OpenVPN
session_id.c
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1 /*
2  * OpenVPN -- An application to securely tunnel IP networks
3  * over a single UDP port, with support for SSL/TLS-based
4  * session authentication and key exchange,
5  * packet encryption, packet authentication, and
6  * packet compression.
7  *
8  * Copyright (C) 2002-2018 OpenVPN Inc <sales@openvpn.net>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2
12  * as published by the Free Software Foundation.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write to the Free Software Foundation, Inc.,
21  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22  */
23 
24 /*
25  * Each session is identified by a random 8-byte session identifier.
26  *
27  * For efficiency, the session id is only transmitted over the control
28  * channel (which only sees traffic occasionally when keys are being
29  * negotiated). The data channel sees a smaller version of the session-id --
30  * it is called the key_id and is currently 2 bits long.
31  */
32 
33 #ifdef HAVE_CONFIG_H
34 #include "config.h"
35 #elif defined(_MSC_VER)
36 #include "config-msvc.h"
37 #endif
38 
39 #include "syshead.h"
40 
41 #include "error.h"
42 #include "common.h"
43 #include "crypto.h"
44 #include "session_id.h"
45 
46 #include "memdbg.h"
47 
49 
50 void
52 {
53  prng_bytes(sid->id, SID_SIZE);
54 }
55 
56 const char *
57 session_id_print(const struct session_id *sid, struct gc_arena *gc)
58 {
59  return format_hex(sid->id, SID_SIZE, 0, gc);
60 }
void session_id_random(struct session_id *sid)
Definition: session_id.c:51
#define SID_SIZE
Definition: session_id.h:45
static char * format_hex(const uint8_t *data, int size, int maxoutput, struct gc_arena *gc)
Definition: buffer.h:509
uint8_t id[8]
Definition: session_id.h:40
void prng_bytes(uint8_t *output, int len)
Definition: crypto.c:1729
const struct session_id x_session_id_zero
Definition: session_id.c:48
Garbage collection arena used to keep track of dynamically allocated memory.
Definition: buffer.h:116
const char * session_id_print(const struct session_id *sid, struct gc_arena *gc)
Definition: session_id.c:57