static const char *
sha1_hash_finish(void *ctx)
{
static char hash[SHA1_DIGEST_STRING_LENGTH];
SHA1_CTX *hash_ctx = ctx;
SHA1End(hash_ctx, hash);
return hash;
}
/*
* skey_fakeprompt()
*
* Generate a fake prompt for the specified user.
*
*/
static void
skey_fakeprompt(char *username, char *skeyprompt)
{
char hseed[SKEY_MAX_SEED_LEN], *secret, pbuf[SKEY_MAX_PW_LEN+1], *p, *u;
u_char flg = 1, *up;
size_t secretlen;
SHA1_CTX ctx;
u_int ptr;
int i;
/*
* Base first 4 chars of seed on hostname.
* Add some filler for short hostnames if necessary.
*/
if (gethostname(pbuf, sizeof(pbuf)) == -1)
*(p = pbuf) = '.';
else
for (p = pbuf; isalnum((unsigned char)*p); p++)
if (isalpha((unsigned char)*p) &&
isupper((unsigned char)*p))
*p = (char)tolower((unsigned char)*p);
if (*p && pbuf - p < 4)
(void)strncpy(p, "asjd", 4 - (pbuf - p));
pbuf[4] = '\0';
/* Hash the username if possible */
if ((up = SHA1Data(username, strlen(username), NULL)) != NULL) {
struct stat sb;
time_t t;
int fd;
/* Collapse the hash */
ptr = hash_collapse(up);
memset(up, 0, strlen(up));
/* See if the random file's there, else use ctime */
if ((fd = open(_SKEY_RAND_FILE_PATH_, O_RDONLY)) != -1 &&
fstat(fd, &sb) == 0 &&
sb.st_size > (off_t)SKEY_MAX_SEED_LEN &&
lseek(fd, ptr % (sb.st_size - SKEY_MAX_SEED_LEN),
SEEK_SET) != -1 && read(fd, hseed,
SKEY_MAX_SEED_LEN) == SKEY_MAX_SEED_LEN) {
close(fd);
fd = -1;
secret = hseed;
secretlen = SKEY_MAX_SEED_LEN;
flg = 0;
} else if (!stat(_PATH_MEM, &sb) || !stat("/", &sb)) {
t = sb.st_ctime;
secret = ctime(&t);
secretlen = strlen(secret);
flg = 0;
}
if (fd != -1)
close(fd);
}
/* Put that in your pipe and smoke it */
if (flg == 0) {
/* Hash secret value with username */
SHA1Init(&ctx);
SHA1Update(&ctx, secret, secretlen);
SHA1Update(&ctx, username, strlen(username));
SHA1End(&ctx, up);
/* Zero out */
memset(secret, 0, secretlen);
/* Now hash the hash */
SHA1Init(&ctx);
SHA1Update(&ctx, up, strlen(up));
SHA1End(&ctx, up);
ptr = hash_collapse(up + 4);
for (i = 4; i < 9; i++) {
pbuf[i] = (ptr % 10) + '0';
ptr /= 10;
}
pbuf[i] = '\0';
/* Sequence number */
ptr = ((up[2] + up[3]) % 99) + 1;
memset(up, 0, 20); /* SHA1 specific */
free(up);
(void)snprintf(skeyprompt, SKEY_MAX_CHALLENGE,
"otp-%.*s %d %.*s", SKEY_MAX_HASHNAME_LEN,
skey_get_algorithm(), ptr, SKEY_MAX_SEED_LEN, pbuf);
} else {
/* Base last 8 chars of seed on username */
u = username;
i = 8;
p = &pbuf[4];
do {
if (*u == 0) {
/* Pad remainder with zeros */
while (--i >= 0)
*p++ = '0';
break;
}
*p++ = (*u++ % 10) + '0';
} while (--i != 0);
pbuf[12] = '\0';
(void)snprintf(skeyprompt, SKEY_MAX_CHALLENGE,
"otp-%.*s %d %.*s", SKEY_MAX_HASHNAME_LEN,
skey_get_algorithm(), 99, SKEY_MAX_SEED_LEN, pbuf);
}
}
