summaryrefslogtreecommitdiff
path: root/usr.bin/sudo/auth/bsdauth.c
blob: a881bf93795e12093713a57cc0a269fb34bf2b27 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/*
 * Copyright (c) 2000-2005 Todd C. Miller <Todd.Miller@courtesan.com>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * Sponsored in part by the Defense Advanced Research Projects
 * Agency (DARPA) and Air Force Research Laboratory, Air Force
 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
 */

#include <config.h>

#include <sys/types.h>
#include <sys/param.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
#  include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#else
# ifdef HAVE_STRINGS_H
#  include <strings.h>
# endif
#endif /* HAVE_STRING_H */
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif /* HAVE_UNISTD_H */
#include <ctype.h>
#include <pwd.h>
#include <signal.h>

#include <login_cap.h>
#include <bsd_auth.h>

#include "sudo.h"
#include "sudo_auth.h"

#ifndef lint
__unused static const char rcsid[] = "$Sudo: bsdauth.c,v 1.16.2.2 2007/06/12 01:28:42 millert Exp $";
#endif /* lint */

extern char *login_style;		/* from sudo.c */

int
bsdauth_init(pw, promptp, auth)
    struct passwd *pw;
    char **promptp;
    sudo_auth *auth;
{
    static auth_session_t *as;
    extern login_cap_t *lc;			/* from sudo.c */

    if ((as = auth_open()) == NULL) {
	log_error(USE_ERRNO|NO_EXIT|NO_MAIL,
	    "unable to begin bsd authentication");
	return(AUTH_FATAL);
    }

    /* XXX - maybe sanity check the auth style earlier? */
    login_style = login_getstyle(lc, login_style, "auth-sudo");
    if (login_style == NULL) {
	log_error(NO_EXIT|NO_MAIL, "invalid authentication type");
	auth_close(as);
	return(AUTH_FATAL);
    }

     if (auth_setitem(as, AUTHV_STYLE, login_style) < 0 ||
	auth_setitem(as, AUTHV_NAME, pw->pw_name) < 0 ||
	auth_setitem(as, AUTHV_CLASS, login_class) < 0) {
	log_error(NO_EXIT|NO_MAIL, "unable to setup authentication");
	auth_close(as);
	return(AUTH_FATAL);
    }

    auth->data = (VOID *) as;
    return(AUTH_SUCCESS);
}

int
bsdauth_verify(pw, prompt, auth)
    struct passwd *pw;
    char *prompt;
    sudo_auth *auth;
{
    char *pass;
    char *s;
    size_t len;
    int authok = 0;
    sigaction_t sa, osa;
    auth_session_t *as = (auth_session_t *) auth->data;
    extern int nil_pw;

    /* save old signal handler */
    sigemptyset(&sa.sa_mask);
    sa.sa_flags = SA_RESTART;
    sa.sa_handler = SIG_DFL;
    (void) sigaction(SIGCHLD, &sa, &osa);

    /*
     * If there is a challenge then print that instead of the normal
     * prompt.  If the user just hits return we prompt again with echo
     * turned on, which is useful for challenge/response things like
     * S/Key.
     */
    if ((s = auth_challenge(as)) == NULL) {
	pass = tgetpass(prompt, def_passwd_timeout * 60, tgetpass_flags);
    } else {
	pass = tgetpass(s, def_passwd_timeout * 60, tgetpass_flags);
	if (pass && *pass == '\0') {
	    if ((prompt = strrchr(s, '\n')))
		prompt++;
	    else
		prompt = s;

	    /*
	     * Append '[echo on]' to the last line of the challenge and
	     * reprompt with echo turned on.
	     */
	    len = strlen(prompt) - 1;
	    while (isspace(prompt[len]) || prompt[len] == ':')
		prompt[len--] = '\0';
	    easprintf(&s, "%s [echo on]: ", prompt);
	    pass = tgetpass(s, def_passwd_timeout * 60,
		tgetpass_flags | TGP_ECHO);
	    free(s);
	}
    }

    if (!pass || *pass == '\0')		/* ^C or empty password */
	nil_pw = 1;

    if (pass) {
	authok = auth_userresponse(as, (char *)pass, 1);
	zero_bytes(pass, strlen(pass));
    }

    /* restore old signal handler */
    (void) sigaction(SIGCHLD, &osa, NULL);

    if (authok)
	return(AUTH_SUCCESS);

    if ((s = auth_getvalue(as, "errormsg")) != NULL)
	log_error(NO_EXIT|NO_MAIL, "%s", s);
    return(AUTH_FAILURE);
}

int
bsdauth_cleanup(pw, auth)
    struct passwd *pw;
    sudo_auth *auth;
{
    auth_session_t *as = (auth_session_t *) auth->data;

    auth_close(as);

    return(AUTH_SUCCESS);
}