diff options
Diffstat (limited to 'crypto/ecc.c')
| -rw-r--r-- | crypto/ecc.c | 44 |
1 files changed, 39 insertions, 5 deletions
diff --git a/crypto/ecc.c b/crypto/ecc.c index 02d35be7702b..8acf8433ca29 100644 --- a/crypto/ecc.c +++ b/crypto/ecc.c @@ -940,7 +940,7 @@ static bool ecc_point_is_zero(const struct ecc_point *point) } /* 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 */ @@ -1404,7 +1404,9 @@ 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; } @@ -1452,6 +1454,33 @@ 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 +1524,16 @@ 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); |