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-rw-r--r--crypto/ecc.c42
-rw-r--r--crypto/ecc_curve_defs.h22
2 files changed, 56 insertions, 8 deletions
diff --git a/crypto/ecc.c b/crypto/ecc.c
index 815541309a95..8facafd67802 100644
--- a/crypto/ecc.c
+++ b/crypto/ecc.c
@@ -1019,6 +1019,36 @@ out:
return ret;
}
+/* SP800-56A section 5.6.2.3.4 partial verification: ephemeral keys only */
+static int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve,
+ struct ecc_point *pk)
+{
+ u64 yy[ECC_MAX_DIGITS], xxx[ECC_MAX_DIGITS], w[ECC_MAX_DIGITS];
+
+ /* Check 1: Verify key is not the zero point. */
+ if (ecc_point_is_zero(pk))
+ return -EINVAL;
+
+ /* Check 2: Verify key is in the range [1, p-1]. */
+ if (vli_cmp(curve->p, pk->x, pk->ndigits) != 1)
+ return -EINVAL;
+ if (vli_cmp(curve->p, pk->y, pk->ndigits) != 1)
+ 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_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 */
+ return -EINVAL;
+
+ return 0;
+
+}
+
int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
const u64 *private_key, const u64 *public_key,
u64 *secret)
@@ -1046,16 +1076,20 @@ int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
goto out;
}
+ ecc_swap_digits(public_key, pk->x, ndigits);
+ ecc_swap_digits(&public_key[ndigits], pk->y, ndigits);
+ ret = ecc_is_pubkey_valid_partial(curve, pk);
+ if (ret)
+ goto err_alloc_product;
+
+ ecc_swap_digits(private_key, priv, ndigits);
+
product = ecc_alloc_point(ndigits);
if (!product) {
ret = -ENOMEM;
goto err_alloc_product;
}
- ecc_swap_digits(public_key, pk->x, ndigits);
- ecc_swap_digits(&public_key[ndigits], pk->y, ndigits);
- ecc_swap_digits(private_key, priv, ndigits);
-
ecc_point_mult(product, pk, priv, rand_z, curve->p, ndigits);
ecc_swap_digits(product->x, secret, ndigits);
diff --git a/crypto/ecc_curve_defs.h b/crypto/ecc_curve_defs.h
index b80f45da829c..94e883a9403f 100644
--- a/crypto/ecc_curve_defs.h
+++ b/crypto/ecc_curve_defs.h
@@ -13,9 +13,11 @@ struct ecc_curve {
struct ecc_point g;
u64 *p;
u64 *n;
+ u64 *a;
+ u64 *b;
};
-/* NIST P-192 */
+/* NIST P-192: a = p - 3 */
static u64 nist_p192_g_x[] = { 0xF4FF0AFD82FF1012ull, 0x7CBF20EB43A18800ull,
0x188DA80EB03090F6ull };
static u64 nist_p192_g_y[] = { 0x73F977A11E794811ull, 0x631011ED6B24CDD5ull,
@@ -24,6 +26,10 @@ static u64 nist_p192_p[] = { 0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFFFFFFFFFEull,
0xFFFFFFFFFFFFFFFFull };
static u64 nist_p192_n[] = { 0x146BC9B1B4D22831ull, 0xFFFFFFFF99DEF836ull,
0xFFFFFFFFFFFFFFFFull };
+static u64 nist_p192_a[] = { 0xFFFFFFFFFFFFFFFCull, 0xFFFFFFFFFFFFFFFEull,
+ 0xFFFFFFFFFFFFFFFEull };
+static u64 nist_p192_b[] = { 0xFEB8DEECC146B9B1ull, 0x0FA7E9AB72243049ull,
+ 0x64210519E59C80E7ull };
static struct ecc_curve nist_p192 = {
.name = "nist_192",
.g = {
@@ -32,10 +38,12 @@ static struct ecc_curve nist_p192 = {
.ndigits = 3,
},
.p = nist_p192_p,
- .n = nist_p192_n
+ .n = nist_p192_n,
+ .a = nist_p192_a,
+ .b = nist_p192_b
};
-/* NIST P-256 */
+/* NIST P-256: a = p - 3 */
static u64 nist_p256_g_x[] = { 0xF4A13945D898C296ull, 0x77037D812DEB33A0ull,
0xF8BCE6E563A440F2ull, 0x6B17D1F2E12C4247ull };
static u64 nist_p256_g_y[] = { 0xCBB6406837BF51F5ull, 0x2BCE33576B315ECEull,
@@ -44,6 +52,10 @@ static u64 nist_p256_p[] = { 0xFFFFFFFFFFFFFFFFull, 0x00000000FFFFFFFFull,
0x0000000000000000ull, 0xFFFFFFFF00000001ull };
static u64 nist_p256_n[] = { 0xF3B9CAC2FC632551ull, 0xBCE6FAADA7179E84ull,
0xFFFFFFFFFFFFFFFFull, 0xFFFFFFFF00000000ull };
+static u64 nist_p256_a[] = { 0xFFFFFFFFFFFFFFFCull, 0x00000000FFFFFFFFull,
+ 0x0000000000000000ull, 0xFFFFFFFF00000001ull };
+static u64 nist_p256_b[] = { 0x3BCE3C3E27D2604Bull, 0x651D06B0CC53B0F6ull,
+ 0xB3EBBD55769886BCull, 0x5AC635D8AA3A93E7ull };
static struct ecc_curve nist_p256 = {
.name = "nist_256",
.g = {
@@ -52,7 +64,9 @@ static struct ecc_curve nist_p256 = {
.ndigits = 4,
},
.p = nist_p256_p,
- .n = nist_p256_n
+ .n = nist_p256_n,
+ .a = nist_p256_a,
+ .b = nist_p256_b
};
#endif