2 * Copyright (c) 1999-2005 Todd C. Miller <Todd.Miller@courtesan.com>
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 * Sponsored in part by the Defense Advanced Research Projects
17 * Agency (DARPA) and Air Force Research Laboratory, Air Force
18 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
23 #include <sys/types.h>
24 #include <sys/param.h>
33 #endif /* STDC_HEADERS */
35 # if defined(HAVE_MEMORY_H) && !defined(STDC_HEADERS)
40 # ifdef HAVE_STRINGS_H
43 #endif /* HAVE_STRING_H */
46 #endif /* HAVE_UNISTD_H */
49 #ifdef HAVE_PAM_PAM_APPL_H
50 # include <pam/pam_appl.h>
52 # include <security/pam_appl.h>
56 #include "sudo_auth.h"
58 /* Only OpenPAM and Linux PAM use const qualifiers. */
59 #if defined(_OPENPAM) || defined(__LIBPAM_VERSION) || defined(__LINUX_PAM__)
60 # define PAM_CONST const
66 __unused static const char rcsid[] = "$Sudo: pam.c,v 1.43.2.7 2007/10/09 00:06:06 millert Exp $";
69 static int sudo_conv __P((int, PAM_CONST struct pam_message **,
70 struct pam_response **, VOID *));
71 static char *def_prompt;
73 #ifndef PAM_DATA_SILENT
74 #define PAM_DATA_SILENT 0
77 static pam_handle_t *pamh; /* global due to pam_prep_user() */
80 pam_init(pw, promptp, auth)
85 static struct pam_conv pam_conv;
86 static int pam_status;
88 /* Initial PAM setup */
90 auth->data = (VOID *) &pam_status;
91 pam_conv.conv = sudo_conv;
92 pam_status = pam_start("sudo", pw->pw_name, &pam_conv, &pamh);
93 if (pam_status != PAM_SUCCESS) {
94 log_error(USE_ERRNO|NO_EXIT|NO_MAIL, "unable to initialize PAM");
98 * Some versions of pam_lastlog have a bug that
99 * will cause a crash if PAM_TTY is not set so if
100 * there is no tty, set PAM_TTY to the empty string.
102 if (user_ttypath == NULL)
103 (void) pam_set_item(pamh, PAM_TTY, "");
105 (void) pam_set_item(pamh, PAM_TTY, user_ttypath);
107 return(AUTH_SUCCESS);
111 pam_verify(pw, prompt, auth)
117 int *pam_status = (int *) auth->data;
119 def_prompt = prompt; /* for sudo_conv */
121 /* PAM_SILENT prevents the authentication service from generating output. */
122 *pam_status = pam_authenticate(pamh, PAM_SILENT);
123 switch (*pam_status) {
125 *pam_status = pam_acct_mgmt(pamh, PAM_SILENT);
126 switch (*pam_status) {
128 return(AUTH_SUCCESS);
130 log_error(NO_EXIT|NO_MAIL, "pam_acct_mgmt: %d",
132 return(AUTH_FAILURE);
133 case PAM_NEW_AUTHTOK_REQD:
134 log_error(NO_EXIT|NO_MAIL, "%s, %s",
135 "Account or password is expired",
136 "reset your password and try again");
137 *pam_status = pam_chauthtok(pamh,
138 PAM_CHANGE_EXPIRED_AUTHTOK);
139 if (*pam_status == PAM_SUCCESS)
140 return(AUTH_SUCCESS);
141 if ((s = pam_strerror(pamh, *pam_status)))
142 log_error(NO_EXIT|NO_MAIL, "pam_chauthtok: %s", s);
143 return(AUTH_FAILURE);
144 case PAM_AUTHTOK_EXPIRED:
145 log_error(NO_EXIT|NO_MAIL,
146 "Password expired, contact your system administrator");
148 case PAM_ACCT_EXPIRED:
149 log_error(NO_EXIT|NO_MAIL, "%s %s",
150 "Account expired or PAM config lacks an \"account\"",
151 "section for sudo, contact your system administrator");
157 case PAM_PERM_DENIED:
158 return(AUTH_FAILURE);
160 if ((s = pam_strerror(pamh, *pam_status)))
161 log_error(NO_EXIT|NO_MAIL, "pam_authenticate: %s", s);
167 pam_cleanup(pw, auth)
171 int *pam_status = (int *) auth->data;
173 /* If successful, we can't close the session until pam_prep_user() */
174 if (auth->status == AUTH_SUCCESS)
175 return(AUTH_SUCCESS);
177 *pam_status = pam_end(pamh, *pam_status | PAM_DATA_SILENT);
178 return(*pam_status == PAM_SUCCESS ? AUTH_SUCCESS : AUTH_FAILURE);
188 pam_init(pw, NULL, NULL);
191 * Set PAM_USER to the user we are changing *to* and
192 * set PAM_RUSER to the user we are coming *from*.
193 * We set PAM_RHOST to avoid a bug in Solaris 7 and below.
195 (void) pam_set_item(pamh, PAM_USER, pw->pw_name);
196 (void) pam_set_item(pamh, PAM_RUSER, user_name);
197 (void) pam_set_item(pamh, PAM_RHOST, user_host);
200 * Set credentials (may include resource limits, device ownership, etc).
201 * We don't check the return value here because in Linux-PAM 0.75
202 * it returns the last saved return code, not the return code
203 * for the setcred module. Because we haven't called pam_authenticate(),
204 * this is not set and so pam_setcred() returns PAM_PERM_DENIED.
205 * We can't call pam_acct_mgmt() with Linux-PAM for a similar reason.
207 (void) pam_setcred(pamh, PAM_ESTABLISH_CRED);
209 #ifndef NO_PAM_SESSION
211 * To fully utilize PAM sessions we would need to keep a
212 * sudo process around until the command exits. However, we
213 * can at least cause pam_limits to be run by opening and then
214 * immediately closing the session.
216 if ((eval = pam_open_session(pamh, 0)) != PAM_SUCCESS) {
217 (void) pam_end(pamh, eval | PAM_DATA_SILENT);
218 return(AUTH_FAILURE);
220 (void) pam_close_session(pamh, 0);
223 if (pam_end(pamh, PAM_SUCCESS | PAM_DATA_SILENT) == PAM_SUCCESS)
224 return(AUTH_SUCCESS);
226 return(AUTH_FAILURE);
230 * ``Conversation function'' for PAM.
231 * XXX - does not handle PAM_BINARY_PROMPT
234 sudo_conv(num_msg, msg, response, appdata_ptr)
236 PAM_CONST struct pam_message **msg;
237 struct pam_response **response;
240 struct pam_response *pr;
241 PAM_CONST struct pam_message *pm;
242 const char *p = def_prompt;
247 if ((*response = malloc(num_msg * sizeof(struct pam_response))) == NULL)
248 return(PAM_CONV_ERR);
249 zero_bytes(*response, num_msg * sizeof(struct pam_response));
251 for (pr = *response, pm = *msg, n = num_msg; n--; pr++, pm++) {
252 flags = tgetpass_flags;
253 switch (pm->msg_style) {
254 case PAM_PROMPT_ECHO_ON:
255 SET(flags, TGP_ECHO);
256 case PAM_PROMPT_ECHO_OFF:
257 /* Only override PAM prompt if it matches /^Password: ?/ */
258 if (strncmp(pm->msg, "Password:", 9) || (pm->msg[9] != '\0'
259 && (pm->msg[9] != ' ' || pm->msg[10] != '\0')))
261 /* Read the password. */
262 pass = tgetpass(p, def_passwd_timeout * 60, flags);
264 /* We got ^C instead of a password; abort quickly. */
268 pr->resp = estrdup(pass);
269 if (*pr->resp == '\0')
270 nil_pw = 1; /* empty password */
272 zero_bytes(pass, strlen(pass));
276 (void) puts(pm->msg);
280 (void) fputs(pm->msg, stderr);
281 (void) fputc('\n', stderr);
292 /* Zero and free allocated memory and return an error. */
293 for (pr = *response, n = num_msg; n--; pr++) {
294 if (pr->resp != NULL) {
295 zero_bytes(pr->resp, strlen(pr->resp));
300 zero_bytes(*response, num_msg * sizeof(struct pam_response));
303 return(PAM_CONV_ERR);