skey.c revision 1.4 
1/* * $OpenBSD: skey.c,v 1.4 1996/09/29 04:33:58 millert Exp $*/
2/*
3 * S/KEY v1.1b (skey.c)
4 *
5 * Authors:
6 *          Neil M. Haller <nmh@thumper.bellcore.com>
7 *          Philip R. Karn <karn@chicago.qualcomm.com>
8 *          John S. Walden <jsw@thumper.bellcore.com>
9 *          Scott Chasin <chasin@crimelab.com>
10 *
11 *
12 * Stand-alone program for computing responses to S/Key challenges.
13 * Takes the iteration count and seed as command line args, prompts
14 * for the user's key, and produces both word and hex format responses.
15 *
16 * Usage example:
17 *	>skey 88 ka9q2
18 *	Enter password:
19 *	OMEN US HORN OMIT BACK AHOY
20 *	>
21 *
22 */
23
24#include <stdio.h>
25#include <stdlib.h>
26#include <string.h>
27#include <err.h>
28#include <unistd.h>
29#include <skey.h>
30
31void    usage __P((char *));
32
33int
34main(argc, argv)
35	int	argc;
36	char	*argv[];
37{
38	int     n, i, cnt = 1, pass = 0, hexmode = 0;
39	char    passwd[256], key[8], buf[33], *seed, *slash;
40
41	while ((i = getopt(argc, argv, "n:p:x45")) != EOF) {
42		switch (i) {
43		case 'n':
44			cnt = atoi(optarg);
45			break;
46		case 'p':
47			strcpy(passwd, optarg);
48			pass = 1;
49			break;
50		case 'x':
51			hexmode = 1;
52			break;
53		case '4':
54			skey_set_MDX(4);
55			break;
56		case '5':
57			skey_set_MDX(5);
58			break;
59		}
60	}
61
62	/* check for md4/md5 argument */
63	if (argv[optind]) {
64		if (strcmp(argv[optind], "MD4") == 0) {
65			skey_set_MDX(4);
66			optind++;
67		} else if (strcmp(argv[optind], "MD5") == 0) {
68			skey_set_MDX(5);
69			optind++;
70		}
71	}
72
73	/* could be in the form <number>/<seed> */
74	if (argc <= optind + 1) {
75		/* look for / in it */
76		if (argc <= optind)
77			usage(argv[0]);
78		slash = strchr(argv[optind], '/');
79		if (slash == NULL)
80			usage(argv[0]);
81		*slash++ = '\0';
82		seed = slash;
83
84		if ((n = atoi(argv[optind])) < 0) {
85			warnx("%s not positive", argv[optind]);
86			usage(argv[0]);
87		}
88	} else {
89		if ((n = atoi(argv[optind])) < 0) {
90			warnx("%s not positive", argv[optind]);
91			usage(argv[0]);
92		}
93		seed = argv[++optind];
94	}
95
96	/* Get user's secret password */
97	if (!pass) {
98		(void)fputs("Reminder - Do not use this program while logged in via telnet or rlogin.\n", stderr);
99		(void)fputs("Enter secret password: ", stderr);
100		readpass(passwd, sizeof(passwd));
101	}
102	rip(passwd);
103
104	/* Crunch seed and password into starting key */
105	if (keycrunch(key, seed, passwd) != 0)
106		errx(1, "key crunch failed");
107
108	if (cnt == 1) {
109		while (n-- != 0)
110			f(key);
111		(void)puts(hexmode ? put8(buf, key) : btoe(buf, key));
112	} else {
113		for (i = 0; i <= n - cnt; i++)
114			f(key);
115		for (; i <= n; i++) {
116			if (hexmode)
117				(void)printf("%d: %-29s  %s\n", i,
118				    btoe(buf, key), put8(buf, key));
119			else
120				(void)printf("%d: %-29s\n", i, btoe(buf, key));
121			f(key);
122		}
123	}
124	exit(0);
125}
126
127void
128usage(s)
129	char   *s;
130{
131	(void)fprintf(stderr, "Usage: %s [-x] [-4|-5] [-n count] [-p password] [MD4|MD5] sequence# [/] key", s);
132	exit(1);
133}
134