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, 8);
19 sprint((char *)buf, "%lud", chal);
20 if(encrypt(key, buf, 8) < 0)
21 abort();
22 chal = (buf[0]<<24)+(buf[1]<<16)+(buf[2]<<8)+buf[3];
23 sprint(answer, "%.8lux", chal);
24 }
25
26 AuthInfo*
auth_userpasswd(char * user,char * passwd)27 auth_userpasswd(char *user, char *passwd)
28 {
29 char key[DESKEYLEN], resp[16];
30 AuthInfo *ai;
31 Chalstate *ch;
32
33 /*
34 * Probably we should have a factotum protocol
35 * to check a raw password. For now, we use
36 * p9cr, which is simplest to speak.
37 */
38 if((ch = auth_challenge("user=%q proto=p9cr role=server", user)) == nil)
39 return nil;
40
41 passtokey(key, passwd);
42 netresp(key, atol(ch->chal), resp);
43 memset(key, 0, sizeof key);
44
45 ch->resp = resp;
46 ch->nresp = strlen(resp);
47 ai = auth_response(ch);
48 auth_freechal(ch);
49 return ai;
50 }
51