diff --git a/src/crypto/crypto_wolfssl.c b/src/crypto/crypto_wolfssl.c index 8d6fdc2fb..c260d4ed0 100644 --- a/src/crypto/crypto_wolfssl.c +++ b/src/crypto/crypto_wolfssl.c @@ -1667,4 +1667,129 @@ int crypto_ec_point_cmp(const struct crypto_ec *e, return wc_ecc_cmp_point((ecc_point *) a, (ecc_point *) b); } + +struct crypto_ecdh { + struct crypto_ec *ec; +}; + +struct crypto_ecdh * crypto_ecdh_init(int group) +{ + struct crypto_ecdh *ecdh = NULL; + WC_RNG rng; + int ret; + + if (wc_InitRng(&rng) != 0) + goto fail; + + ecdh = os_zalloc(sizeof(*ecdh)); + if (!ecdh) + goto fail; + + ecdh->ec = crypto_ec_init(group); + if (!ecdh->ec) + goto fail; + + ret = wc_ecc_make_key_ex(&rng, ecdh->ec->key.dp->size, &ecdh->ec->key, + ecdh->ec->key.dp->id); + if (ret < 0) + goto fail; + +done: + wc_FreeRng(&rng); + + return ecdh; +fail: + crypto_ecdh_deinit(ecdh); + ecdh = NULL; + goto done; +} + + +void crypto_ecdh_deinit(struct crypto_ecdh *ecdh) +{ + if (ecdh) { + crypto_ec_deinit(ecdh->ec); + os_free(ecdh); + } +} + + +struct wpabuf * crypto_ecdh_get_pubkey(struct crypto_ecdh *ecdh, int inc_y) +{ + struct wpabuf *buf = NULL; + int ret; + int len = ecdh->ec->key.dp->size; + + buf = wpabuf_alloc(inc_y ? 2 * len : len); + if (!buf) + goto fail; + + ret = crypto_bignum_to_bin((struct crypto_bignum *) + ecdh->ec->key.pubkey.x, wpabuf_put(buf, len), + len, len); + if (ret < 0) + goto fail; + if (inc_y) { + ret = crypto_bignum_to_bin((struct crypto_bignum *) + ecdh->ec->key.pubkey.y, + wpabuf_put(buf, len), len, len); + if (ret < 0) + goto fail; + } + +done: + return buf; +fail: + wpabuf_free(buf); + buf = NULL; + goto done; +} + + +struct wpabuf * crypto_ecdh_set_peerkey(struct crypto_ecdh *ecdh, int inc_y, + const u8 *key, size_t len) +{ + int ret; + struct wpabuf *pubkey = NULL; + struct wpabuf *secret = NULL; + word32 key_len = ecdh->ec->key.dp->size; + ecc_point *point = NULL; + size_t need_key_len = inc_y ? 2 * key_len : key_len; + + if (len < need_key_len) + goto fail; + pubkey = wpabuf_alloc(1 + 2 * key_len); + if (!pubkey) + goto fail; + wpabuf_put_u8(pubkey, inc_y ? ECC_POINT_UNCOMP : ECC_POINT_COMP_EVEN); + wpabuf_put_data(pubkey, key, need_key_len); + + point = wc_ecc_new_point(); + if (!point) + goto fail; + + ret = wc_ecc_import_point_der(wpabuf_mhead(pubkey), 1 + 2 * key_len, + ecdh->ec->key.dp->id, point); + if (ret != MP_OKAY) + goto fail; + + secret = wpabuf_alloc(key_len); + if (!secret) + goto fail; + + ret = wc_ecc_shared_secret_ex(&ecdh->ec->key, point, + wpabuf_put(secret, key_len), &key_len); + if (ret != MP_OKAY) + goto fail; + +done: + wc_ecc_del_point(point); + wpabuf_free(pubkey); + return secret; +fail: + wpabuf_free(secret); + secret = NULL; + goto done; +} + #endif /* CONFIG_ECC */