From 0a537e488c3eafa2ea0bf8dacdcb4db1769a86f5 Mon Sep 17 00:00:00 2001 From: tb <> Date: Thu, 8 Nov 2018 23:54:59 +0000 Subject: First skeleton of the TLS 1.3 state machine. Based on RFC 8446 and inspired by s2n's state machine. Lots of help and input from jsing. ok beck, jsing --- src/lib/libssl/tls13_handshake.c | 538 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 538 insertions(+) create mode 100644 src/lib/libssl/tls13_handshake.c (limited to 'src/lib/libssl/tls13_handshake.c') diff --git a/src/lib/libssl/tls13_handshake.c b/src/lib/libssl/tls13_handshake.c new file mode 100644 index 0000000000..e383d969f3 --- /dev/null +++ b/src/lib/libssl/tls13_handshake.c @@ -0,0 +1,538 @@ +/* $OpenBSD: tls13_handshake.c,v 1.1 2018/11/08 23:54:59 tb Exp $ */ +/* + * Copyright (c) 2018 Theo Buehler + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include + +#include "tls13_internal.h" + +/* Based on RFC 8446 and inspired by s2n's TLS 1.2 state machine. */ + +/* Record types */ +#define TLS13_HANDSHAKE 1 +#define TLS13_APPLICATION_DATA 2 + +/* Indexing into the state machine */ +struct tls13_handshake { + uint8_t hs_type; +#define INITIAL 0x00 +#define NEGOTIATED 0x01 +#define WITH_CERT_REQ 0x02 +#define WITH_HELLO_RET_REQ 0x04 +#define WITH_PSK 0x08 + int message_number; +}; + +struct tls13_ctx { + uint8_t mode; +#define TLS13_HS_MODE_CLIENT 0 +#define TLS13_HS_MODE_SERVER 1 + struct tls13_handshake handshake; +}; + +struct tls13_handshake_action { + uint8_t record_type; + uint8_t handshake_type; + + uint8_t writer; +#define TLS13_HS_CLIENT_WRITES 1 +#define TLS13_HS_SERVER_WRITES 2 +#define TLS13_HS_BOTH_WRITE (TLS13_HS_CLIENT_WRITES|TLS13_HS_SERVER_WRITES) + + int (*handler[2])(struct tls13_ctx *ctx); +}; + +enum tls13_message_type tls13_handshake_active_state(struct tls13_ctx *ctx); +int tls13_handshake_get_writer(struct tls13_ctx *ctx); + +int tls13_advance_state_machine(struct tls13_ctx *ctx); + +int tls13_connect(struct tls13_ctx *ctx); +int tls13_accept(struct tls13_ctx *ctx); + +int tls13_handshake_advance_state_machine(struct tls13_ctx *ctx); + +int tls13_handshake_write_action(struct tls13_ctx *ctx); +int tls13_handshake_read_action(struct tls13_ctx *ctx); + +enum tls13_message_type { + CLIENT_HELLO, + CLIENT_HELLO_RETRY, + CLIENT_END_OF_EARLY_DATA, + CLIENT_CERTIFICATE, + CLIENT_CERTIFICATE_VERIFY, + CLIENT_FINISHED, + CLIENT_KEY_UPDATE, + SERVER_HELLO, + SERVER_NEW_SESSION_TICKET, + SERVER_ENCRYPTED_EXTENSIONS, + SERVER_CERTIFICATE, + SERVER_CERTIFICATE_VERIFY, + SERVER_CERTIFICATE_REQUEST, + SERVER_FINISHED, + SERVER_KEY_UPDATE, + SERVER_MESSAGE_HASH, + APPLICATION_DATA, +}; + +struct tls13_handshake_action state_machine[] = { + [CLIENT_HELLO] = { + TLS13_HANDSHAKE, + TLS13_MT_CLIENT_HELLO, + TLS13_HS_CLIENT_WRITES, + {tls13_client_hello_send, tls13_client_hello_recv}, + }, + [CLIENT_HELLO_RETRY] = { + TLS13_HANDSHAKE, + TLS13_MT_CLIENT_HELLO, + TLS13_HS_CLIENT_WRITES, + {tls13_client_hello_retry_send, tls13_client_hello_retry_recv}, + }, + [CLIENT_END_OF_EARLY_DATA] = { + TLS13_HANDSHAKE, + TLS13_MT_END_OF_EARLY_DATA, + TLS13_HS_CLIENT_WRITES, + {tls13_client_end_of_early_data_send, + tls13_client_end_of_early_data_recv}, + }, + [CLIENT_CERTIFICATE] = { + TLS13_HANDSHAKE, + TLS13_MT_CERTIFICATE, + TLS13_HS_CLIENT_WRITES, + {tls13_client_certificate_send, + tls13_client_certificate_recv}, + }, + [CLIENT_CERTIFICATE_VERIFY] = { + TLS13_HANDSHAKE, + TLS13_MT_CERTIFICATE_VERIFY, + TLS13_HS_CLIENT_WRITES, + {tls13_client_certificate_verify_send, + tls13_client_certificate_verify_recv}, + }, + [CLIENT_FINISHED] = { + TLS13_HANDSHAKE, + TLS13_MT_FINISHED, + TLS13_HS_CLIENT_WRITES, + {tls13_client_finished_recv, tls13_client_finished_send} + }, + [CLIENT_KEY_UPDATE] = { + TLS13_HANDSHAKE, + TLS13_MT_KEY_UPDATE, + TLS13_HS_CLIENT_WRITES, + {tls13_client_key_update_send, tls13_client_key_update_recv}, + }, + [SERVER_HELLO] = { + TLS13_HANDSHAKE, + TLS13_MT_SERVER_HELLO, + TLS13_HS_SERVER_WRITES, + {tls13_server_hello_recv, tls13_server_hello_send}, + }, + [SERVER_NEW_SESSION_TICKET] = { + TLS13_HANDSHAKE, + TLS13_MT_NEW_SESSION_TICKET, + TLS13_HS_SERVER_WRITES, + {tls13_server_new_session_ticket_recv, + tls13_server_new_session_ticket_send}, + }, + [SERVER_ENCRYPTED_EXTENSIONS] = { + TLS13_HANDSHAKE, + TLS13_MT_ENCRYPTED_EXTENSIONS, + TLS13_HS_SERVER_WRITES, + {tls13_server_encrypted_extensions_recv, + tls13_server_encrypted_extensions_send}, + }, + [SERVER_CERTIFICATE] = { + TLS13_HANDSHAKE, + TLS13_MT_CERTIFICATE, + TLS13_HS_SERVER_WRITES, + {tls13_server_certificate_recv, tls13_server_certificate_send}, + }, + [SERVER_CERTIFICATE_REQUEST] = { + TLS13_HANDSHAKE, + TLS13_MT_CERTIFICATE, + TLS13_HS_SERVER_WRITES, + {tls13_server_certificate_request_recv, + tls13_server_certificate_request_send}, + }, + [SERVER_CERTIFICATE_VERIFY] = { + TLS13_HANDSHAKE, + TLS13_MT_CERTIFICATE_VERIFY, + TLS13_HS_SERVER_WRITES, + {tls13_server_certificate_verify_send, + tls13_server_certificate_verify_recv}, + }, + [SERVER_FINISHED] = { + TLS13_HANDSHAKE, + TLS13_MT_FINISHED, + TLS13_HS_SERVER_WRITES, + {tls13_server_finished_recv, tls13_server_finished_send} + }, + [SERVER_KEY_UPDATE] = { + TLS13_HANDSHAKE, + TLS13_MT_KEY_UPDATE, + TLS13_HS_SERVER_WRITES, + {tls13_server_key_update_recv, tls13_server_key_update_send}, + }, + [SERVER_MESSAGE_HASH] = { + TLS13_HANDSHAKE, + TLS13_MT_MESSAGE_HASH, + TLS13_HS_SERVER_WRITES, + {tls13_server_message_hash_recv, + tls13_server_message_hash_send}, + }, + [APPLICATION_DATA] = { + TLS13_APPLICATION_DATA, + 0, + TLS13_HS_BOTH_WRITE, + {NULL, NULL}, + }, +}; + +static enum tls13_message_type handshakes[][16] = { + [INITIAL] = { + CLIENT_HELLO, + SERVER_HELLO, + }, + [NEGOTIATED] = { + CLIENT_HELLO, + SERVER_HELLO, + SERVER_ENCRYPTED_EXTENSIONS, + SERVER_CERTIFICATE, + SERVER_CERTIFICATE_VERIFY, + SERVER_FINISHED, + CLIENT_FINISHED, + APPLICATION_DATA, + }, + [NEGOTIATED | WITH_HELLO_RET_REQ] = { + CLIENT_HELLO, + SERVER_HELLO, + CLIENT_HELLO_RETRY, + SERVER_ENCRYPTED_EXTENSIONS, + SERVER_CERTIFICATE, + SERVER_CERTIFICATE_VERIFY, + SERVER_FINISHED, + CLIENT_FINISHED, + APPLICATION_DATA, + }, + [NEGOTIATED | WITH_CERT_REQ] = { + CLIENT_HELLO, + SERVER_HELLO, + SERVER_ENCRYPTED_EXTENSIONS, + SERVER_CERTIFICATE_REQUEST, + SERVER_CERTIFICATE, + SERVER_CERTIFICATE_VERIFY, + SERVER_FINISHED, + CLIENT_FINISHED, + APPLICATION_DATA, + }, + [NEGOTIATED | WITH_HELLO_RET_REQ | WITH_CERT_REQ] = { + CLIENT_HELLO, + SERVER_HELLO, + CLIENT_HELLO_RETRY, + SERVER_ENCRYPTED_EXTENSIONS, + SERVER_CERTIFICATE_REQUEST, + SERVER_CERTIFICATE, + SERVER_CERTIFICATE_VERIFY, + SERVER_FINISHED, + CLIENT_FINISHED, + APPLICATION_DATA, + }, + [NEGOTIATED | WITH_PSK] = { + CLIENT_HELLO, + SERVER_HELLO, + SERVER_ENCRYPTED_EXTENSIONS, + SERVER_FINISHED, + CLIENT_FINISHED, + APPLICATION_DATA, + }, + [NEGOTIATED | WITH_HELLO_RET_REQ | WITH_PSK] = { + CLIENT_HELLO, + SERVER_HELLO, + CLIENT_HELLO_RETRY, + SERVER_ENCRYPTED_EXTENSIONS, + SERVER_FINISHED, + CLIENT_FINISHED, + APPLICATION_DATA, + }, +}; + +enum tls13_message_type +tls13_handshake_active_state(struct tls13_ctx *ctx) +{ + struct tls13_handshake hs = ctx->handshake; + return handshakes[hs.hs_type][hs.message_number]; +} + +int +tls13_handshake_get_writer(struct tls13_ctx *ctx) +{ + enum tls13_message_type mt = tls13_handshake_active_state(ctx); + return state_machine[mt].writer; +} + +int +tls13_connect(struct tls13_ctx *ctx) +{ + ctx->mode = TLS13_HS_MODE_CLIENT; + + while (tls13_handshake_get_writer(ctx) != TLS13_HS_BOTH_WRITE) { + if (tls13_handshake_get_writer(ctx) == TLS13_HS_MODE_CLIENT) { + if (!tls13_handshake_write_action(ctx)) + return 0; + } else { + if (!tls13_handshake_read_action(ctx)) + return 0; + } + if (!tls13_handshake_advance_state_machine(ctx)) + return 0; + } + + return 1; +} + +int +tls13_accept(struct tls13_ctx *ctx) +{ + ctx->mode = TLS13_HS_MODE_SERVER; + + while (tls13_handshake_get_writer(ctx) != TLS13_HS_BOTH_WRITE) { + if (tls13_handshake_get_writer(ctx) == TLS13_HS_MODE_CLIENT) { + if (!tls13_handshake_write_action(ctx)) + return 0; + } else { + if (!tls13_handshake_read_action(ctx)) + return 0; + } + if (!tls13_handshake_advance_state_machine(ctx)) + return 0; + } + + return 1; +} + +int +tls13_advance_state_machine(struct tls13_ctx *ctx) +{ + if (tls13_handshake_get_writer(ctx) == TLS13_HS_BOTH_WRITE) + return 0; + ctx->handshake.message_number++; + return 1; +} + +int +tls13_handshake_write_action(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_handshake_read_action(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_hello_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_hello_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_hello_retry_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_hello_retry_recv(struct tls13_ctx *ctx) +{ + return 1; +} + + +int +tls13_client_end_of_early_data_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_end_of_early_data_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_certificate_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_certificate_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_certificate_verify_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_certificate_verify_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_finished_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_finished_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_key_update_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_client_key_update_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_hello_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_hello_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_new_session_ticket_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_new_session_ticket_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_encrypted_extensions_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_encrypted_extensions_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_certificate_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_certificate_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_certificate_request_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_certificate_request_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_certificate_verify_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_certificate_verify_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_finished_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_finished_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_key_update_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_key_update_send(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_message_hash_recv(struct tls13_ctx *ctx) +{ + return 1; +} + +int +tls13_server_message_hash_send(struct tls13_ctx *ctx) +{ + return 1; +} -- cgit v1.2.3-55-g6feb