int
_gnutls_proc_ecdh_common_server_kx(gnutls_session_t session,
uint8_t * data, size_t _data_size)
{
int i, ret, point_size;
gnutls_ecc_curve_t curve;
ssize_t data_size = _data_size;
/* just in case we are resuming a session */
gnutls_pk_params_release(&session->key.ecdh_params);
gnutls_pk_params_init(&session->key.ecdh_params);
i = 0;
DECR_LEN(data_size, 1);
if (data[i++] != 3)
return gnutls_assert_val(GNUTLS_E_ECC_NO_SUPPORTED_CURVES);
DECR_LEN(data_size, 2);
curve = _gnutls_tls_id_to_ecc_curve(_gnutls_read_uint16(&data[i]));
i += 2;
ret = _gnutls_session_supports_ecc_curve(session, curve);
if (ret < 0)
return gnutls_assert_val(ret);
_gnutls_session_ecc_curve_set(session, curve);
DECR_LEN(data_size, 1);
point_size = data[i];
i++;
DECR_LEN(data_size, point_size);
ret =
_gnutls_ecc_ansi_x963_import(&data[i], point_size,
&session->key.ecdh_x,
&session->key.ecdh_y);
if (ret < 0)
return gnutls_assert_val(ret);
i += point_size;
return i;
}
/*
* In case of a server: if a SUPPORTED_ECC extension type is received then it stores
* into the session security parameters the new value. The server may use gnutls_session_certificate_type_get(),
* to access it.
*
* In case of a client: If a supported_eccs have been specified then we send the extension.
*
*/
static int
_gnutls_supported_ecc_recv_params(gnutls_session_t session,
const uint8_t * data, size_t _data_size)
{
int new_type = -1, ret, i;
ssize_t data_size = _data_size;
uint16_t len;
const uint8_t *p = data;
if (session->security_parameters.entity == GNUTLS_CLIENT) {
/* A client shouldn't receive this extension, but of course
* there are servers out there that send it. Just ignore it. */
_gnutls_debug_log("received SUPPORTED ECC extension on client side!!!\n");
return 0;
} else { /* SERVER SIDE - we must check if the sent supported ecc type is the right one
*/
if (data_size < 2)
return
gnutls_assert_val
(GNUTLS_E_RECEIVED_ILLEGAL_EXTENSION);
DECR_LEN(data_size, 2);
len = _gnutls_read_uint16(p);
p += 2;
if (len % 2 != 0)
return gnutls_assert_val(GNUTLS_E_UNEXPECTED_PACKET_LENGTH);
DECR_LEN(data_size, len);
for (i = 0; i < len; i += 2) {
new_type =
_gnutls_tls_id_to_ecc_curve(_gnutls_read_uint16
(&p[i]));
if (new_type < 0)
continue;
/* Check if we support this supported_ecc */
if ((ret =
_gnutls_session_supports_ecc_curve(session,
new_type))
< 0) {
continue;
} else
break;
/* new_type is ok */
}
if (new_type < 0) {
gnutls_assert();
return GNUTLS_E_RECEIVED_ILLEGAL_PARAMETER;
}
if ((ret =
_gnutls_session_supports_ecc_curve(session,
new_type)) < 0) {
/* The peer has requested unsupported ecc
* types. Instead of failing, procceed normally.
* (the ciphersuite selection would fail, or a
* non certificate ciphersuite will be selected).
*/
return gnutls_assert_val(0);
}
_gnutls_session_ecc_curve_set(session, new_type);
}
return 0;
}
