[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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Markus Friedl.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * 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 "servconf.h"

RCSID("$Id$");

#define NEW_AUTHTOK_MSG \
	"Warning: You password has expired, please change it now"

/* Callbacks */
static int pamconv(int num_msg, const struct pam_message **msg,
	  struct pam_response **resp, void *appdata_ptr);
void pam_cleanup_proc(void *context);
void pam_msg_cat(const char *msg);

/* module-local variables */
static struct pam_conv conv = {
	pamconv,
	NULL
};
static struct pam_handle_t *pamh = NULL;
static const char *pampasswd = NULL;
static char *pam_msg = NULL;

/* PAM conversation function. This is really a kludge to get the password */
/* into PAM and to pick up any messages generated by PAM into pamconv_msg */
static int pamconv(int num_msg, const struct pam_message **msg,
	struct pam_response **resp, void *appdata_ptr)
{
	struct pam_response *reply;
	int count;

	/* 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++) {
		switch (msg[count]->msg_style) {
			case PAM_PROMPT_ECHO_OFF:
				if (pampasswd == NULL) {
					free(reply);
					return PAM_CONV_ERR;
				}
				reply[count].resp_retcode = PAM_SUCCESS;
				reply[count].resp = xstrdup(pampasswd);
				break;
			case PAM_TEXT_INFO:
				reply[count].resp_retcode = PAM_SUCCESS;
				reply[count].resp = xstrdup("");

				if (msg[count]->msg != NULL)
					pam_msg_cat(msg[count]->msg);

				break;
			default:
				free(reply);
				return PAM_CONV_ERR;
		}
	}

	*resp = reply;

	return PAM_SUCCESS;
}

/* Called at exit to cleanly shutdown PAM */
void pam_cleanup_proc(void *context)
{
	int pam_retval;

	if (pamh != NULL)
	{
		pam_retval = pam_close_session((pam_handle_t *)pamh, 0);
		if (pam_retval != PAM_SUCCESS) {
			log("Cannot close PAM session: %.200s", 
				PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
		}

		pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_DELETE_CRED);
		if (pam_retval != PAM_SUCCESS) {
			log("Cannot delete credentials: %.200s", 
				PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
		}

		pam_retval = pam_end((pam_handle_t *)pamh, pam_retval);
		if (pam_retval != PAM_SUCCESS) {
			log("Cannot release PAM authentication: %.200s", 
				PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
		}
	}
}

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

	/* 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;
	
	pam_retval = pam_authenticate((pam_handle_t *)pamh, 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: %s", 
			pw->pw_name, PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
		return 0;
	}
}

/* Do account management using PAM */
int do_pam_account(char *username, char *remote_user)
{
	int pam_retval;
	
	debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname());
	pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RHOST, 
		get_canonical_hostname());
	if (pam_retval != PAM_SUCCESS) {
		fatal("PAM set rhost failed: %.200s", 
			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	}

	if (remote_user != NULL) {
		debug("PAM setting ruser to \"%.200s\"", remote_user);
		pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RUSER, remote_user);
		if (pam_retval != PAM_SUCCESS) {
			fatal("PAM set ruser failed: %.200s", 
				PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
		}
	}

	pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0);
	switch (pam_retval) {
		case PAM_SUCCESS:
			/* This is what we want */
			break;
		case PAM_NEW_AUTHTOK_REQD:
			pam_msg_cat(NEW_AUTHTOK_MSG);
			break;
		default:
			log("PAM rejected by account configuration: %.200s", 
				PAM_STRERROR((pam_handle_t *)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((pam_handle_t *)pamh, PAM_TTY, ttyname);
		if (pam_retval != PAM_SUCCESS) {
			fatal("PAM set tty failed: %.200s", 
				PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
		}
	}

	pam_retval = pam_open_session((pam_handle_t *)pamh, 0);
	if (pam_retval != PAM_SUCCESS) {
		fatal("PAM session setup failed: %.200s", 
			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	}
}

/* Set PAM credentials */ 
void do_pam_setcred()
{
	int pam_retval;
 
	debug("PAM establishing creds");
	pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_ESTABLISH_CRED);
	if (pam_retval != PAM_SUCCESS) {
		fatal("PAM setcred failed: %.200s", 
			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	}
}

/* Cleanly shutdown PAM */
void finish_pam(void)
{
	pam_cleanup_proc(NULL);
	fatal_remove_cleanup(&pam_cleanup_proc, NULL);
}

/* Start PAM authentication for specified account */
void start_pam(struct passwd *pw)
{
	int pam_retval;

	debug("Starting up PAM with username \"%.200s\"", pw->pw_name);

	pam_retval = pam_start(SSHD_PAM_SERVICE, pw->pw_name, &conv, 
		(pam_handle_t**)&pamh);

	if (pam_retval != PAM_SUCCESS) {
		fatal("PAM initialisation failed: %.200s", 
			PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	}
	
	fatal_add_cleanup(&pam_cleanup_proc, NULL);
}

/* Return list of PAM enviornment strings */
char **fetch_pam_environment(void)
{
#ifdef HAVE_PAM_GETENVLIST
	return(pam_getenvlist((pam_handle_t *)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)
		fprintf(stderr, pam_msg);
}

/* Append a message to the PAM message buffer */
void pam_msg_cat(const char *msg)
{
	char *p;
	size_t new_msg_len;
	size_t pam_msg_len;
	
	new_msg_len = strlen(msg);
	
	if (pam_msg) {
		pam_msg_len = strlen(pam_msg);
		pam_msg = xrealloc(pam_msg, new_msg_len + pam_msg_len + 2);
		p = pam_msg + pam_msg_len;
	} else {
		pam_msg = p = xmalloc(new_msg_len + 2);
	}

	memcpy(p, msg, new_msg_len);
	p[new_msg_len] = '\n';
	p[new_msg_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.
	12	* 3. All advertising materials mentioning features or use of this software
	13	* must display the following acknowledgement:
	14	* This product includes software developed by Markus Friedl.
	15	* 4. The name of the author may not be used to endorse or promote products
	16	* derived from this software without specific prior written permission.
	17	*
	18	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
	19	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
	20	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
	21	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	22	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	23	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	24	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	25	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	26	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	27	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
a5c9cd31	28	*/
	29
	30	#include "includes.h"
	31
	32	#ifdef USE_PAM
	33	#include "ssh.h"
	34	#include "xmalloc.h"
	35	#include "servconf.h"
	36
	37	RCSID("$Id$");
	38
5daf7064	39	#define NEW_AUTHTOK_MSG \
	40	"Warning: You password has expired, please change it now"
	41
a5c9cd31	42	/* Callbacks */
	43	static int pamconv(int num_msg, const struct pam_message **msg,
	44	struct pam_response *resp, void appdata_ptr);
	45	void pam_cleanup_proc(void *context);
5daf7064	46	void pam_msg_cat(const char *msg);
a5c9cd31	47
	48	/* module-local variables */
	49	static struct pam_conv conv = {
	50	pamconv,
	51	NULL
	52	};
	53	static struct pam_handle_t *pamh = NULL;
	54	static const char *pampasswd = NULL;
5daf7064	55	static char *pam_msg = NULL;
a5c9cd31	56
	57	/* PAM conversation function. This is really a kludge to get the password */
	58	/* into PAM and to pick up any messages generated by PAM into pamconv_msg */
	59	static int pamconv(int num_msg, const struct pam_message **msg,
	60	struct pam_response *resp, void appdata_ptr)
	61	{
	62	struct pam_response *reply;
	63	int count;
a5c9cd31	64
	65	/* PAM will free this later */
	66	reply = malloc(num_msg * sizeof(*reply));
	67	if (reply == NULL)
	68	return PAM_CONV_ERR;
	69
	70	for(count = 0; count < num_msg; count++) {
	71	switch (msg[count]->msg_style) {
	72	case PAM_PROMPT_ECHO_OFF:
	73	if (pampasswd == NULL) {
	74	free(reply);
	75	return PAM_CONV_ERR;
	76	}
	77	reply[count].resp_retcode = PAM_SUCCESS;
	78	reply[count].resp = xstrdup(pampasswd);
	79	break;
a5c9cd31	80	case PAM_TEXT_INFO:
	81	reply[count].resp_retcode = PAM_SUCCESS;
	82	reply[count].resp = xstrdup("");
	83
5daf7064	84	if (msg[count]->msg != NULL)
5daf7064	85	pam_msg_cat(msg[count]->msg);
a5c9cd31	86
a5c9cd31	87	break;
a5c9cd31	88	default:
	89	free(reply);
	90	return PAM_CONV_ERR;
	91	}
	92	}
	93
	94	*resp = reply;
	95
	96	return PAM_SUCCESS;
	97	}
	98
	99	/* Called at exit to cleanly shutdown PAM */
	100	void pam_cleanup_proc(void *context)
	101	{
	102	int pam_retval;
	103
	104	if (pamh != NULL)
	105	{
	106	pam_retval = pam_close_session((pam_handle_t *)pamh, 0);
	107	if (pam_retval != PAM_SUCCESS) {
	108	log("Cannot close PAM session: %.200s",
5daf7064	109	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
a5c9cd31	110	}
	111
	112	pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_DELETE_CRED);
	113	if (pam_retval != PAM_SUCCESS) {
	114	log("Cannot delete credentials: %.200s",
5daf7064	115	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
a5c9cd31	116	}
	117
	118	pam_retval = pam_end((pam_handle_t *)pamh, pam_retval);
	119	if (pam_retval != PAM_SUCCESS) {
	120	log("Cannot release PAM authentication: %.200s",
5daf7064	121	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
a5c9cd31	122	}
	123	}
	124	}
	125
	126	/* Attempt password authentation using PAM */
	127	int auth_pam_password(struct passwd pw, const char password)
	128	{
	129	extern ServerOptions options;
	130	int pam_retval;
	131
	132	/* deny if no user. */
	133	if (pw == NULL)
	134	return 0;
	135	if (pw->pw_uid == 0 && options.permit_root_login == 2)
	136	return 0;
	137	if (*password == '\0' && options.permit_empty_passwd == 0)
	138	return 0;
	139
	140	pampasswd = password;
	141
	142	pam_retval = pam_authenticate((pam_handle_t *)pamh, 0);
	143	if (pam_retval == PAM_SUCCESS) {
5daf7064	144	debug("PAM Password authentication accepted for user \"%.100s\"",
5daf7064	145	pw->pw_name);
a5c9cd31	146	return 1;
	147	} else {
	148	debug("PAM Password authentication for \"%.100s\" failed: %s",
	149	pw->pw_name, PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	150	return 0;
	151	}
	152	}
	153
	154	/* Do account management using PAM */
	155	int do_pam_account(char username, char remote_user)
	156	{
	157	int pam_retval;
5daf7064	158
a5c9cd31	159	debug("PAM setting rhost to \"%.200s\"", get_canonical_hostname());
	160	pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RHOST,
	161	get_canonical_hostname());
	162	if (pam_retval != PAM_SUCCESS) {
5daf7064	163	fatal("PAM set rhost failed: %.200s",
5daf7064	164	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
a5c9cd31	165	}
	166
	167	if (remote_user != NULL) {
	168	debug("PAM setting ruser to \"%.200s\"", remote_user);
	169	pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_RUSER, remote_user);
	170	if (pam_retval != PAM_SUCCESS) {
5daf7064	171	fatal("PAM set ruser failed: %.200s",
5daf7064	172	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
a5c9cd31	173	}
	174	}
	175
	176	pam_retval = pam_acct_mgmt((pam_handle_t *)pamh, 0);
5daf7064	177	switch (pam_retval) {
	178	case PAM_SUCCESS:
	179	/* This is what we want */
	180	break;
	181	case PAM_NEW_AUTHTOK_REQD:
	182	pam_msg_cat(NEW_AUTHTOK_MSG);
	183	break;
	184	default:
	185	log("PAM rejected by account configuration: %.200s",
	186	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	187	return(0);
a5c9cd31	188	}
	189
	190	return(1);
	191	}
	192
	193	/* Do PAM-specific session initialisation */
fd094f49	194	void do_pam_session(char username, const char ttyname)
a5c9cd31	195	{
	196	int pam_retval;
	197
	198	if (ttyname != NULL) {
	199	debug("PAM setting tty to \"%.200s\"", ttyname);
	200	pam_retval = pam_set_item((pam_handle_t *)pamh, PAM_TTY, ttyname);
5daf7064	201	if (pam_retval != PAM_SUCCESS) {
	202	fatal("PAM set tty failed: %.200s",
	203	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	204	}
a5c9cd31	205	}
	206
	207	pam_retval = pam_open_session((pam_handle_t *)pamh, 0);
5daf7064	208	if (pam_retval != PAM_SUCCESS) {
	209	fatal("PAM session setup failed: %.200s",
	210	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	211	}
a5c9cd31	212	}
	213
	214	/* Set PAM credentials */
	215	void do_pam_setcred()
	216	{
	217	int pam_retval;
	218
	219	debug("PAM establishing creds");
	220	pam_retval = pam_setcred((pam_handle_t *)pamh, PAM_ESTABLISH_CRED);
5daf7064	221	if (pam_retval != PAM_SUCCESS) {
	222	fatal("PAM setcred failed: %.200s",
	223	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	224	}
a5c9cd31	225	}
	226
	227	/* Cleanly shutdown PAM */
	228	void finish_pam(void)
	229	{
	230	pam_cleanup_proc(NULL);
	231	fatal_remove_cleanup(&pam_cleanup_proc, NULL);
	232	}
	233
	234	/* Start PAM authentication for specified account */
	235	void start_pam(struct passwd *pw)
	236	{
	237	int pam_retval;
	238
	239	debug("Starting up PAM with username \"%.200s\"", pw->pw_name);
	240
4e577b89	241	pam_retval = pam_start(SSHD_PAM_SERVICE, pw->pw_name, &conv,
4e577b89	242	(pam_handle_t**)&pamh);
a5c9cd31	243
5daf7064	244	if (pam_retval != PAM_SUCCESS) {
	245	fatal("PAM initialisation failed: %.200s",
	246	PAM_STRERROR((pam_handle_t *)pamh, pam_retval));
	247	}
	248
a5c9cd31	249	fatal_add_cleanup(&pam_cleanup_proc, NULL);
	250	}
	251
	252	/* Return list of PAM enviornment strings */
	253	char **fetch_pam_environment(void)
	254	{
2b763e31	255	#ifdef HAVE_PAM_GETENVLIST
a5c9cd31	256	return(pam_getenvlist((pam_handle_t *)pamh));
2b763e31	257	#else /* HAVE_PAM_GETENVLIST */
	258	return(NULL);
	259	#endif /* HAVE_PAM_GETENVLIST */
a5c9cd31	260	}
	261
	262	/* Print any messages that have been generated during authentication */
	263	/* or account checking to stderr */
	264	void print_pam_messages(void)
	265	{
5daf7064	266	if (pam_msg != NULL)
	267	fprintf(stderr, pam_msg);
	268	}
	269
	270	/* Append a message to the PAM message buffer */
	271	void pam_msg_cat(const char *msg)
	272	{
	273	char *p;
	274	size_t new_msg_len;
	275	size_t pam_msg_len;
	276
	277	new_msg_len = strlen(msg);
	278
	279	if (pam_msg) {
	280	pam_msg_len = strlen(pam_msg);
	281	pam_msg = xrealloc(pam_msg, new_msg_len + pam_msg_len + 2);
	282	p = pam_msg + pam_msg_len;
	283	} else {
	284	pam_msg = p = xmalloc(new_msg_len + 2);
	285	}
	286
	287	memcpy(p, msg, new_msg_len);
	288	p[new_msg_len] = '\n';
	289	p[new_msg_len + 1] = '\0';
a5c9cd31	290	}
	291
	292	#endif /* USE_PAM */