diff options
Diffstat (limited to '')
| -rw-r--r-- | crypto/ecc.c | 357 |
1 files changed, 257 insertions, 100 deletions
diff --git a/crypto/ecc.c b/crypto/ecc.c index 02d35be7702b..7315217c8f73 100644 --- a/crypto/ecc.c +++ b/crypto/ecc.c @@ -24,6 +24,7 @@ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ +#include <crypto/ecc_curve.h> #include <linux/module.h> #include <linux/random.h> #include <linux/slab.h> @@ -31,10 +32,10 @@ #include <linux/fips.h> #include <crypto/ecdh.h> #include <crypto/rng.h> +#include <crypto/internal/ecc.h> #include <asm/unaligned.h> #include <linux/ratelimit.h> -#include "ecc.h" #include "ecc_curve_defs.h" typedef struct { @@ -42,7 +43,14 @@ typedef struct { u64 m_high; } uint128_t; -static inline const struct ecc_curve *ecc_get_curve(unsigned int curve_id) +/* Returns curv25519 curve param */ +const struct ecc_curve *ecc_get_curve25519(void) +{ + return &ecc_25519; +} +EXPORT_SYMBOL(ecc_get_curve25519); + +const struct ecc_curve *ecc_get_curve(unsigned int curve_id) { switch (curve_id) { /* In FIPS mode only allow P256 and higher */ @@ -50,10 +58,13 @@ 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; default: return NULL; } } +EXPORT_SYMBOL(ecc_get_curve); static u64 *ecc_alloc_digits_space(unsigned int ndigits) { @@ -67,10 +78,10 @@ static u64 *ecc_alloc_digits_space(unsigned int ndigits) static void ecc_free_digits_space(u64 *space) { - kzfree(space); + kfree_sensitive(space); } -static struct ecc_point *ecc_alloc_point(unsigned int ndigits) +struct ecc_point *ecc_alloc_point(unsigned int ndigits) { struct ecc_point *p = kmalloc(sizeof(*p), GFP_KERNEL); @@ -95,16 +106,18 @@ err_alloc_x: kfree(p); return NULL; } +EXPORT_SYMBOL(ecc_alloc_point); -static void ecc_free_point(struct ecc_point *p) +void ecc_free_point(struct ecc_point *p) { if (!p) return; - kzfree(p->x); - kzfree(p->y); - kzfree(p); + kfree_sensitive(p->x); + kfree_sensitive(p->y); + kfree_sensitive(p); } +EXPORT_SYMBOL(ecc_free_point); static void vli_clear(u64 *vli, unsigned int ndigits) { @@ -128,7 +141,7 @@ bool vli_is_zero(const u64 *vli, unsigned int ndigits) } EXPORT_SYMBOL(vli_is_zero); -/* Returns nonzero if bit bit of vli is set. */ +/* Returns nonzero if bit of vli is set. */ static u64 vli_test_bit(const u64 *vli, unsigned int bit) { return (vli[bit / 64] & ((u64)1 << (bit % 64))); @@ -154,7 +167,7 @@ static unsigned int vli_num_digits(const u64 *vli, unsigned int ndigits) } /* Counts the number of bits required for vli. */ -static unsigned int vli_num_bits(const u64 *vli, unsigned int ndigits) +unsigned int vli_num_bits(const u64 *vli, unsigned int ndigits) { unsigned int i, num_digits; u64 digit; @@ -169,6 +182,7 @@ static unsigned int vli_num_bits(const u64 *vli, unsigned int ndigits) return ((num_digits - 1) * 64 + i); } +EXPORT_SYMBOL(vli_num_bits); /* Set dest from unaligned bit string src. */ void vli_from_be64(u64 *dest, const void *src, unsigned int ndigits) @@ -775,18 +789,133 @@ 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. * * 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) { + /* All NIST curves have name prefix '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 +938,9 @@ 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; default: pr_err_ratelimited("ecc: unsupported digits size!\n"); return false; @@ -832,22 +964,22 @@ EXPORT_SYMBOL(vli_mod_mult_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) + 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); } /* Computes result = left^2 % curve_prime. */ 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]; - 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); } #define EVEN(vli) (!(vli[0] & 1)) @@ -933,37 +1065,40 @@ 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 http://eprint.iacr.org/2011/338.pdf + * coordinates. From https://eprint.iacr.org/2011/338.pdf */ /* 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 +1107,7 @@ 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 +1124,7 @@ 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 +1132,7 @@ 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 +1142,22 @@ 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 +1168,37 @@ 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 +1207,11 @@ 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 +1222,24 @@ 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 +1248,29 @@ 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 +1300,37 @@ 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 +1351,9 @@ 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 +1382,7 @@ 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 +1393,7 @@ 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) { @@ -1270,27 +1403,17 @@ 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); -static inline void ecc_swap_digits(const u64 *in, u64 *out, - unsigned int ndigits) -{ - const __be64 *src = (__force __be64 *)in; - int i; - - for (i = 0; i < ndigits; i++) - out[i] = be64_to_cpu(src[ndigits - 1 - i]); -} - static int __ecc_is_key_valid(const struct ecc_curve *curve, const u64 *private_key, unsigned int ndigits) { @@ -1404,7 +1527,9 @@ int ecc_make_pub_key(unsigned int curve_id, unsigned int ndigits, } ecc_point_mult(pk, &curve->g, priv, NULL, curve, ndigits); - if (ecc_point_is_zero(pk)) { + + /* SP800-56A rev 3 5.6.2.1.3 key check */ + if (ecc_is_pubkey_valid_full(curve, pk)) { ret = -EAGAIN; goto err_free_point; } @@ -1439,10 +1564,10 @@ 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 */ @@ -1452,6 +1577,33 @@ int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve, } EXPORT_SYMBOL(ecc_is_pubkey_valid_partial); +/* SP800-56A section 5.6.2.3.3 full verification */ +int ecc_is_pubkey_valid_full(const struct ecc_curve *curve, + struct ecc_point *pk) +{ + struct ecc_point *nQ; + + /* Checks 1 through 3 */ + int ret = ecc_is_pubkey_valid_partial(curve, pk); + + if (ret) + return ret; + + /* Check 4: Verify that nQ is the zero point. */ + nQ = ecc_alloc_point(pk->ndigits); + if (!nQ) + return -ENOMEM; + + ecc_point_mult(nQ, pk, curve->n, NULL, curve, pk->ndigits); + if (!ecc_point_is_zero(nQ)) + ret = -EINVAL; + + ecc_free_point(nQ); + + return ret; +} +EXPORT_SYMBOL(ecc_is_pubkey_valid_full); + int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, const u64 *private_key, const u64 *public_key, u64 *secret) @@ -1495,11 +1647,16 @@ int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, ecc_point_mult(product, pk, priv, rand_z, curve, ndigits); - ecc_swap_digits(product->x, secret, ndigits); - - if (ecc_point_is_zero(product)) + if (ecc_point_is_zero(product)) { ret = -EFAULT; + goto err_validity; + } + + ecc_swap_digits(product->x, secret, ndigits); +err_validity: + memzero_explicit(priv, sizeof(priv)); + memzero_explicit(rand_z, sizeof(rand_z)); ecc_free_point(product); err_alloc_product: ecc_free_point(pk); |