1 #include <u.h>
2 #include <libc.h>
3 #include <auth.h>
4 #include <authsrv.h>
5 #include "authlocal.h"
6
7 /*
8 * compute the proper response. We encrypt the ascii of
9 * challenge number, with trailing binary zero fill.
10 * This process was derived empirically.
11 * this was copied from inet's guard.
12 */
13 static void
netresp(char * key,long chal,char * answer)14 netresp(char *key, long chal, char *answer)
15 {
16 uchar buf[8];
17
18 memset(buf, 0, sizeof buf);
19 snprint((char *)buf, sizeof buf, "%lud", chal);
20 if(encrypt(key, buf, 8) < 0)
21 abort();
22 sprint(answer, "%.8ux", buf[0]<<24 | buf[1]<<16 | buf[2]<<8 | buf[3]);
23 }
24
25 AuthInfo*
auth_userpasswd(char * user,char * passwd)26 auth_userpasswd(char *user, char *passwd)
27 {
28 char key[DESKEYLEN], resp[16];
29 AuthInfo *ai;
30 Chalstate *ch;
31
32 /*
33 * Probably we should have a factotum protocol
34 * to check a raw password. For now, we use
35 * p9cr, which is simplest to speak.
36 */
37 if((ch = auth_challenge("user=%q proto=p9cr role=server", user)) == nil)
38 return nil;
39
40 passtokey(key, passwd);
41 netresp(key, atol(ch->chal), resp);
42 memset(key, 0, sizeof key);
43
44 ch->resp = resp;
45 ch->nresp = strlen(resp);
46 ai = auth_response(ch);
47 auth_freechal(ch);
48 return ai;
49 }
50