1 /*
2 * SPDX-License-Identifier: ISC
3 *
4 * Copyright (c) 2000-2005, 2007-2008, 2010-2015
5 * Todd C. Miller <Todd.Miller@sudo.ws>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 *
19 * Sponsored in part by the Defense Advanced Research Projects
20 * Agency (DARPA) and Air Force Research Laboratory, Air Force
21 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
22 */
23
24 /*
25 * This is an open source non-commercial project. Dear PVS-Studio, please check it.
26 * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
27 */
28
29 #include <config.h>
30
31 #ifdef HAVE_BSD_AUTH_H
32
33 #include <sys/types.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38 #include <ctype.h>
39 #include <pwd.h>
40 #include <signal.h>
41
42 #include <login_cap.h>
43 #include <bsd_auth.h>
44
45 #include "sudoers.h"
46 #include "sudo_auth.h"
47
48 # ifndef LOGIN_DEFROOTCLASS
49 # define LOGIN_DEFROOTCLASS "daemon"
50 # endif
51
52 struct bsdauth_state {
53 auth_session_t *as;
54 login_cap_t *lc;
55 };
56
57 int
bsdauth_init(struct passwd * pw,sudo_auth * auth)58 bsdauth_init(struct passwd *pw, sudo_auth *auth)
59 {
60 static struct bsdauth_state state;
61 debug_decl(bsdauth_init, SUDOERS_DEBUG_AUTH);
62
63 /* Get login class based on auth user, which may not be invoking user. */
64 if (pw->pw_class && *pw->pw_class)
65 state.lc = login_getclass(pw->pw_class);
66 else
67 state.lc = login_getclass(pw->pw_uid ? LOGIN_DEFCLASS : LOGIN_DEFROOTCLASS);
68 if (state.lc == NULL) {
69 log_warning(0,
70 N_("unable to get login class for user %s"), pw->pw_name);
71 debug_return_int(AUTH_FATAL);
72 }
73
74 if ((state.as = auth_open()) == NULL) {
75 log_warning(0, N_("unable to begin bsd authentication"));
76 login_close(state.lc);
77 debug_return_int(AUTH_FATAL);
78 }
79
80 /* XXX - maybe check the auth style earlier? */
81 login_style = login_getstyle(state.lc, login_style, "auth-sudo");
82 if (login_style == NULL) {
83 log_warningx(0, N_("invalid authentication type"));
84 auth_close(state.as);
85 login_close(state.lc);
86 debug_return_int(AUTH_FATAL);
87 }
88
89 if (auth_setitem(state.as, AUTHV_STYLE, login_style) < 0 ||
90 auth_setitem(state.as, AUTHV_NAME, pw->pw_name) < 0 ||
91 auth_setitem(state.as, AUTHV_CLASS, login_class) < 0) {
92 log_warningx(0, N_("unable to initialize BSD authentication"));
93 auth_close(state.as);
94 login_close(state.lc);
95 debug_return_int(AUTH_FATAL);
96 }
97
98 auth->data = (void *) &state;
99 debug_return_int(AUTH_SUCCESS);
100 }
101
102 int
bsdauth_verify(struct passwd * pw,char * prompt,sudo_auth * auth,struct sudo_conv_callback * callback)103 bsdauth_verify(struct passwd *pw, char *prompt, sudo_auth *auth, struct sudo_conv_callback *callback)
104 {
105 char *pass;
106 char *s;
107 size_t len;
108 int authok = 0;
109 struct sigaction sa, osa;
110 auth_session_t *as = ((struct bsdauth_state *) auth->data)->as;
111 debug_decl(bsdauth_verify, SUDOERS_DEBUG_AUTH);
112
113 /* save old signal handler */
114 sigemptyset(&sa.sa_mask);
115 sa.sa_flags = SA_RESTART;
116 sa.sa_handler = SIG_DFL;
117 (void) sigaction(SIGCHLD, &sa, &osa);
118
119 /*
120 * If there is a challenge then print that instead of the normal
121 * prompt. If the user just hits return we prompt again with echo
122 * turned on, which is useful for challenge/response things like
123 * S/Key.
124 */
125 if ((s = auth_challenge(as)) == NULL) {
126 pass = auth_getpass(prompt, SUDO_CONV_PROMPT_ECHO_OFF, callback);
127 } else {
128 pass = auth_getpass(s, SUDO_CONV_PROMPT_ECHO_OFF, callback);
129 if (pass && *pass == '\0') {
130 if ((prompt = strrchr(s, '\n')))
131 prompt++;
132 else
133 prompt = s;
134
135 /*
136 * Append '[echo on]' to the last line of the challenge and
137 * reprompt with echo turned on.
138 */
139 len = strlen(prompt) - 1;
140 while (isspace(prompt[len]) || prompt[len] == ':')
141 prompt[len--] = '\0';
142 if (asprintf(&s, "%s [echo on]: ", prompt) == -1) {
143 log_warningx(0, N_("unable to allocate memory"));
144 debug_return_int(AUTH_FATAL);
145 }
146 free(pass);
147 pass = auth_getpass(s, SUDO_CONV_PROMPT_ECHO_ON, callback);
148 free(s);
149 }
150 }
151
152 if (pass) {
153 authok = auth_userresponse(as, pass, 1);
154 freezero(pass, strlen(pass));
155 }
156
157 /* restore old signal handler */
158 (void) sigaction(SIGCHLD, &osa, NULL);
159
160 if (authok)
161 debug_return_int(AUTH_SUCCESS);
162
163 if (!pass)
164 debug_return_int(AUTH_INTR);
165
166 if ((s = auth_getvalue(as, "errormsg")) != NULL)
167 log_warningx(0, "%s", s);
168 debug_return_int(AUTH_FAILURE);
169 }
170
171 int
bsdauth_approval(struct passwd * pw,sudo_auth * auth,bool exempt)172 bsdauth_approval(struct passwd *pw, sudo_auth *auth, bool exempt)
173 {
174 struct bsdauth_state *state = auth->data;
175 debug_decl(bsdauth_approval, SUDOERS_DEBUG_AUTH);
176
177 if (auth_approval(state->as, state->lc, pw->pw_name, "auth-sudo") == 0) {
178 if (auth_getstate(state->as) & AUTH_EXPIRED)
179 log_warningx(0, "%s", N_("your account has expired"));
180 else
181 log_warningx(0, "%s", N_("approval failed"));
182 debug_return_int(AUTH_FAILURE);
183 }
184 debug_return_int(AUTH_SUCCESS);
185 }
186
187 int
bsdauth_cleanup(struct passwd * pw,sudo_auth * auth,bool force)188 bsdauth_cleanup(struct passwd *pw, sudo_auth *auth, bool force)
189 {
190 struct bsdauth_state *state = auth->data;
191 debug_decl(bsdauth_cleanup, SUDOERS_DEBUG_AUTH);
192
193 if (state != NULL) {
194 auth_close(state->as);
195 state->as = NULL;
196 login_close(state->lc);
197 state->lc = NULL;
198 auth->data = NULL;
199 }
200 login_style = NULL;
201
202 debug_return_int(AUTH_SUCCESS);
203 }
204
205 #endif /* HAVE_BSD_AUTH_H */
206