[openssh.git] / 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 "servconf.h"

RCSID("$Id$");

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

/* Callbacks */
static int pamconv(int num_msg, const struct pam_message **msg,
	  struct pam_response **resp, void *appdata_ptr);
void pam_cleanup_proc(void *context);
void pam_msg_cat(const char *msg);

/* module-local variables */
static struct pam_conv conv = {
	pamconv,
	NULL
};
static pam_handle_t *pamh = NULL;
static const char *pampasswd = NULL;
static char *pam_msg = NULL;

/* states for pamconv() */
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;

/* accessor which allows us to switch conversation structs according to
 * the authentication method being used */
void 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 pam_msg_cat().  This is used during initial
 * authentication to bypass the normal PAM password prompt.
 *
 * OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase(prompt, 1)
 * and outputs messages to stderr. This mode is used if pam_chauthtok()
 * is called to update expired passwords.
 */
static int pamconv(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++) {
		switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
			case PAM_PROMPT_ECHO_ON:
				if (pamstate == INITIAL_LOGIN) {
					free(reply);
					return PAM_CONV_ERR;
				} else {
					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:
				if (pamstate == INITIAL_LOGIN) {
					if (pampasswd == NULL) {
						free(reply);
						return PAM_CONV_ERR;
					}
					reply[count].resp = xstrdup(pampasswd);
				} else {
					reply[count].resp = 
						xstrdup(read_passphrase(PAM_MSG_MEMBER(msg, count, msg), 1));
				}
				reply[count].resp_retcode = PAM_SUCCESS;
				break;
			case PAM_ERROR_MSG:
			case PAM_TEXT_INFO:
				if ((*msg)[count].msg != NULL) {
					if (pamstate == INITIAL_LOGIN)
						pam_msg_cat(PAM_MSG_MEMBER(msg, count, msg));
					else {
						fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
						fputs("\n", stderr);
					}
				}
				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 pam_cleanup_proc(void *context)
{
	int pam_retval;

	if (pamh != NULL)
	{
		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));
		}

		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));
		}

		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;

	pam_set_conv(&conv);

	/* deny if no user. */
	if (pw == NULL)
		return 0;
	if (pw->pw_uid == 0 && options.permit_root_login == 2)
		return 0;
	if (*password == '\0' && options.permit_empty_passwd == 0)
		return 0;

	pampasswd = password;
	
	pamstate = INITIAL_LOGIN;
	pam_retval = do_pam_authenticate(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;
	
	debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname());
	pam_retval = pam_set_item(pamh, PAM_RHOST, 
		get_canonical_hostname());
	if (pam_retval != PAM_SUCCESS) {
		fatal("PAM set rhost failed[%d]: %.200s", 
			pam_retval, PAM_STRERROR(pamh, pam_retval));
	}

	if (remote_user != NULL) {
		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:
			pam_msg_cat(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;

	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));
	}
}

/* Set PAM credentials */ 
void do_pam_setcred(void)
{
	int pam_retval;
 
	debug("PAM establishing creds");
	pam_retval = pam_setcred(pamh, PAM_ESTABLISH_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));
		}
	}
}

/* accessor function for file scope static variable */
int 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;

	if (password_change_required) {
		pamstate = OTHER;
		/*
		 * XXX: should we really loop forever?
		 */
		do {
			pam_retval = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
			if (pam_retval != PAM_SUCCESS) {
				log("PAM pam_chauthtok failed[%d]: %.200s", 
					pam_retval, PAM_STRERROR(pamh, pam_retval));
			}
		} while (pam_retval != PAM_SUCCESS);
	}
}

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

/* Start PAM authentication for specified account */
void start_pam(const char *user)
{
	int pam_retval;

	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));
	}

#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, "ssh");
	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(&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 the PAM message buffer */
void pam_msg_cat(const char *msg)
{
	char *p;
	size_t new_msg_len;
	size_t pam_msg_len;
	
	new_msg_len = strlen(msg);
	
	if (pam_msg) {
		pam_msg_len = strlen(pam_msg);
		pam_msg = xrealloc(pam_msg, new_msg_len + pam_msg_len + 2);
		p = pam_msg + pam_msg_len;
	} else {
		pam_msg = p = xmalloc(new_msg_len + 2);
	}

	memcpy(p, msg, new_msg_len);
	p[new_msg_len] = '\n';
	p[new_msg_len + 1] = '\0';
}

#endif /* USE_PAM */
Commit	Line	Data
a5c9cd31	1	/*
09564242	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.
09564242	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.
a5c9cd31	23	*/
	24
	25	#include "includes.h"
	26
	27	#ifdef USE_PAM
	28	#include "ssh.h"
	29	#include "xmalloc.h"
	30	#include "servconf.h"
	31
	32	RCSID("$Id$");
	33
5daf7064	34	#define NEW_AUTHTOK_MSG \
ad55cd03	35	"Warning: Your password has expired, please change it now"
5daf7064	36
a5c9cd31	37	/* Callbacks */
	38	static int pamconv(int num_msg, const struct pam_message **msg,
	39	struct pam_response *resp, void appdata_ptr);
	40	void pam_cleanup_proc(void *context);
5daf7064	41	void pam_msg_cat(const char *msg);
a5c9cd31	42
	43	/* module-local variables */
	44	static struct pam_conv conv = {
	45	pamconv,
	46	NULL
	47	};
ad55cd03	48	static pam_handle_t *pamh = NULL;
a5c9cd31	49	static const char *pampasswd = NULL;
5daf7064	50	static char *pam_msg = NULL;
a5c9cd31	51
ad55cd03	52	/* states for pamconv() */
8c9fe09e	53	enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
ad55cd03	54	/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
ad55cd03	55	static int password_change_required = 0;
8c9fe09e	56	/* remember whether the last pam_authenticate() succeeded or not */
	57	static int was_authenticated = 0;
	58
	59	/* accessor which allows us to switch conversation structs according to
	60	* the authentication method being used */
	61	void pam_set_conv(struct pam_conv *conv)
	62	{
	63	pam_set_item(pamh, PAM_CONV, conv);
	64	}
	65
	66	/* start an authentication run */
	67	int do_pam_authenticate(int flags)
	68	{
	69	int retval = pam_authenticate(pamh, flags);
	70	was_authenticated = (retval == PAM_SUCCESS);
	71	return retval;
	72	}
ad55cd03	73
	74	/*
	75	* PAM conversation function.
	76	* There are two states this can run in.
	77	*
	78	* INITIAL_LOGIN mode simply feeds the password from the client into
	79	* PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
	80	* messages with pam_msg_cat(). This is used during initial
	81	* authentication to bypass the normal PAM password prompt.
	82	*
	83	* OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase(prompt, 1)
	84	* and outputs messages to stderr. This mode is used if pam_chauthtok()
	85	* is called to update expired passwords.
	86	*/
a5c9cd31	87	static int pamconv(int num_msg, const struct pam_message **msg,
	88	struct pam_response *resp, void appdata_ptr)
	89	{
	90	struct pam_response *reply;
	91	int count;
ad55cd03	92	char buf[1024];
a5c9cd31	93
	94	/* PAM will free this later */
	95	reply = malloc(num_msg * sizeof(*reply));
	96	if (reply == NULL)
	97	return PAM_CONV_ERR;
	98
ad55cd03	99	for (count = 0; count < num_msg; count++) {
adeebd37	100	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
ad55cd03	101	case PAM_PROMPT_ECHO_ON:
71dfaf1c	102	if (pamstate == INITIAL_LOGIN) {
	103	free(reply);
	104	return PAM_CONV_ERR;
	105	} else {
adeebd37	106	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
71dfaf1c	107	fgets(buf, sizeof(buf), stdin);
	108	reply[count].resp = xstrdup(buf);
	109	reply[count].resp_retcode = PAM_SUCCESS;
	110	break;
	111	}
a5c9cd31	112	case PAM_PROMPT_ECHO_OFF:
ad55cd03	113	if (pamstate == INITIAL_LOGIN) {
	114	if (pampasswd == NULL) {
	115	free(reply);
	116	return PAM_CONV_ERR;
	117	}
	118	reply[count].resp = xstrdup(pampasswd);
71dfaf1c	119	} else {
71dfaf1c	120	reply[count].resp =
adeebd37	121	xstrdup(read_passphrase(PAM_MSG_MEMBER(msg, count, msg), 1));
71dfaf1c	122	}
a5c9cd31	123	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	124	break;
ad55cd03	125	case PAM_ERROR_MSG:
a5c9cd31	126	case PAM_TEXT_INFO:
ad55cd03	127	if ((*msg)[count].msg != NULL) {
ad55cd03	128	if (pamstate == INITIAL_LOGIN)
adeebd37	129	pam_msg_cat(PAM_MSG_MEMBER(msg, count, msg));
ad55cd03	130	else {
adeebd37	131	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
ad55cd03	132	fputs("\n", stderr);
	133	}
	134	}
a5c9cd31	135	reply[count].resp = xstrdup("");
ad55cd03	136	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	137	break;
a5c9cd31	138	default:
	139	free(reply);
	140	return PAM_CONV_ERR;
	141	}
	142	}
	143
	144	*resp = reply;
	145
	146	return PAM_SUCCESS;
	147	}
	148
	149	/* Called at exit to cleanly shutdown PAM */
	150	void pam_cleanup_proc(void *context)
	151	{
	152	int pam_retval;
	153
	154	if (pamh != NULL)
	155	{
ad55cd03	156	pam_retval = pam_close_session(pamh, 0);
a5c9cd31	157	if (pam_retval != PAM_SUCCESS) {
ebd782f7	158	log("Cannot close PAM session[%d]: %.200s",
ebd782f7	159	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	160	}
a5c9cd31	161
ad55cd03	162	pam_retval = pam_setcred(pamh, PAM_DELETE_CRED);
a5c9cd31	163	if (pam_retval != PAM_SUCCESS) {
ebd782f7	164	debug("Cannot delete credentials[%d]: %.200s",
ebd782f7	165	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	166	}
a5c9cd31	167
ad55cd03	168	pam_retval = pam_end(pamh, pam_retval);
a5c9cd31	169	if (pam_retval != PAM_SUCCESS) {
ebd782f7	170	log("Cannot release PAM authentication[%d]: %.200s",
ebd782f7	171	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	172	}
	173	}
	174	}
	175
	176	/* Attempt password authentation using PAM */
	177	int auth_pam_password(struct passwd pw, const char password)
	178	{
	179	extern ServerOptions options;
	180	int pam_retval;
	181
8c9fe09e	182	pam_set_conv(&conv);
8c9fe09e	183
a5c9cd31	184	/* deny if no user. */
	185	if (pw == NULL)
	186	return 0;
	187	if (pw->pw_uid == 0 && options.permit_root_login == 2)
	188	return 0;
	189	if (*password == '\0' && options.permit_empty_passwd == 0)
	190	return 0;
	191
	192	pampasswd = password;
	193
ad55cd03	194	pamstate = INITIAL_LOGIN;
8c9fe09e	195	pam_retval = do_pam_authenticate(0);
a5c9cd31	196	if (pam_retval == PAM_SUCCESS) {
5daf7064	197	debug("PAM Password authentication accepted for user \"%.100s\"",
5daf7064	198	pw->pw_name);
a5c9cd31	199	return 1;
a5c9cd31	200	} else {
ebd782f7	201	debug("PAM Password authentication for \"%.100s\" failed[%d]: %s",
ebd782f7	202	pw->pw_name, pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	203	return 0;
	204	}
	205	}
	206
	207	/* Do account management using PAM */
	208	int do_pam_account(char username, char remote_user)
	209	{
	210	int pam_retval;
5daf7064	211
a5c9cd31	212	debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname());
ad55cd03	213	pam_retval = pam_set_item(pamh, PAM_RHOST,
a5c9cd31	214	get_canonical_hostname());
a5c9cd31	215	if (pam_retval != PAM_SUCCESS) {
ebd782f7	216	fatal("PAM set rhost failed[%d]: %.200s",
ebd782f7	217	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	218	}
	219
	220	if (remote_user != NULL) {
	221	debug("PAM setting ruser to \"%.200s\"", remote_user);
ad55cd03	222	pam_retval = pam_set_item(pamh, PAM_RUSER, remote_user);
a5c9cd31	223	if (pam_retval != PAM_SUCCESS) {
ebd782f7	224	fatal("PAM set ruser failed[%d]: %.200s",
ebd782f7	225	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	226	}
	227	}
	228
ad55cd03	229	pam_retval = pam_acct_mgmt(pamh, 0);
5daf7064	230	switch (pam_retval) {
	231	case PAM_SUCCESS:
	232	/* This is what we want */
	233	break;
	234	case PAM_NEW_AUTHTOK_REQD:
	235	pam_msg_cat(NEW_AUTHTOK_MSG);
ad55cd03	236	/* flag that password change is necessary */
ad55cd03	237	password_change_required = 1;
5daf7064	238	break;
5daf7064	239	default:
ebd782f7	240	log("PAM rejected by account configuration[%d]: %.200s",
ebd782f7	241	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	242	return(0);
a5c9cd31	243	}
	244
	245	return(1);
	246	}
	247
	248	/* Do PAM-specific session initialisation */
fd094f49	249	void do_pam_session(char username, const char ttyname)
a5c9cd31	250	{
	251	int pam_retval;
	252
	253	if (ttyname != NULL) {
	254	debug("PAM setting tty to \"%.200s\"", ttyname);
ad55cd03	255	pam_retval = pam_set_item(pamh, PAM_TTY, ttyname);
5daf7064	256	if (pam_retval != PAM_SUCCESS) {
ebd782f7	257	fatal("PAM set tty failed[%d]: %.200s",
ebd782f7	258	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	259	}
a5c9cd31	260	}
a5c9cd31	261
ad55cd03	262	pam_retval = pam_open_session(pamh, 0);
5daf7064	263	if (pam_retval != PAM_SUCCESS) {
ebd782f7	264	fatal("PAM session setup failed[%d]: %.200s",
ebd782f7	265	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	266	}
a5c9cd31	267	}
	268
	269	/* Set PAM credentials */
a815d7a3	270	void do_pam_setcred(void)
a5c9cd31	271	{
	272	int pam_retval;
	273
	274	debug("PAM establishing creds");
ad55cd03	275	pam_retval = pam_setcred(pamh, PAM_ESTABLISH_CRED);
5daf7064	276	if (pam_retval != PAM_SUCCESS) {
8c9fe09e	277	if(was_authenticated) {
	278	fatal("PAM setcred failed[%d]: %.200s",
	279	pam_retval, PAM_STRERROR(pamh, pam_retval));
	280	} else {
	281	debug("PAM setcred failed[%d]: %.200s",
	282	pam_retval, PAM_STRERROR(pamh, pam_retval));
	283	}
ad55cd03	284	}
	285	}
	286
2919e060	287	/* accessor function for file scope static variable */
	288	int pam_password_change_required(void)
	289	{
	290	return password_change_required;
	291	}
	292
ad55cd03	293	/*
	294	* Have user change authentication token if pam_acct_mgmt() indicated
	295	* it was expired. This needs to be called after an interactive
	296	* session is established and the user's pty is connected to
	297	* stdin/stout/stderr.
	298	*/
a815d7a3	299	void do_pam_chauthtok(void)
ad55cd03	300	{
	301	int pam_retval;
	302
	303	if (password_change_required) {
	304	pamstate = OTHER;
ebd782f7	305	/*
	306	* XXX: should we really loop forever?
	307	*/
ad55cd03	308	do {
ad55cd03	309	pam_retval = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
ebd782f7	310	if (pam_retval != PAM_SUCCESS) {
	311	log("PAM pam_chauthtok failed[%d]: %.200s",
	312	pam_retval, PAM_STRERROR(pamh, pam_retval));
	313	}
ad55cd03	314	} while (pam_retval != PAM_SUCCESS);
5daf7064	315	}
a5c9cd31	316	}
	317
	318	/* Cleanly shutdown PAM */
	319	void finish_pam(void)
	320	{
	321	pam_cleanup_proc(NULL);
	322	fatal_remove_cleanup(&pam_cleanup_proc, NULL);
	323	}
	324
	325	/* Start PAM authentication for specified account */
04fc7a67	326	void start_pam(const char *user)
a5c9cd31	327	{
	328	int pam_retval;
	329
04fc7a67	330	debug("Starting up PAM with username \"%.200s\"", user);
a5c9cd31	331
04fc7a67	332	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &pamh);
a5c9cd31	333
5daf7064	334	if (pam_retval != PAM_SUCCESS) {
ebd782f7	335	fatal("PAM initialisation failed[%d]: %.200s",
ebd782f7	336	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	337	}
ae543aaa	338
a8545c6c	339	#ifdef PAM_TTY_KLUDGE
ae543aaa	340	/*
	341	* Some PAM modules (e.g. pam_time) require a TTY to operate,
	342	* and will fail in various stupid ways if they don't get one.
	343	* sshd doesn't set the tty until too late in the auth process and may
	344	* not even need one (for tty-less connections)
	345	* Kludge: Set a fake PAM_TTY
	346	*/
ad55cd03	347	pam_retval = pam_set_item(pamh, PAM_TTY, "ssh");
cbd7492e	348	if (pam_retval != PAM_SUCCESS) {
ebd782f7	349	fatal("PAM set tty failed[%d]: %.200s",
ebd782f7	350	pam_retval, PAM_STRERROR(pamh, pam_retval));
cbd7492e	351	}
a8545c6c	352	#endif /* PAM_TTY_KLUDGE */
cbd7492e	353
a5c9cd31	354	fatal_add_cleanup(&pam_cleanup_proc, NULL);
	355	}
	356
	357	/* Return list of PAM enviornment strings */
	358	char **fetch_pam_environment(void)
	359	{
2b763e31	360	#ifdef HAVE_PAM_GETENVLIST
ad55cd03	361	return(pam_getenvlist(pamh));
2b763e31	362	#else /* HAVE_PAM_GETENVLIST */
	363	return(NULL);
	364	#endif /* HAVE_PAM_GETENVLIST */
a5c9cd31	365	}
	366
	367	/* Print any messages that have been generated during authentication */
	368	/* or account checking to stderr */
	369	void print_pam_messages(void)
	370	{
5daf7064	371	if (pam_msg != NULL)
264dce47	372	fputs(pam_msg, stderr);
5daf7064	373	}
	374
	375	/* Append a message to the PAM message buffer */
	376	void pam_msg_cat(const char *msg)
	377	{
	378	char *p;
	379	size_t new_msg_len;
	380	size_t pam_msg_len;
	381
	382	new_msg_len = strlen(msg);
	383
	384	if (pam_msg) {
	385	pam_msg_len = strlen(pam_msg);
	386	pam_msg = xrealloc(pam_msg, new_msg_len + pam_msg_len + 2);
	387	p = pam_msg + pam_msg_len;
	388	} else {
	389	pam_msg = p = xmalloc(new_msg_len + 2);
	390	}
	391
	392	memcpy(p, msg, new_msg_len);
	393	p[new_msg_len] = '\n';
	394	p[new_msg_len + 1] = '\0';
a5c9cd31	395	}
	396
	397	#endif /* USE_PAM */