[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_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 ((*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);

	/* 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);
	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, NEW_AUTHTOK_MSG);
			/* flag that password change is necessary */
			password_change_required = 1;
			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) {
		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 \
b992432e	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;
b992432e	58	/* remember whether pam_acct_mgmt() returned PAM_NEW_AUTHTOK_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
a5c9cd31	102	/* PAM will free this later */
b2f295dc	103	reply = xmalloc(num_msg * sizeof(*reply));
a5c9cd31	104
ad55cd03	105	for (count = 0; count < num_msg; count++) {
5c377b3b	106	if (pamstate == INITIAL_LOGIN) {
	107	/*
	108	* We can't use stdio yet, queue messages for
	109	* printing later
	110	*/
	111	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
ad55cd03	112	case PAM_PROMPT_ECHO_ON:
b2f295dc	113	xfree(reply);
5c377b3b	114	return PAM_CONV_ERR;
5c377b3b	115	case PAM_PROMPT_ECHO_OFF:
e11aab29	116	if (__pampasswd == NULL) {
b2f295dc	117	xfree(reply);
71dfaf1c	118	return PAM_CONV_ERR;
71dfaf1c	119	}
e11aab29	120	reply[count].resp = xstrdup(__pampasswd);
a5c9cd31	121	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	122	break;
ad55cd03	123	case PAM_ERROR_MSG:
a5c9cd31	124	case PAM_TEXT_INFO:
b2f295dc	125	if (PAM_MSG_MEMBER(msg, count, msg) != NULL) {
e11aab29	126	message_cat(&__pam_msg,
5c377b3b	127	PAM_MSG_MEMBER(msg, count, msg));
ad55cd03	128	}
a5c9cd31	129	reply[count].resp = xstrdup("");
ad55cd03	130	reply[count].resp_retcode = PAM_SUCCESS;
a5c9cd31	131	break;
a5c9cd31	132	default:
b2f295dc	133	xfree(reply);
a5c9cd31	134	return PAM_CONV_ERR;
5c377b3b	135	}
	136	} else {
	137	/*
	138	* stdio is connected, so interact directly
	139	*/
	140	switch(PAM_MSG_MEMBER(msg, count, msg_style)) {
	141	case PAM_PROMPT_ECHO_ON:
	142	fputs(PAM_MSG_MEMBER(msg, count, msg), stderr);
	143	fgets(buf, sizeof(buf), stdin);
	144	reply[count].resp = xstrdup(buf);
	145	reply[count].resp_retcode = PAM_SUCCESS;
	146	break;
	147	case PAM_PROMPT_ECHO_OFF:
9678565b	148	reply[count].resp =
840ad55e	149	read_passphrase(PAM_MSG_MEMBER(msg, count,
840ad55e	150	msg), RP_ALLOW_STDIN);
5c377b3b	151	reply[count].resp_retcode = PAM_SUCCESS;
	152	break;
	153	case PAM_ERROR_MSG:
	154	case PAM_TEXT_INFO:
	155	if ((*msg)[count].msg != NULL)
	156	fprintf(stderr, "%s\n",
	157	PAM_MSG_MEMBER(msg, count, msg));
	158	reply[count].resp = xstrdup("");
	159	reply[count].resp_retcode = PAM_SUCCESS;
	160	break;
	161	default:
b2f295dc	162	xfree(reply);
5c377b3b	163	return PAM_CONV_ERR;
5c377b3b	164	}
a5c9cd31	165	}
	166	}
	167
	168	*resp = reply;
	169
	170	return PAM_SUCCESS;
	171	}
	172
	173	/* Called at exit to cleanly shutdown PAM */
e11aab29	174	void do_pam_cleanup_proc(void *context)
a5c9cd31	175	{
37eadb90	176	int pam_retval = PAM_SUCCESS;
a5c9cd31	177
e11aab29	178	if (__pamh && session_opened) {
e11aab29	179	pam_retval = pam_close_session(__pamh, 0);
5c377b3b	180	if (pam_retval != PAM_SUCCESS)
2b87da3b	181	log("Cannot close PAM session[%d]: %.200s",
e11aab29	182	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	183	}
a5c9cd31	184
e11aab29	185	if (__pamh && creds_set) {
e11aab29	186	pam_retval = pam_setcred(__pamh, PAM_DELETE_CRED);
5c377b3b	187	if (pam_retval != PAM_SUCCESS)
5c377b3b	188	debug("Cannot delete credentials[%d]: %.200s",
e11aab29	189	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	190	}
a5c9cd31	191
e11aab29	192	if (__pamh) {
e11aab29	193	pam_retval = pam_end(__pamh, pam_retval);
5c377b3b	194	if (pam_retval != PAM_SUCCESS)
2b87da3b	195	log("Cannot release PAM authentication[%d]: %.200s",
e11aab29	196	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	197	}
	198	}
	199
	200	/* Attempt password authentation using PAM */
fde58bd4	201	int auth_pam_password(Authctxt authctxt, const char password)
a5c9cd31	202	{
	203	extern ServerOptions options;
	204	int pam_retval;
fde58bd4	205	struct passwd *pw = authctxt->pw;
a5c9cd31	206
e11aab29	207	do_pam_set_conv(&conv);
8c9fe09e	208
a5c9cd31	209	/* deny if no user. */
	210	if (pw == NULL)
	211	return 0;
3cc990d7	212	if (pw->pw_uid == 0 && options.permit_root_login == PERMIT_NO_PASSWD)
a5c9cd31	213	return 0;
	214	if (*password == '\0' && options.permit_empty_passwd == 0)
	215	return 0;
	216
e11aab29	217	__pampasswd = password;
2b87da3b	218
ad55cd03	219	pamstate = INITIAL_LOGIN;
78afd1dc	220	pam_retval = do_pam_authenticate(
78afd1dc	221	options.permit_empty_passwd == 0 ? PAM_DISALLOW_NULL_AUTHTOK : 0);
a5c9cd31	222	if (pam_retval == PAM_SUCCESS) {
5c377b3b	223	debug("PAM Password authentication accepted for "
5c377b3b	224	"user \"%.100s\"", pw->pw_name);
a5c9cd31	225	return 1;
a5c9cd31	226	} else {
5c377b3b	227	debug("PAM Password authentication for \"%.100s\" "
5c377b3b	228	"failed[%d]: %s", pw->pw_name, pam_retval,
e11aab29	229	PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	230	return 0;
	231	}
	232	}
	233
	234	/* Do account management using PAM */
	235	int do_pam_account(char username, char remote_user)
	236	{
	237	int pam_retval;
2b87da3b	238
e11aab29	239	do_pam_set_conv(&conv);
5c377b3b	240
5c377b3b	241	if (remote_user) {
a5c9cd31	242	debug("PAM setting ruser to \"%.200s\"", remote_user);
e11aab29	243	pam_retval = pam_set_item(__pamh, PAM_RUSER, remote_user);
5c377b3b	244	if (pam_retval != PAM_SUCCESS)
5c377b3b	245	fatal("PAM set ruser failed[%d]: %.200s", pam_retval,
e11aab29	246	PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	247	}
a5c9cd31	248
e11aab29	249	pam_retval = pam_acct_mgmt(__pamh, 0);
ad200abb	250	debug2("pam_acct_mgmt() = %d", pam_retval);
5daf7064	251	switch (pam_retval) {
	252	case PAM_SUCCESS:
	253	/* This is what we want */
	254	break;
e108cd93	255	#if 0
5daf7064	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;
e108cd93	261	#endif
5daf7064	262	default:
5c377b3b	263	log("PAM rejected by account configuration[%d]: "
e11aab29	264	"%.200s", pam_retval, PAM_STRERROR(__pamh,
5c377b3b	265	pam_retval));
5daf7064	266	return(0);
a5c9cd31	267	}
2b87da3b	268
a5c9cd31	269	return(1);
	270	}
	271
	272	/* Do PAM-specific session initialisation */
fd094f49	273	void do_pam_session(char username, const char ttyname)
a5c9cd31	274	{
	275	int pam_retval;
	276
5f404be3	277	do_pam_set_conv(&conv);
5f404be3	278
a5c9cd31	279	if (ttyname != NULL) {
a5c9cd31	280	debug("PAM setting tty to \"%.200s\"", ttyname);
e11aab29	281	pam_retval = pam_set_item(__pamh, PAM_TTY, ttyname);
5c377b3b	282	if (pam_retval != PAM_SUCCESS)
2b87da3b	283	fatal("PAM set tty failed[%d]: %.200s",
e11aab29	284	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a5c9cd31	285	}
a5c9cd31	286
e11aab29	287	pam_retval = pam_open_session(__pamh, 0);
5c377b3b	288	if (pam_retval != PAM_SUCCESS)
2b87da3b	289	fatal("PAM session setup failed[%d]: %.200s",
e11aab29	290	pam_retval, PAM_STRERROR(__pamh, pam_retval));
40a35ff1	291
1c2d0a13	292	session_opened = 1;
a5c9cd31	293	}
a5c9cd31	294
2b87da3b	295	/* Set PAM credentials */
9afbfcfa	296	void do_pam_setcred(int init)
a5c9cd31	297	{
a5c9cd31	298	int pam_retval;
2b87da3b	299
39ce53de	300	if (__pamh == NULL)
	301	return;
	302
5f404be3	303	do_pam_set_conv(&conv);
5f404be3	304
a5c9cd31	305	debug("PAM establishing creds");
9afbfcfa	306	pam_retval = pam_setcred(__pamh,
9afbfcfa	307	init ? PAM_ESTABLISH_CRED : PAM_REINITIALIZE_CRED);
5daf7064	308	if (pam_retval != PAM_SUCCESS) {
5c377b3b	309	if (was_authenticated)
2b87da3b	310	fatal("PAM setcred failed[%d]: %.200s",
e11aab29	311	pam_retval, PAM_STRERROR(__pamh, pam_retval));
5c377b3b	312	else
2b87da3b	313	debug("PAM setcred failed[%d]: %.200s",
e11aab29	314	pam_retval, PAM_STRERROR(__pamh, pam_retval));
1c2d0a13	315	} else
1c2d0a13	316	creds_set = 1;
ad55cd03	317	}
ad55cd03	318
2919e060	319	/* accessor function for file scope static variable */
e11aab29	320	int is_pam_password_change_required(void)
2919e060	321	{
	322	return password_change_required;
	323	}
	324
2b87da3b	325	/*
ad55cd03	326	* Have user change authentication token if pam_acct_mgmt() indicated
	327	* it was expired. This needs to be called after an interactive
	328	* session is established and the user's pty is connected to
b992432e	329	* stdin/stdout/stderr.
ad55cd03	330	*/
a815d7a3	331	void do_pam_chauthtok(void)
ad55cd03	332	{
	333	int pam_retval;
	334
5f404be3	335	do_pam_set_conv(&conv);
5f404be3	336
ad55cd03	337	if (password_change_required) {
ad55cd03	338	pamstate = OTHER;
0a3700ee	339	pam_retval = pam_chauthtok(__pamh, PAM_CHANGE_EXPIRED_AUTHTOK);
	340	if (pam_retval != PAM_SUCCESS)
	341	fatal("PAM pam_chauthtok failed[%d]: %.200s",
	342	pam_retval, PAM_STRERROR(__pamh, pam_retval));
5daf7064	343	}
a5c9cd31	344	}
	345
	346	/* Cleanly shutdown PAM */
	347	void finish_pam(void)
	348	{
e11aab29	349	do_pam_cleanup_proc(NULL);
e11aab29	350	fatal_remove_cleanup(&do_pam_cleanup_proc, NULL);
a5c9cd31	351	}
	352
	353	/* Start PAM authentication for specified account */
04fc7a67	354	void start_pam(const char *user)
a5c9cd31	355	{
a5c9cd31	356	int pam_retval;
dbd97a4d	357	extern ServerOptions options;
46c76c63	358	extern u_int utmp_len;
46c76c63	359	const char *rhost;
a5c9cd31	360
04fc7a67	361	debug("Starting up PAM with username \"%.200s\"", user);
a5c9cd31	362
e11aab29	363	pam_retval = pam_start(SSHD_PAM_SERVICE, user, &conv, &__pamh);
a5c9cd31	364
5c377b3b	365	if (pam_retval != PAM_SUCCESS)
2b87da3b	366	fatal("PAM initialisation failed[%d]: %.200s",
e11aab29	367	pam_retval, PAM_STRERROR(__pamh, pam_retval));
e275684f	368
983784a1	369	rhost = get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping);
46c76c63	370	debug("PAM setting rhost to \"%.200s\"", rhost);
	371
	372	pam_retval = pam_set_item(__pamh, PAM_RHOST, rhost);
e275684f	373	if (pam_retval != PAM_SUCCESS)
e275684f	374	fatal("PAM set rhost failed[%d]: %.200s", pam_retval,
e11aab29	375	PAM_STRERROR(__pamh, pam_retval));
a8545c6c	376	#ifdef PAM_TTY_KLUDGE
ae543aaa	377	/*
ae543aaa	378	* Some PAM modules (e.g. pam_time) require a TTY to operate,
2b87da3b	379	* and will fail in various stupid ways if they don't get one.
ae543aaa	380	* sshd doesn't set the tty until too late in the auth process and may
ae543aaa	381	* not even need one (for tty-less connections)
2b87da3b	382	* Kludge: Set a fake PAM_TTY
ae543aaa	383	*/
9f214051	384	pam_retval = pam_set_item(__pamh, PAM_TTY, "NODEVssh");
5c377b3b	385	if (pam_retval != PAM_SUCCESS)
2b87da3b	386	fatal("PAM set tty failed[%d]: %.200s",
e11aab29	387	pam_retval, PAM_STRERROR(__pamh, pam_retval));
a8545c6c	388	#endif /* PAM_TTY_KLUDGE */
cbd7492e	389
e11aab29	390	fatal_add_cleanup(&do_pam_cleanup_proc, NULL);
a5c9cd31	391	}
	392
	393	/* Return list of PAM enviornment strings */
	394	char **fetch_pam_environment(void)
	395	{
2b763e31	396	#ifdef HAVE_PAM_GETENVLIST
e11aab29	397	return(pam_getenvlist(__pamh));
2b763e31	398	#else /* HAVE_PAM_GETENVLIST */
	399	return(NULL);
	400	#endif /* HAVE_PAM_GETENVLIST */
a5c9cd31	401	}
	402
	403	/* Print any messages that have been generated during authentication */
	404	/* or account checking to stderr */
	405	void print_pam_messages(void)
	406	{
e11aab29	407	if (__pam_msg != NULL)
e11aab29	408	fputs(__pam_msg, stderr);
5daf7064	409	}
5daf7064	410
5c377b3b	411	/* Append a message to buffer */
5c377b3b	412	void message_cat(char *p, const char a)
5daf7064	413	{
5c377b3b	414	char *cp;
5c377b3b	415	size_t new_len;
2b87da3b	416
5c377b3b	417	new_len = strlen(a);
2b87da3b	418
5c377b3b	419	if (*p) {
	420	size_t len = strlen(*p);
	421
	422	p = xrealloc(p, new_len + len + 2);
	423	cp = *p + len;
	424	} else
	425	*p = cp = xmalloc(new_len + 2);
5daf7064	426
5c377b3b	427	memcpy(cp, a, new_len);
	428	cp[new_len] = '\n';
	429	cp[new_len + 1] = '\0';
a5c9cd31	430	}
	431
	432	#endif /* USE_PAM */