NetBSD/usr.bin/skey/skey.c

157 lines
3.5 KiB
C

/* $NetBSD: skey.c,v 1.11 2000/07/07 15:45:00 mjl Exp $ */
/*
* S/KEY v1.1b (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>
*
*
* 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 <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: skey.c,v 1.11 2000/07/07 15:45:00 mjl Exp $");
#endif
#include <ctype.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <skey.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int main __P((int, char **));
void usage __P((char *));
int
main(int argc, char **argv)
{
int n, cnt, i, pass = 0, hexmode = 0;
char passwd[SKEY_MAX_PW_LEN+1], key[SKEY_BINKEY_SIZE];
char buf[33], *seed, *slash, *t;
cnt = 1;
while ((i = getopt(argc, argv, "n:p:t:x")) != -1) {
switch (i) {
case 'n':
cnt = atoi(optarg);
break;
case 'p':
if (strlcpy(passwd, argv[++i], sizeof(passwd)) >=
sizeof(passwd))
errx(1, "Password too long");
pass = 1;
break;
case 't':
if (skey_set_algorithm(optarg) == NULL) {
errx(1, "Unknown hash algorithm %s", optarg);
}
break;
case 'x':
hexmode = 1;
break;
default:
usage(argv[0]);
break;
}
}
/* could be in the form <number>/<seed> */
if (argc <= optind + 1) {
/* look for / in it */
if (argc <= optind)
usage(argv[0]);
slash = strchr(argv[optind], '/');
if (slash == NULL)
usage(argv[0]);
*slash++ = '\0';
seed = slash;
if ((n = atoi(argv[optind])) < 0) {
fprintf(stderr, "%s not positive\n", argv[optind]);
usage(argv[0]);
} else if (n > SKEY_MAX_SEQ) {
warnx("%d is larger than max (%d)", n, SKEY_MAX_SEQ);
usage(argv[0]);
}
} else {
if ((n = atoi(argv[optind])) < 0) {
fprintf(stderr, "%s not positive\n", argv[optind]);
usage(argv[0]);
} else if (n > SKEY_MAX_SEQ) {
warnx("%d is larger than max (%d)", n, SKEY_MAX_SEQ);
usage(argv[0]);
}
seed = argv[++optind];
}
for(t = seed; *t; t++) {
if(!isalnum(*t))
errx(1, "seed must be alphanumeric");
}
if(!*seed || strlen(seed) > SKEY_MAX_SEED_LEN)
errx(1, "seed must be between 1 and %d long", SKEY_MAX_SEED_LEN);
/* Get user's secret password */
if (!pass) {
(void)fputs("Reminder - Do not use this program while "
"logged in via telnet or rlogin.\n", stderr);
fprintf(stderr, "Enter secret password: ");
readpass(passwd, sizeof(passwd));
if (passwd[0] == '\0')
exit(1);
}
if(strlen(passwd) < SKEY_MIN_PW_LEN)
errx(1, "password must be at least %d long", SKEY_MIN_PW_LEN);
/* Crunch seed and password 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++) {
(void)printf("%3d: %-29s", i, btoe(buf, key));
if (hexmode)
(void)printf("\t%s", put8(buf, key));
puts("");
f(key);
}
}
exit(0);
}
void
usage(char *s)
{
fprintf(stderr,
"Usage: %s [-n count] [-p password ] [-t hash] [-x] sequence#"
"[/] key\n", s);
exit(1);
}