/*

 * cryptsetup volume key implementation

 *

 * Copyright (C) 2004-2006 Clemens Fruhwirth <clemens@endorphin.org>

 * Copyright (C) 2010-2020 Red Hat, Inc. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU 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 General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include <string.h>

#include <stdint.h>

#include <stdlib.h>

#include <errno.h>

#include "internal.h"

struct volume_key *crypt_alloc_volume_key(size_t keylength, const char *key)

{

	struct volume_key *vk;

	if (keylength > (SIZE_MAX - sizeof(*vk)))

		return NULL;

	vk = malloc(sizeof(*vk) + keylength);

	if (!vk)

		return NULL;

	vk->key_description = NULL;

	vk->keylength = keylength;

	vk->id = -1;

	vk->next = NULL;

	/* keylength 0 is valid => no key */

	if (vk->keylength) {

		if (key)

			memcpy(&vk->key, key, keylength);

		else

			crypt_safe_memzero(&vk->key, keylength);

	}

	return vk;

}

int crypt_volume_key_set_description(struct volume_key *vk, const char *key_description)

{

	if (!vk)

		return -EINVAL;

	free(CONST_CAST(void*)vk->key_description);

	vk->key_description = NULL;

	if (key_description && !(vk->key_description = strdup(key_description)))

		return -ENOMEM;

	return 0;

}

void crypt_volume_key_set_id(struct volume_key *vk, int id)

{

	if (vk && id >= 0)

		vk->id = id;

}

int crypt_volume_key_get_id(const struct volume_key *vk)

{

	return vk ? vk->id : -1;

}

struct volume_key *crypt_volume_key_by_id(struct volume_key *vks, int id)

{

	struct volume_key *vk = vks;

	if (id < 0)

		return NULL;

	while (vk && vk->id != id)

		vk = vk->next;

	return vk;

}

void crypt_volume_key_add_next(struct volume_key **vks, struct volume_key *vk)

{

	struct volume_key *tmp;

	if (!vks)

		return;

	if (!*vks) {

		*vks = vk;

		return;

	}

	tmp = *vks;

	while (tmp->next)

		tmp = tmp->next;

	tmp->next = vk;

}

struct volume_key *crypt_volume_key_next(struct volume_key *vk)

{

	return vk ? vk->next : NULL;

}

void crypt_free_volume_key(struct volume_key *vk)

{

	struct volume_key *vk_next;

	while (vk) {

		crypt_safe_memzero(vk->key, vk->keylength);

		vk->keylength = 0;

		free(CONST_CAST(void*)vk->key_description);

		vk_next = vk->next;

		free(vk);

		vk = vk_next;

	}

}

struct volume_key *crypt_generate_volume_key(struct crypt_device *cd, size_t keylength)

{

	int r;

	struct volume_key *vk;

	vk = crypt_alloc_volume_key(keylength, NULL);

	if (!vk)

		return NULL;

	r = crypt_random_get(cd, vk->key, keylength, CRYPT_RND_KEY);

	if(r < 0) {

		crypt_free_volume_key(vk);

		return NULL;

	}

	return vk;

}