xref: /illumos-gate/usr/src/lib/libpam/pam_framework.c (revision 1d276e0b)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright 2020, Joyent, Inc.
 */

#include <syslog.h>
#include <dlfcn.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <strings.h>
#include <malloc.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

#include <security/pam_appl.h>
#include <security/pam_modules.h>
#include <sys/mman.h>

#include <libintl.h>

#include "pam_impl.h"

static char *pam_snames [PAM_NUM_MODULE_TYPES] = {
	PAM_ACCOUNT_NAME,
	PAM_AUTH_NAME,
	PAM_PASSWORD_NAME,
	PAM_SESSION_NAME
};

static char *pam_inames [PAM_MAX_ITEMS] = {
/* NONE */		NULL,
/* PAM_SERVICE */	"service",
/* PAM_USER */		"user",
/* PAM_TTY */		"tty",
/* PAM_RHOST */		"rhost",
/* PAM_CONV */		"conv",
/* PAM_AUTHTOK */	"authtok",
/* PAM_OLDAUTHTOK */	"oldauthtok",
/* PAM_RUSER */		"ruser",
/* PAM_USER_PROMPT */	"user_prompt",
/* PAM_REPOSITORY */	"repository",
/* PAM_RESOURCE */	"resource",
/* PAM_AUSER */		"auser",
/* Undefined Items */
};

/*
 * This extra definition is needed in order to build this library
 * on pre-64-bit-aware systems.
 */
#if !defined(_LFS64_LARGEFILE)
#define	stat64	stat
#endif	/* !defined(_LFS64_LARGEFILE) */

/* functions to dynamically load modules */
static int	load_modules(pam_handle_t *, int, char *, pamtab_t *);
static void	*open_module(pam_handle_t *, char *);
static int	load_function(void *, char *, int (**func)());

/* functions to read and store the pam.conf configuration file */
static int	open_pam_conf(struct pam_fh **, pam_handle_t *, char *);
static void	close_pam_conf(struct pam_fh *);
static int	read_pam_conf(pam_handle_t *, char *);
static int	get_pam_conf_entry(struct pam_fh *, pam_handle_t *,
    pamtab_t **);
static char	*read_next_token(char **);
static char	*nextline(struct pam_fh *, pam_handle_t *, int *);
static int	verify_pam_conf(pamtab_t *, char *);

/* functions to clean up and free memory */
static void	clean_up(pam_handle_t *);
static void	free_pamconf(pamtab_t *);
static void	free_pam_conf_info(pam_handle_t *);
static void	free_env(env_list *);

/* convenience functions for I18N/L10N communication */

static void	free_resp(int, struct pam_response *);
static int	do_conv(pam_handle_t *, int, int,
    char messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE], void *,
    struct pam_response **);

static int	log_priority;	/* pam_trace syslog priority & facility */
static int	pam_debug = 0;

static char *
pam_trace_iname(int item_type, char *iname_buf)
{
	char *name;

	if (item_type <= 0 ||
	    item_type >= PAM_MAX_ITEMS ||
	    (name = pam_inames[item_type]) == NULL) {
		(void) sprintf(iname_buf, "%d", item_type);
		return (iname_buf);
	}
	return (name);
}

static char *
pam_trace_fname(int flag)
{
	if (flag & PAM_BINDING)
		return (PAM_BINDING_NAME);
	if (flag & PAM_INCLUDE)
		return (PAM_INCLUDE_NAME);
	if (flag & PAM_OPTIONAL)
		return (PAM_OPTIONAL_NAME);
	if (flag & PAM_REQUIRED)
		return (PAM_REQUIRED_NAME);
	if (flag & PAM_REQUISITE)
		return (PAM_REQUISITE_NAME);
	if (flag & PAM_SUFFICIENT)
		return (PAM_SUFFICIENT_NAME);
	return ("bad flag name");
}

static char *
pam_trace_cname(pam_handle_t *pamh)
{
	if (pamh->pam_conf_name[pamh->include_depth] == NULL)
		return ("NULL");
	return (pamh->pam_conf_name[pamh->include_depth]);
}

#include <deflt.h>
#include <stdarg.h>
/*
 * pam_settrace - setup configuration for pam tracing
 *
 * turn on PAM debug if "magic" file exists
 * if exists (original), pam_debug = PAM_DEBUG_DEFAULT,
 * log_priority = LOG_DEBUG(7) and log_facility = LOG_AUTH(4).
 *
 * if has contents, keywork=value pairs:
 *
 *	"log_priority=" 0-7, the pam_trace syslog priority to use
 *		(see sys/syslog.h)
 *	"log_facility=" 0-23, the pam_trace syslog facility to use
 *		(see sys/syslog.h)
 *	"debug_flags=" PAM_DEBUG_DEFAULT (0x0001), log traditional
 *			(original) debugging.
 *		Plus the logical or of:
 *		    PAM_DEBUG_ITEM (0x0002), log item values and
 *			pam_get_item.
 *		    PAM_DEBUG_MODULE (0x0004), log module return status.
 *		    PAM_DEBUG_CONF (0x0008), log pam.conf parsing.
 *		    PAM_DEBUG_DATA (0x0010), get/set_data.
 *		    PAM_DEBUG_CONV (0x0020), conversation/response.
 *
 *		    If compiled with DEBUG:
 *		    PAM_DEBUG_AUTHTOK (0x8000), display AUTHTOK value if
 *				PAM_DEBUG_ITEM is set and results from
 *				PAM_PROMPT_ECHO_OFF responses.
 *		    USE CAREFULLY, THIS EXPOSES THE USER'S PASSWORDS.
 *
 *		or set to 0 and off even if PAM_DEBUG file exists.
 *
 * Output has the general form:
 * <whatever was set syslog> PAM[<pid>]: <interface>(<handle> and other info)
 * <whatever was set syslog> PAM[<pid>]: details requested for <interface> call
 *	Where:	<pid> is the process ID of the calling process.
 *		<handle> is the Hex value of the pam_handle associated with the
 *			call.
 */

static void
pam_settrace()
{
	void	*defp;

	if ((defp = defopen_r(PAM_DEBUG)) != NULL) {
		char	*arg;
		int	code;
		int	facility = LOG_AUTH;

		pam_debug = PAM_DEBUG_DEFAULT;
		log_priority = LOG_DEBUG;

		(void) defcntl_r(DC_SETFLAGS, DC_CASE, defp);
		if ((arg = defread_r(LOG_PRIORITY, defp)) != NULL) {
			code = (int)strtol(arg, NULL, 10);
			if ((code & ~LOG_PRIMASK) == 0) {
				log_priority = code;
			}
		}
		if ((arg = defread_r(LOG_FACILITY, defp)) != NULL) {
			code = (int)strtol(arg, NULL, 10);
			if (code < LOG_NFACILITIES) {
				facility = code << 3;
			}
		}
		if ((arg = defread_r(DEBUG_FLAGS, defp)) != NULL) {
			pam_debug = (int)strtol(arg, NULL, 0);
		}
		defclose_r(defp);

		log_priority |= facility;
	}
}

/*
 * pam_trace - logs tracing messages
 *
 *	flag = debug_flags from /etc/pam_debug
 *	format and args = message to print (PAM[<pid>]: is prepended).
 *
 *	global log_priority = pam_trace syslog (log_priority | log_facility)
 *		from /etc/pam_debug
 */
/*PRINTFLIKE2*/
static void
pam_trace(int flag, char *format, ...)
{
	va_list args;
	char message[1024];
	int savemask;

	if ((pam_debug & flag) == 0)
		return;

	savemask = setlogmask(LOG_MASK(log_priority & LOG_PRIMASK));
	(void) snprintf(message, sizeof (message), "PAM[%ld]: %s",
	    (long)getpid(), format);
	va_start(args, format);
	(void) vsyslog(log_priority, message, args);
	va_end(args);
	(void) setlogmask(savemask);
}

/*
 * __pam_log - logs PAM syslog messages
 *
 *	priority = message priority
 *	format and args = message to log
 */
/*PRINTFLIKE2*/
void
__pam_log(int priority, const char *format, ...)
{
	va_list args;
	int savemask = setlogmask(LOG_MASK(priority & LOG_PRIMASK));

	va_start(args, format);
	(void) vsyslog(priority, format, args);
	va_end(args);
	(void) setlogmask(savemask);
}


/*
 *			pam_XXXXX routines
 *
 *	These are the entry points to the authentication switch
 */

/*
 * pam_start		- initiate an authentication transaction and
 *			  set parameter values to be used during the
 *			  transaction
 */

int
pam_start(const char *service, const char *user,
    const struct pam_conv *pam_conv, pam_handle_t **pamh)
{
	int	err;

	*pamh = calloc(1, sizeof (struct pam_handle));

	pam_settrace();
	pam_trace(PAM_DEBUG_DEFAULT,
	    "pam_start(%s,%s,%p:%p) - debug = %x",
	    service ? service : "NULL", user ? user : "NULL", (void *)pam_conv,
	    (void *)*pamh, pam_debug);

	if (*pamh == NULL)
		return (PAM_BUF_ERR);

	(*pamh)->pam_inmodule = RO_OK;		/* OK to set RO items */
	if ((err = pam_set_item(*pamh, PAM_SERVICE, (void *)service))
	    != PAM_SUCCESS) {
		clean_up(*pamh);
		*pamh = NULL;
		return (err);
	}

	if ((err = pam_set_item(*pamh, PAM_USER, (void *)user))
	    != PAM_SUCCESS) {
		clean_up(*pamh);
		*pamh = NULL;
		return (err);
	}

	if ((err = pam_set_item(*pamh, PAM_CONV, (void *)pam_conv))
	    != PAM_SUCCESS) {
		clean_up(*pamh);
		*pamh = NULL;
		return (err);
	}

	(*pamh)->pam_inmodule = RW_OK;
	return (PAM_SUCCESS);
}

/*
 * pam_end - terminate an authentication transaction
 */

int
pam_end(pam_handle_t *pamh, int pam_status)
{
	struct pam_module_data *psd, *p;
	fd_list *expired;
	fd_list *traverse;
	env_list *env_expired;
	env_list *env_traverse;

	pam_trace(PAM_DEBUG_DEFAULT,
	    "pam_end(%p): status = %s", (void *)pamh,
	    pam_strerror(pamh, pam_status));

	if (pamh == NULL)
		return (PAM_SYSTEM_ERR);

	/* call the cleanup routines for module specific data */

	psd = pamh->ssd;
	while (psd) {
		if (psd->cleanup) {
			psd->cleanup(pamh, psd->data, pam_status);
		}
		p = psd;
		psd = p->next;
		free(p->module_data_name);
		free(p);
	}
	pamh->ssd = NULL;

	/* dlclose all module fds */
	traverse = pamh->fd;
	while (traverse) {
		expired = traverse;
		traverse = traverse->next;
		(void) dlclose(expired->mh);
		free(expired);
	}
	pamh->fd = 0;

	/* remove all environment variables */
	env_traverse = pamh->pam_env;
	while (env_traverse) {
		env_expired = env_traverse;
		env_traverse = env_traverse->next;
		free_env(env_expired);
	}

	clean_up(pamh);
	return (PAM_SUCCESS);
}

/*
 * pam_set_item		- set the value of a parameter that can be
 *			  retrieved via a call to pam_get_item()
 */

int
pam_set_item(pam_handle_t *pamh, int item_type, const void *item)
{
	struct pam_item *pip;
	int	size;
	char	iname_buf[PAM_MAX_MSG_SIZE];

	if (((pam_debug & PAM_DEBUG_ITEM) == 0) || (pamh == NULL)) {
		pam_trace(PAM_DEBUG_DEFAULT,
		    "pam_set_item(%p:%s)", (void *)pamh,
		    pam_trace_iname(item_type, iname_buf));
	}

	if (pamh == NULL)
		return (PAM_SYSTEM_ERR);

	/* check read only items */
	if ((item_type == PAM_SERVICE) && (pamh->pam_inmodule != RO_OK))
		return (PAM_PERM_DENIED);

	/*
	 * Check that item_type is within valid range
	 */

	if (item_type <= 0 || item_type >= PAM_MAX_ITEMS)
		return (PAM_SYMBOL_ERR);

	pip = &(pamh->ps_item[item_type]);

	switch (item_type) {
	case PAM_AUTHTOK:
	case PAM_OLDAUTHTOK:
		if (pip->pi_addr != NULL)
			(void) memset(pip->pi_addr, 0, pip->pi_size);
		/*FALLTHROUGH*/
	case PAM_SERVICE:
	case PAM_USER:
	case PAM_TTY:
	case PAM_RHOST:
	case PAM_RUSER:
	case PAM_USER_PROMPT:
	case PAM_RESOURCE:
	case PAM_AUSER:
		if (pip->pi_addr != NULL) {
			free(pip->pi_addr);
		}

		if (item == NULL) {
			pip->pi_addr = NULL;
			pip->pi_size = 0;
		} else {
			pip->pi_addr = strdup((char *)item);
			if (pip->pi_addr == NULL) {
				pip->pi_size = 0;
				return (PAM_BUF_ERR);
			}
			pip->pi_size = strlen(pip->pi_addr);
		}
		break;
	case PAM_CONV:
		if (pip->pi_addr != NULL)
			free(pip->pi_addr);
		size = sizeof (struct pam_conv);
		if ((pip->pi_addr = calloc(1, size)) == NULL)
			return (PAM_BUF_ERR);
		if (item != NULL)
			(void) memcpy(pip->pi_addr, item, (unsigned int) size);
		else
			(void) memset(pip->pi_addr, 0, size);
		pip->pi_size = size;
		break;
	case PAM_REPOSITORY:
		if (pip->pi_addr != NULL) {
			pam_repository_t *auth_rep;

			auth_rep = (pam_repository_t *)pip->pi_addr;
			if (auth_rep->type != NULL)
				free(auth_rep->type);
			if (auth_rep->scope != NULL)
				free(auth_rep->scope);
			free(auth_rep);
		}
		if (item != NULL) {
			pam_repository_t *s, *d;

			size = sizeof (struct pam_repository);
			pip->pi_addr = calloc(1, size);
			if (pip->pi_addr == NULL)
				return (PAM_BUF_ERR);

			s = (struct pam_repository *)item;
			d = (struct pam_repository *)pip->pi_addr;

			d->type = strdup(s->type);
			if (d->type == NULL)
				return (PAM_BUF_ERR);
			d->scope = malloc(s->scope_len);
			if (d->scope == NULL)
				return (PAM_BUF_ERR);
			(void) memcpy(d->scope, s->scope, s->scope_len);
			d->scope_len = s->scope_len;
		}
		pip->pi_size = size;
		break;
	default:
		return (PAM_SYMBOL_ERR);
	}
	switch (item_type) {
	case PAM_CONV:
		pam_trace(PAM_DEBUG_ITEM, "pam_set_item(%p:%s)=%p",
		    (void *)pamh,
		    pam_trace_iname(item_type, iname_buf),
		    item ? (void *)((struct pam_conv *)item)->conv :
		    (void *)0);
		break;
	case PAM_REPOSITORY:
		pam_trace(PAM_DEBUG_ITEM, "pam_set_item(%p:%s)=%s",
		    (void *)pamh,
		    pam_trace_iname(item_type, iname_buf),
		    item ? (((struct pam_repository *)item)->type ?
		    ((struct pam_repository *)item)->type : "NULL") :
		    "NULL");
		break;
	case PAM_AUTHTOK:
	case PAM_OLDAUTHTOK:
#ifdef	DEBUG
		if (pam_debug & PAM_DEBUG_AUTHTOK)
			pam_trace(PAM_DEBUG_ITEM,
			    "pam_set_item(%p:%s)=%s", (void *)pamh,
			    pam_trace_iname(item_type, iname_buf),
			    item ? (char *)item : "NULL");
		else
#endif	/* DEBUG */
			pam_trace(PAM_DEBUG_ITEM,
			    "pam_set_item(%p:%s)=%s", (void *)pamh,
			    pam_trace_iname(item_type, iname_buf),
			    item ? "********" : "NULL");
		break;
	default:
		pam_trace(PAM_DEBUG_ITEM, "pam_set_item(%p:%s)=%s",
		    (void *)pamh,
		    pam_trace_iname(item_type, iname_buf),
		    item ? (char *)item : "NULL");
	}

	return (PAM_SUCCESS);
}

/*
 * pam_get_item		- read the value of a parameter specified in
 *			  the call to pam_set_item()
 */

int
pam_get_item(const pam_handle_t *pamh, int item_type, void **item)
{
	struct pam_item *pip;
	char	iname_buf[PAM_MAX_MSG_SIZE];

	if (((pam_debug & PAM_DEBUG_ITEM) == 0) || (pamh == NULL)) {
		pam_trace(PAM_DEBUG_ITEM, "pam_get_item(%p:%s)",
		    (void *)pamh, pam_trace_iname(item_type, iname_buf));
	}

	if (pamh == NULL)
		return (PAM_SYSTEM_ERR);

	if (item_type <= 0 || item_type >= PAM_MAX_ITEMS)
		return (PAM_SYMBOL_ERR);

	if ((pamh->pam_inmodule != WO_OK) &&
	    ((item_type == PAM_AUTHTOK || item_type == PAM_OLDAUTHTOK))) {
		__pam_log(LOG_AUTH | LOG_NOTICE, "pam_get_item(%s) called from "
		    "a non module context",
		    pam_trace_iname(item_type, iname_buf));
		return (PAM_PERM_DENIED);
	}

	pip = (struct pam_item *)&(pamh->ps_item[item_type]);

	*item = pip->pi_addr;
	switch (item_type) {
	case PAM_CONV:
		pam_trace(PAM_DEBUG_ITEM, "pam_get_item(%p:%s)=%p",
		    (void *)pamh,
		    pam_trace_iname(item_type, iname_buf),
		    (void *)((struct pam_conv *)*item)->conv);
		break;
	case PAM_REPOSITORY:
		pam_trace(PAM_DEBUG_ITEM, "pam_get_item(%p:%s)=%s",
		    (void *)pamh,
		    pam_trace_iname(item_type, iname_buf),
		    *item ? (((struct pam_repository *)*item)->type ?
		    ((struct pam_repository *)*item)->type : "NULL") :
		    "NULL");
		break;
	case PAM_AUTHTOK:
	case PAM_OLDAUTHTOK:
#ifdef	DEBUG
		if (pam_debug & PAM_DEBUG_AUTHTOK)
			pam_trace(PAM_DEBUG_ITEM,
			    "pam_get_item(%p:%s)=%s", (void *)pamh,
			    pam_trace_iname(item_type, iname_buf),
			    *item ? *(char **)item : "NULL");
		else
#endif	/* DEBUG */
			pam_trace(PAM_DEBUG_ITEM,
			    "pam_get_item(%p:%s)=%s", (void *)pamh,
			    pam_trace_iname(item_type, iname_buf),
			    *item ? "********" : "NULL");
		break;
	default:
		pam_trace(PAM_DEBUG_ITEM, "pam_get_item(%p:%s)=%s",
		    (void *)pamh,
		    pam_trace_iname(item_type, iname_buf),
		    *item ? *(char **)item : "NULL");
	}

	return (PAM_SUCCESS);
}

/*
 * parse_user_name         - process the user response: ignore
 *                           '\t' or ' ' before or after a user name.
 *                           user_input is a null terminated string.
 *                           *ret_username will be the user name.
 */

static int
parse_user_name(char *user_input, char **ret_username)
{
	register char *ptr;
	register int index = 0;
	char username[PAM_MAX_RESP_SIZE];

	/* Set the default value for *ret_username */
	*ret_username = NULL;

	/*
	 * Set the initial value for username - this is a buffer holds
	 * the user name.
	 */
	bzero((void *)username, PAM_MAX_RESP_SIZE);

	/*
	 * The user_input is guaranteed to be terminated by a null character.
	 */
	ptr = user_input;

	/* Skip all the leading whitespaces if there are any. */
	while ((*ptr == ' ') || (*ptr == '\t'))
		ptr++;

	if (*ptr == '\0') {
		/*
		 * We should never get here since the user_input we got
		 * in pam_get_user() is not all whitespaces nor just "\0".
		 */
		return (PAM_BUF_ERR);
	}

	/*
	 * username will be the first string we get from user_input
	 * - we skip leading whitespaces and ignore trailing whitespaces
	 */
	while (*ptr != '\0') {
		if ((*ptr == ' ') || (*ptr == '\t') ||
		    (index >= PAM_MAX_RESP_SIZE)) {
			break;
		} else {
			username[index] = *ptr;
			index++;
			ptr++;
		}
	}

	/* ret_username will be freed in pam_get_user(). */
	if (index >= PAM_MAX_RESP_SIZE ||
	    (*ret_username = strdup(username)) == NULL)
		return (PAM_BUF_ERR);
	return (PAM_SUCCESS);
}

/*
 * Get the value of PAM_USER. If not set, then use the convenience function
 * to prompt for the user. Use prompt if specified, else use PAM_USER_PROMPT
 * if it is set, else use default.
 */
#define	WHITESPACE	0
#define	USERNAME	1

int
pam_get_user(pam_handle_t *pamh, char **user, const char *prompt_override)
{
	int	status;
	char	*prompt = NULL;
	char    *real_username;
	struct pam_response *ret_resp = NULL;
	char messages[PAM_MAX_NUM_MSG][PAM_MAX_MSG_SIZE];

	pam_trace(PAM_DEBUG_DEFAULT,
	    "pam_get_user(%p, %p, %s)", (void *)pamh, (void *)*user,
	    prompt_override ? prompt_override : "NULL");
	if (pamh == NULL)
		return (PAM_SYSTEM_ERR);

	if ((status = pam_get_item(pamh, PAM_USER, (void **)user))
	    != PAM_SUCCESS) {
		return (status);
	}

	/* if the user is set, return it */

	if (*user != NULL && *user[0] != '\0') {
		return (PAM_SUCCESS);
	}

	/*
	 * if the module is requesting a special prompt, use it.
	 * else use PAM_USER_PROMPT.
	 */

	if (prompt_override != NULL) {
		prompt = (char *)prompt_override;
	} else {
		status = pam_get_item(pamh, PAM_USER_PROMPT, (void**)&prompt);
		if (status != PAM_SUCCESS) {
			return (status);
		}
	}

	/* if the prompt is not set, use default */

	if (prompt == NULL || prompt[0] == '\0') {
		prompt = dgettext(TEXT_DOMAIN, "Please enter user name: ");
	}

	/* prompt for the user */

	(void) strncpy(messages[0], prompt, sizeof (messages[0]));

	for (;;) {
		int state = WHITESPACE;

		status = do_conv(pamh, PAM_PROMPT_ECHO_ON, 1, messages,
		    NULL, &ret_resp);

		if (status != PAM_SUCCESS) {
			return (status);
		}

		if (ret_resp->resp && ret_resp->resp[0] != '\0') {
			int len = strlen(ret_resp->resp);
			int i;

			for (i = 0; i < len; i++) {
				if ((ret_resp->resp[i] != ' ') &&
				    (ret_resp->resp[i] != '\t')) {
					state = USERNAME;
					break;
				}
			}

			if (state == USERNAME)
				break;
		}
		/* essentially empty response, try again */
		free_resp(1, ret_resp);
		ret_resp = NULL;
	}

	/* set PAM_USER */
	/* Parse the user input to get the user name. */
	status = parse_user_name(ret_resp->resp, &real_username);

	if (status != PAM_SUCCESS) {
		if (real_username != NULL)
			free(real_username);
		free_resp(1, ret_resp);
		return (status);
	}

	status = pam_set_item(pamh, PAM_USER, real_username);

	free(real_username);

	free_resp(1, ret_resp);
	if (status != PAM_SUCCESS) {
		return (status);
	}

	/*
	 * finally, get PAM_USER. We have to call pam_get_item to get
	 * the value of user because pam_set_item mallocs the memory.
	 */

	status = pam_get_item(pamh, PAM_USER, (void**)user);
	return (status);
}

/*
 * Set module specific data
 */

int
pam_set_data(pam_handle_t *pamh, const char *module_data_name, void *data,
    void (*cleanup)(pam_handle_t *pamh, void *data, int pam_end_status))
{
	struct pam_module_data *psd;

	pam_trace(PAM_DEBUG_DATA,
	    "pam_set_data(%p:%s:%d)=%p", (void *)pamh,
	    (module_data_name != NULL) ? module_data_name : "NULL",
	    (pamh != NULL) ? pamh->pam_inmodule : -1, data);
	if (pamh == NULL || (pamh->pam_inmodule != WO_OK) ||
	    module_data_name == NULL) {
		return (PAM_SYSTEM_ERR);
	}

	/* check if module data already exists */

	for (psd = pamh->ssd; psd; psd = psd->next) {
		if (strcmp(psd->module_data_name, module_data_name) == 0) {
			/* clean up original data before setting the new data */
			if (psd->cleanup) {
				psd->cleanup(pamh, psd->data, PAM_SUCCESS);
			}
			psd->data = (void *)data;
			psd->cleanup = cleanup;
			return (PAM_SUCCESS);
		}
	}

	psd = malloc(sizeof (struct pam_module_data));
	if (psd == NULL)
		return (PAM_BUF_ERR);

	psd->module_data_name = strdup(module_data_name);
	if (psd->module_data_name == NULL) {
		free(psd);
		return (PAM_BUF_ERR);
	}

	psd->data = (void *)data;
	psd->cleanup = cleanup;
	psd->next = pamh->ssd;
	pamh->ssd = psd;
	return (PAM_SUCCESS);
}

/*
 * get module specific data
 */

int
pam_get_data(const pam_handle_t *pamh, const char *module_data_name,
    const void **data)
{
	struct pam_module_data *psd;

	if (pamh == NULL || (pamh->pam_inmodule != WO_OK) ||
	    module_data_name == NULL) {
		pam_trace(PAM_DEBUG_DATA,
		    "pam_get_data(%p:%s:%d)=%p", (void *)pamh,
		    module_data_name ? module_data_name : "NULL",
		    pamh->pam_inmodule, *data);
		return (PAM_SYSTEM_ERR);
	}

	for (psd = pamh->ssd; psd; psd = psd->next) {
		if (strcmp(psd->module_data_name, module_data_name) == 0) {
			*data = psd->data;
			pam_trace(PAM_DEBUG_DATA,
			    "pam_get_data(%p:%s)=%p", (void *)pamh,
			    module_data_name, *data);
			return (PAM_SUCCESS);
		}
	}
	pam_trace(PAM_DEBUG_DATA,
	    "pam_get_data(%p:%s)=%s", (void *)pamh, module_data_name,
	    "PAM_NO_MODULE_DATA");

	return (PAM_NO_MODULE_DATA);
}

/*
 * PAM equivalent to strerror()
 */
/* ARGSUSED */
const char *
pam_strerror(pam_handle_t *pamh, int errnum)
{
	switch (errnum) {
	case PAM_SUCCESS:
		return (dgettext(TEXT_DOMAIN, "Success"));
	case PAM_OPEN_ERR:
		return (dgettext(TEXT_DOMAIN, "Dlopen failure"));
	case PAM_SYMBOL_ERR:
		return (dgettext(TEXT_DOMAIN, "Symbol not found"));
	case PAM_SERVICE_ERR:
		return (dgettext(TEXT_DOMAIN,
		    "Error in underlying service module"));
	case PAM_SYSTEM_ERR:
		return (dgettext(TEXT_DOMAIN, "System error"));
	case PAM_BUF_ERR:
		return (dgettext(TEXT_DOMAIN, "Memory buffer error"));
	case PAM_CONV_ERR:
		return (dgettext(TEXT_DOMAIN, "Conversation failure"));
	case PAM_PERM_DENIED:
		return (dgettext(TEXT_DOMAIN, "Permission denied"));
	case PAM_MAXTRIES:
		return (dgettext(TEXT_DOMAIN,
		    "Maximum number of attempts exceeded"));
	case PAM_AUTH_ERR:
		return (dgettext(TEXT_DOMAIN, "Authentication failed"));
	case PAM_NEW_AUTHTOK_REQD:
		return (dgettext(TEXT_DOMAIN, "Get new authentication token"));
	case PAM_CRED_INSUFFICIENT:
		return (dgettext(TEXT_DOMAIN, "Insufficient credentials"));
	case PAM_AUTHINFO_UNAVAIL:
		return (dgettext(TEXT_DOMAIN,
		    "Can not retrieve authentication info"));
	case PAM_USER_UNKNOWN:
		return (dgettext(TEXT_DOMAIN, "No account present for user"));
	case PAM_CRED_UNAVAIL:
		return (dgettext(TEXT_DOMAIN,
		    "Can not retrieve user credentials"));
	case PAM_CRED_EXPIRED:
		return (dgettext(TEXT_DOMAIN,
		    "User credentials have expired"));
	case PAM_CRED_ERR:
		return (dgettext(TEXT_DOMAIN,
		    "Failure setting user credentials"));
	case PAM_ACCT_EXPIRED:
		return (dgettext(TEXT_DOMAIN, "User account has expired"));
	case PAM_AUTHTOK_EXPIRED:
		return (dgettext(TEXT_DOMAIN, "User password has expired"));
	case PAM_SESSION_ERR:
		return (dgettext(TEXT_DOMAIN,
		    "Can not make/remove entry for session"));
	case PAM_AUTHTOK_ERR:
		return (dgettext(TEXT_DOMAIN,
		    "Authentication token manipulation error"));
	case PAM_AUTHTOK_RECOVERY_ERR:
		return (dgettext(TEXT_DOMAIN,
		    "Authentication token can not be recovered"));
	case PAM_AUTHTOK_LOCK_BUSY:
		return (dgettext(TEXT_DOMAIN,
		    "Authentication token lock busy"));
	case PAM_AUTHTOK_DISABLE_AGING:
		return (dgettext(TEXT_DOMAIN,
		    "Authentication token aging disabled"));
	case PAM_NO_MODULE_DATA:
		return (dgettext(TEXT_DOMAIN,
		    "Module specific data not found"));
	case PAM_IGNORE:
		return (dgettext(TEXT_DOMAIN, "Ignore module"));
	case PAM_ABORT:
		return (dgettext(TEXT_DOMAIN, "General PAM failure "));
	case PAM_TRY_AGAIN:
		return (dgettext(TEXT_DOMAIN,
		    "Unable to complete operation. Try again"));
	default:
		return (dgettext(TEXT_DOMAIN, "Unknown error"));
	}
}

static void *
sm_name(int ind)
{
	switch (ind) {
	case PAM_AUTHENTICATE:
		return (PAM_SM_AUTHENTICATE);
	case PAM_SETCRED:
		return (PAM_SM_SETCRED);
	case PAM_ACCT_MGMT:
		return (PAM_SM_ACCT_MGMT);
	case PAM_OPEN_SESSION:
		return (PAM_SM_OPEN_SESSION);
	case PAM_CLOSE_SESSION:
		return (PAM_SM_CLOSE_SESSION);
	case PAM_CHAUTHTOK:
		return (PAM_SM_CHAUTHTOK);
	}
	return (NULL);
}

static int
(*func(pamtab_t *modulep, int ind))()
{
	void	*funcp;

	if ((funcp = modulep->function_ptr) == NULL)
		return (NULL);

	switch (ind) {
	case PAM_AUTHENTICATE:
		return (((struct auth_module *)funcp)->pam_sm_authenticate);
	case PAM_SETCRED:
		return (((struct auth_module *)funcp)->pam_sm_setcred);
	case PAM_ACCT_MGMT:
		return (((struct account_module *)funcp)->pam_sm_acct_mgmt);
	case PAM_OPEN_SESSION:
		return (((struct session_module *)funcp)->pam_sm_open_session);
	case PAM_CLOSE_SESSION:
		return (((struct session_module *)funcp)->pam_sm_close_session);
	case PAM_CHAUTHTOK:
		return (((struct password_module *)funcp)->pam_sm_chauthtok);
	}
	return (NULL);
}

/*
 * Run through the PAM service module stack for the given module type.
 */
static int
run_stack(pam_handle_t *pamh, int flags, int type, int def_err, int ind,
    char *function_name)
{
	int	err = PAM_SYSTEM_ERR;  /* preset */
	int	optional_error = 0;
	int	required_error = 0;
	int	success = 0;
	pamtab_t *modulep;
	int	(*sm_func)();

	if (pamh == NULL)
		return (PAM_SYSTEM_ERR);

	/* read initial entries from pam.conf */
	if ((err = read_pam_conf(pamh, PAM_CONFIG)) != PAM_SUCCESS) {
		return (err);
	}

	if ((modulep =
	    pamh->pam_conf_info[pamh->include_depth][type]) == NULL) {
		__pam_log(LOG_AUTH | LOG_ERR, "%s no initial module present",
		    pam_trace_cname(pamh));
		goto exit_return;
	}

	pamh->pam_inmodule = WO_OK;	/* OK to get AUTHTOK */
include:
	pam_trace(PAM_DEBUG_MODULE,
	    "[%d:%s]:run_stack:%s(%p, %x): %s", pamh->include_depth,
	    pam_trace_cname(pamh), function_name, (void *)pamh, flags,
	    modulep ? modulep->module_path : "NULL");

	while (modulep != NULL) {
		if (modulep->pam_flag & PAM_INCLUDE) {
			/* save the return location */
			pamh->pam_conf_modulep[pamh->include_depth] =
			    modulep->next;
			pam_trace(PAM_DEBUG_MODULE,
			    "setting for include[%d:%p]",
			    pamh->include_depth, (void *)modulep->next);
			if (pamh->include_depth++ >= PAM_MAX_INCLUDE) {
				__pam_log(LOG_AUTH | LOG_ERR,
				    "run_stack: includes too deep %d "
				    "found trying to include %s from %s, %d "
				    "allowed", pamh->include_depth,
				    modulep->module_path, pamh->pam_conf_name
				    [PAM_MAX_INCLUDE] == NULL ? "NULL" :
				    pamh->pam_conf_name[PAM_MAX_INCLUDE],
				    PAM_MAX_INCLUDE);
				goto exit_return;
			}
			if ((err = read_pam_conf(pamh,
			    modulep->module_path)) != PAM_SUCCESS) {
				__pam_log(LOG_AUTH | LOG_ERR,
				    "run_stack[%d:%s]: can't read included "
				    "conf %s", pamh->include_depth,
				    pam_trace_cname(pamh),
				    modulep->module_path);
				goto exit_return;
			}
			if ((modulep = pamh->pam_conf_info
			    [pamh->include_depth][type]) == NULL) {
				__pam_log(LOG_AUTH | LOG_ERR,
				    "run_stack[%d:%s]: no include module "
				    "present %s", pamh->include_depth,
				    pam_trace_cname(pamh), function_name);
				goto exit_return;
			}
			if (modulep->pam_flag & PAM_INCLUDE) {
				/* first line another include */
				goto include;
			}
			pam_trace(PAM_DEBUG_DEFAULT, "include[%d:%s]"
			    "(%p, %s)=%s", pamh->include_depth,
			    pam_trace_cname(pamh), (void *)pamh,
			    function_name, modulep->module_path);
			if ((err = load_modules(pamh, type, sm_name(ind),
			    pamh->pam_conf_info
			    [pamh->include_depth][type])) != PAM_SUCCESS) {
				pam_trace(PAM_DEBUG_DEFAULT,
				    "[%d:%s]:%s(%p, %x): load_modules failed",
				    pamh->include_depth, pam_trace_cname(pamh),
				    function_name, (void *)pamh, flags);
				goto exit_return;
			}
			if ((modulep = pamh->pam_conf_info
			    [pamh->include_depth][type]) == NULL) {
				__pam_log(LOG_AUTH | LOG_ERR,
				    "%s no initial module present",
				    pam_trace_cname(pamh));
				goto exit_return;
			}
		} else if ((err = load_modules(pamh, type, sm_name(ind),
		    modulep)) != PAM_SUCCESS) {
			pam_trace(PAM_DEBUG_DEFAULT,
			    "[%d:%s]:%s(%p, %x): load_modules failed",
			    pamh->include_depth, pam_trace_cname(pamh),
			    function_name, (void *)pamh, flags);
			goto exit_return;
		}  /* PAM_INCLUDE */
		sm_func = func(modulep, ind);
		if (sm_func) {
			err = sm_func(pamh, flags, modulep->module_argc,
			    (const char **)modulep->module_argv);

			pam_trace(PAM_DEBUG_MODULE,
			    "[%d:%s]:%s(%p, %x): %s returned %s",
			    pamh->include_depth, pam_trace_cname(pamh),
			    function_name, (void *)pamh, flags,
			    modulep->module_path, pam_strerror(pamh, err));

			switch (err) {
			case PAM_IGNORE:
				/* do nothing */
				break;
			case PAM_SUCCESS:
				if ((modulep->pam_flag & PAM_SUFFI_BIND) &&
				    !required_error) {
					pamh->pam_inmodule = RW_OK;
					pam_trace(PAM_DEBUG_MODULE,
					    "[%d:%s]:%s(%p, %x): %s: success",
					    pamh->include_depth,
					    pam_trace_cname(pamh),
					    function_name, (void *)pamh, flags,
					    (modulep->pam_flag & PAM_BINDING) ?
					    PAM_BINDING_NAME :
					    PAM_SUFFICIENT_NAME);
					goto exit_return;
				}
				success = 1;
				break;
			case PAM_TRY_AGAIN:
				/*
				 * We need to return immediately, and
				 * we shouldn't reset the AUTHTOK item
				 * since it is not an error per-se.
				 */
				pamh->pam_inmodule = RW_OK;
				pam_trace(PAM_DEBUG_MODULE,
				    "[%d:%s]:%s(%p, %x): TRY_AGAIN: %s",
				    pamh->include_depth, pam_trace_cname(pamh),
				    function_name, (void *)pamh, flags,
				    pam_strerror(pamh, required_error ?
				    required_error : err));
				err = required_error ? required_error : err;
				goto exit_return;
			default:
				if (modulep->pam_flag & PAM_REQUISITE) {
					pamh->pam_inmodule = RW_OK;
					pam_trace(PAM_DEBUG_MODULE,
					    "[%d:%s]:%s(%p, %x): requisite: %s",
					    pamh->include_depth,
					    pam_trace_cname(pamh),
					    function_name, (void *)pamh, flags,
					    pam_strerror(pamh,
					    required_error ? required_error :
					    err));
					err = required_error ?
					    required_error : err;
					goto exit_return;
				} else if (modulep->pam_flag & PAM_REQRD_BIND) {
					if (!required_error)
						required_error = err;
				} else {
					if (!optional_error)