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
|
/*
* chap-md5.c - New CHAP/MD5 implementation.
*
* Copyright (c) 2003 Paul Mackerras. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. The name(s) of the authors of this software must not be used to
* endorse or promote products derived from this software without
* prior written permission.
*
* 3. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Paul Mackerras
* <[email protected]>".
*
* THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
* SPECIAL, 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 "lwip/opt.h"
#if PPP_SUPPORT && CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */
#if 0 /* UNUSED */
#include <stdlib.h>
#include <string.h>
#endif /* UNUSED */
#include "netif/ppp/ppp_impl.h"
#include "netif/ppp/chap-new.h"
#include "netif/ppp/chap-md5.h"
#include "netif/ppp/magic.h"
#if LWIP_INCLUDED_POLARSSL_MD5
#include "netif/ppp/polarssl/md5.h"
#else
#include "polarssl/md5.h"
#endif
#define MD5_HASH_SIZE 16
#define MD5_MIN_CHALLENGE 16
#define MD5_MAX_CHALLENGE 24
#if PPP_SERVER
static void chap_md5_generate_challenge(unsigned char *cp) {
int clen;
clen = (int)(drand48() * (MD5_MAX_CHALLENGE - MD5_MIN_CHALLENGE))
+ MD5_MIN_CHALLENGE;
*cp++ = clen;
random_bytes(cp, clen);
}
static int chap_md5_verify_response(int id, char *name,
unsigned char *secret, int secret_len,
unsigned char *challenge, unsigned char *response,
char *message, int message_space) {
md5_context ctx;
unsigned char idbyte = id;
unsigned char hash[MD5_HASH_SIZE];
int challenge_len, response_len;
challenge_len = *challenge++;
response_len = *response++;
if (response_len == MD5_HASH_SIZE) {
/* Generate hash of ID, secret, challenge */
md5_starts(&ctx);
md5_update(&ctx, &idbyte, 1);
md5_update(&ctx, secret, secret_len);
md5_update(&ctx, challenge, challenge_len);
md5_finish(&ctx, hash);
/* Test if our hash matches the peer's response */
if (memcmp(hash, response, MD5_HASH_SIZE) == 0) {
ppp_slprintf(message, message_space, "Access granted");
return 1;
}
}
ppp_slprintf(message, message_space, "Access denied");
return 0;
}
#endif /* PPP_SERVER */
static void chap_md5_make_response(unsigned char *response, int id, char *our_name,
unsigned char *challenge, char *secret, int secret_len,
unsigned char *private) {
md5_context ctx;
unsigned char idbyte = id;
int challenge_len = *challenge++;
md5_starts(&ctx);
md5_update(&ctx, &idbyte, 1);
md5_update(&ctx, (u_char *)secret, secret_len);
md5_update(&ctx, challenge, challenge_len);
md5_finish(&ctx, &response[1]);
response[0] = MD5_HASH_SIZE;
}
const struct chap_digest_type md5_digest = {
CHAP_MD5, /* code */
#if PPP_SERVER
chap_md5_generate_challenge,
chap_md5_verify_response,
#endif /* PPP_SERVER */
chap_md5_make_response,
NULL, /* check_success */
NULL, /* handle_failure */
};
#endif /* PPP_SUPPORT && CHAP_SUPPORT */
|
