xref: /freebsd/crypto/openssl/include/internal/statem.h (revision e7be843b4a162e68651d3911f0357ed464915629)
1 /*
2  * Copyright 2015-2025 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 #ifndef OSSL_INTERNAL_STATEM_H
10 # define OSSL_INTERNAL_STATEM_H
11 
12 /*****************************************************************************
13  *                                                                           *
14  * These enums should be considered PRIVATE to the state machine. No         *
15  * non-state machine code should need to use these                           *
16  *                                                                           *
17  *****************************************************************************/
18 /*
19  * Valid return codes used for functions performing work prior to or after
20  * sending or receiving a message
21  */
22 typedef enum {
23     /* Something went wrong */
24     WORK_ERROR,
25     /* We're done working and there shouldn't be anything else to do after */
26     WORK_FINISHED_STOP,
27     /* We're done working move onto the next thing */
28     WORK_FINISHED_CONTINUE,
29     /* We're done writing, start reading (or vice versa) */
30     WORK_FINISHED_SWAP,
31     /* We're working on phase A */
32     WORK_MORE_A,
33     /* We're working on phase B */
34     WORK_MORE_B,
35     /* We're working on phase C */
36     WORK_MORE_C
37 } WORK_STATE;
38 
39 /* Write transition return codes */
40 typedef enum {
41     /* Something went wrong */
42     WRITE_TRAN_ERROR,
43     /* A transition was successfully completed and we should continue */
44     WRITE_TRAN_CONTINUE,
45     /* There is no more write work to be done */
46     WRITE_TRAN_FINISHED
47 } WRITE_TRAN;
48 
49 /* Message flow states */
50 typedef enum {
51     /* No handshake in progress */
52     MSG_FLOW_UNINITED,
53     /* A permanent error with this connection */
54     MSG_FLOW_ERROR,
55     /* We are reading messages */
56     MSG_FLOW_READING,
57     /* We are writing messages */
58     MSG_FLOW_WRITING,
59     /* Handshake has finished */
60     MSG_FLOW_FINISHED
61 } MSG_FLOW_STATE;
62 
63 /* Read states */
64 typedef enum {
65     READ_STATE_HEADER,
66     READ_STATE_BODY,
67     READ_STATE_POST_PROCESS
68 } READ_STATE;
69 
70 /* Write states */
71 typedef enum {
72     WRITE_STATE_TRANSITION,
73     WRITE_STATE_PRE_WORK,
74     WRITE_STATE_SEND,
75     WRITE_STATE_POST_WORK
76 } WRITE_STATE;
77 
78 typedef enum {
79     CON_FUNC_ERROR = 0,
80     CON_FUNC_SUCCESS,
81     CON_FUNC_DONT_SEND
82 } CON_FUNC_RETURN;
83 
84 typedef int (*ossl_statem_mutate_handshake_cb)(const unsigned char *msgin,
85                                                size_t inlen,
86                                                unsigned char **msgout,
87                                                size_t *outlen,
88                                                void *arg);
89 
90 typedef void (*ossl_statem_finish_mutate_handshake_cb)(void *arg);
91 
92 /*****************************************************************************
93  *                                                                           *
94  * This structure should be considered "opaque" to anything outside of the   *
95  * state machine. No non-state machine code should be accessing the members  *
96  * of this structure.                                                        *
97  *                                                                           *
98  *****************************************************************************/
99 
100 struct ossl_statem_st {
101     MSG_FLOW_STATE state;
102     WRITE_STATE write_state;
103     WORK_STATE write_state_work;
104     READ_STATE read_state;
105     WORK_STATE read_state_work;
106     OSSL_HANDSHAKE_STATE hand_state;
107     /* The handshake state requested by an API call (e.g. HelloRequest) */
108     OSSL_HANDSHAKE_STATE request_state;
109     int in_init;
110     int read_state_first_init;
111     /* true when we are actually in SSL_accept() or SSL_connect() */
112     int in_handshake;
113     /*
114      * True when are processing a "real" handshake that needs cleaning up (not
115      * just a HelloRequest or similar).
116      */
117     int cleanuphand;
118     /* Should we skip the CertificateVerify message? */
119     unsigned int no_cert_verify;
120     int use_timer;
121 
122     /* Test harness message mutator callbacks */
123     ossl_statem_mutate_handshake_cb mutate_handshake_cb;
124     ossl_statem_finish_mutate_handshake_cb finish_mutate_handshake_cb;
125     void *mutatearg;
126     unsigned int write_in_progress : 1;
127 };
128 typedef struct ossl_statem_st OSSL_STATEM;
129 
130 /*****************************************************************************
131  *                                                                           *
132  * The following macros/functions represent the libssl internal API to the   *
133  * state machine. Any libssl code may call these functions/macros            *
134  *                                                                           *
135  *****************************************************************************/
136 
137 typedef struct ssl_connection_st SSL_CONNECTION;
138 
139 __owur int ossl_statem_accept(SSL *s);
140 __owur int ossl_statem_connect(SSL *s);
141 OSSL_HANDSHAKE_STATE ossl_statem_get_state(SSL_CONNECTION *s);
142 void ossl_statem_clear(SSL_CONNECTION *s);
143 void ossl_statem_set_renegotiate(SSL_CONNECTION *s);
144 void ossl_statem_send_fatal(SSL_CONNECTION *s, int al);
145 void ossl_statem_fatal(SSL_CONNECTION *s, int al, int reason,
146                        const char *fmt, ...);
147 # define SSLfatal_alert(s, al) ossl_statem_send_fatal((s), (al))
148 # define SSLfatal(s, al, r) SSLfatal_data((s), (al), (r), NULL)
149 # define SSLfatal_data                                          \
150     (ERR_new(),                                                 \
151      ERR_set_debug(OPENSSL_FILE, OPENSSL_LINE, OPENSSL_FUNC),   \
152      ossl_statem_fatal)
153 
154 int ossl_statem_in_error(const SSL_CONNECTION *s);
155 void ossl_statem_set_in_init(SSL_CONNECTION *s, int init);
156 int ossl_statem_get_in_handshake(SSL_CONNECTION *s);
157 void ossl_statem_set_in_handshake(SSL_CONNECTION *s, int inhand);
158 __owur int ossl_statem_skip_early_data(SSL_CONNECTION *s);
159 int ossl_statem_check_finish_init(SSL_CONNECTION *s, int send);
160 void ossl_statem_set_hello_verify_done(SSL_CONNECTION *s);
161 __owur int ossl_statem_app_data_allowed(SSL_CONNECTION *s);
162 __owur int ossl_statem_export_allowed(SSL_CONNECTION *s);
163 __owur int ossl_statem_export_early_allowed(SSL_CONNECTION *s);
164 
165 /* Flush the write BIO */
166 int statem_flush(SSL_CONNECTION *s);
167 
168 int ossl_statem_set_mutator(SSL *s,
169                             ossl_statem_mutate_handshake_cb mutate_handshake_cb,
170                             ossl_statem_finish_mutate_handshake_cb finish_mutate_handshake_cb,
171                             void *mutatearg);
172 
173 #endif
174