2 * Copyright (c) 1999-2005, 2007-2013 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>
32 #endif /* STDC_HEADERS */
35 #endif /* HAVE_STRING_H */
38 #endif /* HAVE_STRINGS_H */
41 #endif /* HAVE_UNISTD_H */
45 #ifdef HAVE_PAM_PAM_APPL_H
46 # include <pam/pam_appl.h>
48 # include <security/pam_appl.h>
52 # if defined(__LINUX_PAM__)
53 # define PAM_TEXT_DOMAIN "Linux-PAM"
54 # elif defined(__sun__)
55 # define PAM_TEXT_DOMAIN "SUNW_OST_SYSOSPAM"
59 /* We don't want to translate the strings in the calls to dgt(). */
60 #ifdef PAM_TEXT_DOMAIN
61 # define dgt(d, t) dgettext(d, t)
65 #include "sudo_auth.h"
67 /* Only OpenPAM and Linux PAM use const qualifiers. */
68 #if defined(_OPENPAM) || defined(OPENPAM_VERSION) || \
69 defined(__LIBPAM_VERSION) || defined(__LINUX_PAM__)
70 # define PAM_CONST const
75 #ifndef PAM_DATA_SILENT
76 #define PAM_DATA_SILENT 0
79 static int converse(int, PAM_CONST struct pam_message **,
80 struct pam_response **, void *);
81 static char *def_prompt = "Password:";
82 static bool sudo_pam_cred_established;
83 static bool sudo_pam_authenticated;
84 static int getpass_error;
85 static pam_handle_t *pamh;
88 sudo_pam_init(struct passwd *pw, sudo_auth *auth)
90 static struct pam_conv pam_conv;
91 static int pam_status;
92 debug_decl(sudo_pam_init, SUDO_DEBUG_AUTH)
94 /* Initial PAM setup */
96 auth->data = (void *) &pam_status;
97 pam_conv.conv = converse;
99 if (ISSET(sudo_mode, MODE_LOGIN_SHELL))
100 pam_status = pam_start("sudo-i", pw->pw_name, &pam_conv, &pamh);
103 pam_status = pam_start("sudo", pw->pw_name, &pam_conv, &pamh);
104 if (pam_status != PAM_SUCCESS) {
105 log_warning(USE_ERRNO|NO_MAIL, N_("unable to initialize PAM"));
106 debug_return_int(AUTH_FATAL);
110 * Set PAM_RUSER to the invoking user (the "from" user).
111 * We set PAM_RHOST to avoid a bug in Solaris 7 and below.
113 (void) pam_set_item(pamh, PAM_RUSER, user_name);
115 (void) pam_set_item(pamh, PAM_RHOST, user_host);
119 * Some versions of pam_lastlog have a bug that
120 * will cause a crash if PAM_TTY is not set so if
121 * there is no tty, set PAM_TTY to the empty string.
123 if (user_ttypath == NULL)
124 (void) pam_set_item(pamh, PAM_TTY, "");
126 (void) pam_set_item(pamh, PAM_TTY, user_ttypath);
128 debug_return_int(AUTH_SUCCESS);
132 sudo_pam_verify(struct passwd *pw, char *prompt, sudo_auth *auth)
135 int *pam_status = (int *) auth->data;
136 debug_decl(sudo_pam_verify, SUDO_DEBUG_AUTH)
138 def_prompt = prompt; /* for converse */
140 /* PAM_SILENT prevents the authentication service from generating output. */
141 *pam_status = pam_authenticate(pamh, PAM_SILENT);
142 switch (*pam_status) {
144 *pam_status = pam_acct_mgmt(pamh, PAM_SILENT);
145 switch (*pam_status) {
147 sudo_pam_authenticated = true;
148 debug_return_int(AUTH_SUCCESS);
150 log_warning(NO_MAIL, N_("account validation failure, "
151 "is your account locked?"));
152 debug_return_int(AUTH_FATAL);
153 case PAM_NEW_AUTHTOK_REQD:
154 log_warning(NO_MAIL, N_("Account or password is "
155 "expired, reset your password and try again"));
156 *pam_status = pam_chauthtok(pamh,
157 PAM_CHANGE_EXPIRED_AUTHTOK);
158 if (*pam_status == PAM_SUCCESS)
159 debug_return_int(AUTH_SUCCESS);
160 if ((s = pam_strerror(pamh, *pam_status)) != NULL) {
162 N_("unable to change expired password: %s"), s);
164 debug_return_int(AUTH_FAILURE);
165 case PAM_AUTHTOK_EXPIRED:
167 N_("Password expired, contact your system administrator"));
168 debug_return_int(AUTH_FATAL);
169 case PAM_ACCT_EXPIRED:
171 N_("Account expired or PAM config lacks an \"account\" "
172 "section for sudo, contact your system administrator"));
173 debug_return_int(AUTH_FATAL);
177 case PAM_AUTHINFO_UNAVAIL:
179 /* error or ^C from tgetpass() */
180 debug_return_int(AUTH_INTR);
184 case PAM_PERM_DENIED:
185 debug_return_int(AUTH_FAILURE);
187 if ((s = pam_strerror(pamh, *pam_status)) != NULL)
188 log_warning(NO_MAIL, N_("PAM authentication error: %s"), s);
189 debug_return_int(AUTH_FATAL);
194 sudo_pam_cleanup(struct passwd *pw, sudo_auth *auth)
196 int *pam_status = (int *) auth->data;
197 debug_decl(sudo_pam_cleanup, SUDO_DEBUG_AUTH)
199 /* If successful, we can't close the session until pam_end_session() */
200 if (*pam_status == AUTH_SUCCESS)
201 debug_return_int(AUTH_SUCCESS);
203 *pam_status = pam_end(pamh, *pam_status | PAM_DATA_SILENT);
205 debug_return_int(*pam_status == PAM_SUCCESS ? AUTH_SUCCESS : AUTH_FAILURE);
209 sudo_pam_begin_session(struct passwd *pw, char **user_envp[], sudo_auth *auth)
211 int status = PAM_SUCCESS;
212 debug_decl(sudo_pam_begin_session, SUDO_DEBUG_AUTH)
215 * If there is no valid user we cannot open a PAM session.
216 * This is not an error as sudo can run commands with arbitrary
217 * uids, it just means we are done from a session management standpoint.
221 (void) pam_end(pamh, PAM_SUCCESS | PAM_DATA_SILENT);
228 * Update PAM_USER to reference the user we are running the command
229 * as, as opposed to the user we authenticated as.
231 (void) pam_set_item(pamh, PAM_USER, pw->pw_name);
234 * Set credentials (may include resource limits, device ownership, etc).
235 * We don't check the return value here because in Linux-PAM 0.75
236 * it returns the last saved return code, not the return code
237 * for the setcred module. Because we haven't called pam_authenticate(),
238 * this is not set and so pam_setcred() returns PAM_PERM_DENIED.
239 * We can't call pam_acct_mgmt() with Linux-PAM for a similar reason.
241 status = pam_setcred(pamh, PAM_ESTABLISH_CRED);
242 if (status == PAM_SUCCESS) {
243 sudo_pam_cred_established = true;
244 } else if (sudo_pam_authenticated) {
245 const char *s = pam_strerror(pamh, status);
247 log_warning(NO_MAIL, N_("unable to establish credentials: %s"), s);
251 #ifdef HAVE_PAM_GETENVLIST
253 * Update environment based on what is stored in pamh.
254 * If no authentication is done we will only have environment
255 * variables if pam_env is called via session.
257 if (user_envp != NULL) {
258 char **pam_envp = pam_getenvlist(pamh);
259 if (pam_envp != NULL) {
260 /* Merge pam env with user env but do not overwrite. */
261 env_init(*user_envp);
262 env_merge(pam_envp, false);
263 *user_envp = env_get();
266 /* XXX - we leak any duplicates that were in pam_envp */
269 #endif /* HAVE_PAM_GETENVLIST */
271 if (def_pam_session) {
272 status = pam_open_session(pamh, 0);
273 if (status != PAM_SUCCESS) {
274 (void) pam_end(pamh, status | PAM_DATA_SILENT);
280 debug_return_int(status == PAM_SUCCESS ? AUTH_SUCCESS : AUTH_FAILURE);
284 sudo_pam_end_session(struct passwd *pw, sudo_auth *auth)
286 int status = PAM_SUCCESS;
287 debug_decl(sudo_pam_end_session, SUDO_DEBUG_AUTH)
291 * Update PAM_USER to reference the user we are running the command
292 * as, as opposed to the user we authenticated as.
293 * XXX - still needed now that session init is in parent?
295 (void) pam_set_item(pamh, PAM_USER, pw->pw_name);
297 (void) pam_close_session(pamh, PAM_SILENT);
298 if (sudo_pam_cred_established)
299 (void) pam_setcred(pamh, PAM_DELETE_CRED | PAM_SILENT);
300 status = pam_end(pamh, PAM_SUCCESS | PAM_DATA_SILENT);
304 debug_return_int(status == PAM_SUCCESS ? AUTH_SUCCESS : AUTH_FAILURE);
308 * ``Conversation function'' for PAM.
309 * XXX - does not handle PAM_BINARY_PROMPT
312 converse(int num_msg, PAM_CONST struct pam_message **msg,
313 struct pam_response **response, void *appdata_ptr)
315 struct pam_response *pr;
316 PAM_CONST struct pam_message *pm;
319 int n, type, std_prompt;
320 int ret = PAM_AUTH_ERR;
321 debug_decl(converse, SUDO_DEBUG_AUTH)
323 if ((*response = malloc(num_msg * sizeof(struct pam_response))) == NULL)
324 debug_return_int(PAM_SYSTEM_ERR);
325 zero_bytes(*response, num_msg * sizeof(struct pam_response));
327 for (pr = *response, pm = *msg, n = num_msg; n--; pr++, pm++) {
328 type = SUDO_CONV_PROMPT_ECHO_OFF;
329 switch (pm->msg_style) {
330 case PAM_PROMPT_ECHO_ON:
331 type = SUDO_CONV_PROMPT_ECHO_ON;
333 case PAM_PROMPT_ECHO_OFF:
336 /* Error out if the last password read was interrupted. */
340 /* Is the sudo prompt standard? (If so, we'll just use PAM's) */
341 std_prompt = strncmp(def_prompt, "Password:", 9) == 0 &&
342 (def_prompt[9] == '\0' ||
343 (def_prompt[9] == ' ' && def_prompt[10] == '\0'));
345 /* Only override PAM prompt if it matches /^Password: ?/ */
346 #if defined(PAM_TEXT_DOMAIN) && defined(HAVE_LIBINTL_H)
347 if (!def_passprompt_override && (std_prompt ||
348 (strcmp(pm->msg, dgt(PAM_TEXT_DOMAIN, "Password: ")) &&
349 strcmp(pm->msg, dgt(PAM_TEXT_DOMAIN, "Password:")))))
352 if (!def_passprompt_override && (std_prompt ||
353 strncmp(pm->msg, "Password:", 9) || (pm->msg[9] != '\0'
354 && (pm->msg[9] != ' ' || pm->msg[10] != '\0'))))
357 /* Read the password unless interrupted. */
358 pass = auth_getpass(prompt, def_passwd_timeout * 60, type);
360 /* Error (or ^C) reading password, don't try again. */
362 #if (defined(__darwin__) || defined(__APPLE__)) && !defined(OPENPAM_VERSION)
368 pr->resp = estrdup(pass);
369 zero_bytes(pass, strlen(pass));
373 (void) puts(pm->msg);
377 (void) fputs(pm->msg, stderr);
378 (void) fputc('\n', stderr);
389 if (ret != PAM_SUCCESS) {
390 /* Zero and free allocated memory and return an error. */
391 for (pr = *response, n = num_msg; n--; pr++) {
392 if (pr->resp != NULL) {
393 zero_bytes(pr->resp, strlen(pr->resp));
398 zero_bytes(*response, num_msg * sizeof(struct pam_response));
402 debug_return_int(ret);