1 /*
2 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License").
5 * You may not use this file except in compliance with the License.
6 * A copy of the License is located at
7 *
8 * http://aws.amazon.com/apache2.0
9 *
10 * or in the "license" file accompanying this file. This file is distributed
11 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
12 * express or implied. See the License for the specific language governing
13 * permissions and limitations under the License.
14 */
15
16 #include "tls/extensions/s2n_quic_transport_params.h"
17
18 #include "tls/s2n_connection.h"
19 #include "tls/s2n_tls.h"
20
21 #include "stuffer/s2n_stuffer.h"
22 #include "utils/s2n_safety.h"
23
24 /*
25 * The quic_transport_params extension is required by the QUIC protocol to
26 * negotiate additional connection parameters when using S2N.
27 *
28 * This extension should not be sent or received unless using S2N with QUIC.
29 * S2N treats the extension data as opaque bytes and performs no validation.
30 */
31
s2n_quic_transport_params_should_send(struct s2n_connection * conn)32 static bool s2n_quic_transport_params_should_send(struct s2n_connection *conn)
33 {
34 return s2n_connection_is_quic_enabled(conn);
35 }
36
s2n_quic_transport_params_if_missing(struct s2n_connection * conn)37 static int s2n_quic_transport_params_if_missing(struct s2n_connection *conn)
38 {
39 POSIX_ENSURE_REF(conn);
40 POSIX_ENSURE_REF(conn->config);
41 POSIX_ENSURE(!s2n_connection_is_quic_enabled(conn), S2N_ERR_MISSING_EXTENSION);
42 return S2N_SUCCESS;
43 }
44
s2n_quic_transport_params_send(struct s2n_connection * conn,struct s2n_stuffer * out)45 static int s2n_quic_transport_params_send(struct s2n_connection *conn, struct s2n_stuffer *out)
46 {
47 POSIX_ENSURE_REF(conn);
48 POSIX_ENSURE_REF(out);
49
50 if (conn->our_quic_transport_parameters.size) {
51 POSIX_GUARD(s2n_stuffer_write(out, &conn->our_quic_transport_parameters));
52 }
53 return S2N_SUCCESS;
54 }
55
s2n_quic_transport_params_recv(struct s2n_connection * conn,struct s2n_stuffer * extension)56 static int s2n_quic_transport_params_recv(struct s2n_connection *conn, struct s2n_stuffer *extension)
57 {
58 POSIX_ENSURE_REF(conn);
59 POSIX_ENSURE_REF(extension);
60 POSIX_ENSURE_REF(conn->config);
61 POSIX_ENSURE(s2n_connection_is_quic_enabled(conn), S2N_ERR_UNSUPPORTED_EXTENSION);
62
63 if (s2n_stuffer_data_available(extension)) {
64 POSIX_GUARD(s2n_alloc(&conn->peer_quic_transport_parameters, s2n_stuffer_data_available(extension)));
65 POSIX_GUARD(s2n_stuffer_read(extension, &conn->peer_quic_transport_parameters));
66 }
67 return S2N_SUCCESS;
68 }
69
70 const s2n_extension_type s2n_quic_transport_parameters_extension = {
71 .iana_value = TLS_QUIC_TRANSPORT_PARAMETERS,
72 .minimum_version = S2N_TLS13,
73 .is_response = false,
74 .send = s2n_quic_transport_params_send,
75 .recv = s2n_quic_transport_params_recv,
76 .should_send = s2n_quic_transport_params_should_send,
77 .if_missing = s2n_quic_transport_params_if_missing,
78 };
79