/* -*- C -*-
 * Copyright (C) 2000-2002, 2008 Red Hat, Inc.
 *
 * This is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Library General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* This file contains functions suitable for inclusion in modules, for
   initializing user and group records. */

#ident "$Id: default.-c,v 1.11 2005/10/09 05:15:47 mitr Exp $"

#include <sys/param.h>
#include <stdio.h>
#include <stdlib.h>
#include <glib.h>
#include <glib-object.h>
#include <string.h>

/* Define _LIBUSER_MODULE if your module is being built alongside libuser. */
#ifdef _LIBUSER_MODULE
#include "../lib/user_private.h"
#else
#include <libuser/user_private.h>
#endif

#define DEFAULT_PASSWORD	"!!"
#define DEFAULT_SHADOW_PASSWORD	"x"
#define DEFAULT_SHELL		"/bin/bash"

#define HASH_ROUNDS_MIN 1000
#define HASH_ROUNDS_MAX 999999999

/* Populate the fields of a user structure with non-name, non-ID data. */
static gboolean
lu_common_user_default(struct lu_module *module,
		       const char *name, gboolean is_system,
		       struct lu_ent *ent, struct lu_error **error)
{
	GValue value;

	(void)module;
	(void)is_system;
	(void)error;
	g_return_val_if_fail(name != NULL, FALSE);
	memset(&value, 0, sizeof(value));
	if (lu_ent_get(ent, LU_USERPASSWORD) == NULL) {
		g_value_init(&value, G_TYPE_STRING);
		g_value_set_string(&value, DEFAULT_PASSWORD);
		lu_ent_add(ent, LU_USERPASSWORD, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWPASSWORD) == NULL) {
		g_value_init(&value, G_TYPE_STRING);
		g_value_set_string(&value, DEFAULT_PASSWORD);
		lu_ent_add(ent, LU_SHADOWPASSWORD, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_GECOS) == NULL) {
		g_value_init(&value, G_TYPE_STRING);
		g_value_set_string(&value, name);
		lu_ent_add(ent, LU_GECOS, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_HOMEDIRECTORY) == NULL) {
		char *tmp;

		g_value_init(&value, G_TYPE_STRING);
		tmp = g_strdup_printf("/home/%s", name);
		g_value_set_string(&value, tmp);
		g_free(tmp);
		lu_ent_add(ent, LU_HOMEDIRECTORY, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_LOGINSHELL) == NULL) {
		g_value_init(&value, G_TYPE_STRING);
		g_value_set_string(&value, DEFAULT_SHELL);
		lu_ent_add(ent, LU_LOGINSHELL, &value);
		g_value_unset(&value);
	}
	return TRUE;
}

/* Populate the fields of a group structure with non-name, non-ID data. */
static gboolean
lu_common_group_default(struct lu_module *module,
		        const char *name, gboolean is_system,
		        struct lu_ent *ent, struct lu_error **error)
{
	(void)module;
	(void)is_system;
	(void)error;
	g_return_val_if_fail(name != NULL, FALSE);
	if (lu_ent_get(ent, LU_SHADOWPASSWORD) == NULL) {
		GValue value;

		memset(&value, 0, sizeof(value));
		g_value_init(&value, G_TYPE_STRING);
		g_value_set_string(&value, DEFAULT_PASSWORD);
		lu_ent_add(ent, LU_SHADOWPASSWORD, &value);
		g_value_unset(&value);
	}
	return TRUE;
}

/* Populate the fields of a user structure with non-name, non-ID data. */
static gboolean
lu_common_suser_default(struct lu_module *module,
		        const char *name, gboolean is_system,
		        struct lu_ent *ent, struct lu_error **error)
{
	GValue value;
	const char *today;

	(void)module;
	(void)is_system;
	(void)error;
	g_return_val_if_fail(name != NULL, FALSE);
	today = lu_util_shadow_current_date(ent->cache);
	memset(&value, 0, sizeof(value));
	if (lu_ent_get(ent, LU_SHADOWPASSWORD) == NULL) {
		g_value_init(&value, G_TYPE_STRING);
		g_value_set_string(&value, DEFAULT_PASSWORD);
		lu_ent_add(ent, LU_SHADOWPASSWORD, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWLASTCHANGE) == NULL) {
		g_value_init(&value, G_TYPE_STRING);
		g_value_set_string(&value, today);
		lu_ent_add(ent, LU_SHADOWLASTCHANGE, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWMIN) == NULL) {
		g_value_init(&value, G_TYPE_LONG);
		g_value_set_long(&value, 0);
		lu_ent_add(ent, LU_SHADOWMIN, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWMAX) == NULL) {
		g_value_init(&value, G_TYPE_LONG);
		g_value_set_long(&value, 99999);
		lu_ent_add(ent, LU_SHADOWMAX, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWWARNING) == NULL) {
		g_value_init(&value, G_TYPE_LONG);
		g_value_set_long(&value, 7);
		lu_ent_add(ent, LU_SHADOWWARNING, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWINACTIVE) == NULL) {
		g_value_init(&value, G_TYPE_LONG);
		g_value_set_long(&value, -1);
		lu_ent_add(ent, LU_SHADOWINACTIVE, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWEXPIRE) == NULL) {
		g_value_init(&value, G_TYPE_LONG);
		g_value_set_long(&value, -1);
		lu_ent_add(ent, LU_SHADOWEXPIRE, &value);
		g_value_unset(&value);
	}
	if (lu_ent_get(ent, LU_SHADOWFLAG) == NULL) {
		g_value_init(&value, G_TYPE_LONG);
		g_value_set_long(&value, -1);
		lu_ent_add(ent, LU_SHADOWFLAG, &value);
		g_value_unset(&value);
	}
	return TRUE;
}

static gboolean
lu_common_sgroup_default(struct lu_module *module,
		         const char *name, gboolean is_system,
		         struct lu_ent *ent, struct lu_error **error)
{
	g_return_val_if_fail(name != NULL, FALSE);
	return lu_common_group_default(module, name, is_system, ent, error);
}

static const char *
lu_common_parse_hash_rounds(struct lu_module *module, const char *key,
			    unsigned long *value)
{
	const char *s;

	s = lu_cfg_read_single(module->lu_context, key, NULL);
	if (s != NULL) {
		char *end;

		errno = 0;
		*value = strtoul(s, &end, 10);
		if (errno != 0 || *end != 0 || end == s) {
			g_warning("Invalid %s value '%s'", key, s);
			s = NULL;
		}
	}
	return s;
}

static unsigned long
lu_common_select_hash_rounds(struct lu_module *module)
{
	const char *min_s, *max_s;
	unsigned long min, max, rounds;

	min_s = lu_common_parse_hash_rounds(module, "defaults/hash_rounds_min",
					    &min);
	max_s = lu_common_parse_hash_rounds(module, "defaults/hash_rounds_max",
					    &max);
	if (min_s == NULL && max_s == NULL)
		return 0;
	if (min_s != NULL && max_s != NULL) {
		if (min <= max) {
			if (max > HASH_ROUNDS_MAX)
				/* To avoid overflow in (max + 1) below */
				max = HASH_ROUNDS_MAX;
			rounds = g_random_int_range(min, max + 1);
		} else
			rounds = min;
	} else if (min_s != NULL)
		rounds = min;
	else /* max_s != NULL */
		rounds = max;
	if (rounds < HASH_ROUNDS_MIN)
		rounds = HASH_ROUNDS_MIN;
	else if (rounds > HASH_ROUNDS_MAX)
		rounds = HASH_ROUNDS_MAX;
	return rounds;
}

static char *
lu_common_default_salt_specifier(struct lu_module *module)
{
	static const struct {
		const char *name, *initializer;
		gboolean sha_rounds;
	} salt_types[] = {
		{ "des", "", FALSE },
		{ "md5", "$1$", FALSE },
		{ "blowfish", "$2a$", FALSE },
		{ "sha256", "$5$", TRUE },
		{ "sha512", "$6$", TRUE },
	};

	const char *salt_type;
	size_t i;

	g_return_val_if_fail(module != NULL, "");

	salt_type = lu_cfg_read_single(module->lu_context,
				       "defaults/crypt_style",
				       "des");

	for (i = 0; i < G_N_ELEMENTS(salt_types); i++) {
		if (strcasecmp(salt_types[i].name, salt_type) == 0) {
			goto found;
		}
	}
	return g_strdup("");

found:
	if (salt_types[i].sha_rounds != FALSE) {
		unsigned long rounds;

		rounds = lu_common_select_hash_rounds(module);
		if (rounds != 0)
			return g_strdup_printf("%srounds=%lu$",
					       salt_types[i].initializer,
					       rounds);
	}
	return g_strdup(salt_types[i].initializer);
}