[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 "log.h"
#include "auth-pam.h"
#include "servconf.h"
#include "canohost.h"
#include "readpass.h"

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;

/* 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 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(prompt, 1)
 * 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 = 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)
					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 pam_cleanup_proc(void *context)
{
	int pam_retval;

	if (pamh) {
		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;

	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;

	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;
	extern ServerOptions options;

	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));

	debug("PAM setting rhost to \"%.200s\"",
	    get_canonical_hostname(options.reverse_mapping_check));
	pam_retval = pam_set_item(pamh, PAM_RHOST,
		get_canonical_hostname(options.reverse_mapping_check));
	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, "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 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
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"
42f11eb2	30	#include "log.h"
5c377b3b	31	#include "auth-pam.h"
a5c9cd31	32	#include "servconf.h"
42f11eb2	33	#include "canohost.h"
42f11eb2	34	#include "readpass.h"
a5c9cd31	35
	36	RCSID("$Id$");
	37
5daf7064	38	#define NEW_AUTHTOK_MSG \
ad55cd03	39	"Warning: Your password has expired, please change it now"
5daf7064	40
5c377b3b	41	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
5c377b3b	42	struct pam_response *resp, void appdata_ptr);
a5c9cd31	43
	44	/* module-local variables */
	45	static struct pam_conv conv = {
5c377b3b	46	do_pam_conversation,
a5c9cd31	47	NULL
a5c9cd31	48	};
5c377b3b	49	static char *pam_msg = NULL;
ad55cd03	50	static pam_handle_t *pamh = NULL;
a5c9cd31	51	static const char *pampasswd = NULL;
a5c9cd31	52
5c377b3b	53	/* states for do_pam_conversation() */
8c9fe09e	54	enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
ad55cd03	55	/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
ad55cd03	56	static int password_change_required = 0;
8c9fe09e	57	/* remember whether the last pam_authenticate() succeeded or not */
	58	static int was_authenticated = 0;
	59
	60	/* accessor which allows us to switch conversation structs according to
	61	* the authentication method being used */
	62	void pam_set_conv(struct pam_conv *conv)
	63	{
	64	pam_set_item(pamh, PAM_CONV, conv);
	65	}
	66
	67	/* start an authentication run */
	68	int do_pam_authenticate(int flags)
	69	{
	70	int retval = pam_authenticate(pamh, flags);
	71	was_authenticated = (retval == PAM_SUCCESS);
	72	return retval;
	73	}
ad55cd03	74
	75	/*
	76	* PAM conversation function.
	77	* There are two states this can run in.
	78	*
	79	* INITIAL_LOGIN mode simply feeds the password from the client into
	80	* PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
5c377b3b	81	* messages with into pam_msg. This is used during initial
ad55cd03	82	* authentication to bypass the normal PAM password prompt.
	83	*
	84	* OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase(prompt, 1)
	85	* and outputs messages to stderr. This mode is used if pam_chauthtok()
	86	* is called to update expired passwords.
	87	*/
5c377b3b	88	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
a5c9cd31	89	struct pam_response *resp, void appdata_ptr)
	90	{
	91	struct pam_response *reply;
	92	int count;
ad55cd03	93	char buf[1024];
a5c9cd31	94
	95	/* PAM will free this later */
	96	reply = malloc(num_msg * sizeof(*reply));
	97	if (reply == NULL)
2b87da3b	98	return PAM_CONV_ERR;
a5c9cd31	99
ad55cd03	100	for (count = 0; count < num_msg; count++) {
5c377b3b	101	if (pamstate == INITIAL_LOGIN) {
	102	/*
	103	* We can't use stdio yet, queue messages for
	104	* printing later
	105	*/
	106	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
ad55cd03	107	case PAM_PROMPT_ECHO_ON:
5c377b3b	108	free(reply);
	109	return PAM_CONV_ERR;
	110	case PAM_PROMPT_ECHO_OFF:
	111	if (pampasswd == NULL) {
71dfaf1c	112	free(reply);
71dfaf1c	113	return PAM_CONV_ERR;
71dfaf1c	114	}
5c377b3b	115	reply[count].resp = xstrdup(pampasswd);
a5c9cd31	116	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	117	break;
ad55cd03	118	case PAM_ERROR_MSG:
a5c9cd31	119	case PAM_TEXT_INFO:
ad55cd03	120	if ((*msg)[count].msg != NULL) {
5c377b3b	121	message_cat(&pam_msg,
5c377b3b	122	PAM_MSG_MEMBER(msg, count, msg));
ad55cd03	123	}
a5c9cd31	124	reply[count].resp = xstrdup("");
ad55cd03	125	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	126	break;
a5c9cd31	127	default:
	128	free(reply);
	129	return PAM_CONV_ERR;
5c377b3b	130	}
	131	} else {
	132	/*
	133	* stdio is connected, so interact directly
	134	*/
	135	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
	136	case PAM_PROMPT_ECHO_ON:
	137	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
	138	fgets(buf, sizeof(buf), stdin);
	139	reply[count].resp = xstrdup(buf);
	140	reply[count].resp_retcode = PAM_SUCCESS;
	141	break;
	142	case PAM_PROMPT_ECHO_OFF:
	143	reply[count].resp = xstrdup(
	144	read_passphrase(PAM_MSG_MEMBER(msg, count,
	145	msg), 1));
	146	reply[count].resp_retcode = PAM_SUCCESS;
	147	break;
	148	case PAM_ERROR_MSG:
	149	case PAM_TEXT_INFO:
	150	if ((*msg)[count].msg != NULL)
	151	fprintf(stderr, "%s\n",
	152	PAM_MSG_MEMBER(msg, count, msg));
	153	reply[count].resp = xstrdup("");
	154	reply[count].resp_retcode = PAM_SUCCESS;
	155	break;
	156	default:
	157	free(reply);
	158	return PAM_CONV_ERR;
	159	}
a5c9cd31	160	}
	161	}
	162
	163	*resp = reply;
	164
	165	return PAM_SUCCESS;
	166	}
	167
	168	/* Called at exit to cleanly shutdown PAM */
	169	void pam_cleanup_proc(void *context)
	170	{
	171	int pam_retval;
	172
5c377b3b	173	if (pamh) {
ad55cd03	174	pam_retval = pam_close_session(pamh, 0);
5c377b3b	175	if (pam_retval != PAM_SUCCESS)
2b87da3b	176	log("Cannot close PAM session[%d]: %.200s",
5c377b3b	177	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	178
ad55cd03	179	pam_retval = pam_setcred(pamh, PAM_DELETE_CRED);
5c377b3b	180	if (pam_retval != PAM_SUCCESS)
	181	debug("Cannot delete credentials[%d]: %.200s",
	182	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	183
ad55cd03	184	pam_retval = pam_end(pamh, pam_retval);
5c377b3b	185	if (pam_retval != PAM_SUCCESS)
2b87da3b	186	log("Cannot release PAM authentication[%d]: %.200s",
5c377b3b	187	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	188	}
	189	}
	190
	191	/* Attempt password authentation using PAM */
	192	int auth_pam_password(struct passwd pw, const char password)
	193	{
	194	extern ServerOptions options;
	195	int pam_retval;
	196
8c9fe09e	197	pam_set_conv(&conv);
8c9fe09e	198
a5c9cd31	199	/* deny if no user. */
	200	if (pw == NULL)
	201	return 0;
	202	if (pw->pw_uid == 0 && options.permit_root_login == 2)
	203	return 0;
	204	if (*password == '\0' && options.permit_empty_passwd == 0)
	205	return 0;
	206
	207	pampasswd = password;
2b87da3b	208
ad55cd03	209	pamstate = INITIAL_LOGIN;
8c9fe09e	210	pam_retval = do_pam_authenticate(0);
a5c9cd31	211	if (pam_retval == PAM_SUCCESS) {
5c377b3b	212	debug("PAM Password authentication accepted for "
5c377b3b	213	"user \"%.100s\"", pw->pw_name);
a5c9cd31	214	return 1;
a5c9cd31	215	} else {
5c377b3b	216	debug("PAM Password authentication for \"%.100s\" "
	217	"failed[%d]: %s", pw->pw_name, pam_retval,
	218	PAM_STRERROR(pamh, pam_retval));
a5c9cd31	219	return 0;
	220	}
	221	}
	222
	223	/* Do account management using PAM */
	224	int do_pam_account(char username, char remote_user)
	225	{
	226	int pam_retval;
2b87da3b	227
5c377b3b	228	pam_set_conv(&conv);
5c377b3b	229
5c377b3b	230	if (remote_user) {
a5c9cd31	231	debug("PAM setting ruser to \"%.200s\"", remote_user);
ad55cd03	232	pam_retval = pam_set_item(pamh, PAM_RUSER, remote_user);
5c377b3b	233	if (pam_retval != PAM_SUCCESS)
	234	fatal("PAM set ruser failed[%d]: %.200s", pam_retval,
	235	PAM_STRERROR(pamh, pam_retval));
a5c9cd31	236	}
a5c9cd31	237
ad55cd03	238	pam_retval = pam_acct_mgmt(pamh, 0);
5daf7064	239	switch (pam_retval) {
	240	case PAM_SUCCESS:
	241	/* This is what we want */
	242	break;
	243	case PAM_NEW_AUTHTOK_REQD:
5c377b3b	244	message_cat(&pam_msg, NEW_AUTHTOK_MSG);
ad55cd03	245	/* flag that password change is necessary */
ad55cd03	246	password_change_required = 1;
5daf7064	247	break;
5daf7064	248	default:
5c377b3b	249	log("PAM rejected by account configuration[%d]: "
	250	"%.200s", pam_retval, PAM_STRERROR(pamh,
	251	pam_retval));
5daf7064	252	return(0);
a5c9cd31	253	}
2b87da3b	254
a5c9cd31	255	return(1);
	256	}
	257
	258	/* Do PAM-specific session initialisation */
fd094f49	259	void do_pam_session(char username, const char ttyname)
a5c9cd31	260	{
	261	int pam_retval;
	262
	263	if (ttyname != NULL) {
	264	debug("PAM setting tty to \"%.200s\"", ttyname);
ad55cd03	265	pam_retval = pam_set_item(pamh, PAM_TTY, ttyname);
5c377b3b	266	if (pam_retval != PAM_SUCCESS)
2b87da3b	267	fatal("PAM set tty failed[%d]: %.200s",
5c377b3b	268	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	269	}
a5c9cd31	270
ad55cd03	271	pam_retval = pam_open_session(pamh, 0);
5c377b3b	272	if (pam_retval != PAM_SUCCESS)
2b87da3b	273	fatal("PAM session setup failed[%d]: %.200s",
5c377b3b	274	pam_retval, PAM_STRERROR(pamh, pam_retval));
a5c9cd31	275	}
a5c9cd31	276
2b87da3b	277	/* Set PAM credentials */
a815d7a3	278	void do_pam_setcred(void)
a5c9cd31	279	{
a5c9cd31	280	int pam_retval;
2b87da3b	281
a5c9cd31	282	debug("PAM establishing creds");
ad55cd03	283	pam_retval = pam_setcred(pamh, PAM_ESTABLISH_CRED);
5daf7064	284	if (pam_retval != PAM_SUCCESS) {
5c377b3b	285	if (was_authenticated)
2b87da3b	286	fatal("PAM setcred failed[%d]: %.200s",
5c377b3b	287	pam_retval, PAM_STRERROR(pamh, pam_retval));
5c377b3b	288	else
2b87da3b	289	debug("PAM setcred failed[%d]: %.200s",
5c377b3b	290	pam_retval, PAM_STRERROR(pamh, pam_retval));
ad55cd03	291	}
	292	}
	293
2919e060	294	/* accessor function for file scope static variable */
	295	int pam_password_change_required(void)
	296	{
	297	return password_change_required;
	298	}
	299
2b87da3b	300	/*
ad55cd03	301	* Have user change authentication token if pam_acct_mgmt() indicated
	302	* it was expired. This needs to be called after an interactive
	303	* session is established and the user's pty is connected to
	304	* stdin/stout/stderr.
	305	*/
a815d7a3	306	void do_pam_chauthtok(void)
ad55cd03	307	{
	308	int pam_retval;
	309
	310	if (password_change_required) {
	311	pamstate = OTHER;
5c377b3b	312	/* XXX: should we really loop forever? */
ad55cd03	313	do {
5c377b3b	314	pam_retval = pam_chauthtok(pamh,
	315	PAM_CHANGE_EXPIRED_AUTHTOK);
	316	if (pam_retval != PAM_SUCCESS)
2b87da3b	317	log("PAM pam_chauthtok failed[%d]: %.200s",
5c377b3b	318	pam_retval, PAM_STRERROR(pamh, pam_retval));
ad55cd03	319	} while (pam_retval != PAM_SUCCESS);
5daf7064	320	}
a5c9cd31	321	}
	322
	323	/* Cleanly shutdown PAM */
	324	void finish_pam(void)
	325	{
	326	pam_cleanup_proc(NULL);
	327	fatal_remove_cleanup(&pam_cleanup_proc, NULL);
	328	}
	329
	330	/* Start PAM authentication for specified account */
04fc7a67	331	void start_pam(const char *user)
a5c9cd31	332	{
a5c9cd31	333	int pam_retval;
dbd97a4d	334	extern ServerOptions options;
a5c9cd31	335
04fc7a67	336	debug("Starting up PAM with username \"%.200s\"", user);
a5c9cd31	337
04fc7a67	338	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &pamh);
a5c9cd31	339
5c377b3b	340	if (pam_retval != PAM_SUCCESS)
2b87da3b	341	fatal("PAM initialisation failed[%d]: %.200s",
5c377b3b	342	pam_retval, PAM_STRERROR(pamh, pam_retval));
e275684f	343
	344	debug("PAM setting rhost to \"%.200s\"",
	345	get_canonical_hostname(options.reverse_mapping_check));
	346	pam_retval = pam_set_item(pamh, PAM_RHOST,
	347	get_canonical_hostname(options.reverse_mapping_check));
	348	if (pam_retval != PAM_SUCCESS)
	349	fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
	350	PAM_STRERROR(pamh, pam_retval));
a8545c6c	351	#ifdef PAM_TTY_KLUDGE
ae543aaa	352	/*
ae543aaa	353	* Some PAM modules (e.g. pam_time) require a TTY to operate,
2b87da3b	354	* and will fail in various stupid ways if they don't get one.
ae543aaa	355	* sshd doesn't set the tty until too late in the auth process and may
ae543aaa	356	* not even need one (for tty-less connections)
2b87da3b	357	* Kludge: Set a fake PAM_TTY
ae543aaa	358	*/
ad55cd03	359	pam_retval = pam_set_item(pamh, PAM_TTY, "ssh");
5c377b3b	360	if (pam_retval != PAM_SUCCESS)
2b87da3b	361	fatal("PAM set tty failed[%d]: %.200s",
5c377b3b	362	pam_retval, PAM_STRERROR(pamh, pam_retval));
a8545c6c	363	#endif /* PAM_TTY_KLUDGE */
cbd7492e	364
a5c9cd31	365	fatal_add_cleanup(&pam_cleanup_proc, NULL);
	366	}
	367
	368	/* Return list of PAM enviornment strings */
	369	char **fetch_pam_environment(void)
	370	{
2b763e31	371	#ifdef HAVE_PAM_GETENVLIST
ad55cd03	372	return(pam_getenvlist(pamh));
2b763e31	373	#else /* HAVE_PAM_GETENVLIST */
	374	return(NULL);
	375	#endif /* HAVE_PAM_GETENVLIST */
a5c9cd31	376	}
	377
	378	/* Print any messages that have been generated during authentication */
	379	/* or account checking to stderr */
	380	void print_pam_messages(void)
	381	{
5daf7064	382	if (pam_msg != NULL)
264dce47	383	fputs(pam_msg, stderr);
5daf7064	384	}
5daf7064	385
5c377b3b	386	/* Append a message to buffer */
5c377b3b	387	void message_cat(char *p, const char a)
5daf7064	388	{
5c377b3b	389	char *cp;
5c377b3b	390	size_t new_len;
2b87da3b	391
5c377b3b	392	new_len = strlen(a);
2b87da3b	393
5c377b3b	394	if (*p) {
	395	size_t len = strlen(*p);
	396
	397	p = xrealloc(p, new_len + len + 2);
	398	cp = *p + len;
	399	} else
	400	*p = cp = xmalloc(new_len + 2);
5daf7064	401
5c377b3b	402	memcpy(cp, a, new_len);
	403	cp[new_len] = '\n';
	404	cp[new_len + 1] = '\0';
a5c9cd31	405	}
	406
	407	#endif /* USE_PAM */