[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.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(Authctxt *authctxt, const char *password)
{
	extern ServerOptions options;
	int pam_retval;
	struct passwd *pw = authctxt->pw;

	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.verify_reverse_mapping);
	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
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"
fde58bd4	31	#include "auth.h"
5c377b3b	32	#include "auth-pam.h"
a5c9cd31	33	#include "servconf.h"
42f11eb2	34	#include "canohost.h"
42f11eb2	35	#include "readpass.h"
a5c9cd31	36
1ddee76b	37	extern char *__progname;
1ddee76b	38
a5c9cd31	39	RCSID("$Id$");
a5c9cd31	40
5daf7064	41	#define NEW_AUTHTOK_MSG \
ad55cd03	42	"Warning: Your password has expired, please change it now"
5daf7064	43
5c377b3b	44	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
5c377b3b	45	struct pam_response *resp, void appdata_ptr);
a5c9cd31	46
	47	/* module-local variables */
	48	static struct pam_conv conv = {
5c377b3b	49	do_pam_conversation,
a5c9cd31	50	NULL
a5c9cd31	51	};
e11aab29	52	static char *__pam_msg = NULL;
	53	static pam_handle_t *__pamh = NULL;
	54	static const char *__pampasswd = NULL;
a5c9cd31	55
5c377b3b	56	/* states for do_pam_conversation() */
8c9fe09e	57	enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
ad55cd03	58	/* remember whether pam_acct_mgmt() returned PAM_NEWAUTHTOK_REQD */
ad55cd03	59	static int password_change_required = 0;
8c9fe09e	60	/* remember whether the last pam_authenticate() succeeded or not */
	61	static int was_authenticated = 0;
	62
e11aab29	63	/* Remember what has been initialised */
	64	static int session_opened = 0;
	65	static int creds_set = 0;
	66
8c9fe09e	67	/* accessor which allows us to switch conversation structs according to
8c9fe09e	68	* the authentication method being used */
e11aab29	69	void do_pam_set_conv(struct pam_conv *conv)
8c9fe09e	70	{
e11aab29	71	pam_set_item(__pamh, PAM_CONV, conv);
8c9fe09e	72	}
	73
	74	/* start an authentication run */
	75	int do_pam_authenticate(int flags)
	76	{
e11aab29	77	int retval = pam_authenticate(__pamh, flags);
8c9fe09e	78	was_authenticated = (retval == PAM_SUCCESS);
	79	return retval;
	80	}
ad55cd03	81
	82	/*
	83	* PAM conversation function.
	84	* There are two states this can run in.
	85	*
	86	* INITIAL_LOGIN mode simply feeds the password from the client into
	87	* PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
e11aab29	88	* messages with into __pam_msg. This is used during initial
ad55cd03	89	* authentication to bypass the normal PAM password prompt.
ad55cd03	90	*
9678565b	91	* OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase()
ad55cd03	92	* and outputs messages to stderr. This mode is used if pam_chauthtok()
	93	* is called to update expired passwords.
	94	*/
5c377b3b	95	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
a5c9cd31	96	struct pam_response *resp, void appdata_ptr)
	97	{
	98	struct pam_response *reply;
	99	int count;
ad55cd03	100	char buf[1024];
a5c9cd31	101
	102	/* PAM will free this later */
	103	reply = malloc(num_msg * sizeof(*reply));
	104	if (reply == NULL)
2b87da3b	105	return PAM_CONV_ERR;
a5c9cd31	106
ad55cd03	107	for (count = 0; count < num_msg; count++) {
5c377b3b	108	if (pamstate == INITIAL_LOGIN) {
	109	/*
	110	* We can't use stdio yet, queue messages for
	111	* printing later
	112	*/
	113	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
ad55cd03	114	case PAM_PROMPT_ECHO_ON:
5c377b3b	115	free(reply);
	116	return PAM_CONV_ERR;
	117	case PAM_PROMPT_ECHO_OFF:
e11aab29	118	if (__pampasswd == NULL) {
71dfaf1c	119	free(reply);
71dfaf1c	120	return PAM_CONV_ERR;
71dfaf1c	121	}
e11aab29	122	reply[count].resp = xstrdup(__pampasswd);
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) {
e11aab29	128	message_cat(&__pam_msg,
5c377b3b	129	PAM_MSG_MEMBER(msg, count, msg));
ad55cd03	130	}
a5c9cd31	131	reply[count].resp = xstrdup("");
ad55cd03	132	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	133	break;
a5c9cd31	134	default:
	135	free(reply);
	136	return PAM_CONV_ERR;
5c377b3b	137	}
	138	} else {
	139	/*
	140	* stdio is connected, so interact directly
	141	*/
	142	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
	143	case PAM_PROMPT_ECHO_ON:
	144	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
	145	fgets(buf, sizeof(buf), stdin);
	146	reply[count].resp = xstrdup(buf);
	147	reply[count].resp_retcode = PAM_SUCCESS;
	148	break;
	149	case PAM_PROMPT_ECHO_OFF:
9678565b	150	reply[count].resp =
840ad55e	151	read_passphrase(PAM_MSG_MEMBER(msg, count,
840ad55e	152	msg), RP_ALLOW_STDIN);
5c377b3b	153	reply[count].resp_retcode = PAM_SUCCESS;
	154	break;
	155	case PAM_ERROR_MSG:
	156	case PAM_TEXT_INFO:
	157	if ((*msg)[count].msg != NULL)
	158	fprintf(stderr, "%s\n",
	159	PAM_MSG_MEMBER(msg, count, msg));
	160	reply[count].resp = xstrdup("");
	161	reply[count].resp_retcode = PAM_SUCCESS;
	162	break;
	163	default:
	164	free(reply);
	165	return PAM_CONV_ERR;
	166	}
a5c9cd31	167	}
	168	}
	169
	170	*resp = reply;
	171
	172	return PAM_SUCCESS;
	173	}
	174
	175	/* Called at exit to cleanly shutdown PAM */
e11aab29	176	void do_pam_cleanup_proc(void *context)
a5c9cd31	177	{
37eadb90	178	int pam_retval = PAM_SUCCESS;
a5c9cd31	179
e11aab29	180	if (__pamh && session_opened) {
e11aab29	181	pam_retval = pam_close_session(__pamh, 0);
5c377b3b	182	if (pam_retval != PAM_SUCCESS)
2b87da3b	183	log("Cannot close PAM session[%d]: %.200s",
e11aab29	184	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	185	}
a5c9cd31	186
e11aab29	187	if (__pamh && creds_set) {
e11aab29	188	pam_retval = pam_setcred(__pamh, PAM_DELETE_CRED);
5c377b3b	189	if (pam_retval != PAM_SUCCESS)
5c377b3b	190	debug("Cannot delete credentials[%d]: %.200s",
e11aab29	191	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	192	}
a5c9cd31	193
e11aab29	194	if (__pamh) {
e11aab29	195	pam_retval = pam_end(__pamh, pam_retval);
5c377b3b	196	if (pam_retval != PAM_SUCCESS)
2b87da3b	197	log("Cannot release PAM authentication[%d]: %.200s",
e11aab29	198	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	199	}
	200	}
	201
	202	/* Attempt password authentation using PAM */
fde58bd4	203	int auth_pam_password(Authctxt authctxt, const char password)
a5c9cd31	204	{
	205	extern ServerOptions options;
	206	int pam_retval;
fde58bd4	207	struct passwd *pw = authctxt->pw;
a5c9cd31	208
e11aab29	209	do_pam_set_conv(&conv);
8c9fe09e	210
a5c9cd31	211	/* deny if no user. */
	212	if (pw == NULL)
	213	return 0;
3cc990d7	214	if (pw->pw_uid == 0 && options.permit_root_login == PERMIT_NO_PASSWD)
a5c9cd31	215	return 0;
	216	if (*password == '\0' && options.permit_empty_passwd == 0)
	217	return 0;
	218
e11aab29	219	__pampasswd = password;
2b87da3b	220
ad55cd03	221	pamstate = INITIAL_LOGIN;
78afd1dc	222	pam_retval = do_pam_authenticate(
78afd1dc	223	options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0);
a5c9cd31	224	if (pam_retval == PAM_SUCCESS) {
5c377b3b	225	debug("PAM Password authentication accepted for "
5c377b3b	226	"user \"%.100s\"", pw->pw_name);
a5c9cd31	227	return 1;
a5c9cd31	228	} else {
5c377b3b	229	debug("PAM Password authentication for \"%.100s\" "
5c377b3b	230	"failed[%d]: %s", pw->pw_name, pam_retval,
e11aab29	231	PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	232	return 0;
	233	}
	234	}
	235
	236	/* Do account management using PAM */
	237	int do_pam_account(char username, char remote_user)
	238	{
	239	int pam_retval;
2b87da3b	240
e11aab29	241	do_pam_set_conv(&conv);
5c377b3b	242
5c377b3b	243	if (remote_user) {
a5c9cd31	244	debug("PAM setting ruser to \"%.200s\"", remote_user);
e11aab29	245	pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
5c377b3b	246	if (pam_retval != PAM_SUCCESS)
5c377b3b	247	fatal("PAM set ruser failed[%d]: %.200s", pam_retval,
e11aab29	248	PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	249	}
a5c9cd31	250
e11aab29	251	pam_retval = pam_acct_mgmt(__pamh, 0);
5daf7064	252	switch (pam_retval) {
	253	case PAM_SUCCESS:
	254	/* This is what we want */
	255	break;
	256	case PAM_NEW_AUTHTOK_REQD:
e11aab29	257	message_cat(&__pam_msg, NEW_AUTHTOK_MSG);
ad55cd03	258	/* flag that password change is necessary */
ad55cd03	259	password_change_required = 1;
5daf7064	260	break;
5daf7064	261	default:
5c377b3b	262	log("PAM rejected by account configuration[%d]: "
e11aab29	263	"%.200s", pam_retval, PAM_STRERROR(__pamh,
5c377b3b	264	pam_retval));
5daf7064	265	return(0);
a5c9cd31	266	}
2b87da3b	267
a5c9cd31	268	return(1);
	269	}
	270
	271	/* Do PAM-specific session initialisation */
fd094f49	272	void do_pam_session(char username, const char ttyname)
a5c9cd31	273	{
	274	int pam_retval;
	275
5f404be3	276	do_pam_set_conv(&conv);
5f404be3	277
a5c9cd31	278	if (ttyname != NULL) {
a5c9cd31	279	debug("PAM setting tty to \"%.200s\"", ttyname);
e11aab29	280	pam_retval = pam_set_item(__pamh, PAM_TTY, ttyname);
5c377b3b	281	if (pam_retval != PAM_SUCCESS)
2b87da3b	282	fatal("PAM set tty failed[%d]: %.200s",
e11aab29	283	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	284	}
a5c9cd31	285
e11aab29	286	pam_retval = pam_open_session(__pamh, 0);
5c377b3b	287	if (pam_retval != PAM_SUCCESS)
2b87da3b	288	fatal("PAM session setup failed[%d]: %.200s",
e11aab29	289	pam_retval, PAM_STRERROR(__pamh, pam_retval));
40a35ff1	290
1c2d0a13	291	session_opened = 1;
a5c9cd31	292	}
a5c9cd31	293
2b87da3b	294	/* Set PAM credentials */
9afbfcfa	295	void do_pam_setcred(int init)
a5c9cd31	296	{
a5c9cd31	297	int pam_retval;
2b87da3b	298
5f404be3	299	do_pam_set_conv(&conv);
5f404be3	300
a5c9cd31	301	debug("PAM establishing creds");
9afbfcfa	302	pam_retval = pam_setcred(__pamh,
9afbfcfa	303	init ? PAM_ESTABLISH_CRED : PAM_REINITIALIZE_CRED);
5daf7064	304	if (pam_retval != PAM_SUCCESS) {
5c377b3b	305	if (was_authenticated)
2b87da3b	306	fatal("PAM setcred failed[%d]: %.200s",
e11aab29	307	pam_retval, PAM_STRERROR(__pamh, pam_retval));
5c377b3b	308	else
2b87da3b	309	debug("PAM setcred failed[%d]: %.200s",
e11aab29	310	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	311	} else
1c2d0a13	312	creds_set = 1;
ad55cd03	313	}
ad55cd03	314
2919e060	315	/* accessor function for file scope static variable */
e11aab29	316	int is_pam_password_change_required(void)
2919e060	317	{
	318	return password_change_required;
	319	}
	320
2b87da3b	321	/*
ad55cd03	322	* Have user change authentication token if pam_acct_mgmt() indicated
	323	* it was expired. This needs to be called after an interactive
	324	* session is established and the user's pty is connected to
	325	* stdin/stout/stderr.
	326	*/
a815d7a3	327	void do_pam_chauthtok(void)
ad55cd03	328	{
	329	int pam_retval;
	330
5f404be3	331	do_pam_set_conv(&conv);
5f404be3	332
ad55cd03	333	if (password_change_required) {
ad55cd03	334	pamstate = OTHER;
0a3700ee	335	pam_retval = pam_chauthtok(__pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
	336	if (pam_retval != PAM_SUCCESS)
	337	fatal("PAM pam_chauthtok failed[%d]: %.200s",
	338	pam_retval, PAM_STRERROR(__pamh, pam_retval));
5daf7064	339	}
a5c9cd31	340	}
	341
	342	/* Cleanly shutdown PAM */
	343	void finish_pam(void)
	344	{
e11aab29	345	do_pam_cleanup_proc(NULL);
e11aab29	346	fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
a5c9cd31	347	}
	348
	349	/* Start PAM authentication for specified account */
04fc7a67	350	void start_pam(const char *user)
a5c9cd31	351	{
a5c9cd31	352	int pam_retval;
dbd97a4d	353	extern ServerOptions options;
46c76c63	354	extern u_int utmp_len;
46c76c63	355	const char *rhost;
a5c9cd31	356
04fc7a67	357	debug("Starting up PAM with username \"%.200s\"", user);
a5c9cd31	358
e11aab29	359	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);
a5c9cd31	360
5c377b3b	361	if (pam_retval != PAM_SUCCESS)
2b87da3b	362	fatal("PAM initialisation failed[%d]: %.200s",
e11aab29	363	pam_retval, PAM_STRERROR(__pamh, pam_retval));
e275684f	364
983784a1	365	rhost = get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping);
46c76c63	366	debug("PAM setting rhost to \"%.200s\"", rhost);
	367
	368	pam_retval = pam_set_item(__pamh, PAM_RHOST, rhost);
e275684f	369	if (pam_retval != PAM_SUCCESS)
e275684f	370	fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
e11aab29	371	PAM_STRERROR(__pamh, pam_retval));
a8545c6c	372	#ifdef PAM_TTY_KLUDGE
ae543aaa	373	/*
ae543aaa	374	* Some PAM modules (e.g. pam_time) require a TTY to operate,
2b87da3b	375	* and will fail in various stupid ways if they don't get one.
ae543aaa	376	* sshd doesn't set the tty until too late in the auth process and may
ae543aaa	377	* not even need one (for tty-less connections)
2b87da3b	378	* Kludge: Set a fake PAM_TTY
ae543aaa	379	*/
9f214051	380	pam_retval = pam_set_item(__pamh, PAM_TTY, "NODEVssh");
5c377b3b	381	if (pam_retval != PAM_SUCCESS)
2b87da3b	382	fatal("PAM set tty failed[%d]: %.200s",
e11aab29	383	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a8545c6c	384	#endif /* PAM_TTY_KLUDGE */
cbd7492e	385
e11aab29	386	fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
a5c9cd31	387	}
	388
	389	/* Return list of PAM enviornment strings */
	390	char **fetch_pam_environment(void)
	391	{
2b763e31	392	#ifdef HAVE_PAM_GETENVLIST
e11aab29	393	return(pam_getenvlist(__pamh));
2b763e31	394	#else /* HAVE_PAM_GETENVLIST */
	395	return(NULL);
	396	#endif /* HAVE_PAM_GETENVLIST */
a5c9cd31	397	}
	398
	399	/* Print any messages that have been generated during authentication */
	400	/* or account checking to stderr */
	401	void print_pam_messages(void)
	402	{
e11aab29	403	if (__pam_msg != NULL)
e11aab29	404	fputs(__pam_msg, stderr);
5daf7064	405	}
5daf7064	406
5c377b3b	407	/* Append a message to buffer */
5c377b3b	408	void message_cat(char *p, const char a)
5daf7064	409	{
5c377b3b	410	char *cp;
5c377b3b	411	size_t new_len;
2b87da3b	412
5c377b3b	413	new_len = strlen(a);
2b87da3b	414
5c377b3b	415	if (*p) {
	416	size_t len = strlen(*p);
	417
	418	p = xrealloc(p, new_len + len + 2);
	419	cp = *p + len;
	420	} else
	421	*p = cp = xmalloc(new_len + 2);
5daf7064	422
5c377b3b	423	memcpy(cp, a, new_len);
	424	cp[new_len] = '\n';
	425	cp[new_len + 1] = '\0';
a5c9cd31	426	}
	427
	428	#endif /* USE_PAM */