[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;

/* 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(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 do_pam_cleanup_proc(void *context)
{
	int pam_retval;

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

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

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

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

	do_pam_set_conv(&conv);

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

	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;

	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(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));
	} 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;

	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)
{
	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;

	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(&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"
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	};
e11aab29	49	static char *__pam_msg = NULL;
	50	static pam_handle_t *__pamh = NULL;
	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
e11aab29	60	/* Remember what has been initialised */
	61	static int session_opened = 0;
	62	static int creds_set = 0;
	63
8c9fe09e	64	/* accessor which allows us to switch conversation structs according to
8c9fe09e	65	* the authentication method being used */
e11aab29	66	void do_pam_set_conv(struct pam_conv *conv)
8c9fe09e	67	{
e11aab29	68	pam_set_item(__pamh, PAM_CONV, conv);
8c9fe09e	69	}
	70
	71	/* start an authentication run */
	72	int do_pam_authenticate(int flags)
	73	{
e11aab29	74	int retval = pam_authenticate(__pamh, flags);
8c9fe09e	75	was_authenticated = (retval == PAM_SUCCESS);
	76	return retval;
	77	}
ad55cd03	78
	79	/*
	80	* PAM conversation function.
	81	* There are two states this can run in.
	82	*
	83	* INITIAL_LOGIN mode simply feeds the password from the client into
	84	* PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
e11aab29	85	* messages with into __pam_msg. This is used during initial
ad55cd03	86	* authentication to bypass the normal PAM password prompt.
	87	*
	88	* OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase(prompt, 1)
	89	* and outputs messages to stderr. This mode is used if pam_chauthtok()
	90	* is called to update expired passwords.
	91	*/
5c377b3b	92	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
a5c9cd31	93	struct pam_response *resp, void appdata_ptr)
	94	{
	95	struct pam_response *reply;
	96	int count;
ad55cd03	97	char buf[1024];
a5c9cd31	98
	99	/* PAM will free this later */
	100	reply = malloc(num_msg * sizeof(*reply));
	101	if (reply == NULL)
2b87da3b	102	return PAM_CONV_ERR;
a5c9cd31	103
ad55cd03	104	for (count = 0; count < num_msg; count++) {
5c377b3b	105	if (pamstate == INITIAL_LOGIN) {
	106	/*
	107	* We can't use stdio yet, queue messages for
	108	* printing later
	109	*/
	110	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
ad55cd03	111	case PAM_PROMPT_ECHO_ON:
5c377b3b	112	free(reply);
	113	return PAM_CONV_ERR;
	114	case PAM_PROMPT_ECHO_OFF:
e11aab29	115	if (__pampasswd == NULL) {
71dfaf1c	116	free(reply);
71dfaf1c	117	return PAM_CONV_ERR;
71dfaf1c	118	}
e11aab29	119	reply[count].resp = xstrdup(__pampasswd);
a5c9cd31	120	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	121	break;
ad55cd03	122	case PAM_ERROR_MSG:
a5c9cd31	123	case PAM_TEXT_INFO:
ad55cd03	124	if ((*msg)[count].msg != NULL) {
e11aab29	125	message_cat(&__pam_msg,
5c377b3b	126	PAM_MSG_MEMBER(msg, count, msg));
ad55cd03	127	}
a5c9cd31	128	reply[count].resp = xstrdup("");
ad55cd03	129	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	130	break;
a5c9cd31	131	default:
	132	free(reply);
	133	return PAM_CONV_ERR;
5c377b3b	134	}
	135	} else {
	136	/*
	137	* stdio is connected, so interact directly
	138	*/
	139	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
	140	case PAM_PROMPT_ECHO_ON:
	141	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
	142	fgets(buf, sizeof(buf), stdin);
	143	reply[count].resp = xstrdup(buf);
	144	reply[count].resp_retcode = PAM_SUCCESS;
	145	break;
	146	case PAM_PROMPT_ECHO_OFF:
	147	reply[count].resp = xstrdup(
	148	read_passphrase(PAM_MSG_MEMBER(msg, count,
	149	msg), 1));
	150	reply[count].resp_retcode = PAM_SUCCESS;
	151	break;
	152	case PAM_ERROR_MSG:
	153	case PAM_TEXT_INFO:
	154	if ((*msg)[count].msg != NULL)
	155	fprintf(stderr, "%s\n",
	156	PAM_MSG_MEMBER(msg, count, msg));
	157	reply[count].resp = xstrdup("");
	158	reply[count].resp_retcode = PAM_SUCCESS;
	159	break;
	160	default:
	161	free(reply);
	162	return PAM_CONV_ERR;
	163	}
a5c9cd31	164	}
	165	}
	166
	167	*resp = reply;
	168
	169	return PAM_SUCCESS;
	170	}
	171
	172	/* Called at exit to cleanly shutdown PAM */
e11aab29	173	void do_pam_cleanup_proc(void *context)
a5c9cd31	174	{
	175	int pam_retval;
	176
e11aab29	177	if (__pamh && session_opened) {
e11aab29	178	pam_retval = pam_close_session(__pamh, 0);
5c377b3b	179	if (pam_retval != PAM_SUCCESS)
2b87da3b	180	log("Cannot close PAM session[%d]: %.200s",
e11aab29	181	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	182	}
a5c9cd31	183
e11aab29	184	if (__pamh && creds_set) {
e11aab29	185	pam_retval = pam_setcred(__pamh, PAM_DELETE_CRED);
5c377b3b	186	if (pam_retval != PAM_SUCCESS)
5c377b3b	187	debug("Cannot delete credentials[%d]: %.200s",
e11aab29	188	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	189	}
a5c9cd31	190
e11aab29	191	if (__pamh) {
e11aab29	192	pam_retval = pam_end(__pamh, pam_retval);
5c377b3b	193	if (pam_retval != PAM_SUCCESS)
2b87da3b	194	log("Cannot release PAM authentication[%d]: %.200s",
e11aab29	195	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	196	}
	197	}
	198
	199	/* Attempt password authentation using PAM */
	200	int auth_pam_password(struct passwd pw, const char password)
	201	{
	202	extern ServerOptions options;
	203	int pam_retval;
	204
e11aab29	205	do_pam_set_conv(&conv);
8c9fe09e	206
a5c9cd31	207	/* deny if no user. */
	208	if (pw == NULL)
	209	return 0;
	210	if (pw->pw_uid == 0 && options.permit_root_login == 2)
	211	return 0;
	212	if (*password == '\0' && options.permit_empty_passwd == 0)
	213	return 0;
	214
e11aab29	215	__pampasswd = password;
2b87da3b	216
ad55cd03	217	pamstate = INITIAL_LOGIN;
8c9fe09e	218	pam_retval = do_pam_authenticate(0);
a5c9cd31	219	if (pam_retval == PAM_SUCCESS) {
5c377b3b	220	debug("PAM Password authentication accepted for "
5c377b3b	221	"user \"%.100s\"", pw->pw_name);
a5c9cd31	222	return 1;
a5c9cd31	223	} else {
5c377b3b	224	debug("PAM Password authentication for \"%.100s\" "
5c377b3b	225	"failed[%d]: %s", pw->pw_name, pam_retval,
e11aab29	226	PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	227	return 0;
	228	}
	229	}
	230
	231	/* Do account management using PAM */
	232	int do_pam_account(char username, char remote_user)
	233	{
	234	int pam_retval;
2b87da3b	235
e11aab29	236	do_pam_set_conv(&conv);
5c377b3b	237
5c377b3b	238	if (remote_user) {
a5c9cd31	239	debug("PAM setting ruser to \"%.200s\"", remote_user);
e11aab29	240	pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
5c377b3b	241	if (pam_retval != PAM_SUCCESS)
5c377b3b	242	fatal("PAM set ruser failed[%d]: %.200s", pam_retval,
e11aab29	243	PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	244	}
a5c9cd31	245
e11aab29	246	pam_retval = pam_acct_mgmt(__pamh, 0);
5daf7064	247	switch (pam_retval) {
	248	case PAM_SUCCESS:
	249	/* This is what we want */
	250	break;
	251	case PAM_NEW_AUTHTOK_REQD:
e11aab29	252	message_cat(&__pam_msg, NEW_AUTHTOK_MSG);
ad55cd03	253	/* flag that password change is necessary */
ad55cd03	254	password_change_required = 1;
5daf7064	255	break;
5daf7064	256	default:
5c377b3b	257	log("PAM rejected by account configuration[%d]: "
e11aab29	258	"%.200s", pam_retval, PAM_STRERROR(__pamh,
5c377b3b	259	pam_retval));
5daf7064	260	return(0);
a5c9cd31	261	}
2b87da3b	262
a5c9cd31	263	return(1);
	264	}
	265
	266	/* Do PAM-specific session initialisation */
fd094f49	267	void do_pam_session(char username, const char ttyname)
a5c9cd31	268	{
	269	int pam_retval;
	270
	271	if (ttyname != NULL) {
	272	debug("PAM setting tty to \"%.200s\"", ttyname);
e11aab29	273	pam_retval = pam_set_item(__pamh, PAM_TTY, ttyname);
5c377b3b	274	if (pam_retval != PAM_SUCCESS)
2b87da3b	275	fatal("PAM set tty failed[%d]: %.200s",
e11aab29	276	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	277	}
a5c9cd31	278
e11aab29	279	pam_retval = pam_open_session(__pamh, 0);
5c377b3b	280	if (pam_retval != PAM_SUCCESS)
2b87da3b	281	fatal("PAM session setup failed[%d]: %.200s",
e11aab29	282	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	283	session_opened = 1;
a5c9cd31	284	}
a5c9cd31	285
2b87da3b	286	/* Set PAM credentials */
a815d7a3	287	void do_pam_setcred(void)
a5c9cd31	288	{
a5c9cd31	289	int pam_retval;
2b87da3b	290
a5c9cd31	291	debug("PAM establishing creds");
e11aab29	292	pam_retval = pam_setcred(__pamh, PAM_ESTABLISH_CRED);
5daf7064	293	if (pam_retval != PAM_SUCCESS) {
5c377b3b	294	if (was_authenticated)
2b87da3b	295	fatal("PAM setcred failed[%d]: %.200s",
e11aab29	296	pam_retval, PAM_STRERROR(__pamh, pam_retval));
5c377b3b	297	else
2b87da3b	298	debug("PAM setcred failed[%d]: %.200s",
e11aab29	299	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	300	} else
1c2d0a13	301	creds_set = 1;
ad55cd03	302	}
ad55cd03	303
2919e060	304	/* accessor function for file scope static variable */
e11aab29	305	int is_pam_password_change_required(void)
2919e060	306	{
	307	return password_change_required;
	308	}
	309
2b87da3b	310	/*
ad55cd03	311	* Have user change authentication token if pam_acct_mgmt() indicated
	312	* it was expired. This needs to be called after an interactive
	313	* session is established and the user's pty is connected to
	314	* stdin/stout/stderr.
	315	*/
a815d7a3	316	void do_pam_chauthtok(void)
ad55cd03	317	{
	318	int pam_retval;
	319
	320	if (password_change_required) {
	321	pamstate = OTHER;
5c377b3b	322	/* XXX: should we really loop forever? */
ad55cd03	323	do {
e11aab29	324	pam_retval = pam_chauthtok(__pamh,
5c377b3b	325	PAM_CHANGE_EXPIRED_AUTHTOK);
5c377b3b	326	if (pam_retval != PAM_SUCCESS)
2b87da3b	327	log("PAM pam_chauthtok failed[%d]: %.200s",
e11aab29	328	pam_retval, PAM_STRERROR(__pamh, pam_retval));
ad55cd03	329	} while (pam_retval != PAM_SUCCESS);
5daf7064	330	}
a5c9cd31	331	}
	332
	333	/* Cleanly shutdown PAM */
	334	void finish_pam(void)
	335	{
e11aab29	336	do_pam_cleanup_proc(NULL);
e11aab29	337	fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
a5c9cd31	338	}
	339
	340	/* Start PAM authentication for specified account */
04fc7a67	341	void start_pam(const char *user)
a5c9cd31	342	{
a5c9cd31	343	int pam_retval;
dbd97a4d	344	extern ServerOptions options;
a5c9cd31	345
04fc7a67	346	debug("Starting up PAM with username \"%.200s\"", user);
a5c9cd31	347
e11aab29	348	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);
a5c9cd31	349
5c377b3b	350	if (pam_retval != PAM_SUCCESS)
2b87da3b	351	fatal("PAM initialisation failed[%d]: %.200s",
e11aab29	352	pam_retval, PAM_STRERROR(__pamh, pam_retval));
e275684f	353
	354	debug("PAM setting rhost to \"%.200s\"",
	355	get_canonical_hostname(options.reverse_mapping_check));
e11aab29	356	pam_retval = pam_set_item(__pamh, PAM_RHOST,
e275684f	357	get_canonical_hostname(options.reverse_mapping_check));
	358	if (pam_retval != PAM_SUCCESS)
	359	fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
e11aab29	360	PAM_STRERROR(__pamh, pam_retval));
a8545c6c	361	#ifdef PAM_TTY_KLUDGE
ae543aaa	362	/*
ae543aaa	363	* Some PAM modules (e.g. pam_time) require a TTY to operate,
2b87da3b	364	* and will fail in various stupid ways if they don't get one.
ae543aaa	365	* sshd doesn't set the tty until too late in the auth process and may
ae543aaa	366	* not even need one (for tty-less connections)
2b87da3b	367	* Kludge: Set a fake PAM_TTY
ae543aaa	368	*/
e11aab29	369	pam_retval = pam_set_item(__pamh, PAM_TTY, "ssh");
5c377b3b	370	if (pam_retval != PAM_SUCCESS)
2b87da3b	371	fatal("PAM set tty failed[%d]: %.200s",
e11aab29	372	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a8545c6c	373	#endif /* PAM_TTY_KLUDGE */
cbd7492e	374
e11aab29	375	fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
a5c9cd31	376	}
	377
	378	/* Return list of PAM enviornment strings */
	379	char **fetch_pam_environment(void)
	380	{
2b763e31	381	#ifdef HAVE_PAM_GETENVLIST
e11aab29	382	return(pam_getenvlist(__pamh));
2b763e31	383	#else /* HAVE_PAM_GETENVLIST */
	384	return(NULL);
	385	#endif /* HAVE_PAM_GETENVLIST */
a5c9cd31	386	}
	387
	388	/* Print any messages that have been generated during authentication */
	389	/* or account checking to stderr */
	390	void print_pam_messages(void)
	391	{
e11aab29	392	if (__pam_msg != NULL)
e11aab29	393	fputs(__pam_msg, stderr);
5daf7064	394	}
5daf7064	395
5c377b3b	396	/* Append a message to buffer */
5c377b3b	397	void message_cat(char *p, const char a)
5daf7064	398	{
5c377b3b	399	char *cp;
5c377b3b	400	size_t new_len;
2b87da3b	401
5c377b3b	402	new_len = strlen(a);
2b87da3b	403
5c377b3b	404	if (*p) {
	405	size_t len = strlen(*p);
	406
	407	p = xrealloc(p, new_len + len + 2);
	408	cp = *p + len;
	409	} else
	410	*p = cp = xmalloc(new_len + 2);
5daf7064	411
5c377b3b	412	memcpy(cp, a, new_len);
	413	cp[new_len] = '\n';
	414	cp[new_len + 1] = '\0';
a5c9cd31	415	}
	416
	417	#endif /* USE_PAM */