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
|
/* $OpenBSD: skey.c,v 1.28 2015/04/18 18:28:38 deraadt Exp $ */
/*
* OpenBSD S/Key (skey.c)
*
* Authors:
* Neil M. Haller <nmh@thumper.bellcore.com>
* Philip R. Karn <karn@chicago.qualcomm.com>
* John S. Walden <jsw@thumper.bellcore.com>
* Scott Chasin <chasin@crimelab.com>
* Todd C. Miller <Todd.Miller@courtesan.com>
*
*
* Stand-alone program for computing responses to S/Key challenges.
* Takes the iteration count and seed as command line args, prompts
* for the user's key, and produces both word and hex format responses.
*
* Usage example:
* >skey 88 ka9q2
* Enter password:
* OMEN US HORN OMIT BACK AHOY
* >
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include <unistd.h>
#include <limits.h>
#include <skey.h>
void usage(char *);
int
main(int argc, char *argv[])
{
int n, i, cnt = 1, pass = 0, hexmode = 0;
char passwd[SKEY_MAX_PW_LEN+1], key[SKEY_BINKEY_SIZE];
char buf[33], *seed, *slash;
const char *errstr;
/* If we were called as otp-METHOD, set algorithm based on that */
if ((slash = strrchr(argv[0], '/')))
slash++;
else
slash = argv[0];
if (strncmp(slash, "otp-", 4) == 0) {
slash += 4;
if (skey_set_algorithm(slash) == NULL)
errx(1, "Unknown hash algorithm %s", slash);
}
for (i = 1; i < argc && argv[i][0] == '-' && strcmp(argv[i], "--");) {
if (argv[i][2] == '\0') {
/* Single character switch */
switch (argv[i][1]) {
case 'n':
if (++i == argc)
usage(argv[0]);
cnt = strtonum(argv[i], 1, SKEY_MAX_SEQ -1, &errstr);
if (errstr)
usage(argv[0]);
break;
case 'p':
if (++i == argc)
usage(argv[0]);
if (strlcpy(passwd, argv[i], sizeof(passwd)) >=
sizeof(passwd))
errx(1, "Password too long");
pass = 1;
break;
case 'x':
hexmode = 1;
break;
default:
usage(argv[0]);
}
} else {
/* Multi character switches are hash types */
if (skey_set_algorithm(&argv[i][1]) == NULL) {
warnx("Unknown hash algorithm %s", &argv[i][1]);
usage(argv[0]);
}
}
i++;
}
if (argc > i + 2)
usage(argv[0]);
/* Could be in the form <number>/<seed> */
if (argc <= i + 1) {
/* look for / in it */
if (argc <= i)
usage(argv[0]);
slash = strchr(argv[i], '/');
if (slash == NULL)
usage(argv[0]);
*slash++ = '\0';
seed = slash;
n = strtonum(argv[i], 0, SKEY_MAX_SEQ, &errstr);
if (errstr) {
warnx("%s: %s", argv[i], errstr);
usage(argv[0]);
}
} else {
n = strtonum(argv[i], 0, SKEY_MAX_SEQ, &errstr);
if (errstr) {
warnx("%s: %s", argv[i], errstr);
usage(argv[0]);
}
seed = argv[++i];
}
/* Get user's secret passphrase */
if (!pass) {
fputs("Reminder - Do not use this program while"
" logged in via telnet.\n", stderr);
(void)fputs("Enter secret passphrase: ", stderr);
readpass(passwd, sizeof(passwd));
if (passwd[0] == '\0')
exit(1);
}
/* Crunch seed and passphrase into starting key */
if (keycrunch(key, seed, passwd) != 0)
errx(1, "key crunch failed");
if (cnt == 1) {
while (n-- != 0)
f(key);
(void)puts(hexmode ? put8(buf, key) : btoe(buf, key));
} else {
for (i = 0; i <= n - cnt; i++)
f(key);
for (; i <= n; i++) {
if (hexmode)
(void)printf("%d: %s\n", i, put8(buf, key));
else
(void)printf("%d: %-29s\n", i, btoe(buf, key));
f(key);
}
}
exit(0);
}
void
usage(char *s)
{
fprintf(stderr,
"usage: %s [-x] [-md5 | -rmd160 | -sha1] [-n count]\n\t"
"[-p passphrase] <sequence#>[/] key\n", s);
exit(1);
}
|
