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/* $OpenBSD: skey.c,v 1.24 2008/11/12 16:13:46 sobrado 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 <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;
/* 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 = atoi(argv[i]);
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;
if ((n = atoi(argv[i])) < 0) {
warnx("%d not positive", n);
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[i])) < 0) {
warnx("%d not positive", n);
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[++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++) {
(void)printf("%d: %-29s", i, btoe(buf, key));
if (hexmode)
(void)printf(" %s", put8(buf, key));
putchar('\n');
f(key);
}
}
exit(0);
}
void
usage(char *s)
{
fprintf(stderr,
"usage: %s [-x] [-md4 | -md5 | -rmd160 | -sha1] [-n count]\n\t"
"[-p passphrase] <sequence#>[/] key\n", s);
exit(1);
}
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