1_ge_set_table_gej_var(size_t len, secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_fe *zr); -/** Set a group element (jacobian) equal to the point at infinity. */ -static void secp256k1_gej_set_infinity(secp256k1_gej_t *r); +/** Bring a batch inputs given in jacobian coordinates (with known z-ratios) to + * the same global z "denominator". zr must contain the known z-ratios such + * that mul(a[i].z, zr[i+1]) == a[i+1].z. zr[0] is ignored. The x and y + * coordinates of the result are stored in r, the common z coordinate is + * stored in globalz. */ +static void secp256k1_ge_globalz_set_table_gej(size_t len, secp256k1_ge *r, secp256k1_fe *globalz, const secp256k1_gej *a, const secp256k1_fe *zr); -/** Set a group element (jacobian) equal to the point with given X and Y coordinates. */ -static void secp256k1_gej_set_xy(secp256k1_gej_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y); +/** Set a group element (jacobian) equal to the point at infinity. */ +static void secp256k1_gej_set_infinity(secp256k1_gej *r); /** Set a group element (jacobian) equal to another which is given in affine coordinates. */ -static void secp256k1_gej_set_ge(secp256k1_gej_t *r, const secp256k1_ge_t *a); +static void secp256k1_gej_set_ge(secp256k1_gej *r, const secp256k1_ge *a); /** Compare the X coordinate of a group element (jacobian). */ -static int secp256k1_gej_eq_x_var(const secp256k1_fe_t *x, const secp256k1_gej_t *a); +static int secp256k1_gej_eq_x_var(const secp256k1_fe *x, const secp256k1_gej *a); /** Set r equal to the inverse of a (i.e., mirrored around the X axis) */ -static void secp256k1_gej_neg(secp256k1_gej_t *r, const secp256k1_gej_t *a); +static void secp256k1_gej_neg(secp256k1_gej *r, const secp256k1_gej *a); /** Check whether a group element is the point at infinity. */ -static int secp256k1_gej_is_infinity(const secp256k1_gej_t *a); +static int secp256k1_gej_is_infinity(const secp256k1_gej *a); -/** Set r equal to the double of a. */ -static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t *a); +/** Set r equal to the double of a. If rzr is not-NULL, r->z = a->z * *rzr (where infinity means an implicit z = 0). + * a may not be zero. Constant time. */ +static void secp256k1_gej_double_nonzero(secp256k1_gej *r, const secp256k1_gej *a, secp256k1_fe *rzr); -/** Set r equal to the sum of a and b. */ -static void secp256k1_gej_add_var(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_gej_t *b); +/** Set r equal to the double of a. If rzr is not-NULL, r->z = a->z * *rzr (where infinity means an implicit z = 0). */ +static void secp256k1_gej_double_var(secp256k1_gej *r, const secp256k1_gej *a, secp256k1_fe *rzr); + +/** Set r equal to the sum of a and b. If rzr is non-NULL, r->z = a->z * *rzr (a cannot be infinity in that case). */ +static void secp256k1_gej_add_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_gej *b, secp256k1_fe *rzr); /** Set r equal to the sum of a and b (with b given in affine coordinates, and not infinity). */ -static void secp256k1_gej_add_ge(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b); +static void secp256k1_gej_add_ge(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b); /** Set r equal to the sum of a and b (with b given in affine coordinates). This is more efficient than secp256k1_gej_add_var. It is identical to secp256k1_gej_add_ge but without constant-time - guarantee, and b is allowed to be infinity. */ -static void secp256k1_gej_add_ge_var(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b); + guarantee, and b is allowed to be infinity. If rzr is non-NULL, r->z = a->z * *rzr (a cannot be infinity in that case). */ +static void secp256k1_gej_add_ge_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b, secp256k1_fe *rzr); + +/** Set r equal to the sum of a and b (with the inverse of b's Z coordinate passed as bzinv). */ +static void secp256k1_gej_add_zinv_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b, const secp256k1_fe *bzinv); #ifdef USE_ENDOMORPHISM /** Set r to be equal to lambda times a, where lambda is chosen in a way such that this is very fast. */ -static void secp256k1_gej_mul_lambda(secp256k1_gej_t *r, const secp256k1_gej_t *a); +static void secp256k1_ge_mul_lambda(secp256k1_ge *r, const secp256k1_ge *a); #endif -/** Clear a secp256k1_gej_t to prevent leaking sensitive information. */ -static void secp256k1_gej_clear(secp256k1_gej_t *r); +/** Clear a secp256k1_gej to prevent leaking sensitive information. */ +static void secp256k1_gej_clear(secp256k1_gej *r); -/** Clear a secp256k1_ge_t to prevent leaking sensitive information. */ -static void secp256k1_ge_clear(secp256k1_ge_t *r); +/** Clear a secp256k1_ge to prevent leaking sensitive information. */ +static void secp256k1_ge_clear(secp256k1_ge *r); /** Convert a group element to the storage type. */ -static void secp256k1_ge_to_storage(secp256k1_ge_storage_t *r, const secp256k1_ge_t*); +static void secp256k1_ge_to_storage(secp256k1_ge_storage *r, const secp256k1_ge *a); /** Convert a group element back from the storage type. */ -static void secp256k1_ge_from_storage(secp256k1_ge_t *r, const secp256k1_ge_storage_t*); +static void secp256k1_ge_from_storage(secp256k1_ge *r, const secp256k1_ge_storage *a); /** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. */ -static void secp256k1_ge_storage_cmov(secp256k1_ge_storage_t *r, const secp256k1_ge_storage_t *a, int flag); +static void secp256k1_ge_storage_cmov(secp256k1_ge_storage *r, const secp256k1_ge_storage *a, int flag); /** Rescale a jacobian point by b which must be non-zero. Constant-time. */ -static void secp256k1_gej_rescale(secp256k1_gej_t *r, const secp256k1_fe_t *b); +static void secp256k1_gej_rescale(secp256k1_gej *r, const secp256k1_fe *b); #endif |