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/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
#pragma once
#include <stdint.h>
#include "api/s2n.h"
#include "crypto/s2n_certificate.h"
#include "crypto/s2n_hash.h"
#include "stuffer/s2n_stuffer.h"
#include "tls/s2n_crypto.h"
#include "tls/s2n_handshake_hashes.h"
#include "tls/s2n_handshake_type.h"
#include "tls/s2n_signature_algorithms.h"
#include "tls/s2n_tls_parameters.h"
/* From RFC 8446: https://tools.ietf.org/html/rfc8446#appendix-B.3 */
#define TLS_HELLO_REQUEST 0
#define TLS_CLIENT_HELLO 1
#define TLS_SERVER_HELLO 2
#define TLS_SERVER_NEW_SESSION_TICKET 4
#define TLS_END_OF_EARLY_DATA 5
#define TLS_ENCRYPTED_EXTENSIONS 8
#define TLS_CERTIFICATE 11
#define TLS_SERVER_KEY 12
#define TLS_CERT_REQ 13
#define TLS_SERVER_HELLO_DONE 14
#define TLS_CERT_VERIFY 15
#define TLS_CLIENT_KEY 16
#define TLS_FINISHED 20
#define TLS_SERVER_CERT_STATUS 22
#define TLS_SERVER_SESSION_LOOKUP 23
#define TLS_KEY_UPDATE 24
#define TLS_NPN 67
#define TLS_MESSAGE_HASH 254
/* This is the list of message types that we support */
typedef enum {
CLIENT_HELLO = 0,
SERVER_HELLO,
SERVER_CERT,
SERVER_NEW_SESSION_TICKET,
SERVER_CERT_STATUS,
SERVER_KEY,
SERVER_CERT_REQ,
SERVER_HELLO_DONE,
CLIENT_CERT,
CLIENT_KEY,
CLIENT_CERT_VERIFY,
CLIENT_CHANGE_CIPHER_SPEC,
/* Not a standardized message. Defined: https://datatracker.ietf.org/doc/html/draft-agl-tls-nextprotoneg-04 */
CLIENT_NPN,
CLIENT_FINISHED,
SERVER_CHANGE_CIPHER_SPEC,
SERVER_FINISHED,
/* TLS1.3 message types. Defined: https://tools.ietf.org/html/rfc8446#appendix-B.3 */
ENCRYPTED_EXTENSIONS,
SERVER_CERT_VERIFY,
HELLO_RETRY_MSG,
END_OF_EARLY_DATA,
APPLICATION_DATA,
} message_type_t;
typedef enum {
S2N_ASYNC_NOT_INVOKED = 0,
S2N_ASYNC_INVOKED,
S2N_ASYNC_COMPLETE,
} s2n_async_state;
/* Indicates which state machine is being used. The handshake
* starts off on the initial enum, which indicates we're using
* the TLS12 state machine. Once the handshake version is determined
* the enum is set to either the TLS12 or TLS13 state machine.
* This works because the initial entries in both the TLS12 and
* TLS13 state machines are the same. */
typedef enum {
S2N_STATE_MACHINE_INITIAL = 0,
S2N_STATE_MACHINE_TLS12,
S2N_STATE_MACHINE_TLS13,
} s2n_state_machine;
struct s2n_handshake_parameters {
/* Public keys for server / client */
struct s2n_pkey server_public_key;
struct s2n_pkey client_public_key;
struct s2n_blob client_cert_chain;
s2n_pkey_type client_cert_pkey_type;
/* Signature/hash algorithm pairs offered by the client in the signature_algorithms extension */
struct s2n_sig_scheme_list client_sig_hash_algs;
/* Signature scheme chosen by the server */
const struct s2n_signature_scheme *server_cert_sig_scheme;
/* Signature/hash algorithm pairs offered by the server in the certificate request */
struct s2n_sig_scheme_list server_sig_hash_algs;
/* Signature scheme chosen by the client */
const struct s2n_signature_scheme *client_cert_sig_scheme;
/* The cert chain we will send the peer. */
struct s2n_cert_chain_and_key *our_chain_and_key;
/* The subset of certificates that match the server_name presented in the ClientHello.
* In the case of multiple certificates matching a server_name, s2n will prefer certificates
* in FIFO order based on calls to s2n_config_add_cert_chain_and_key_to_store
*
* Note that in addition to domain matching, the key type for the certificate must also be
* suitable for a negotiation in order to be selected. The set of matching certs here are indexed
* by s2n_authentication_method.
*
* Example:
* - Assume certA is added to s2n_config via s2n_config_add_cert_chain_and_key_to_store
* - Next certB is added.
* - if certA matches www.foo.com and certB matches www.foo.com, s2n will prefer certA
*
* Note that in addition to domain matching, the key type for the certificate must also be
* suitable for a negotiation in order to be selected.
*
* Example:
* - Assume certA and certB match server_name www.foo.com
* - certA is ECDSA and certB is RSA.
* - Client only supports RSA ciphers
* - certB will be selected.
*/
struct s2n_cert_chain_and_key *exact_sni_matches[S2N_CERT_TYPE_COUNT];
struct s2n_cert_chain_and_key *wc_sni_matches[S2N_CERT_TYPE_COUNT];
uint8_t exact_sni_match_exists;
uint8_t wc_sni_match_exists;
uint8_t client_random[S2N_TLS_RANDOM_DATA_LEN];
uint8_t server_random[S2N_TLS_RANDOM_DATA_LEN];
};
struct s2n_handshake {
struct s2n_stuffer io;
struct s2n_handshake_hashes *hashes;
/* Hash algorithms required for this handshake. The set of required hashes can be reduced as session parameters are
* negotiated, i.e. cipher suite and protocol version.
*/
uint8_t required_hash_algs[S2N_HASH_SENTINEL];
/*
* Data required by the Finished messages.
* In TLS1.2 and earlier, the data is the verify_data.
* In TLS1.3, the data is the finished_key used to calculate the verify_data.
*
* The data will be different for the client and server.
* The length of the data will be the same for the client and server.
* The length of the data depends on protocol version and cipher suite.
*/
uint8_t server_finished[S2N_TLS_SECRET_LEN];
uint8_t client_finished[S2N_TLS_SECRET_LEN];
uint8_t finished_len;
/* Which message-order affecting features are enabled */
uint32_t handshake_type;
/* Which handshake message number are we processing */
int message_number;
/* Last message in the handshake. Unless using early data or testing,
* should always be APPLICATION_DATA. */
message_type_t end_of_messages;
/* State of the async pkey operation during handshake */
s2n_async_state async_state;
/* State of the async early data callback.
* If not initialized, then the callback has not been triggered yet. */
struct s2n_offered_early_data early_data_async_state;
/* Indicates the CLIENT_HELLO message has been completely received */
unsigned client_hello_received : 1;
/* Indicates the handshake blocked while trying to read or write data, and has been paused */
unsigned paused : 1;
/* Set to 1 if the RSA verification failed */
unsigned rsa_failed : 1;
/* Indicates that this is a renegotiation handshake */
unsigned renegotiation : 1;
s2n_state_machine state_machine;
};
/* Only used in our test cases. */
message_type_t s2n_conn_get_current_message_type(struct s2n_connection *conn);
/* s2n_handshake */
int s2n_handshake_require_all_hashes(struct s2n_handshake *handshake);
uint8_t s2n_handshake_is_hash_required(struct s2n_handshake *handshake, s2n_hash_algorithm hash_alg);
int s2n_conn_update_required_handshake_hashes(struct s2n_connection *conn);
S2N_RESULT s2n_handshake_copy_hash_state(struct s2n_connection *conn, s2n_hash_algorithm hash_alg, struct s2n_hash_state *hash_state);
S2N_RESULT s2n_handshake_reset_hash_state(struct s2n_connection *conn, s2n_hash_algorithm hash_alg);
int s2n_conn_find_name_matching_certs(struct s2n_connection *conn);
int s2n_create_wildcard_hostname(struct s2n_stuffer *hostname, struct s2n_stuffer *output);
struct s2n_cert_chain_and_key *s2n_get_compatible_cert_chain_and_key(struct s2n_connection *conn, const s2n_pkey_type cert_type);
S2N_RESULT s2n_negotiate_until_message(struct s2n_connection *conn, s2n_blocked_status *blocked, message_type_t end_message);
S2N_RESULT s2n_handshake_validate(const struct s2n_handshake *s2n_handshake);
S2N_RESULT s2n_handshake_set_finished_len(struct s2n_connection *conn, uint8_t len);
bool s2n_handshake_is_renegotiation(struct s2n_connection *conn);
S2N_RESULT s2n_handshake_message_send(struct s2n_connection *conn, uint8_t content_type, s2n_blocked_status *blocked);
/* s2n_handshake_io */
int s2n_conn_set_handshake_type(struct s2n_connection *conn);
int s2n_conn_set_handshake_no_client_cert(struct s2n_connection *conn);
S2N_RESULT s2n_conn_choose_state_machine(struct s2n_connection *conn, uint8_t protocol_version);
bool s2n_handshake_is_complete(struct s2n_connection *conn);
/* s2n_handshake_transcript */
S2N_RESULT s2n_handshake_transcript_update(struct s2n_connection *conn);
int s2n_conn_update_handshake_hashes(struct s2n_connection *conn, struct s2n_blob *data);
/* s2n_quic_support */
S2N_RESULT s2n_quic_read_handshake_message(struct s2n_connection *conn, uint8_t *message_type);
S2N_RESULT s2n_quic_write_handshake_message(struct s2n_connection *conn);
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