auth-passwd.c revision 57430 
1/*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 *                    All rights reserved
5 * Created: Sat Mar 18 05:11:38 1995 ylo
6 * Password authentication.  This file contains the functions to check whether
7 * the password is valid for the user.
8 */
9
10#include "includes.h"
11RCSID("$Id: auth-passwd.c,v 1.14 1999/12/29 12:47:46 markus Exp $");
12
13#include "packet.h"
14#include "ssh.h"
15#include "servconf.h"
16#include "xmalloc.h"
17
18/*
19 * Tries to authenticate the user using password.  Returns true if
20 * authentication succeeds.
21 */
22int
23auth_password(struct passwd * pw, const char *password)
24{
25	extern ServerOptions options;
26	char *encrypted_password;
27
28	/* deny if no user. */
29	if (pw == NULL)
30		return 0;
31	if (pw->pw_uid == 0 && options.permit_root_login == 2)
32		return 0;
33	if (*password == '\0' && options.permit_empty_passwd == 0)
34		return 0;
35
36#ifdef SKEY
37	if (options.skey_authentication == 1) {
38		int ret = auth_skey_password(pw, password);
39		if (ret == 1 || ret == 0)
40			return ret;
41		/* Fall back to ordinary passwd authentication. */
42	}
43#endif
44#ifdef KRB4
45	if (options.kerberos_authentication == 1) {
46		int ret = auth_krb4_password(pw, password);
47		if (ret == 1 || ret == 0)
48			return ret;
49		/* Fall back to ordinary passwd authentication. */
50	}
51#endif
52
53	/* Check for users with no password. */
54	if (strcmp(password, "") == 0 && strcmp(pw->pw_passwd, "") == 0)
55		return 1;
56	/* Encrypt the candidate password using the proper salt. */
57	encrypted_password = crypt(password,
58	    (pw->pw_passwd[0] && pw->pw_passwd[1]) ? pw->pw_passwd : "xx");
59
60	/* Authentication is accepted if the encrypted passwords are identical. */
61	return (strcmp(encrypted_password, pw->pw_passwd) == 0);
62}
63