/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 * \brief Execute arbitrary authenticate commands
 * 
 * \ingroup applications
 */

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/lock.h"
#include "asterisk/file.h"
#include "asterisk/logger.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/module.h"
#include "asterisk/app.h"
#include "asterisk/astdb.h"
#include "asterisk/utils.h"

static char *tdesc = "Authentication Application";

static char *app = "Authenticate";

static char *synopsis = "Authenticate a user";

static char *descrip =
"  Authenticate(password[|options]): Requires a user to enter a"
"given password in order to continue execution.  If the\n"
"password begins with the '/' character, it is interpreted as\n"
"a file which contains a list of valid passwords (1 per line).\n"
"an optional set of opions may be provided by concatenating any\n"
"of the following letters:\n"
"     a - Set account code to the password that is entered\n"
"     d - Interpret path as database key, not literal file\n"
"     j - Support jumping to n+101\n"
"     m - Interpret path as a file which contains a list of\n"
"         account codes and password hashes delimited with ':'\n"
"         one per line. When password matched, corresponding\n"
"         account code will be set\n"
"     r - Remove database key upon successful entry (valid with 'd' only)\n"
"\n"
"When using a database key, the value associated with the key can be\n"
"anything.  Users have three attempts to authenticate before the line is \n"
"hungup.  If the passsword is invalid, and the 'j' flag is specified, \n"
"and priority n+101 exists, the call would be sent to the n+101 priority \n"
"and executed \n";

STANDARD_LOCAL_USER;

LOCAL_USER_DECL;

static int auth_exec(struct ast_channel *chan, void *data)
{
	int res=0;
	int jump = 0;
	int retries;
	struct localuser *u;
	char password[256]="";
	char passwd[256];
	char *opts;
	char *prompt;
	
	if (ast_strlen_zero(data)) {
		ast_log(LOG_WARNING, "Authenticate requires an argument(password)\n");
		return -1;
	}
	
	LOCAL_USER_ADD(u);

	if (chan->_state != AST_STATE_UP) {
		res = ast_answer(chan);
		if (res) {
			LOCAL_USER_REMOVE(u);
			return -1;
		}
	}
	
	strncpy(password, data, sizeof(password) - 1);
	opts=strchr(password, '|');
	if (opts) {
		*opts = 0;
		opts++;
	} else
		opts = "";
	if (strchr(opts, 'j'))
		jump = 1;
	/* Start asking for password */
	prompt = "agent-pass";
	for (retries = 0; retries < 3; retries++) {
		res = ast_app_getdata(chan, prompt, passwd, sizeof(passwd) - 2, 0);
		if (res < 0)
			break;
		res = 0;
		if (password[0] == '/') {
			if (strchr(opts, 'd')) {
				char tmp[256];
				/* Compare against a database key */
				if (!ast_db_get(password + 1, passwd, tmp, sizeof(tmp))) {
					/* It's a good password */
					if (strchr(opts, 'r')) {
						ast_db_del(password + 1, passwd);
					}
					break;
				}
			} else {
				/* Compare against a file */
				FILE *f;
				f = fopen(password, "r");
				if (f) {
					char buf[256] = "";
					char md5passwd[33] = "";
					char *md5secret = NULL;

					while (!feof(f)) {
						fgets(buf, sizeof(buf), f);
						if (!feof(f) && !ast_strlen_zero(buf)) {
							buf[strlen(buf) - 1] = '\0';
							if (strchr(opts, 'm')) {
								md5secret = strchr(buf, ':');
								if (md5secret == NULL)
									continue;
								*md5secret = '\0';
								md5secret++;
								ast_md5_hash(md5passwd, passwd);
								if (!strcmp(md5passwd, md5secret)) {
									if (strchr(opts, 'a'))
										ast_cdr_setaccount(chan, buf);
									break;
								}
							} else {
								if (!strcmp(passwd, buf)) {
									if (strchr(opts, 'a'))
										ast_cdr_setaccount(chan, buf);
									break;
								}
							}
						}
					}
					fclose(f);
					if (!ast_strlen_zero(buf)) {
						if (strchr(opts, 'm')) {
							if (md5secret && !strcmp(md5passwd, md5secret))
								break;
						} else {
							if (!strcmp(passwd, buf))
								break;
						}
					}
				} else 
					ast_log(LOG_WARNING, "Unable to open file '%s' for authentication: %s\n", password, strerror(errno));
			}
		} else {
			/* Compare against a fixed password */
			if (!strcmp(passwd, password)) 
				break;
		}
		prompt="auth-incorrect";
	}
	if ((retries < 3) && !res) {
		if (strchr(opts, 'a') && !strchr(opts, 'm')) 
			ast_cdr_setaccount(chan, passwd);
		res = ast_streamfile(chan, "auth-thankyou", chan->language);
		if (!res)
			res = ast_waitstream(chan, "");
	} else {
		if (jump && ast_goto_if_exists(chan, chan->context, chan->exten, chan->priority + 101)) {
			res = 0;
		} else {
			if (!ast_streamfile(chan, "vm-goodbye", chan->language))
				res = ast_waitstream(chan, "");
			res = -1;
		}
	}
	LOCAL_USER_REMOVE(u);
	return res;
}

int unload_module(void)
{
	int res;

	res = ast_unregister_application(app);

	STANDARD_HANGUP_LOCALUSERS;
	
	return res;
}

int load_module(void)
{
	return ast_register_application(app, auth_exec, synopsis, descrip);
}

char *description(void)
{
	return tdesc;
}

int usecount(void)
{
	int res;
	STANDARD_USECOUNT(res);
	return res;
}

char *key()
{
	return ASTERISK_GPL_KEY;
}