1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
|
/*
* Copyright (C) 2000-2012 Free Software Foundation, Inc.
* Copyright (C) 2015-2018 Red Hat, Inc.
*
* Author: Nikos Mavrogiannopoulos
*
* This file is part of GnuTLS.
*
* The GnuTLS is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>
*
*/
#ifndef GNUTLS_LIB_HELLO_EXT_H
# define GNUTLS_LIB_HELLO_EXT_H
# include "gnutls_int.h"
# include <gnutls/gnutls.h>
# include "str.h"
/* Functions for hello extension parsing.
*/
int _gnutls_parse_hello_extensions(gnutls_session_t session,
gnutls_ext_flags_t msg,
gnutls_ext_parse_type_t parse_type,
const uint8_t * data, int data_size);
int _gnutls_gen_hello_extensions(gnutls_session_t session,
gnutls_buffer_st * extdata,
gnutls_ext_flags_t msg,
gnutls_ext_parse_type_t);
int _gnutls_hello_ext_init(void);
void _gnutls_hello_ext_deinit(void);
void _gnutls_hello_ext_priv_deinit(gnutls_session_t session);
/* functions to be used by extensions internally
*/
void _gnutls_hello_ext_unset_priv(gnutls_session_t session, extensions_t ext);
void _gnutls_hello_ext_set_priv(gnutls_session_t session, extensions_t ext,
gnutls_ext_priv_data_t);
int _gnutls_hello_ext_get_priv(gnutls_session_t session, extensions_t ext,
gnutls_ext_priv_data_t *);
int _gnutls_hello_ext_get_resumed_priv(gnutls_session_t session,
extensions_t ext,
gnutls_ext_priv_data_t * data);
# define GNUTLS_EXT_FLAG_MSG_MASK (GNUTLS_EXT_FLAG_CLIENT_HELLO | GNUTLS_EXT_FLAG_TLS12_SERVER_HELLO| \
GNUTLS_EXT_FLAG_TLS13_SERVER_HELLO | GNUTLS_EXT_FLAG_EE | GNUTLS_EXT_FLAG_HRR)
/* these flags can only be set in the extensions, but cannot be requested;
* they are handled internally by the hello parsing/generating functions. */
# define GNUTLS_EXT_FLAG_SET_ONLY_FLAGS_MASK ~(GNUTLS_EXT_FLAG_DTLS | GNUTLS_EXT_FLAG_TLS)
/* obtain the message this extension was received at */
inline static gnutls_ext_flags_t _gnutls_ext_get_msg(gnutls_session_t session)
{
return session->internals.ext_msg & GNUTLS_EXT_FLAG_MSG_MASK;
}
inline static void _gnutls_ext_set_msg(gnutls_session_t session,
gnutls_ext_flags_t msg)
{
session->internals.ext_msg = msg;
}
inline static void _gnutls_ext_set_extensions_offset(gnutls_session_t session,
int offset)
{
session->internals.extensions_offset = offset;
}
inline static int _gnutls_ext_get_extensions_offset(gnutls_session_t session)
{
return session->internals.extensions_offset;
}
int _gnutls_ext_set_full_client_hello(gnutls_session_t session,
handshake_buffer_st * recv_buf);
unsigned _gnutls_ext_get_full_client_hello(gnutls_session_t session,
gnutls_datum_t * datum);
/* for session packing */
int _gnutls_hello_ext_pack(gnutls_session_t session, gnutls_buffer_st * packed);
int _gnutls_hello_ext_unpack(gnutls_session_t session,
gnutls_buffer_st * packed);
inline static const char *ext_msg_validity_to_str(gnutls_ext_flags_t msg)
{
msg &= GNUTLS_EXT_FLAG_MSG_MASK;
switch (msg) {
case GNUTLS_EXT_FLAG_CLIENT_HELLO:
return "client hello";
case GNUTLS_EXT_FLAG_TLS12_SERVER_HELLO:
return "TLS 1.2 server hello";
case GNUTLS_EXT_FLAG_TLS13_SERVER_HELLO:
return "TLS 1.3 server hello";
case GNUTLS_EXT_FLAG_EE:
return "encrypted extensions";
case GNUTLS_EXT_FLAG_HRR:
return "hello retry request";
default:
return "(unknown)";
}
}
typedef struct hello_ext_entry_st {
const char *name; /* const overridden when free_struct is set */
unsigned free_struct;
uint16_t tls_id;
unsigned gid; /* gnutls internal ID */
gnutls_ext_parse_type_t client_parse_point;
gnutls_ext_parse_type_t server_parse_point;
unsigned validity; /* multiple items of gnutls_ext_flags_t */
/* this function must return 0 when Not Applicable
* size of extension data if ok
* < 0 on other error.
*/
gnutls_ext_recv_func recv_func;
/* this function must return 0 when Not Applicable
* size of extension data if ok
* GNUTLS_E_INT_RET_0 if extension data size is zero
* < 0 on other error.
*/
gnutls_ext_send_func send_func;
gnutls_ext_deinit_data_func deinit_func; /* this will be called to deinitialize
* internal data
*/
gnutls_ext_pack_func pack_func; /* packs internal data to machine independent format */
gnutls_ext_unpack_func unpack_func; /* unpacks internal data */
/* non-zero if that extension cannot be overridden by the applications.
* That should be set to extensions which allocate data early, e.g., on
* gnutls_init(), or modify the TLS protocol in a way that the application
* cannot control. */
unsigned cannot_be_overriden;
} hello_ext_entry_st;
/* Checks if the extension @id provided has been requested
* by us (in client side).In server side it checks whether this
* extension was advertized by the client.
*
* It returns non-zero for true, otherwise zero.
*/
inline static unsigned
_gnutls_hello_ext_is_present(gnutls_session_t session, extensions_t id)
{
if (session->internals.used_exts & ((ext_track_t) 1 << id))
return 1;
return 0;
}
/* Adds the extension we want to send in the extensions list.
* This list is used in client side to check whether the (later) received
* extensions are the ones we requested.
*
* In server side, this list is used to ensure we don't send
* extensions that we didn't receive a corresponding value.
*
* Returns zero if failed, non-zero on success.
*/
inline static
unsigned _gnutls_hello_ext_save(gnutls_session_t session,
extensions_t id, unsigned check_dup)
{
if (check_dup && _gnutls_hello_ext_is_present(session, id)) {
return 0;
}
session->internals.used_exts |= ((ext_track_t) 1 << id);
return 1;
}
inline static
void _gnutls_hello_ext_save_sr(gnutls_session_t session)
{
_gnutls_hello_ext_save(session, GNUTLS_EXTENSION_SAFE_RENEGOTIATION, 1);
}
#endif /* GNUTLS_LIB_HELLO_EXT_H */
|
