[gssapi-openssh.git] / openssh / 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 "xmalloc.h"
#include "log.h"
#include "auth.h"
#include "auth-options.h"
#include "auth-pam.h"
#include "servconf.h"
#include "canohost.h"
#include "readpass.h"

extern char *__progname;

extern int use_privsep;

RCSID("$Id$");

#define NEW_AUTHTOK_MSG \
	"Warning: Your password has expired, please change it now."
#define NEW_AUTHTOK_MSG_PRIVSEP \
	"Your password has expired, the session cannot proceed."

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 = {
	(int (*)())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_NEW_AUTHTOK_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 = xmalloc(num_msg * sizeof(*reply));

	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:
				xfree(reply);
				return PAM_CONV_ERR;
			case PAM_PROMPT_ECHO_OFF:
				if (__pampasswd == NULL) {
					xfree(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 (PAM_MSG_MEMBER(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:
				xfree(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 (PAM_MSG_MEMBER(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:
				xfree(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);

	__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);
	debug2("pam_acct_mgmt() = %d", pam_retval);
	switch (pam_retval) {
		case PAM_SUCCESS:
			/* This is what we want */
			break;
#if 0
		case PAM_NEW_AUTHTOK_REQD:
			message_cat(&__pam_msg, use_privsep ?
			    NEW_AUTHTOK_MSG_PRIVSEP : NEW_AUTHTOK_MSG);
			/* flag that password change is necessary */
			password_change_required = 1;
			/* disallow other functionality for now */
			no_port_forwarding_flag |= 2;
			no_agent_forwarding_flag |= 2;
			no_x11_forwarding_flag |= 2;
			break;
#endif
		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;

	if (__pamh == NULL)
		return;

	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/stdout/stderr.
 */
void do_pam_chauthtok(void)
{
	int pam_retval;

	do_pam_set_conv(&conv);

	if (password_change_required) {
		if (use_privsep)
			fatal("Password changing is currently unsupported"
			    " with privilege separation");
		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));
#if 0
		/* XXX: This would need to be done in the parent process,
		 * but there's currently no way to pass such request. */
		no_port_forwarding_flag &= ~2;
		no_agent_forwarding_flag &= ~2;
		no_x11_forwarding_flag &= ~2;
		if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
			channel_permit_all_opens();
#endif
	}
}

/* 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 environment strings */
char **fetch_pam_environment(void)
{
#ifdef HAVE_PAM_GETENVLIST
	return(pam_getenvlist(__pamh));
#else /* HAVE_PAM_GETENVLIST */
	return(NULL);
#endif /* HAVE_PAM_GETENVLIST */
}

/* Set a PAM environment string. We need to do this so that the session
 * modules can handle things like Kerberos/GSI credentials that appear
 * during the ssh authentication process.
 */

int do_pam_putenv(char *name, char *value) {
	char *compound;
	int ret=1;

#ifdef HAVE_PAM_PUTENV	
	compound=xmalloc(strlen(name)+strlen(value)+2);
	if (compound) {
		sprintf(compound,"%s=%s",name,value);
		ret=pam_putenv(__pamh,compound);
		xfree(compound);
	}
#endif
	return(ret);
}

void free_pam_environment(char **env)
{
	int i;

	if (env != NULL) {
		for (i = 0; env[i] != NULL; i++)
			xfree(env[i]);
	}
}

/* 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
3c0ef626	1	/*
	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.
	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.
	23	*/
	24
	25	#include "includes.h"
	26
	27	#ifdef USE_PAM
3c0ef626	28	#include "xmalloc.h"
3c0ef626	29	#include "log.h"
350391c5	30	#include "auth.h"
d03f4262	31	#include "auth-options.h"
3c0ef626	32	#include "auth-pam.h"
	33	#include "servconf.h"
	34	#include "canohost.h"
	35	#include "readpass.h"
	36
	37	extern char *__progname;
	38
d03f4262	39	extern int use_privsep;
d03f4262	40
3c0ef626	41	RCSID("$Id$");
	42
	43	#define NEW_AUTHTOK_MSG \
d03f4262	44	"Warning: Your password has expired, please change it now."
	45	#define NEW_AUTHTOK_MSG_PRIVSEP \
	46	"Your password has expired, the session cannot proceed."
3c0ef626	47
	48	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
	49	struct pam_response *resp, void appdata_ptr);
	50
	51	/* module-local variables */
	52	static struct pam_conv conv = {
d03f4262	53	(int (*)())do_pam_conversation,
3c0ef626	54	NULL
	55	};
	56	static char *__pam_msg = NULL;
	57	static pam_handle_t *__pamh = NULL;
	58	static const char *__pampasswd = NULL;
	59
	60	/* states for do_pam_conversation() */
	61	enum { INITIAL_LOGIN, OTHER } pamstate = INITIAL_LOGIN;
d03f4262	62	/* remember whether pam_acct_mgmt() returned PAM_NEW_AUTHTOK_REQD */
3c0ef626	63	static int password_change_required = 0;
	64	/* remember whether the last pam_authenticate() succeeded or not */
	65	static int was_authenticated = 0;
	66
	67	/* Remember what has been initialised */
	68	static int session_opened = 0;
	69	static int creds_set = 0;
	70
	71	/* accessor which allows us to switch conversation structs according to
	72	* the authentication method being used */
	73	void do_pam_set_conv(struct pam_conv *conv)
	74	{
	75	pam_set_item(__pamh, PAM_CONV, conv);
	76	}
	77
	78	/* start an authentication run */
	79	int do_pam_authenticate(int flags)
	80	{
	81	int retval = pam_authenticate(__pamh, flags);
	82	was_authenticated = (retval == PAM_SUCCESS);
	83	return retval;
	84	}
	85
	86	/*
	87	* PAM conversation function.
	88	* There are two states this can run in.
	89	*
	90	* INITIAL_LOGIN mode simply feeds the password from the client into
	91	* PAM in response to PAM_PROMPT_ECHO_OFF, and collects output
	92	* messages with into __pam_msg. This is used during initial
	93	* authentication to bypass the normal PAM password prompt.
	94	*
	95	* OTHER mode handles PAM_PROMPT_ECHO_OFF with read_passphrase()
	96	* and outputs messages to stderr. This mode is used if pam_chauthtok()
	97	* is called to update expired passwords.
	98	*/
	99	static int do_pam_conversation(int num_msg, const struct pam_message **msg,
	100	struct pam_response *resp, void appdata_ptr)
	101	{
	102	struct pam_response *reply;
	103	int count;
	104	char buf[1024];
	105
	106	/* PAM will free this later */
d03f4262	107	reply = xmalloc(num_msg * sizeof(*reply));
3c0ef626	108
	109	for (count = 0; count < num_msg; count++) {
	110	if (pamstate == INITIAL_LOGIN) {
	111	/*
	112	* We can't use stdio yet, queue messages for
	113	* printing later
	114	*/
	115	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
	116	case PAM_PROMPT_ECHO_ON:
d03f4262	117	xfree(reply);
3c0ef626	118	return PAM_CONV_ERR;
	119	case PAM_PROMPT_ECHO_OFF:
	120	if (__pampasswd == NULL) {
d03f4262	121	xfree(reply);
3c0ef626	122	return PAM_CONV_ERR;
	123	}
	124	reply[count].resp = xstrdup(__pampasswd);
	125	reply[count].resp_retcode = PAM_SUCCESS;
	126	break;
	127	case PAM_ERROR_MSG:
	128	case PAM_TEXT_INFO:
d03f4262	129	if (PAM_MSG_MEMBER(msg, count, msg) != NULL) {
3c0ef626	130	message_cat(&__pam_msg,
	131	PAM_MSG_MEMBER(msg, count, msg));
	132	}
	133	reply[count].resp = xstrdup("");
	134	reply[count].resp_retcode = PAM_SUCCESS;
	135	break;
	136	default:
d03f4262	137	xfree(reply);
3c0ef626	138	return PAM_CONV_ERR;
	139	}
	140	} else {
	141	/*
	142	* stdio is connected, so interact directly
	143	*/
	144	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
	145	case PAM_PROMPT_ECHO_ON:
	146	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
	147	fgets(buf, sizeof(buf), stdin);
	148	reply[count].resp = xstrdup(buf);
	149	reply[count].resp_retcode = PAM_SUCCESS;
	150	break;
	151	case PAM_PROMPT_ECHO_OFF:
	152	reply[count].resp =
	153	read_passphrase(PAM_MSG_MEMBER(msg, count,
	154	msg), RP_ALLOW_STDIN);
	155	reply[count].resp_retcode = PAM_SUCCESS;
	156	break;
	157	case PAM_ERROR_MSG:
	158	case PAM_TEXT_INFO:
d03f4262	159	if (PAM_MSG_MEMBER(msg, count, msg) != NULL)
3c0ef626	160	fprintf(stderr, "%s\n",
	161	PAM_MSG_MEMBER(msg, count, msg));
	162	reply[count].resp = xstrdup("");
	163	reply[count].resp_retcode = PAM_SUCCESS;
	164	break;
	165	default:
d03f4262	166	xfree(reply);
3c0ef626	167	return PAM_CONV_ERR;
	168	}
	169	}
	170	}
	171
	172	*resp = reply;
	173
	174	return PAM_SUCCESS;
	175	}
	176
	177	/* Called at exit to cleanly shutdown PAM */
	178	void do_pam_cleanup_proc(void *context)
	179	{
	180	int pam_retval = PAM_SUCCESS;
	181
	182	if (__pamh && session_opened) {
	183	pam_retval = pam_close_session(__pamh, 0);
	184	if (pam_retval != PAM_SUCCESS)
	185	log("Cannot close PAM session[%d]: %.200s",
	186	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	187	}
	188
	189	if (__pamh && creds_set) {
	190	pam_retval = pam_setcred(__pamh, PAM_DELETE_CRED);
	191	if (pam_retval != PAM_SUCCESS)
	192	debug("Cannot delete credentials[%d]: %.200s",
	193	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	194	}
	195
	196	if (__pamh) {
	197	pam_retval = pam_end(__pamh, pam_retval);
	198	if (pam_retval != PAM_SUCCESS)
	199	log("Cannot release PAM authentication[%d]: %.200s",
	200	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	201	}
	202	}
	203
	204	/* Attempt password authentation using PAM */
350391c5	205	int auth_pam_password(Authctxt authctxt, const char password)
3c0ef626	206	{
	207	extern ServerOptions options;
	208	int pam_retval;
350391c5	209	struct passwd *pw = authctxt->pw;
3c0ef626	210
	211	do_pam_set_conv(&conv);
	212
3c0ef626	213	__pampasswd = password;
	214
	215	pamstate = INITIAL_LOGIN;
	216	pam_retval = do_pam_authenticate(
	217	options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0);
	218	if (pam_retval == PAM_SUCCESS) {
	219	debug("PAM Password authentication accepted for "
	220	"user \"%.100s\"", pw->pw_name);
	221	return 1;
	222	} else {
	223	debug("PAM Password authentication for \"%.100s\" "
	224	"failed[%d]: %s", pw->pw_name, pam_retval,
	225	PAM_STRERROR(__pamh, pam_retval));
	226	return 0;
	227	}
	228	}
	229
	230	/* Do account management using PAM */
	231	int do_pam_account(char username, char remote_user)
	232	{
	233	int pam_retval;
	234
	235	do_pam_set_conv(&conv);
	236
	237	if (remote_user) {
	238	debug("PAM setting ruser to \"%.200s\"", remote_user);
	239	pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
	240	if (pam_retval != PAM_SUCCESS)
	241	fatal("PAM set ruser failed[%d]: %.200s", pam_retval,
	242	PAM_STRERROR(__pamh, pam_retval));
	243	}
	244
	245	pam_retval = pam_acct_mgmt(__pamh, 0);
350391c5	246	debug2("pam_acct_mgmt() = %d", pam_retval);
3c0ef626	247	switch (pam_retval) {
	248	case PAM_SUCCESS:
	249	/* This is what we want */
	250	break;
350391c5	251	#if 0
3c0ef626	252	case PAM_NEW_AUTHTOK_REQD:
d03f4262	253	message_cat(&__pam_msg, use_privsep ?
d03f4262	254	NEW_AUTHTOK_MSG_PRIVSEP : NEW_AUTHTOK_MSG);
3c0ef626	255	/* flag that password change is necessary */
3c0ef626	256	password_change_required = 1;
d03f4262	257	/* disallow other functionality for now */
	258	no_port_forwarding_flag \|= 2;
	259	no_agent_forwarding_flag \|= 2;
	260	no_x11_forwarding_flag \|= 2;
3c0ef626	261	break;
350391c5	262	#endif
3c0ef626	263	default:
	264	log("PAM rejected by account configuration[%d]: "
	265	"%.200s", pam_retval, PAM_STRERROR(__pamh,
	266	pam_retval));
	267	return(0);
	268	}
	269
	270	return(1);
	271	}
	272
	273	/* Do PAM-specific session initialisation */
	274	void do_pam_session(char username, const char ttyname)
	275	{
	276	int pam_retval;
	277
	278	do_pam_set_conv(&conv);
	279
	280	if (ttyname != NULL) {
	281	debug("PAM setting tty to \"%.200s\"", ttyname);
	282	pam_retval = pam_set_item(__pamh, PAM_TTY, ttyname);
	283	if (pam_retval != PAM_SUCCESS)
	284	fatal("PAM set tty failed[%d]: %.200s",
	285	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	286	}
	287
	288	pam_retval = pam_open_session(__pamh, 0);
	289	if (pam_retval != PAM_SUCCESS)
	290	fatal("PAM session setup failed[%d]: %.200s",
	291	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	292
	293	session_opened = 1;
	294	}
	295
	296	/* Set PAM credentials */
	297	void do_pam_setcred(int init)
	298	{
	299	int pam_retval;
	300
350391c5	301	if (__pamh == NULL)
	302	return;
	303
3c0ef626	304	do_pam_set_conv(&conv);
	305
	306	debug("PAM establishing creds");
	307	pam_retval = pam_setcred(__pamh,
	308	init ? PAM_ESTABLISH_CRED : PAM_REINITIALIZE_CRED);
	309	if (pam_retval != PAM_SUCCESS) {
	310	if (was_authenticated)
	311	fatal("PAM setcred failed[%d]: %.200s",
	312	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	313	else
	314	debug("PAM setcred failed[%d]: %.200s",
	315	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	316	} else
	317	creds_set = 1;
	318	}
	319
	320	/* accessor function for file scope static variable */
	321	int is_pam_password_change_required(void)
	322	{
	323	return password_change_required;
	324	}
	325
	326	/*
	327	* Have user change authentication token if pam_acct_mgmt() indicated
	328	* it was expired. This needs to be called after an interactive
	329	* session is established and the user's pty is connected to
d03f4262	330	* stdin/stdout/stderr.
3c0ef626	331	*/
	332	void do_pam_chauthtok(void)
	333	{
	334	int pam_retval;
	335
	336	do_pam_set_conv(&conv);
	337
	338	if (password_change_required) {
d03f4262	339	if (use_privsep)
	340	fatal("Password changing is currently unsupported"
	341	" with privilege separation");
3c0ef626	342	pamstate = OTHER;
	343	pam_retval = pam_chauthtok(__pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
	344	if (pam_retval != PAM_SUCCESS)
	345	fatal("PAM pam_chauthtok failed[%d]: %.200s",
	346	pam_retval, PAM_STRERROR(__pamh, pam_retval));
d03f4262	347	#if 0
	348	/* XXX: This would need to be done in the parent process,
	349	* but there's currently no way to pass such request. */
	350	no_port_forwarding_flag &= ~2;
	351	no_agent_forwarding_flag &= ~2;
	352	no_x11_forwarding_flag &= ~2;
	353	if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
	354	channel_permit_all_opens();
	355	#endif
3c0ef626	356	}
	357	}
	358
	359	/* Cleanly shutdown PAM */
	360	void finish_pam(void)
	361	{
	362	do_pam_cleanup_proc(NULL);
	363	fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
	364	}
	365
	366	/* Start PAM authentication for specified account */
	367	void start_pam(const char *user)
	368	{
	369	int pam_retval;
	370	extern ServerOptions options;
	371	extern u_int utmp_len;
	372	const char *rhost;
	373
	374	debug("Starting up PAM with username \"%.200s\"", user);
	375
	376	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);
	377
	378	if (pam_retval != PAM_SUCCESS)
	379	fatal("PAM initialisation failed[%d]: %.200s",
	380	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	381
e9702f7d	382	rhost = get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping);
3c0ef626	383	debug("PAM setting rhost to \"%.200s\"", rhost);
	384
	385	pam_retval = pam_set_item(__pamh, PAM_RHOST, rhost);
	386	if (pam_retval != PAM_SUCCESS)
	387	fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
	388	PAM_STRERROR(__pamh, pam_retval));
	389	#ifdef PAM_TTY_KLUDGE
	390	/*
	391	* Some PAM modules (e.g. pam_time) require a TTY to operate,
	392	* and will fail in various stupid ways if they don't get one.
	393	* sshd doesn't set the tty until too late in the auth process and may
	394	* not even need one (for tty-less connections)
	395	* Kludge: Set a fake PAM_TTY
	396	*/
	397	pam_retval = pam_set_item(__pamh, PAM_TTY, "NODEVssh");
	398	if (pam_retval != PAM_SUCCESS)
	399	fatal("PAM set tty failed[%d]: %.200s",
	400	pam_retval, PAM_STRERROR(__pamh, pam_retval));
	401	#endif /* PAM_TTY_KLUDGE */
	402
	403	fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
	404	}
	405
d03f4262	406	/* Return list of PAM environment strings */
3c0ef626	407	char **fetch_pam_environment(void)
	408	{
	409	#ifdef HAVE_PAM_GETENVLIST
	410	return(pam_getenvlist(__pamh));
	411	#else /* HAVE_PAM_GETENVLIST */
	412	return(NULL);
	413	#endif /* HAVE_PAM_GETENVLIST */
	414	}
	415
5598e598	416	/* Set a PAM environment string. We need to do this so that the session
	417	* modules can handle things like Kerberos/GSI credentials that appear
	418	* during the ssh authentication process.
	419	*/
	420
	421	int do_pam_putenv(char name, char value) {
	422	char *compound;
	423	int ret=1;
905081a4	424
905081a4	425	#ifdef HAVE_PAM_PUTENV
5598e598	426	compound=xmalloc(strlen(name)+strlen(value)+2);
	427	if (compound) {
	428	sprintf(compound,"%s=%s",name,value);
	429	ret=pam_putenv(__pamh,compound);
	430	xfree(compound);
	431	}
905081a4	432	#endif
5598e598	433	return(ret);
	434	}
	435
d03f4262	436	void free_pam_environment(char **env)
	437	{
	438	int i;
	439
	440	if (env != NULL) {
	441	for (i = 0; env[i] != NULL; i++)
	442	xfree(env[i]);
	443	}
	444	}
	445
3c0ef626	446	/* Print any messages that have been generated during authentication */
	447	/* or account checking to stderr */
	448	void print_pam_messages(void)
	449	{
	450	if (__pam_msg != NULL)
	451	fputs(__pam_msg, stderr);
	452	}
	453
	454	/* Append a message to buffer */
	455	void message_cat(char *p, const char a)
	456	{
	457	char *cp;
	458	size_t new_len;
	459
	460	new_len = strlen(a);
	461
	462	if (*p) {
	463	size_t len = strlen(*p);
	464
	465	p = xrealloc(p, new_len + len + 2);
	466	cp = *p + len;
	467	} else
	468	*p = cp = xmalloc(new_len + 2);
	469
	470	memcpy(cp, a, new_len);
	471	cp[new_len] = '\n';
	472	cp[new_len + 1] = '\0';
	473	}
	474
	475	#endif /* USE_PAM */