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crypto: ecc - Add math to support fast NIST P384 

Add the math needed for NIST P384 and adapt certain functions'
parameters so that the ecc_curve is passed to vli_mmod_fast. This
allows to identify the curve by its name prefix and the appropriate
function for fast mmod calculation can be used.

Summary of changes:

* crypto/ecc.c
  - add vli_mmod_fast_384
  - change some routines to pass ecc_curve forward until vli_mmod_fast

* crypto/ecc.h
  - add ECC_CURVE_NIST_P384_DIGITS
  - change ECC_MAX_DIGITS to P384 size

Signed-off-by: Saulo Alessandre <saulo.alessandre@tse.jus.br>
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Saulo Alessandre 2021-03-16 17:07:34 -04:00 committed by Herbert Xu
parent 703c748d5f
commit 149ca1611d
2 changed files with 194 additions and 75 deletions
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266
crypto/ecc.c
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@ -778,18 +778,133 @@ static void vli_mmod_fast_256(u64 *result, const u64 *product,
} }
} }
#define SL32OR32(x32, y32) (((u64)x32 << 32) | y32)
#define AND64H(x64) (x64 & 0xffFFffFF00000000ull)
#define AND64L(x64) (x64 & 0x00000000ffFFffFFull)
/* Computes result = product % curve_prime
* from "Mathematical routines for the NIST prime elliptic curves"
*/
static void vli_mmod_fast_384(u64 *result, const u64 *product,
const u64 *curve_prime, u64 *tmp)
{
int carry;
const unsigned int ndigits = 6;
/* t */
vli_set(result, product, ndigits);
/* s1 */
tmp[0] = 0; // 0 || 0
tmp[1] = 0; // 0 || 0
tmp[2] = SL32OR32(product[11], (product[10]>>32)); //a22||a21
tmp[3] = product[11]>>32; // 0 ||a23
tmp[4] = 0; // 0 || 0
tmp[5] = 0; // 0 || 0
carry = vli_lshift(tmp, tmp, 1, ndigits);
carry += vli_add(result, result, tmp, ndigits);
/* s2 */
tmp[0] = product[6]; //a13||a12
tmp[1] = product[7]; //a15||a14
tmp[2] = product[8]; //a17||a16
tmp[3] = product[9]; //a19||a18
tmp[4] = product[10]; //a21||a20
tmp[5] = product[11]; //a23||a22
carry += vli_add(result, result, tmp, ndigits);
/* s3 */
tmp[0] = SL32OR32(product[11], (product[10]>>32)); //a22||a21
tmp[1] = SL32OR32(product[6], (product[11]>>32)); //a12||a23
tmp[2] = SL32OR32(product[7], (product[6])>>32); //a14||a13
tmp[3] = SL32OR32(product[8], (product[7]>>32)); //a16||a15
tmp[4] = SL32OR32(product[9], (product[8]>>32)); //a18||a17
tmp[5] = SL32OR32(product[10], (product[9]>>32)); //a20||a19
carry += vli_add(result, result, tmp, ndigits);
/* s4 */
tmp[0] = AND64H(product[11]); //a23|| 0
tmp[1] = (product[10]<<32); //a20|| 0
tmp[2] = product[6]; //a13||a12
tmp[3] = product[7]; //a15||a14
tmp[4] = product[8]; //a17||a16
tmp[5] = product[9]; //a19||a18
carry += vli_add(result, result, tmp, ndigits);
/* s5 */
tmp[0] = 0; // 0|| 0
tmp[1] = 0; // 0|| 0
tmp[2] = product[10]; //a21||a20
tmp[3] = product[11]; //a23||a22
tmp[4] = 0; // 0|| 0
tmp[5] = 0; // 0|| 0
carry += vli_add(result, result, tmp, ndigits);
/* s6 */
tmp[0] = AND64L(product[10]); // 0 ||a20
tmp[1] = AND64H(product[10]); //a21|| 0
tmp[2] = product[11]; //a23||a22
tmp[3] = 0; // 0 || 0
tmp[4] = 0; // 0 || 0
tmp[5] = 0; // 0 || 0
carry += vli_add(result, result, tmp, ndigits);
/* d1 */
tmp[0] = SL32OR32(product[6], (product[11]>>32)); //a12||a23
tmp[1] = SL32OR32(product[7], (product[6]>>32)); //a14||a13
tmp[2] = SL32OR32(product[8], (product[7]>>32)); //a16||a15
tmp[3] = SL32OR32(product[9], (product[8]>>32)); //a18||a17
tmp[4] = SL32OR32(product[10], (product[9]>>32)); //a20||a19
tmp[5] = SL32OR32(product[11], (product[10]>>32)); //a22||a21
carry -= vli_sub(result, result, tmp, ndigits);
/* d2 */
tmp[0] = (product[10]<<32); //a20|| 0
tmp[1] = SL32OR32(product[11], (product[10]>>32)); //a22||a21
tmp[2] = (product[11]>>32); // 0 ||a23
tmp[3] = 0; // 0 || 0
tmp[4] = 0; // 0 || 0
tmp[5] = 0; // 0 || 0
carry -= vli_sub(result, result, tmp, ndigits);
/* d3 */
tmp[0] = 0; // 0 || 0
tmp[1] = AND64H(product[11]); //a23|| 0
tmp[2] = product[11]>>32; // 0 ||a23
tmp[3] = 0; // 0 || 0
tmp[4] = 0; // 0 || 0
tmp[5] = 0; // 0 || 0
carry -= vli_sub(result, result, tmp, ndigits);
if (carry < 0) {
do {
carry += vli_add(result, result, curve_prime, ndigits);
} while (carry < 0);
} else {
while (carry || vli_cmp(curve_prime, result, ndigits) != 1)
carry -= vli_sub(result, result, curve_prime, ndigits);
}
}
#undef SL32OR32
#undef AND64H
#undef AND64L
/* Computes result = product % curve_prime for different curve_primes. /* Computes result = product % curve_prime for different curve_primes.
* *
* Note that curve_primes are distinguished just by heuristic check and * Note that curve_primes are distinguished just by heuristic check and
* not by complete conformance check. * not by complete conformance check.
*/ */
static bool vli_mmod_fast(u64 *result, u64 *product, static bool vli_mmod_fast(u64 *result, u64 *product,
const u64 *curve_prime, unsigned int ndigits) const struct ecc_curve *curve)
{ {
u64 tmp[2 * ECC_MAX_DIGITS]; u64 tmp[2 * ECC_MAX_DIGITS];
const u64 *curve_prime = curve->p;
const unsigned int ndigits = curve->g.ndigits;
/* Currently, both NIST primes have -1 in lowest qword. */ /* All NIST curves have name prefix 'nist_' */
if (curve_prime[0] != -1ull) { if (strncmp(curve->name, "nist_", 5) != 0) {
/* Try to handle Pseudo-Marsenne primes. */ /* Try to handle Pseudo-Marsenne primes. */
if (curve_prime[ndigits - 1] == -1ull) { if (curve_prime[ndigits - 1] == -1ull) {
vli_mmod_special(result, product, curve_prime, vli_mmod_special(result, product, curve_prime,
@ -812,6 +927,9 @@ static bool vli_mmod_fast(u64 *result, u64 *product,
case 4: case 4:
vli_mmod_fast_256(result, product, curve_prime, tmp); vli_mmod_fast_256(result, product, curve_prime, tmp);
break; break;
case 6:
vli_mmod_fast_384(result, product, curve_prime, tmp);
break;
default: default:
pr_err_ratelimited("ecc: unsupported digits size!\n"); pr_err_ratelimited("ecc: unsupported digits size!\n");
return false; return false;
@ -835,22 +953,22 @@ EXPORT_SYMBOL(vli_mod_mult_slow);
/* Computes result = (left * right) % curve_prime. */ /* Computes result = (left * right) % curve_prime. */
static void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right, static void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right,
const u64 *curve_prime, unsigned int ndigits) const struct ecc_curve *curve)
{ {
u64 product[2 * ECC_MAX_DIGITS]; u64 product[2 * ECC_MAX_DIGITS];
vli_mult(product, left, right, ndigits); vli_mult(product, left, right, curve->g.ndigits);
vli_mmod_fast(result, product, curve_prime, ndigits); vli_mmod_fast(result, product, curve);
} }
/* Computes result = left^2 % curve_prime. */ /* Computes result = left^2 % curve_prime. */
static void vli_mod_square_fast(u64 *result, const u64 *left, static void vli_mod_square_fast(u64 *result, const u64 *left,
const u64 *curve_prime, unsigned int ndigits) const struct ecc_curve *curve)
{ {
u64 product[2 * ECC_MAX_DIGITS]; u64 product[2 * ECC_MAX_DIGITS];
vli_square(product, left, ndigits); vli_square(product, left, curve->g.ndigits);
vli_mmod_fast(result, product, curve_prime, ndigits); vli_mmod_fast(result, product, curve);
} }
#define EVEN(vli) (!(vli[0] & 1)) #define EVEN(vli) (!(vli[0] & 1))
@ -948,25 +1066,27 @@ static bool ecc_point_is_zero(const struct ecc_point *point)
/* Double in place */ /* Double in place */
static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1, static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1,
u64 *curve_prime, unsigned int ndigits) const struct ecc_curve *curve)
{ {
/* t1 = x, t2 = y, t3 = z */ /* t1 = x, t2 = y, t3 = z */
u64 t4[ECC_MAX_DIGITS]; u64 t4[ECC_MAX_DIGITS];
u64 t5[ECC_MAX_DIGITS]; u64 t5[ECC_MAX_DIGITS];
const u64 *curve_prime = curve->p;
const unsigned int ndigits = curve->g.ndigits;
if (vli_is_zero(z1, ndigits)) if (vli_is_zero(z1, ndigits))
return; return;
/* t4 = y1^2 */ /* t4 = y1^2 */
vli_mod_square_fast(t4, y1, curve_prime, ndigits); vli_mod_square_fast(t4, y1, curve);
/* t5 = x1*y1^2 = A */ /* t5 = x1*y1^2 = A */
vli_mod_mult_fast(t5, x1, t4, curve_prime, ndigits); vli_mod_mult_fast(t5, x1, t4, curve);
/* t4 = y1^4 */ /* t4 = y1^4 */
vli_mod_square_fast(t4, t4, curve_prime, ndigits); vli_mod_square_fast(t4, t4, curve);
/* t2 = y1*z1 = z3 */ /* t2 = y1*z1 = z3 */
vli_mod_mult_fast(y1, y1, z1, curve_prime, ndigits); vli_mod_mult_fast(y1, y1, z1, curve);
/* t3 = z1^2 */ /* t3 = z1^2 */
vli_mod_square_fast(z1, z1, curve_prime, ndigits); vli_mod_square_fast(z1, z1, curve);
/* t1 = x1 + z1^2 */ /* t1 = x1 + z1^2 */
vli_mod_add(x1, x1, z1, curve_prime, ndigits); vli_mod_add(x1, x1, z1, curve_prime, ndigits);
@ -975,7 +1095,7 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1,
/* t3 = x1 - z1^2 */ /* t3 = x1 - z1^2 */
vli_mod_sub(z1, x1, z1, curve_prime, ndigits); vli_mod_sub(z1, x1, z1, curve_prime, ndigits);
/* t1 = x1^2 - z1^4 */ /* t1 = x1^2 - z1^4 */
vli_mod_mult_fast(x1, x1, z1, curve_prime, ndigits); vli_mod_mult_fast(x1, x1, z1, curve);
/* t3 = 2*(x1^2 - z1^4) */ /* t3 = 2*(x1^2 - z1^4) */
vli_mod_add(z1, x1, x1, curve_prime, ndigits); vli_mod_add(z1, x1, x1, curve_prime, ndigits);
@ -992,7 +1112,7 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1,
/* t1 = 3/2*(x1^2 - z1^4) = B */ /* t1 = 3/2*(x1^2 - z1^4) = B */
/* t3 = B^2 */ /* t3 = B^2 */
vli_mod_square_fast(z1, x1, curve_prime, ndigits); vli_mod_square_fast(z1, x1, curve);
/* t3 = B^2 - A */ /* t3 = B^2 - A */
vli_mod_sub(z1, z1, t5, curve_prime, ndigits); vli_mod_sub(z1, z1, t5, curve_prime, ndigits);
/* t3 = B^2 - 2A = x3 */ /* t3 = B^2 - 2A = x3 */
@ -1000,7 +1120,7 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1,
/* t5 = A - x3 */ /* t5 = A - x3 */
vli_mod_sub(t5, t5, z1, curve_prime, ndigits); vli_mod_sub(t5, t5, z1, curve_prime, ndigits);
/* t1 = B * (A - x3) */ /* t1 = B * (A - x3) */
vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); vli_mod_mult_fast(x1, x1, t5, curve);
/* t4 = B * (A - x3) - y1^4 = y3 */ /* t4 = B * (A - x3) - y1^4 = y3 */
vli_mod_sub(t4, x1, t4, curve_prime, ndigits); vli_mod_sub(t4, x1, t4, curve_prime, ndigits);
@ -1010,23 +1130,22 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1,
} }
/* Modify (x1, y1) => (x1 * z^2, y1 * z^3) */ /* Modify (x1, y1) => (x1 * z^2, y1 * z^3) */
static void apply_z(u64 *x1, u64 *y1, u64 *z, u64 *curve_prime, static void apply_z(u64 *x1, u64 *y1, u64 *z, const struct ecc_curve *curve)
unsigned int ndigits)
{ {
u64 t1[ECC_MAX_DIGITS]; u64 t1[ECC_MAX_DIGITS];
vli_mod_square_fast(t1, z, curve_prime, ndigits); /* z^2 */ vli_mod_square_fast(t1, z, curve); /* z^2 */
vli_mod_mult_fast(x1, x1, t1, curve_prime, ndigits); /* x1 * z^2 */ vli_mod_mult_fast(x1, x1, t1, curve); /* x1 * z^2 */
vli_mod_mult_fast(t1, t1, z, curve_prime, ndigits); /* z^3 */ vli_mod_mult_fast(t1, t1, z, curve); /* z^3 */
vli_mod_mult_fast(y1, y1, t1, curve_prime, ndigits); /* y1 * z^3 */ vli_mod_mult_fast(y1, y1, t1, curve); /* y1 * z^3 */
} }
/* P = (x1, y1) => 2P, (x2, y2) => P' */ /* P = (x1, y1) => 2P, (x2, y2) => P' */
static void xycz_initial_double(u64 *x1, u64 *y1, u64 *x2, u64 *y2, static void xycz_initial_double(u64 *x1, u64 *y1, u64 *x2, u64 *y2,
u64 *p_initial_z, u64 *curve_prime, u64 *p_initial_z, const struct ecc_curve *curve)
unsigned int ndigits)
{ {
u64 z[ECC_MAX_DIGITS]; u64 z[ECC_MAX_DIGITS];
const unsigned int ndigits = curve->g.ndigits;
vli_set(x2, x1, ndigits); vli_set(x2, x1, ndigits);
vli_set(y2, y1, ndigits); vli_set(y2, y1, ndigits);
@ -1037,35 +1156,37 @@ static void xycz_initial_double(u64 *x1, u64 *y1, u64 *x2, u64 *y2,
if (p_initial_z) if (p_initial_z)
vli_set(z, p_initial_z, ndigits); vli_set(z, p_initial_z, ndigits);
apply_z(x1, y1, z, curve_prime, ndigits); apply_z(x1, y1, z, curve);
ecc_point_double_jacobian(x1, y1, z, curve_prime, ndigits); ecc_point_double_jacobian(x1, y1, z, curve);
apply_z(x2, y2, z, curve_prime, ndigits); apply_z(x2, y2, z, curve);
} }
/* Input P = (x1, y1, Z), Q = (x2, y2, Z) /* Input P = (x1, y1, Z), Q = (x2, y2, Z)
* Output P' = (x1', y1', Z3), P + Q = (x3, y3, Z3) * Output P' = (x1', y1', Z3), P + Q = (x3, y3, Z3)
* or P => P', Q => P + Q * or P => P', Q => P + Q
*/ */
static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2,
unsigned int ndigits) const struct ecc_curve *curve)
{ {
/* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */
u64 t5[ECC_MAX_DIGITS]; u64 t5[ECC_MAX_DIGITS];
const u64 *curve_prime = curve->p;
const unsigned int ndigits = curve->g.ndigits;
/* t5 = x2 - x1 */ /* t5 = x2 - x1 */
vli_mod_sub(t5, x2, x1, curve_prime, ndigits); vli_mod_sub(t5, x2, x1, curve_prime, ndigits);
/* t5 = (x2 - x1)^2 = A */ /* t5 = (x2 - x1)^2 = A */
vli_mod_square_fast(t5, t5, curve_prime, ndigits); vli_mod_square_fast(t5, t5, curve);
/* t1 = x1*A = B */ /* t1 = x1*A = B */
vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); vli_mod_mult_fast(x1, x1, t5, curve);
/* t3 = x2*A = C */ /* t3 = x2*A = C */
vli_mod_mult_fast(x2, x2, t5, curve_prime, ndigits); vli_mod_mult_fast(x2, x2, t5, curve);
/* t4 = y2 - y1 */ /* t4 = y2 - y1 */
vli_mod_sub(y2, y2, y1, curve_prime, ndigits); vli_mod_sub(y2, y2, y1, curve_prime, ndigits);
/* t5 = (y2 - y1)^2 = D */ /* t5 = (y2 - y1)^2 = D */
vli_mod_square_fast(t5, y2, curve_prime, ndigits); vli_mod_square_fast(t5, y2, curve);
/* t5 = D - B */ /* t5 = D - B */
vli_mod_sub(t5, t5, x1, curve_prime, ndigits); vli_mod_sub(t5, t5, x1, curve_prime, ndigits);
@ -1074,11 +1195,11 @@ static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime,
/* t3 = C - B */ /* t3 = C - B */
vli_mod_sub(x2, x2, x1, curve_prime, ndigits); vli_mod_sub(x2, x2, x1, curve_prime, ndigits);
/* t2 = y1*(C - B) */ /* t2 = y1*(C - B) */
vli_mod_mult_fast(y1, y1, x2, curve_prime, ndigits); vli_mod_mult_fast(y1, y1, x2, curve);
/* t3 = B - x3 */ /* t3 = B - x3 */
vli_mod_sub(x2, x1, t5, curve_prime, ndigits); vli_mod_sub(x2, x1, t5, curve_prime, ndigits);
/* t4 = (y2 - y1)*(B - x3) */ /* t4 = (y2 - y1)*(B - x3) */
vli_mod_mult_fast(y2, y2, x2, curve_prime, ndigits); vli_mod_mult_fast(y2, y2, x2, curve);
/* t4 = y3 */ /* t4 = y3 */
vli_mod_sub(y2, y2, y1, curve_prime, ndigits); vli_mod_sub(y2, y2, y1, curve_prime, ndigits);
@ -1089,22 +1210,24 @@ static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime,
* Output P + Q = (x3, y3, Z3), P - Q = (x3', y3', Z3) * Output P + Q = (x3, y3, Z3), P - Q = (x3', y3', Z3)
* or P => P - Q, Q => P + Q * or P => P - Q, Q => P + Q
*/ */
static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2,
unsigned int ndigits) const struct ecc_curve *curve)
{ {
/* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */
u64 t5[ECC_MAX_DIGITS]; u64 t5[ECC_MAX_DIGITS];
u64 t6[ECC_MAX_DIGITS]; u64 t6[ECC_MAX_DIGITS];
u64 t7[ECC_MAX_DIGITS]; u64 t7[ECC_MAX_DIGITS];
const u64 *curve_prime = curve->p;
const unsigned int ndigits = curve->g.ndigits;
/* t5 = x2 - x1 */ /* t5 = x2 - x1 */
vli_mod_sub(t5, x2, x1, curve_prime, ndigits); vli_mod_sub(t5, x2, x1, curve_prime, ndigits);
/* t5 = (x2 - x1)^2 = A */ /* t5 = (x2 - x1)^2 = A */
vli_mod_square_fast(t5, t5, curve_prime, ndigits); vli_mod_square_fast(t5, t5, curve);
/* t1 = x1*A = B */ /* t1 = x1*A = B */
vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); vli_mod_mult_fast(x1, x1, t5, curve);
/* t3 = x2*A = C */ /* t3 = x2*A = C */
vli_mod_mult_fast(x2, x2, t5, curve_prime, ndigits); vli_mod_mult_fast(x2, x2, t5, curve);
/* t4 = y2 + y1 */ /* t4 = y2 + y1 */
vli_mod_add(t5, y2, y1, curve_prime, ndigits); vli_mod_add(t5, y2, y1, curve_prime, ndigits);
/* t4 = y2 - y1 */ /* t4 = y2 - y1 */
@ -1113,29 +1236,29 @@ static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime,
/* t6 = C - B */ /* t6 = C - B */
vli_mod_sub(t6, x2, x1, curve_prime, ndigits); vli_mod_sub(t6, x2, x1, curve_prime, ndigits);
/* t2 = y1 * (C - B) */ /* t2 = y1 * (C - B) */
vli_mod_mult_fast(y1, y1, t6, curve_prime, ndigits); vli_mod_mult_fast(y1, y1, t6, curve);
/* t6 = B + C */ /* t6 = B + C */
vli_mod_add(t6, x1, x2, curve_prime, ndigits); vli_mod_add(t6, x1, x2, curve_prime, ndigits);
/* t3 = (y2 - y1)^2 */ /* t3 = (y2 - y1)^2 */
vli_mod_square_fast(x2, y2, curve_prime, ndigits); vli_mod_square_fast(x2, y2, curve);
/* t3 = x3 */ /* t3 = x3 */
vli_mod_sub(x2, x2, t6, curve_prime, ndigits); vli_mod_sub(x2, x2, t6, curve_prime, ndigits);
/* t7 = B - x3 */ /* t7 = B - x3 */
vli_mod_sub(t7, x1, x2, curve_prime, ndigits); vli_mod_sub(t7, x1, x2, curve_prime, ndigits);
/* t4 = (y2 - y1)*(B - x3) */ /* t4 = (y2 - y1)*(B - x3) */
vli_mod_mult_fast(y2, y2, t7, curve_prime, ndigits); vli_mod_mult_fast(y2, y2, t7, curve);
/* t4 = y3 */ /* t4 = y3 */
vli_mod_sub(y2, y2, y1, curve_prime, ndigits); vli_mod_sub(y2, y2, y1, curve_prime, ndigits);
/* t7 = (y2 + y1)^2 = F */ /* t7 = (y2 + y1)^2 = F */
vli_mod_square_fast(t7, t5, curve_prime, ndigits); vli_mod_square_fast(t7, t5, curve);
/* t7 = x3' */ /* t7 = x3' */
vli_mod_sub(t7, t7, t6, curve_prime, ndigits); vli_mod_sub(t7, t7, t6, curve_prime, ndigits);
/* t6 = x3' - B */ /* t6 = x3' - B */
vli_mod_sub(t6, t7, x1, curve_prime, ndigits); vli_mod_sub(t6, t7, x1, curve_prime, ndigits);
/* t6 = (y2 + y1)*(x3' - B) */ /* t6 = (y2 + y1)*(x3' - B) */
vli_mod_mult_fast(t6, t6, t5, curve_prime, ndigits); vli_mod_mult_fast(t6, t6, t5, curve);
/* t2 = y3' */ /* t2 = y3' */
vli_mod_sub(y1, t6, y1, curve_prime, ndigits); vli_mod_sub(y1, t6, y1, curve_prime, ndigits);
@ -1165,41 +1288,37 @@ static void ecc_point_mult(struct ecc_point *result,
vli_set(rx[1], point->x, ndigits); vli_set(rx[1], point->x, ndigits);
vli_set(ry[1], point->y, ndigits); vli_set(ry[1], point->y, ndigits);
xycz_initial_double(rx[1], ry[1], rx[0], ry[0], initial_z, curve_prime, xycz_initial_double(rx[1], ry[1], rx[0], ry[0], initial_z, curve);
ndigits);
for (i = num_bits - 2; i > 0; i--) { for (i = num_bits - 2; i > 0; i--) {
nb = !vli_test_bit(scalar, i); nb = !vli_test_bit(scalar, i);
xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve_prime, xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve);
ndigits); xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve);
xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve_prime,
ndigits);
} }
nb = !vli_test_bit(scalar, 0); nb = !vli_test_bit(scalar, 0);
xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve_prime, xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve);
ndigits);
/* Find final 1/Z value. */ /* Find final 1/Z value. */
/* X1 - X0 */ /* X1 - X0 */
vli_mod_sub(z, rx[1], rx[0], curve_prime, ndigits); vli_mod_sub(z, rx[1], rx[0], curve_prime, ndigits);
/* Yb * (X1 - X0) */ /* Yb * (X1 - X0) */
vli_mod_mult_fast(z, z, ry[1 - nb], curve_prime, ndigits); vli_mod_mult_fast(z, z, ry[1 - nb], curve);
/* xP * Yb * (X1 - X0) */ /* xP * Yb * (X1 - X0) */
vli_mod_mult_fast(z, z, point->x, curve_prime, ndigits); vli_mod_mult_fast(z, z, point->x, curve);
/* 1 / (xP * Yb * (X1 - X0)) */ /* 1 / (xP * Yb * (X1 - X0)) */
vli_mod_inv(z, z, curve_prime, point->ndigits); vli_mod_inv(z, z, curve_prime, point->ndigits);
/* yP / (xP * Yb * (X1 - X0)) */ /* yP / (xP * Yb * (X1 - X0)) */
vli_mod_mult_fast(z, z, point->y, curve_prime, ndigits); vli_mod_mult_fast(z, z, point->y, curve);
/* Xb * yP / (xP * Yb * (X1 - X0)) */ /* Xb * yP / (xP * Yb * (X1 - X0)) */
vli_mod_mult_fast(z, z, rx[1 - nb], curve_prime, ndigits); vli_mod_mult_fast(z, z, rx[1 - nb], curve);
/* End 1/Z calculation */ /* End 1/Z calculation */
xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve_prime, ndigits); xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve);
apply_z(rx[0], ry[0], z, curve_prime, ndigits); apply_z(rx[0], ry[0], z, curve);
vli_set(result->x, rx[0], ndigits); vli_set(result->x, rx[0], ndigits);
vli_set(result->y, ry[0], ndigits); vli_set(result->y, ry[0], ndigits);
@ -1220,9 +1339,9 @@ static void ecc_point_add(const struct ecc_point *result,
vli_mod_sub(z, result->x, p->x, curve->p, ndigits); vli_mod_sub(z, result->x, p->x, curve->p, ndigits);
vli_set(px, p->x, ndigits); vli_set(px, p->x, ndigits);
vli_set(py, p->y, ndigits); vli_set(py, p->y, ndigits);
xycz_add(px, py, result->x, result->y, curve->p, ndigits); xycz_add(px, py, result->x, result->y, curve);
vli_mod_inv(z, z, curve->p, ndigits); vli_mod_inv(z, z, curve->p, ndigits);
apply_z(result->x, result->y, z, curve->p, ndigits); apply_z(result->x, result->y, z, curve);
} }
/* Computes R = u1P + u2Q mod p using Shamir's trick. /* Computes R = u1P + u2Q mod p using Shamir's trick.
@ -1251,8 +1370,7 @@ void ecc_point_mult_shamir(const struct ecc_point *result,
points[2] = q; points[2] = q;
points[3] = &sum; points[3] = &sum;
num_bits = max(vli_num_bits(u1, ndigits), num_bits = max(vli_num_bits(u1, ndigits), vli_num_bits(u2, ndigits));
vli_num_bits(u2, ndigits));
i = num_bits - 1; i = num_bits - 1;
idx = (!!vli_test_bit(u1, i)) | ((!!vli_test_bit(u2, i)) << 1); idx = (!!vli_test_bit(u1, i)) | ((!!vli_test_bit(u2, i)) << 1);
point = points[idx]; point = points[idx];
@ -1263,7 +1381,7 @@ void ecc_point_mult_shamir(const struct ecc_point *result,
z[0] = 1; z[0] = 1;
for (--i; i >= 0; i--) { for (--i; i >= 0; i--) {
ecc_point_double_jacobian(rx, ry, z, curve->p, ndigits); ecc_point_double_jacobian(rx, ry, z, curve);
idx = (!!vli_test_bit(u1, i)) | ((!!vli_test_bit(u2, i)) << 1); idx = (!!vli_test_bit(u1, i)) | ((!!vli_test_bit(u2, i)) << 1);
point = points[idx]; point = points[idx];
if (point) { if (point) {
@ -1273,14 +1391,14 @@ void ecc_point_mult_shamir(const struct ecc_point *result,
vli_set(tx, point->x, ndigits); vli_set(tx, point->x, ndigits);
vli_set(ty, point->y, ndigits); vli_set(ty, point->y, ndigits);
apply_z(tx, ty, z, curve->p, ndigits); apply_z(tx, ty, z, curve);
vli_mod_sub(tz, rx, tx, curve->p, ndigits); vli_mod_sub(tz, rx, tx, curve->p, ndigits);
xycz_add(tx, ty, rx, ry, curve->p, ndigits); xycz_add(tx, ty, rx, ry, curve);
vli_mod_mult_fast(z, z, tz, curve->p, ndigits); vli_mod_mult_fast(z, z, tz, curve);
} }
} }
vli_mod_inv(z, z, curve->p, ndigits); vli_mod_inv(z, z, curve->p, ndigits);
apply_z(rx, ry, z, curve->p, ndigits); apply_z(rx, ry, z, curve);
} }
EXPORT_SYMBOL(ecc_point_mult_shamir); EXPORT_SYMBOL(ecc_point_mult_shamir);
@ -1434,10 +1552,10 @@ int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve,
return -EINVAL; return -EINVAL;
/* Check 3: Verify that y^2 == (x^3 + a·x + b) mod p */ /* Check 3: Verify that y^2 == (x^3 + a·x + b) mod p */
vli_mod_square_fast(yy, pk->y, curve->p, pk->ndigits); /* y^2 */ vli_mod_square_fast(yy, pk->y, curve); /* y^2 */
vli_mod_square_fast(xxx, pk->x, curve->p, pk->ndigits); /* x^2 */ vli_mod_square_fast(xxx, pk->x, curve); /* x^2 */
vli_mod_mult_fast(xxx, xxx, pk->x, curve->p, pk->ndigits); /* x^3 */ vli_mod_mult_fast(xxx, xxx, pk->x, curve); /* x^3 */
vli_mod_mult_fast(w, curve->a, pk->x, curve->p, pk->ndigits); /* a·x */ vli_mod_mult_fast(w, curve->a, pk->x, curve); /* a·x */
vli_mod_add(w, w, curve->b, curve->p, pk->ndigits); /* a·x + b */ vli_mod_add(w, w, curve->b, curve->p, pk->ndigits); /* a·x + b */
vli_mod_add(w, w, xxx, curve->p, pk->ndigits); /* x^3 + a·x + b */ vli_mod_add(w, w, xxx, curve->p, pk->ndigits); /* x^3 + a·x + b */
if (vli_cmp(yy, w, pk->ndigits) != 0) /* Equation */ if (vli_cmp(yy, w, pk->ndigits) != 0) /* Equation */

3
crypto/ecc.h
View File

@ -29,7 +29,8 @@
/* One digit is u64 qword. */ /* One digit is u64 qword. */
#define ECC_CURVE_NIST_P192_DIGITS 3 #define ECC_CURVE_NIST_P192_DIGITS 3
#define ECC_CURVE_NIST_P256_DIGITS 4 #define ECC_CURVE_NIST_P256_DIGITS 4
#define ECC_MAX_DIGITS (512 / 64) #define ECC_CURVE_NIST_P384_DIGITS 6
#define ECC_MAX_DIGITS (512 / 64) /* due to ecrdsa */
#define ECC_DIGITS_TO_BYTES_SHIFT 3 #define ECC_DIGITS_TO_BYTES_SHIFT 3