From: Saulo Alessandre <saulo.alessan...@tse.jus.br> * crypto/ecc.c - ecc_get_curve - modified to recognize NIST_P384 and NISTP521; - vli_rshift - created for use on vli_mmod_fast_521 for ecdsa; - vli_mod_add - exported for use on ecdsa.c; - vli_mmod_fast_384 - implements fast elliptic curve nist p384 [4]; - vli_mmod_fast_521 - implements fast elliptic curve nist p521 [4]; - vli_mmod_fast - changed params to receive struct ecc_curve*; changed condition to use correct way to detect nist algo; added new curves (384 and 521); - vli_mmod_fast - changed params to receive ecc_curve; - vli_mod_slow - moved from .h to .c and exported for use on ecdsa.c; - vli_mod_mult_fast - changed params to receive struct ecc_curve*; exported for use on ecdsa.c; - vli_mod_square_fast - changed params to receive struct ecc_curve*; exported for use on ecdsa.c; - ecc_point_is_zero - exported for use on ecdsa.c; - ecc_point_double_jacobian - changed params to receive struct ecc_curve*; - apply_z - changed params to receive struct ecc_curve*; - xycz_initial_double - changed params to receive struct ecc_curve*; - xycz_add - changed params to receive struct ecc_curve*; - xycz_add_c - changed params to receive struct ecc_curve*; - ecc_point_mult - changed to pass struct ecc_curve* forward; - ecc_point_mult_shamir - changed to pass struct ecc_curve* forward; - ecc_is_pubkey_valid_partial - changed to pass struct ecc_curve*;
* crypto/ecc.h - NIST_P384 and NIST_P521 constants defined; - ecc_point_is_zero - added to export; - vli_mod_slow - added to export; - vli_mod_add - added to export - vli_mod_fast - added to export; - vli_mod_mult_fast - added to export. --- crypto/ecc.c | 338 +++++++++++++++++++++++++++++++++++++++------------ crypto/ecc.h | 59 ++++++++- 2 files changed, 318 insertions(+), 79 deletions(-) diff --git a/crypto/ecc.c b/crypto/ecc.c index c80aa25994a0..f9e8b155f493 100644 --- a/crypto/ecc.c +++ b/crypto/ecc.c @@ -50,6 +50,10 @@ static inline const struct ecc_curve *ecc_get_curve(unsigned int curve_id) return fips_enabled ? NULL : &nist_p192; case ECC_CURVE_NIST_P256: return &nist_p256; + case ECC_CURVE_NIST_P384: + return &nist_p384; + case ECC_CURVE_NIST_P521: + return &nist_p521; default: return NULL; } @@ -235,6 +239,25 @@ static u64 vli_lshift(u64 *result, const u64 *in, unsigned int shift, return carry; } +/* Computes result = in >> c, returning carry. */ +static u64 vli_rshift(u64 *result, const u64 *in, unsigned int shift, + unsigned int ndigits) +{ + u64 carry = 0; + int i; + + for (i = 0; i < ndigits; i++) { + if (i + 1 < ndigits) + carry = in[i + 1] << (64 - shift); + else + carry = 0; + + result[i] = (in[i] >> shift) | carry; + } + + return carry; +} + /* Computes vli = vli >> 1. */ static void vli_rshift1(u64 *vli, unsigned int ndigits) { @@ -474,7 +497,7 @@ static void vli_square(u64 *result, const u64 *left, unsigned int ndigits) /* Computes result = (left + right) % mod. * Assumes that left < mod and right < mod, result != mod. */ -static void vli_mod_add(u64 *result, const u64 *left, const u64 *right, +void vli_mod_add(u64 *result, const u64 *left, const u64 *right, const u64 *mod, unsigned int ndigits) { u64 carry; @@ -487,6 +510,7 @@ static void vli_mod_add(u64 *result, const u64 *left, const u64 *right, if (carry || vli_cmp(result, mod, ndigits) >= 0) vli_sub(result, result, mod, ndigits); } +EXPORT_SYMBOL(vli_mod_add); /* Computes result = (left - right) % mod. * Assumes that left < mod and right < mod, result != mod. @@ -775,18 +799,156 @@ 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 + * from "Mathematical routines for the NIST prime elliptic curves" + */ +static void vli_mmod_fast_521(u64 *result, const u64 *product, + const u64 *curve_prime, u64 *tmp) +{ + int carry; + const unsigned int ndigits = 9; + + /* t 512 bits + 9 bits a0 .. a520 */ + vli_set(result, product, 9); + result[8] &= 0x000001ff; + + /* t 512 bits + 9 bits a521 .. a1041 */ + vli_set(tmp, product + 8, ndigits); + vli_rshift(tmp, tmp, 9, ndigits); + + carry = vli_add(result, result, tmp, ndigits); + + while (carry || vli_cmp(curve_prime, result, ndigits) != 1) + carry -= vli_sub(result, result, curve_prime, ndigits); +} + /* Computes result = product % curve_prime for different curve_primes. * * Note that curve_primes are distinguished just by heuristic check and * not by complete conformance check. */ 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]; + const u64 *curve_prime = curve->p; + const unsigned int ndigits = curve->g.ndigits; - /* Currently, both NIST primes have -1 in lowest qword. */ - if (curve_prime[0] != -1ull) { + /* Currently, all NIST have name nist_*. */ + if (strncmp(curve->name, "nist_", 5) != 0) { /* Try to handle Pseudo-Marsenne primes. */ if (curve_prime[ndigits - 1] == -1ull) { vli_mmod_special(result, product, curve_prime, @@ -809,6 +971,12 @@ static bool vli_mmod_fast(u64 *result, u64 *product, case 4: vli_mmod_fast_256(result, product, curve_prime, tmp); break; + case 6: + vli_mmod_fast_384(result, product, curve_prime, tmp); + break; + case 9: + vli_mmod_fast_521(result, product, curve_prime, tmp); + break; default: pr_err_ratelimited("ecc: unsupported digits size!\n"); return false; @@ -830,25 +998,38 @@ void vli_mod_mult_slow(u64 *result, const u64 *left, const u64 *right, } EXPORT_SYMBOL(vli_mod_mult_slow); +/* Computes result = input % curve_prime. */ +void vli_mod_slow(u64 *result, const u64 *input, + const u64 *mod, unsigned int ndigits) +{ + u64 product[ECC_MAX_DIGITS * 2] = { 0 }; + + vli_set(&product[0], input, ndigits); + vli_mmod_slow(result, product, mod, ndigits); +} +EXPORT_SYMBOL(vli_mod_slow); + /* Computes result = (left * right) % curve_prime. */ -static void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right, - const u64 *curve_prime, unsigned int ndigits) +void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right, + const struct ecc_curve *curve) { u64 product[2 * ECC_MAX_DIGITS]; - vli_mult(product, left, right, ndigits); - vli_mmod_fast(result, product, curve_prime, ndigits); + vli_mult(product, left, right, curve->g.ndigits); + vli_mmod_fast(result, product, curve); } +EXPORT_SYMBOL(vli_mod_mult_fast); /* Computes result = left^2 % curve_prime. */ -static void vli_mod_square_fast(u64 *result, const u64 *left, - const u64 *curve_prime, unsigned int ndigits) +void vli_mod_square_fast(u64 *result, const u64 *left, + const struct ecc_curve *curve) { u64 product[2 * ECC_MAX_DIGITS]; - vli_square(product, left, ndigits); - vli_mmod_fast(result, product, curve_prime, ndigits); + vli_square(product, left, curve->g.ndigits); + vli_mmod_fast(result, product, curve); } +EXPORT_SYMBOL(vli_mod_square_fast); #define EVEN(vli) (!(vli[0] & 1)) /* Computes result = (1 / p_input) % mod. All VLIs are the same size. @@ -933,11 +1114,12 @@ EXPORT_SYMBOL(vli_mod_inv); /* ------ Point operations ------ */ /* Returns true if p_point is the point at infinity, false otherwise. */ -static bool ecc_point_is_zero(const struct ecc_point *point) +bool ecc_point_is_zero(const struct ecc_point *point) { return (vli_is_zero(point->x, point->ndigits) && vli_is_zero(point->y, point->ndigits)); } +EXPORT_SYMBOL(ecc_point_is_zero); /* Point multiplication algorithm using Montgomery's ladder with co-Z * coordinates. From https://eprint.iacr.org/2011/338.pdf @@ -945,25 +1127,27 @@ static bool ecc_point_is_zero(const struct ecc_point *point) /* Double in place */ 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 */ u64 t4[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)) return; /* t4 = y1^2 */ - vli_mod_square_fast(t4, y1, curve_prime, ndigits); + vli_mod_square_fast(t4, y1, curve); /* 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 */ - vli_mod_square_fast(t4, t4, curve_prime, ndigits); + vli_mod_square_fast(t4, t4, curve); /* 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 */ - vli_mod_square_fast(z1, z1, curve_prime, ndigits); + vli_mod_square_fast(z1, z1, curve); /* t1 = x1 + z1^2 */ vli_mod_add(x1, x1, z1, curve_prime, ndigits); @@ -972,7 +1156,7 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1, /* t3 = x1 - z1^2 */ vli_mod_sub(z1, x1, z1, curve_prime, ndigits); /* 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) */ vli_mod_add(z1, x1, x1, curve_prime, ndigits); @@ -989,7 +1173,7 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1, /* t1 = 3/2*(x1^2 - z1^4) = B */ /* t3 = B^2 */ - vli_mod_square_fast(z1, x1, curve_prime, ndigits); + vli_mod_square_fast(z1, x1, curve); /* t3 = B^2 - A */ vli_mod_sub(z1, z1, t5, curve_prime, ndigits); /* t3 = B^2 - 2A = x3 */ @@ -997,7 +1181,7 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1, /* t5 = A - x3 */ vli_mod_sub(t5, t5, z1, curve_prime, ndigits); /* 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 */ vli_mod_sub(t4, x1, t4, curve_prime, ndigits); @@ -1007,23 +1191,22 @@ static void ecc_point_double_jacobian(u64 *x1, u64 *y1, u64 *z1, } /* Modify (x1, y1) => (x1 * z^2, y1 * z^3) */ -static void apply_z(u64 *x1, u64 *y1, u64 *z, u64 *curve_prime, - unsigned int ndigits) +static void apply_z(u64 *x1, u64 *y1, u64 *z, const struct ecc_curve *curve) { u64 t1[ECC_MAX_DIGITS]; - vli_mod_square_fast(t1, z, curve_prime, ndigits); /* z^2 */ - vli_mod_mult_fast(x1, x1, t1, curve_prime, ndigits); /* x1 * z^2 */ - vli_mod_mult_fast(t1, t1, z, curve_prime, ndigits); /* z^3 */ - vli_mod_mult_fast(y1, y1, t1, curve_prime, ndigits); /* y1 * z^3 */ + vli_mod_square_fast(t1, z, curve); /* z^2 */ + vli_mod_mult_fast(x1, x1, t1, curve); /* x1 * z^2 */ + vli_mod_mult_fast(t1, t1, z, curve); /* z^3 */ + vli_mod_mult_fast(y1, y1, t1, curve); /* y1 * z^3 */ } /* P = (x1, y1) => 2P, (x2, y2) => P' */ static void xycz_initial_double(u64 *x1, u64 *y1, u64 *x2, u64 *y2, - u64 *p_initial_z, u64 *curve_prime, - unsigned int ndigits) + u64 *p_initial_z, const struct ecc_curve *curve) { u64 z[ECC_MAX_DIGITS]; + const unsigned int ndigits = curve->g.ndigits; vli_set(x2, x1, ndigits); vli_set(y2, y1, ndigits); @@ -1034,35 +1217,37 @@ static void xycz_initial_double(u64 *x1, u64 *y1, u64 *x2, u64 *y2, if (p_initial_z) 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) * Output P' = (x1', y1', Z3), P + Q = (x3, y3, Z3) * or P => P', Q => P + Q */ -static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, - unsigned int ndigits) +static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2, + const struct ecc_curve *curve) { /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ u64 t5[ECC_MAX_DIGITS]; + const u64 *curve_prime = curve->p; + const unsigned int ndigits = curve->g.ndigits; /* t5 = x2 - x1 */ vli_mod_sub(t5, x2, x1, curve_prime, ndigits); /* 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 */ - vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); + vli_mod_mult_fast(x1, x1, t5, curve); /* 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 */ vli_mod_sub(y2, y2, y1, curve_prime, ndigits); /* t5 = (y2 - y1)^2 = D */ - vli_mod_square_fast(t5, y2, curve_prime, ndigits); + vli_mod_square_fast(t5, y2, curve); /* t5 = D - B */ vli_mod_sub(t5, t5, x1, curve_prime, ndigits); @@ -1071,11 +1256,11 @@ static void xycz_add(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, /* t3 = C - B */ vli_mod_sub(x2, x2, x1, curve_prime, ndigits); /* 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 */ vli_mod_sub(x2, x1, t5, curve_prime, ndigits); /* 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 */ vli_mod_sub(y2, y2, y1, curve_prime, ndigits); @@ -1086,22 +1271,24 @@ 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) * or P => P - Q, Q => P + Q */ -static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, - unsigned int ndigits) +static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2, + const struct ecc_curve *curve) { /* t1 = X1, t2 = Y1, t3 = X2, t4 = Y2 */ u64 t5[ECC_MAX_DIGITS]; u64 t6[ECC_MAX_DIGITS]; u64 t7[ECC_MAX_DIGITS]; + const u64 *curve_prime = curve->p; + const unsigned int ndigits = curve->g.ndigits; /* t5 = x2 - x1 */ vli_mod_sub(t5, x2, x1, curve_prime, ndigits); /* 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 */ - vli_mod_mult_fast(x1, x1, t5, curve_prime, ndigits); + vli_mod_mult_fast(x1, x1, t5, curve); /* 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 */ vli_mod_add(t5, y2, y1, curve_prime, ndigits); /* t4 = y2 - y1 */ @@ -1110,29 +1297,29 @@ static void xycz_add_c(u64 *x1, u64 *y1, u64 *x2, u64 *y2, u64 *curve_prime, /* t6 = C - B */ vli_mod_sub(t6, x2, x1, curve_prime, ndigits); /* 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 */ vli_mod_add(t6, x1, x2, curve_prime, ndigits); /* t3 = (y2 - y1)^2 */ - vli_mod_square_fast(x2, y2, curve_prime, ndigits); + vli_mod_square_fast(x2, y2, curve); /* t3 = x3 */ vli_mod_sub(x2, x2, t6, curve_prime, ndigits); /* t7 = B - x3 */ vli_mod_sub(t7, x1, x2, curve_prime, ndigits); /* 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 */ vli_mod_sub(y2, y2, y1, curve_prime, ndigits); /* t7 = (y2 + y1)^2 = F */ - vli_mod_square_fast(t7, t5, curve_prime, ndigits); + vli_mod_square_fast(t7, t5, curve); /* t7 = x3' */ vli_mod_sub(t7, t7, t6, curve_prime, ndigits); /* t6 = x3' - B */ vli_mod_sub(t6, t7, x1, curve_prime, ndigits); /* 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' */ vli_mod_sub(y1, t6, y1, curve_prime, ndigits); @@ -1162,41 +1349,37 @@ static void ecc_point_mult(struct ecc_point *result, vli_set(rx[1], point->x, ndigits); vli_set(ry[1], point->y, ndigits); - xycz_initial_double(rx[1], ry[1], rx[0], ry[0], initial_z, curve_prime, - ndigits); + xycz_initial_double(rx[1], ry[1], rx[0], ry[0], initial_z, curve); for (i = num_bits - 2; i > 0; i--) { nb = !vli_test_bit(scalar, i); - xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve_prime, - ndigits); - xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve_prime, - ndigits); + xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve); + xycz_add(rx[nb], ry[nb], rx[1 - nb], ry[1 - nb], curve); } nb = !vli_test_bit(scalar, 0); - xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve_prime, - ndigits); + xycz_add_c(rx[1 - nb], ry[1 - nb], rx[nb], ry[nb], curve); /* Find final 1/Z value. */ /* X1 - X0 */ vli_mod_sub(z, rx[1], rx[0], curve_prime, ndigits); /* 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) */ - 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)) */ vli_mod_inv(z, z, curve_prime, point->ndigits); /* 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)) */ - 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 */ - 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->y, ry[0], ndigits); @@ -1217,9 +1400,9 @@ static void ecc_point_add(const struct ecc_point *result, vli_mod_sub(z, result->x, p->x, curve->p, ndigits); vli_set(px, p->x, 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); - 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. @@ -1248,8 +1431,7 @@ void ecc_point_mult_shamir(const struct ecc_point *result, points[2] = q; points[3] = ∑ - num_bits = max(vli_num_bits(u1, ndigits), - vli_num_bits(u2, ndigits)); + num_bits = max(vli_num_bits(u1, ndigits), vli_num_bits(u2, ndigits)); i = num_bits - 1; idx = (!!vli_test_bit(u1, i)) | ((!!vli_test_bit(u2, i)) << 1); point = points[idx]; @@ -1260,7 +1442,7 @@ void ecc_point_mult_shamir(const struct ecc_point *result, z[0] = 1; 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); point = points[idx]; if (point) { @@ -1270,14 +1452,14 @@ void ecc_point_mult_shamir(const struct ecc_point *result, vli_set(tx, point->x, 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); - xycz_add(tx, ty, rx, ry, curve->p, ndigits); - vli_mod_mult_fast(z, z, tz, curve->p, ndigits); + xycz_add(tx, ty, rx, ry, curve); + vli_mod_mult_fast(z, z, tz, curve); } } 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); @@ -1441,10 +1623,10 @@ int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve, return -EINVAL; /* 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(xxx, pk->x, curve->p, pk->ndigits); /* x^2 */ - vli_mod_mult_fast(xxx, xxx, pk->x, curve->p, pk->ndigits); /* x^3 */ - vli_mod_mult_fast(w, curve->a, pk->x, curve->p, pk->ndigits); /* a·x */ + vli_mod_square_fast(yy, pk->y, curve); /* y^2 */ + vli_mod_square_fast(xxx, pk->x, curve); /* x^2 */ + vli_mod_mult_fast(xxx, xxx, pk->x, curve); /* x^3 */ + 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, xxx, curve->p, pk->ndigits); /* x^3 + a·x + b */ if (vli_cmp(yy, w, pk->ndigits) != 0) /* Equation */ diff --git a/crypto/ecc.h b/crypto/ecc.h index d4e546b9ad79..f02ea6cfd10d 100644 --- a/crypto/ecc.h +++ b/crypto/ecc.h @@ -29,7 +29,9 @@ /* One digit is u64 qword. */ #define ECC_CURVE_NIST_P192_DIGITS 3 #define ECC_CURVE_NIST_P256_DIGITS 4 -#define ECC_MAX_DIGITS (512 / 64) +#define ECC_CURVE_NIST_P384_DIGITS 6 +#define ECC_CURVE_NIST_P521_DIGITS 9 +#define ECC_MAX_DIGITS (ECC_CURVE_NIST_P521_DIGITS) #define ECC_DIGITS_TO_BYTES_SHIFT 3 @@ -147,6 +149,9 @@ int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve, struct ecc_point *pk); +/* Returns true if p_point is the point at infinity, false otherwise. */ +bool ecc_point_is_zero(const struct ecc_point *point); + /** * ecc_is_pubkey_valid_full() - Full public key validation * @@ -225,6 +230,22 @@ void vli_from_le64(u64 *dest, const void *src, unsigned int ndigits); void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod, unsigned int ndigits); +/** + * vli_mod_slow() - Computes result = product % mod, where product is 2N words + * long. + * Reference: Ken MacKay's micro-ecc. + * Currently only designed to work for curve_p or curve_n. + * + * @result: where to write result value + * @product: vli number to operate mod on + * @mod: modulus + * @ndigits: length of all vlis + * + * Note: Assumes that mod is big enough curve order. + */ +void vli_mod_slow(u64 *result, const u64 *input, const u64 *mod, + unsigned int ndigits); + /** * vli_mod_mult_slow() - Modular multiplication * @@ -239,6 +260,42 @@ void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod, void vli_mod_mult_slow(u64 *result, const u64 *left, const u64 *right, const u64 *mod, unsigned int ndigits); +/* Computes result = (left + right) % mod. + * Assumes that left < mod and right < mod, result != mod. + */ +void vli_mod_add(u64 *result, const u64 *left, const u64 *right, + const u64 *mod, unsigned int ndigits); + +/** + * vli_mod_fast() - Computes result = product % curve_prime for different + * curve_primes. + * + * Note that curve_primes are distinguished just by heuristic check and + * not by complete conformance check. + * + * @result: where to write result value + * @input: vli number to multiply with @right + * @mod: mod + * @ndigits: length of all vlis + * + * Note: Assumes that mod is big enough curve order. + */ +void vli_mod_fast(u64 *result, const u64 *input, const struct ecc_curve *curve); + +/** + * vli_mod_mult_fast() - Modular multiplication + * + * @result: where to write result value + * @left: vli number to multiply with @right + * @right: vli number to multiply with @left + * @mod: modulus + * @ndigits: length of all vlis + * + * Note: Assumes that mod is big enough curve order. + */ +void vli_mod_mult_fast(u64 *result, const u64 *left, const u64 *right, + const struct ecc_curve *curve); + /** * ecc_point_mult_shamir() - Add two points multiplied by scalars * -- 2.25.1