[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() */
typedef enum { INITIAL_LOGIN, OTHER } pamstates;
static pamstates pamstate = INITIAL_LOGIN;
/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
static int password_change_required = 0;

/*
 * 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 ((*msg)[count].msg_style) {
			case PAM_PROMPT_ECHO_ON:
				if (pamstate == INITIAL_LOGIN) {
					free(reply);
					return PAM_CONV_ERR;
				} else {
					fputs((*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((*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((*msg)[count].msg);
					else {
						fputs((*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;

	/* 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 = pam_authenticate(pamh, 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) {
		fatal("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(struct passwd *pw)
{
	int pam_retval;

	debug("Starting up PAM with username \"%.200s\"", pw->pw_name);

	pam_retval = pam_start(SSHD_PAM_SERVICE, pw->pw_name, &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() */
	53	typedef enum { INITIAL_LOGIN, OTHER } pamstates;
	54	static pamstates pamstate = INITIAL_LOGIN;
	55	/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
	56	static int password_change_required = 0;
	57
	58	/*
	59	* PAM conversation function.
	60	* There are two states this can run in.
	61	*
	62	* INITIAL_LOGIN mode simply feeds the password from the client into
	63	* PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
	64	* messages with pam_msg_cat(). This is used during initial
	65	* authentication to bypass the normal PAM password prompt.
	66	*
	67	* OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase(prompt, 1)
	68	* and outputs messages to stderr. This mode is used if pam_chauthtok()
	69	* is called to update expired passwords.
	70	*/
a5c9cd31	71	static int pamconv(int num_msg, const struct pam_message **msg,
	72	struct pam_response *resp, void appdata_ptr)
	73	{
	74	struct pam_response *reply;
	75	int count;
ad55cd03	76	char buf[1024];
a5c9cd31	77
	78	/* PAM will free this later */
	79	reply = malloc(num_msg * sizeof(*reply));
	80	if (reply == NULL)
	81	return PAM_CONV_ERR;
	82
ad55cd03	83	for (count = 0; count < num_msg; count++) {
	84	switch ((*msg)[count].msg_style) {
	85	case PAM_PROMPT_ECHO_ON:
71dfaf1c	86	if (pamstate == INITIAL_LOGIN) {
	87	free(reply);
	88	return PAM_CONV_ERR;
	89	} else {
	90	fputs((*msg)[count].msg, stderr);
	91	fgets(buf, sizeof(buf), stdin);
	92	reply[count].resp = xstrdup(buf);
	93	reply[count].resp_retcode = PAM_SUCCESS;
	94	break;
	95	}
a5c9cd31	96	case PAM_PROMPT_ECHO_OFF:
ad55cd03	97	if (pamstate == INITIAL_LOGIN) {
	98	if (pampasswd == NULL) {
	99	free(reply);
	100	return PAM_CONV_ERR;
	101	}
	102	reply[count].resp = xstrdup(pampasswd);
71dfaf1c	103	} else {
	104	reply[count].resp =
	105	xstrdup(read_passphrase((*msg)[count].msg, 1));
	106	}
a5c9cd31	107	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	108	break;
ad55cd03	109	case PAM_ERROR_MSG:
a5c9cd31	110	case PAM_TEXT_INFO:
ad55cd03	111	if ((*msg)[count].msg != NULL) {
	112	if (pamstate == INITIAL_LOGIN)
	113	pam_msg_cat((*msg)[count].msg);
	114	else {
	115	fputs((*msg)[count].msg, stderr);
	116	fputs("\n", stderr);
	117	}
	118	}
a5c9cd31	119	reply[count].resp = xstrdup("");
ad55cd03	120	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	121	break;
a5c9cd31	122	default:
	123	free(reply);
	124	return PAM_CONV_ERR;
	125	}
	126	}
	127
	128	*resp = reply;
	129
	130	return PAM_SUCCESS;
	131	}
	132
	133	/* Called at exit to cleanly shutdown PAM */
	134	void pam_cleanup_proc(void *context)
	135	{
	136	int pam_retval;
	137
	138	if (pamh != NULL)
	139	{
ad55cd03	140	pam_retval = pam_close_session(pamh, 0);
a5c9cd31	141	if (pam_retval != PAM_SUCCESS) {
ebd782f7	142	log("Cannot close PAM session[%d]: %.200s",
ebd782f7	143	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	144	}
a5c9cd31	145
ad55cd03	146	pam_retval = pam_setcred(pamh, PAM_DELETE_CRED);
a5c9cd31	147	if (pam_retval != PAM_SUCCESS) {
ebd782f7	148	debug("Cannot delete credentials[%d]: %.200s",
ebd782f7	149	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	150	}
a5c9cd31	151
ad55cd03	152	pam_retval = pam_end(pamh, pam_retval);
a5c9cd31	153	if (pam_retval != PAM_SUCCESS) {
ebd782f7	154	log("Cannot release PAM authentication[%d]: %.200s",
ebd782f7	155	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	156	}
	157	}
	158	}
	159
	160	/* Attempt password authentation using PAM */
	161	int auth_pam_password(struct passwd pw, const char password)
	162	{
	163	extern ServerOptions options;
	164	int pam_retval;
	165
	166	/* deny if no user. */
	167	if (pw == NULL)
	168	return 0;
	169	if (pw->pw_uid == 0 && options.permit_root_login == 2)
	170	return 0;
	171	if (*password == '\0' && options.permit_empty_passwd == 0)
	172	return 0;
	173
	174	pampasswd = password;
	175
ad55cd03	176	pamstate = INITIAL_LOGIN;
ad55cd03	177	pam_retval = pam_authenticate(pamh, 0);
a5c9cd31	178	if (pam_retval == PAM_SUCCESS) {
5daf7064	179	debug("PAM Password authentication accepted for user \"%.100s\"",
5daf7064	180	pw->pw_name);
a5c9cd31	181	return 1;
a5c9cd31	182	} else {
ebd782f7	183	debug("PAM Password authentication for \"%.100s\" failed[%d]: %s",
ebd782f7	184	pw->pw_name, pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	185	return 0;
	186	}
	187	}
	188
	189	/* Do account management using PAM */
	190	int do_pam_account(char username, char remote_user)
	191	{
	192	int pam_retval;
5daf7064	193
a5c9cd31	194	debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname());
ad55cd03	195	pam_retval = pam_set_item(pamh, PAM_RHOST,
a5c9cd31	196	get_canonical_hostname());
a5c9cd31	197	if (pam_retval != PAM_SUCCESS) {
ebd782f7	198	fatal("PAM set rhost failed[%d]: %.200s",
ebd782f7	199	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	200	}
	201
	202	if (remote_user != NULL) {
	203	debug("PAM setting ruser to \"%.200s\"", remote_user);
ad55cd03	204	pam_retval = pam_set_item(pamh, PAM_RUSER, remote_user);
a5c9cd31	205	if (pam_retval != PAM_SUCCESS) {
ebd782f7	206	fatal("PAM set ruser failed[%d]: %.200s",
ebd782f7	207	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	208	}
	209	}
	210
ad55cd03	211	pam_retval = pam_acct_mgmt(pamh, 0);
5daf7064	212	switch (pam_retval) {
	213	case PAM_SUCCESS:
	214	/* This is what we want */
	215	break;
	216	case PAM_NEW_AUTHTOK_REQD:
	217	pam_msg_cat(NEW_AUTHTOK_MSG);
ad55cd03	218	/* flag that password change is necessary */
ad55cd03	219	password_change_required = 1;
5daf7064	220	break;
5daf7064	221	default:
ebd782f7	222	log("PAM rejected by account configuration[%d]: %.200s",
ebd782f7	223	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	224	return(0);
a5c9cd31	225	}
	226
	227	return(1);
	228	}
	229
	230	/* Do PAM-specific session initialisation */
fd094f49	231	void do_pam_session(char username, const char ttyname)
a5c9cd31	232	{
	233	int pam_retval;
	234
	235	if (ttyname != NULL) {
	236	debug("PAM setting tty to \"%.200s\"", ttyname);
ad55cd03	237	pam_retval = pam_set_item(pamh, PAM_TTY, ttyname);
5daf7064	238	if (pam_retval != PAM_SUCCESS) {
ebd782f7	239	fatal("PAM set tty failed[%d]: %.200s",
ebd782f7	240	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	241	}
a5c9cd31	242	}
a5c9cd31	243
ad55cd03	244	pam_retval = pam_open_session(pamh, 0);
5daf7064	245	if (pam_retval != PAM_SUCCESS) {
ebd782f7	246	fatal("PAM session setup failed[%d]: %.200s",
ebd782f7	247	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	248	}
a5c9cd31	249	}
	250
	251	/* Set PAM credentials */
a815d7a3	252	void do_pam_setcred(void)
a5c9cd31	253	{
	254	int pam_retval;
	255
	256	debug("PAM establishing creds");
ad55cd03	257	pam_retval = pam_setcred(pamh, PAM_ESTABLISH_CRED);
5daf7064	258	if (pam_retval != PAM_SUCCESS) {
ebd782f7	259	fatal("PAM setcred failed[%d]: %.200s",
94ec8c6b	260	pam_retval, PAM_STRERROR(pamh, pam_retval));
ad55cd03	261	}
	262	}
	263
2919e060	264	/* accessor function for file scope static variable */
	265	int pam_password_change_required(void)
	266	{
	267	return password_change_required;
	268	}
	269
ad55cd03	270	/*
	271	* Have user change authentication token if pam_acct_mgmt() indicated
	272	* it was expired. This needs to be called after an interactive
	273	* session is established and the user's pty is connected to
	274	* stdin/stout/stderr.
	275	*/
a815d7a3	276	void do_pam_chauthtok(void)
ad55cd03	277	{
	278	int pam_retval;
	279
	280	if (password_change_required) {
	281	pamstate = OTHER;
ebd782f7	282	/*
	283	* XXX: should we really loop forever?
	284	*/
ad55cd03	285	do {
ad55cd03	286	pam_retval = pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
ebd782f7	287	if (pam_retval != PAM_SUCCESS) {
	288	log("PAM pam_chauthtok failed[%d]: %.200s",
	289	pam_retval, PAM_STRERROR(pamh, pam_retval));
	290	}
ad55cd03	291	} while (pam_retval != PAM_SUCCESS);
5daf7064	292	}
a5c9cd31	293	}
	294
	295	/* Cleanly shutdown PAM */
	296	void finish_pam(void)
	297	{
	298	pam_cleanup_proc(NULL);
	299	fatal_remove_cleanup(&pam_cleanup_proc, NULL);
	300	}
	301
	302	/* Start PAM authentication for specified account */
	303	void start_pam(struct passwd *pw)
	304	{
	305	int pam_retval;
	306
	307	debug("Starting up PAM with username \"%.200s\"", pw->pw_name);
	308
ad55cd03	309	pam_retval = pam_start(SSHD_PAM_SERVICE, pw->pw_name, &conv, &pamh);
a5c9cd31	310
5daf7064	311	if (pam_retval != PAM_SUCCESS) {
ebd782f7	312	fatal("PAM initialisation failed[%d]: %.200s",
ebd782f7	313	pam_retval, PAM_STRERROR(pamh, pam_retval));
5daf7064	314	}
ae543aaa	315
a8545c6c	316	#ifdef PAM_TTY_KLUDGE
ae543aaa	317	/*
	318	* Some PAM modules (e.g. pam_time) require a TTY to operate,
	319	* and will fail in various stupid ways if they don't get one.
	320	* sshd doesn't set the tty until too late in the auth process and may
	321	* not even need one (for tty-less connections)
	322	* Kludge: Set a fake PAM_TTY
	323	*/
ad55cd03	324	pam_retval = pam_set_item(pamh, PAM_TTY, "ssh");
cbd7492e	325	if (pam_retval != PAM_SUCCESS) {
ebd782f7	326	fatal("PAM set tty failed[%d]: %.200s",
ebd782f7	327	pam_retval, PAM_STRERROR(pamh, pam_retval));
cbd7492e	328	}
a8545c6c	329	#endif /* PAM_TTY_KLUDGE */
cbd7492e	330
a5c9cd31	331	fatal_add_cleanup(&pam_cleanup_proc, NULL);
	332	}
	333
	334	/* Return list of PAM enviornment strings */
	335	char **fetch_pam_environment(void)
	336	{
2b763e31	337	#ifdef HAVE_PAM_GETENVLIST
ad55cd03	338	return(pam_getenvlist(pamh));
2b763e31	339	#else /* HAVE_PAM_GETENVLIST */
	340	return(NULL);
	341	#endif /* HAVE_PAM_GETENVLIST */
a5c9cd31	342	}
	343
	344	/* Print any messages that have been generated during authentication */
	345	/* or account checking to stderr */
	346	void print_pam_messages(void)
	347	{
5daf7064	348	if (pam_msg != NULL)
264dce47	349	fputs(pam_msg, stderr);
5daf7064	350	}
	351
	352	/* Append a message to the PAM message buffer */
	353	void pam_msg_cat(const char *msg)
	354	{
	355	char *p;
	356	size_t new_msg_len;
	357	size_t pam_msg_len;
	358
	359	new_msg_len = strlen(msg);
	360
	361	if (pam_msg) {
	362	pam_msg_len = strlen(pam_msg);
	363	pam_msg = xrealloc(pam_msg, new_msg_len + pam_msg_len + 2);
	364	p = pam_msg + pam_msg_len;
	365	} else {
	366	pam_msg = p = xmalloc(new_msg_len + 2);
	367	}
	368
	369	memcpy(p, msg, new_msg_len);
	370	p[new_msg_len] = '\n';
	371	p[new_msg_len + 1] = '\0';
a5c9cd31	372	}
	373
	374	#endif /* USE_PAM */