[gssapi-openssh.git] / openssh / auth-pam.c

/*
 * Copyright (c) 2000 Damien Miller.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "includes.h"

#ifdef USE_PAM
#include "ssh.h"
#include "xmalloc.h"
#include "log.h"
#include "auth-pam.h"
#include "servconf.h"
#include "canohost.h"
#include "readpass.h"

extern char *__progname;

RCSID("$Id$");

#define NEW_AUTHTOK_MSG \
	"Warning: Your password has expired, please change it now"

static int do_pam_conversation(int num_msg, const struct pam_message **msg,
	struct pam_response **resp, void *appdata_ptr);

/* module-local variables */
static struct pam_conv conv = {
	do_pam_conversation,
	NULL
};
static char *__pam_msg = NULL;
static pam_handle_t *__pamh = NULL;
static const char *__pampasswd = NULL;

/* states for do_pam_conversation() */
enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
static int password_change_required = 0;
/* remember whether the last pam_authenticate() succeeded or not */
static int was_authenticated = 0;

/* Remember what has been initialised */
static int session_opened = 0;
static int creds_set = 0;

/* accessor which allows us to switch conversation structs according to
 * the authentication method being used */
void do_pam_set_conv(struct pam_conv *conv)
{
	pam_set_item(__pamh, PAM_CONV, conv);
}

/* start an authentication run */
int do_pam_authenticate(int flags)
{
	int retval = pam_authenticate(__pamh, flags);
	was_authenticated = (retval == PAM_SUCCESS);
	return retval;
}

/*
 * PAM conversation function.
 * There are two states this can run in.
 *
 * INITIAL_LOGIN mode simply feeds the password from the client into
 * PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
 * messages with into __pam_msg.  This is used during initial
 * authentication to bypass the normal PAM password prompt.
 *
 * OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase()
 * and outputs messages to stderr. This mode is used if pam_chauthtok()
 * is called to update expired passwords.
 */
static int do_pam_conversation(int num_msg, const struct pam_message **msg,
	struct pam_response **resp, void *appdata_ptr)
{
	struct pam_response *reply;
	int count;
	char buf[1024];

	/* PAM will free this later */
	reply = malloc(num_msg * sizeof(*reply));
	if (reply == NULL)
		return PAM_CONV_ERR;

	for (count = 0; count < num_msg; count++) {
		if (pamstate == INITIAL_LOGIN) {
			/*
			 * We can't use stdio yet, queue messages for 
			 * printing later
			 */
			switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
			case PAM_PROMPT_ECHO_ON:
				free(reply);
				return PAM_CONV_ERR;
			case PAM_PROMPT_ECHO_OFF:
				if (__pampasswd == NULL) {
					free(reply);
					return PAM_CONV_ERR;
				}
				reply[count].resp = xstrdup(__pampasswd);
				reply[count].resp_retcode = PAM_SUCCESS;
				break;
			case PAM_ERROR_MSG:
			case PAM_TEXT_INFO:
				if ((*msg)[count].msg != NULL) {
					message_cat(&__pam_msg, 
					    PAM_MSG_MEMBER(msg, count, msg));
				}
				reply[count].resp = xstrdup("");
				reply[count].resp_retcode = PAM_SUCCESS;
				break;
			default:
				free(reply);
				return PAM_CONV_ERR;
			}
		} else {
			/*
			 * stdio is connected, so interact directly
			 */
			switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
			case PAM_PROMPT_ECHO_ON:
				fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
				fgets(buf, sizeof(buf), stdin);
				reply[count].resp = xstrdup(buf);
				reply[count].resp_retcode = PAM_SUCCESS;
				break;
			case PAM_PROMPT_ECHO_OFF:
				reply[count].resp = 
				    read_passphrase(PAM_MSG_MEMBER(msg, count,
					msg), RP_ALLOW_STDIN);
				reply[count].resp_retcode = PAM_SUCCESS;
				break;
			case PAM_ERROR_MSG:
			case PAM_TEXT_INFO:
				if ((*msg)[count].msg != NULL)
					fprintf(stderr, "%s\n", 
					    PAM_MSG_MEMBER(msg, count, msg));
				reply[count].resp = xstrdup("");
				reply[count].resp_retcode = PAM_SUCCESS;
				break;
			default:
				free(reply);
				return PAM_CONV_ERR;
			}
		}
	}

	*resp = reply;

	return PAM_SUCCESS;
}

/* Called at exit to cleanly shutdown PAM */
void do_pam_cleanup_proc(void *context)
{
	int pam_retval = PAM_SUCCESS;

	if (__pamh && session_opened) {
		pam_retval = pam_close_session(__pamh, 0);
		if (pam_retval != PAM_SUCCESS)
			log("Cannot close PAM session[%d]: %.200s",
			    pam_retval, PAM_STRERROR(__pamh, pam_retval));
	}

	if (__pamh && creds_set) {
		pam_retval = pam_setcred(__pamh, PAM_DELETE_CRED);
		if (pam_retval != PAM_SUCCESS)
			debug("Cannot delete credentials[%d]: %.200s", 
			    pam_retval, PAM_STRERROR(__pamh, pam_retval));
	}

	if (__pamh) {
		pam_retval = pam_end(__pamh, pam_retval);
		if (pam_retval != PAM_SUCCESS)
			log("Cannot release PAM authentication[%d]: %.200s",
			    pam_retval, PAM_STRERROR(__pamh, pam_retval));
	}
}

/* Attempt password authentation using PAM */
int auth_pam_password(struct passwd *pw, const char *password)
{
	extern ServerOptions options;
	int pam_retval;

	do_pam_set_conv(&conv);

	/* deny if no user. */
	if (pw == NULL)
		return 0;
	if (pw->pw_uid == 0 && options.permit_root_login == PERMIT_NO_PASSWD)
		return 0;
	if (*password == '\0' && options.permit_empty_passwd == 0)
		return 0;

	__pampasswd = password;

	pamstate = INITIAL_LOGIN;
	pam_retval = do_pam_authenticate(
	    options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0);
	if (pam_retval == PAM_SUCCESS) {
		debug("PAM Password authentication accepted for "
		    "user \"%.100s\"", pw->pw_name);
		return 1;
	} else {
		debug("PAM Password authentication for \"%.100s\" "
		    "failed[%d]: %s", pw->pw_name, pam_retval, 
		    PAM_STRERROR(__pamh, pam_retval));
		return 0;
	}
}

/* Do account management using PAM */
int do_pam_account(char *username, char *remote_user)
{
	int pam_retval;

	do_pam_set_conv(&conv);

	if (remote_user) {
		debug("PAM setting ruser to \"%.200s\"", remote_user);
		pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
		if (pam_retval != PAM_SUCCESS)
			fatal("PAM set ruser failed[%d]: %.200s", pam_retval, 
			    PAM_STRERROR(__pamh, pam_retval));
	}

	pam_retval = pam_acct_mgmt(__pamh, 0);
	switch (pam_retval) {
		case PAM_SUCCESS:
			/* This is what we want */
			break;
		case PAM_NEW_AUTHTOK_REQD:
			message_cat(&__pam_msg, NEW_AUTHTOK_MSG);
			/* flag that password change is necessary */
			password_change_required = 1;
			break;
		default:
			log("PAM rejected by account configuration[%d]: "
			    "%.200s", pam_retval, PAM_STRERROR(__pamh, 
			    pam_retval));
			return(0);
	}

	return(1);
}

/* Do PAM-specific session initialisation */
void do_pam_session(char *username, const char *ttyname)
{
	int pam_retval;

	do_pam_set_conv(&conv);

	if (ttyname != NULL) {
		debug("PAM setting tty to \"%.200s\"", ttyname);
		pam_retval = pam_set_item(__pamh, PAM_TTY, ttyname);
		if (pam_retval != PAM_SUCCESS)
			fatal("PAM set tty failed[%d]: %.200s",
			    pam_retval, PAM_STRERROR(__pamh, pam_retval));
	}

	pam_retval = pam_open_session(__pamh, 0);
	if (pam_retval != PAM_SUCCESS)
		fatal("PAM session setup failed[%d]: %.200s",
		    pam_retval, PAM_STRERROR(__pamh, pam_retval));

	session_opened = 1;
}

/* Set PAM credentials */
void do_pam_setcred(int init)
{
	int pam_retval;

	do_pam_set_conv(&conv);

	debug("PAM establishing creds");
	pam_retval = pam_setcred(__pamh, 
	    init ? PAM_ESTABLISH_CRED : PAM_REINITIALIZE_CRED);
	if (pam_retval != PAM_SUCCESS) {
		if (was_authenticated)
			fatal("PAM setcred failed[%d]: %.200s",
			    pam_retval, PAM_STRERROR(__pamh, pam_retval));
		else
			debug("PAM setcred failed[%d]: %.200s",
			    pam_retval, PAM_STRERROR(__pamh, pam_retval));
	} else
		creds_set = 1;
}

/* accessor function for file scope static variable */
int is_pam_password_change_required(void)
{
	return password_change_required;
}

/*
 * Have user change authentication token if pam_acct_mgmt() indicated
 * it was expired.  This needs to be called after an interactive
 * session is established and the user's pty is connected to
 * stdin/stout/stderr.
 */
void do_pam_chauthtok(void)
{
	int pam_retval;

	do_pam_set_conv(&conv);

	if (password_change_required) {
		pamstate = OTHER;
		pam_retval = pam_chauthtok(__pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
		if (pam_retval != PAM_SUCCESS)
			fatal("PAM pam_chauthtok failed[%d]: %.200s",
			    pam_retval, PAM_STRERROR(__pamh, pam_retval));
	}
}

/* Cleanly shutdown PAM */
void finish_pam(void)
{
	do_pam_cleanup_proc(NULL);
	fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
}

/* Start PAM authentication for specified account */
void start_pam(const char *user)
{
	int pam_retval;
	extern ServerOptions options;
	extern u_int utmp_len;
	const char *rhost;

	debug("Starting up PAM with username \"%.200s\"", user);

	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);

	if (pam_retval != PAM_SUCCESS)
		fatal("PAM initialisation failed[%d]: %.200s",
		    pam_retval, PAM_STRERROR(__pamh, pam_retval));

	rhost = get_remote_name_or_ip(utmp_len, options.reverse_mapping_check);
	debug("PAM setting rhost to \"%.200s\"", rhost);

	pam_retval = pam_set_item(__pamh, PAM_RHOST, rhost);
	if (pam_retval != PAM_SUCCESS)
		fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
		    PAM_STRERROR(__pamh, pam_retval));
#ifdef PAM_TTY_KLUDGE
	/*
	 * Some PAM modules (e.g. pam_time) require a TTY to operate,
	 * and will fail in various stupid ways if they don't get one.
	 * sshd doesn't set the tty until too late in the auth process and may
	 * not even need one (for tty-less connections)
	 * Kludge: Set a fake PAM_TTY
	 */
	pam_retval = pam_set_item(__pamh, PAM_TTY, "NODEVssh");
	if (pam_retval != PAM_SUCCESS)
		fatal("PAM set tty failed[%d]: %.200s",
		    pam_retval, PAM_STRERROR(__pamh, pam_retval));
#endif /* PAM_TTY_KLUDGE */

	fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
}

/* Return list of PAM enviornment strings */
char **fetch_pam_environment(void)
{
#ifdef HAVE_PAM_GETENVLIST
	return(pam_getenvlist(__pamh));
#else /* HAVE_PAM_GETENVLIST */
	return(NULL);
#endif /* HAVE_PAM_GETENVLIST */
}

/* Print any messages that have been generated during authentication */
/* or account checking to stderr */
void print_pam_messages(void)
{
	if (__pam_msg != NULL)
		fputs(__pam_msg, stderr);
}

/* Append a message to buffer */
void message_cat(char **p, const char *a)
{
	char *cp;
	size_t new_len;

	new_len = strlen(a);

	if (*p) {
		size_t len = strlen(*p);

		*p = xrealloc(*p, new_len + len + 2);
		cp = *p + len;
	} else
		*p = cp = xmalloc(new_len + 2);

	memcpy(cp, a, new_len);
	cp[new_len] = '\n';
	cp[new_len + 1] = '\0';
}

#endif /* USE_PAM */
Commit	Line	Data
3c0ef626	1	/*
	2	* Copyright (c) 2000 Damien Miller. All rights reserved.
	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	7	* 1. Redistributions of source code must retain the above copyright
	8	* notice, this list of conditions and the following disclaimer.
	9	* 2. Redistributions in binary form must reproduce the above copyright
	10	* notice, this list of conditions and the following disclaimer in the
	11	* documentation and/or other materials provided with the distribution.
	12	*
	13	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	14	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	15	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	16	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	17	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	18	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	19	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	20	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	21	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	22	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	23	*/
	24
	25	#include "includes.h"
	26
	27	#ifdef USE_PAM
	28	#include "ssh.h"
	29	#include "xmalloc.h"
	30	#include "log.h"
	31	#include "auth-pam.h"
	32	#include "servconf.h"
	33	#include "canohost.h"
	34	#include "readpass.h"
	35
	36	extern char *__progname;
	37
	38	RCSID("$Id$");
	39
	40	#define NEW_AUTHTOK_MSG \
	41	"Warning: Your password has expired, please change it now"
	42
	43	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
	44	struct pam_response *resp, void appdata_ptr);
	45
	46	/* module-local variables */
	47	static struct pam_conv conv = {
	48	do_pam_conversation,
	49	NULL
	50	};
	51	static char *__pam_msg = NULL;
	52	static pam_handle_t *__pamh = NULL;
	53	static const char *__pampasswd = NULL;
	54
	55	/* states for do_pam_conversation() */
	56	enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
	57	/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
	58	static int password_change_required = 0;
	59	/* remember whether the last pam_authenticate() succeeded or not */
	60	static int was_authenticated = 0;
	61
	62	/* Remember what has been initialised */
	63	static int session_opened = 0;
	64	static int creds_set = 0;
65
66	/* accessor which allows us to switch conversation structs according to
67	* the authentication method being used */
68	void do_pam_set_conv(struct pam_conv *conv)
69	{
70	pam_set_item(__pamh, PAM_CONV, conv);
71	}
72
73	/* start an authentication run */
74	int do_pam_authenticate(int flags)
75	{
76	int retval = pam_authenticate(__pamh, flags);
77	was_authenticated = (retval == PAM_SUCCESS);
78	return retval;
79	}
80
81	/*
82	* PAM conversation function.
83	* There are two states this can run in.
84	*
85	* INITIAL_LOGIN mode simply feeds the password from the client into
86	* PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
87	* messages with into __pam_msg. This is used during initial
88	* authentication to bypass the normal PAM password prompt.
89	*
90	* OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase()
91	* and outputs messages to stderr. This mode is used if pam_chauthtok()
92	* is called to update expired passwords.
93	*/
94	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
95	struct pam_response *resp, void appdata_ptr)
96	{
97	struct pam_response *reply;
98	int count;
99	char buf[1024];
100
101	/* PAM will free this later */
102	reply = malloc(num_msg * sizeof(*reply));
103	if (reply == NULL)
104	return PAM_CONV_ERR;
105
106	for (count = 0; count < num_msg; count++) {
107	if (pamstate == INITIAL_LOGIN) {
108	/*
109	* We can't use stdio yet, queue messages for
110	* printing later
111	*/
112	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
113	case PAM_PROMPT_ECHO_ON:
114	free(reply);
115	return PAM_CONV_ERR;
116	case PAM_PROMPT_ECHO_OFF:
117	if (__pampasswd == NULL) {
118	free(reply);
119	return PAM_CONV_ERR;
120	}
121	reply[count].resp = xstrdup(__pampasswd);
122	reply[count].resp_retcode = PAM_SUCCESS;
123	break;
124	case PAM_ERROR_MSG:
125	case PAM_TEXT_INFO:
126	if ((*msg)[count].msg != NULL) {
127	message_cat(&__pam_msg,
128	PAM_MSG_MEMBER(msg, count, msg));
129	}
130	reply[count].resp = xstrdup("");
131	reply[count].resp_retcode = PAM_SUCCESS;
132	break;
133	default:
134	free(reply);
135	return PAM_CONV_ERR;
136	}
137	} else {
138	/*
139	* stdio is connected, so interact directly
140	*/
141	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
142	case PAM_PROMPT_ECHO_ON:
143	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
144	fgets(buf, sizeof(buf), stdin);
145	reply[count].resp = xstrdup(buf);
146	reply[count].resp_retcode = PAM_SUCCESS;
147	break;
148	case PAM_PROMPT_ECHO_OFF:
149	reply[count].resp =
150	read_passphrase(PAM_MSG_MEMBER(msg, count,
151	msg), RP_ALLOW_STDIN);
152	reply[count].resp_retcode = PAM_SUCCESS;
153	break;
154	case PAM_ERROR_MSG:
155	case PAM_TEXT_INFO:
156	if ((*msg)[count].msg != NULL)
157	fprintf(stderr, "%s\n",
158	PAM_MSG_MEMBER(msg, count, msg));
159	reply[count].resp = xstrdup("");
160	reply[count].resp_retcode = PAM_SUCCESS;
161	break;
162	default:
163	free(reply);
164	return PAM_CONV_ERR;
165	}
166	}
167	}
168
169	*resp = reply;
170
171	return PAM_SUCCESS;
172	}
173
174	/* Called at exit to cleanly shutdown PAM */
175	void do_pam_cleanup_proc(void *context)
176	{
177	int pam_retval = PAM_SUCCESS;
178
179	if (__pamh && session_opened) {
180	pam_retval = pam_close_session(__pamh, 0);
181	if (pam_retval != PAM_SUCCESS)
182	log("Cannot close PAM session[%d]: %.200s",
183	pam_retval, PAM_STRERROR(__pamh, pam_retval));
184	}
185
186	if (__pamh && creds_set) {
187	pam_retval = pam_setcred(__pamh, PAM_DELETE_CRED);
188	if (pam_retval != PAM_SUCCESS)
189	debug("Cannot delete credentials[%d]: %.200s",
190	pam_retval, PAM_STRERROR(__pamh, pam_retval));
191	}
192
193	if (__pamh) {
194	pam_retval = pam_end(__pamh, pam_retval);
195	if (pam_retval != PAM_SUCCESS)
196	log("Cannot release PAM authentication[%d]: %.200s",
197	pam_retval, PAM_STRERROR(__pamh, pam_retval));
198	}
199	}
200
201	/* Attempt password authentation using PAM */
202	int auth_pam_password(struct passwd pw, const char password)
203	{
204	extern ServerOptions options;
205	int pam_retval;
206
207	do_pam_set_conv(&conv);
208
209	/* deny if no user. */
210	if (pw == NULL)
211	return 0;
212	if (pw->pw_uid == 0 && options.permit_root_login == PERMIT_NO_PASSWD)
213	return 0;
214	if (*password == '\0' && options.permit_empty_passwd == 0)
215	return 0;
216
217	__pampasswd = password;
218
219	pamstate = INITIAL_LOGIN;
220	pam_retval = do_pam_authenticate(
221	options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0);
222	if (pam_retval == PAM_SUCCESS) {
223	debug("PAM Password authentication accepted for "
224	"user \"%.100s\"", pw->pw_name);
225	return 1;
226	} else {
227	debug("PAM Password authentication for \"%.100s\" "
228	"failed[%d]: %s", pw->pw_name, pam_retval,
229	PAM_STRERROR(__pamh, pam_retval));
230	return 0;
231	}
232	}
233
234	/* Do account management using PAM */
235	int do_pam_account(char username, char remote_user)
236	{
237	int pam_retval;
238
239	do_pam_set_conv(&conv);
240
241	if (remote_user) {
242	debug("PAM setting ruser to \"%.200s\"", remote_user);
243	pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
244	if (pam_retval != PAM_SUCCESS)
245	fatal("PAM set ruser failed[%d]: %.200s", pam_retval,
246	PAM_STRERROR(__pamh, pam_retval));
247	}
248
249	pam_retval = pam_acct_mgmt(__pamh, 0);
250	switch (pam_retval) {
251	case PAM_SUCCESS:
252	/* This is what we want */
253	break;
254	case PAM_NEW_AUTHTOK_REQD:
255	message_cat(&__pam_msg, NEW_AUTHTOK_MSG);
256	/* flag that password change is necessary */
257	password_change_required = 1;
258	break;
259	default:
260	log("PAM rejected by account configuration[%d]: "
261	"%.200s", pam_retval, PAM_STRERROR(__pamh,
262	pam_retval));
263	return(0);
264	}
265
266	return(1);
267	}
268
269	/* Do PAM-specific session initialisation */
270	void do_pam_session(char username, const char ttyname)
271	{
272	int pam_retval;
273
274	do_pam_set_conv(&conv);
275
276	if (ttyname != NULL) {
277	debug("PAM setting tty to \"%.200s\"", ttyname);
278	pam_retval = pam_set_item(__pamh, PAM_TTY, ttyname);
279	if (pam_retval != PAM_SUCCESS)
280	fatal("PAM set tty failed[%d]: %.200s",
281	pam_retval, PAM_STRERROR(__pamh, pam_retval));
282	}
283
284	pam_retval = pam_open_session(__pamh, 0);
285	if (pam_retval != PAM_SUCCESS)
286	fatal("PAM session setup failed[%d]: %.200s",
287	pam_retval, PAM_STRERROR(__pamh, pam_retval));
288
289	session_opened = 1;
290	}
291
292	/* Set PAM credentials */
293	void do_pam_setcred(int init)
294	{
295	int pam_retval;
296
297	do_pam_set_conv(&conv);
298
299	debug("PAM establishing creds");
300	pam_retval = pam_setcred(__pamh,
301	init ? PAM_ESTABLISH_CRED : PAM_REINITIALIZE_CRED);
302	if (pam_retval != PAM_SUCCESS) {
303	if (was_authenticated)
304	fatal("PAM setcred failed[%d]: %.200s",
305	pam_retval, PAM_STRERROR(__pamh, pam_retval));
306	else
307	debug("PAM setcred failed[%d]: %.200s",
308	pam_retval, PAM_STRERROR(__pamh, pam_retval));
309	} else
310	creds_set = 1;
311	}
312
313	/* accessor function for file scope static variable */
314	int is_pam_password_change_required(void)
315	{
316	return password_change_required;
317	}
318
319	/*
320	* Have user change authentication token if pam_acct_mgmt() indicated
321	* it was expired. This needs to be called after an interactive
322	* session is established and the user's pty is connected to
323	* stdin/stout/stderr.
324	*/
325	void do_pam_chauthtok(void)
326	{
327	int pam_retval;
328
329	do_pam_set_conv(&conv);
330
331	if (password_change_required) {
332	pamstate = OTHER;
333	pam_retval = pam_chauthtok(__pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
334	if (pam_retval != PAM_SUCCESS)
335	fatal("PAM pam_chauthtok failed[%d]: %.200s",
336	pam_retval, PAM_STRERROR(__pamh, pam_retval));
337	}
338	}
339
340	/* Cleanly shutdown PAM */
341	void finish_pam(void)
342	{
343	do_pam_cleanup_proc(NULL);
344	fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
345	}
346
347	/* Start PAM authentication for specified account */
348	void start_pam(const char *user)
349	{
350	int pam_retval;
351	extern ServerOptions options;
352	extern u_int utmp_len;
353	const char *rhost;
354
355	debug("Starting up PAM with username \"%.200s\"", user);
356
357	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);
358
359	if (pam_retval != PAM_SUCCESS)
360	fatal("PAM initialisation failed[%d]: %.200s",
361	pam_retval, PAM_STRERROR(__pamh, pam_retval));
362
363	rhost = get_remote_name_or_ip(utmp_len, options.reverse_mapping_check);
364	debug("PAM setting rhost to \"%.200s\"", rhost);
365
366	pam_retval = pam_set_item(__pamh, PAM_RHOST, rhost);
367	if (pam_retval != PAM_SUCCESS)
368	fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
369	PAM_STRERROR(__pamh, pam_retval));
370	#ifdef PAM_TTY_KLUDGE
371	/*
372	* Some PAM modules (e.g. pam_time) require a TTY to operate,
373	* and will fail in various stupid ways if they don't get one.
374	* sshd doesn't set the tty until too late in the auth process and may
375	* not even need one (for tty-less connections)
376	* Kludge: Set a fake PAM_TTY
377	*/
378	pam_retval = pam_set_item(__pamh, PAM_TTY, "NODEVssh");
379	if (pam_retval != PAM_SUCCESS)
380	fatal("PAM set tty failed[%d]: %.200s",
381	pam_retval, PAM_STRERROR(__pamh, pam_retval));
382	#endif /* PAM_TTY_KLUDGE */
383
384	fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
385	}
386
387	/* Return list of PAM enviornment strings */
388	char **fetch_pam_environment(void)
389	{
390	#ifdef HAVE_PAM_GETENVLIST
391	return(pam_getenvlist(__pamh));
392	#else /* HAVE_PAM_GETENVLIST */
393	return(NULL);
394	#endif /* HAVE_PAM_GETENVLIST */
395	}
396
397	/* Print any messages that have been generated during authentication */
398	/* or account checking to stderr */
399	void print_pam_messages(void)
400	{
401	if (__pam_msg != NULL)
402	fputs(__pam_msg, stderr);
403	}
404
405	/* Append a message to buffer */
406	void message_cat(char *p, const char a)
407	{
408	char *cp;
409	size_t new_len;
410
411	new_len = strlen(a);
412
413	if (*p) {
414	size_t len = strlen(*p);
415
416	p = xrealloc(p, new_len + len + 2);
417	cp = *p + len;
418	} else
419	*p = cp = xmalloc(new_len + 2);
420
421	memcpy(cp, a, new_len);
422	cp[new_len] = '\n';
423	cp[new_len + 1] = '\0';
424	}
425
426	#endif /* USE_PAM */