1/*
2 * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10/*****************************************************************************
11 * *
12 * These enums should be considered PRIVATE to the state machine. No *
13 * non-state machine code should need to use these *
14 * *
15 *****************************************************************************/
16/*
17 * Valid return codes used for functions performing work prior to or after
18 * sending or receiving a message
19 */
20typedef enum {
21 /* Something went wrong */
22 WORK_ERROR,
23 /* We're done working and there shouldn't be anything else to do after */
24 WORK_FINISHED_STOP,
25 /* We're done working move onto the next thing */
26 WORK_FINISHED_CONTINUE,
27 /* We're working on phase A */
28 WORK_MORE_A,
29 /* We're working on phase B */
30 WORK_MORE_B,
31 /* We're working on phase C */
32 WORK_MORE_C
33} WORK_STATE;
34
35/* Write transition return codes */
36typedef enum {
37 /* Something went wrong */
38 WRITE_TRAN_ERROR,
39 /* A transition was successfully completed and we should continue */
40 WRITE_TRAN_CONTINUE,
41 /* There is no more write work to be done */
42 WRITE_TRAN_FINISHED
43} WRITE_TRAN;
44
45/* Message flow states */
46typedef enum {
47 /* No handshake in progress */
48 MSG_FLOW_UNINITED,
49 /* A permanent error with this connection */
50 MSG_FLOW_ERROR,
51 /* We are reading messages */
52 MSG_FLOW_READING,
53 /* We are writing messages */
54 MSG_FLOW_WRITING,
55 /* Handshake has finished */
56 MSG_FLOW_FINISHED
57} MSG_FLOW_STATE;
58
59/* Read states */
60typedef enum {
61 READ_STATE_HEADER,
62 READ_STATE_BODY,
63 READ_STATE_POST_PROCESS
64} READ_STATE;
65
66/* Write states */
67typedef enum {
68 WRITE_STATE_TRANSITION,
69 WRITE_STATE_PRE_WORK,
70 WRITE_STATE_SEND,
71 WRITE_STATE_POST_WORK
72} WRITE_STATE;
73
74typedef enum {
75 /* The enc_write_ctx can be used normally */
76 ENC_WRITE_STATE_VALID,
77 /* The enc_write_ctx cannot be used */
78 ENC_WRITE_STATE_INVALID,
79 /* Write alerts in plaintext, but otherwise use the enc_write_ctx */
80 ENC_WRITE_STATE_WRITE_PLAIN_ALERTS
81} ENC_WRITE_STATES;
82
83typedef enum {
84 /* The enc_read_ctx can be used normally */
85 ENC_READ_STATE_VALID,
86 /* We may receive encrypted or plaintext alerts */
87 ENC_READ_STATE_ALLOW_PLAIN_ALERTS
88} ENC_READ_STATES;
89
90/*****************************************************************************
91 * *
92 * This structure should be considered "opaque" to anything outside of the *
93 * state machine. No non-state machine code should be accessing the members *
94 * of this structure. *
95 * *
96 *****************************************************************************/
97
98struct ossl_statem_st {
99 MSG_FLOW_STATE state;
100 WRITE_STATE write_state;
101 WORK_STATE write_state_work;
102 READ_STATE read_state;
103 WORK_STATE read_state_work;
104 OSSL_HANDSHAKE_STATE hand_state;
105 /* The handshake state requested by an API call (e.g. HelloRequest) */
106 OSSL_HANDSHAKE_STATE request_state;
107 int in_init;
108 int read_state_first_init;
109 /* true when we are actually in SSL_accept() or SSL_connect() */
110 int in_handshake;
111 /*
112 * True when are processing a "real" handshake that needs cleaning up (not
113 * just a HelloRequest or similar).
114 */
115 int cleanuphand;
116 /* Should we skip the CertificateVerify message? */
117 unsigned int no_cert_verify;
118 int use_timer;
119 ENC_WRITE_STATES enc_write_state;
120 ENC_READ_STATES enc_read_state;
121};
122typedef struct ossl_statem_st OSSL_STATEM;
123
124/*****************************************************************************
125 * *
126 * The following macros/functions represent the libssl internal API to the *
127 * state machine. Any libssl code may call these functions/macros *
128 * *
129 *****************************************************************************/
130
131__owur int ossl_statem_accept(SSL *s);
132__owur int ossl_statem_connect(SSL *s);
133void ossl_statem_clear(SSL *s);
134void ossl_statem_set_renegotiate(SSL *s);
135void ossl_statem_fatal(SSL *s, int al, int func, int reason, const char *file,
136 int line);
137# define SSL_AD_NO_ALERT -1
138# ifndef OPENSSL_NO_ERR
139# define SSLfatal(s, al, f, r) ossl_statem_fatal((s), (al), (0), (r), \
140 OPENSSL_FILE, OPENSSL_LINE)
141# else
142# define SSLfatal(s, al, f, r) ossl_statem_fatal((s), (al), (0), (r), NULL, 0)
143# endif
144
145int ossl_statem_in_error(const SSL *s);
146void ossl_statem_set_in_init(SSL *s, int init);
147int ossl_statem_get_in_handshake(SSL *s);
148void ossl_statem_set_in_handshake(SSL *s, int inhand);
149__owur int ossl_statem_skip_early_data(SSL *s);
150void ossl_statem_check_finish_init(SSL *s, int send);
151void ossl_statem_set_hello_verify_done(SSL *s);
152__owur int ossl_statem_app_data_allowed(SSL *s);
153__owur int ossl_statem_export_allowed(SSL *s);
154__owur int ossl_statem_export_early_allowed(SSL *s);
155
156/* Flush the write BIO */
157int statem_flush(SSL *s);
158