/*

 * Helper utilities for LUKS2 features

 *

 * Copyright (C) 2018-2020 Red Hat, Inc. All rights reserved.

 * Copyright (C) 2018-2020 Milan Broz

 * Copyright (C) 2018-2020 Ondrej Kozina

 *

 * 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 "cryptsetup.h"

/*

 * FIXME: 4MiBs is max LUKS2 mda length (including binary header).

 * In future, read max allowed JSON size from config section.

 */

#define LUKS2_MAX_MDA_SIZE 0x400000

int tools_read_json_file(struct crypt_device *cd, const char *file, char **json, size_t *json_size)

{

	ssize_t ret;

	int fd, block, r;

	void *buf = NULL;

	block = tools_signals_blocked();

	if (block)

		set_int_block(0);

	if (tools_is_stdin(file)) {

		fd = STDIN_FILENO;

		log_dbg("STDIN descriptor JSON read requested.");

	} else {

		log_dbg("File descriptor JSON read requested.");

		fd = open(file, O_RDONLY);

		if (fd < 0) {

			log_err(_("Failed to open file %s in read-only mode."), file);

			r = -EINVAL;

			goto out;

		}

	}

	buf = malloc(LUKS2_MAX_MDA_SIZE);

	if (!buf) {

		r = -ENOMEM;

		goto out;

	}

	if (isatty(fd) && !opt_batch_mode)

		log_std(_("Provide valid LUKS2 token JSON:\n"));

	/* we expect JSON (string) */

	r = 0;

	ret = read_buffer_intr(fd, buf, LUKS2_MAX_MDA_SIZE - 1, &quit);

	if (ret < 0) {

		r = -EIO;

		log_err(_("Failed to read JSON file."));

		goto out;

	}

	check_signal(&r);

	if (r) {

		log_err(_("\nRead interrupted."));

		goto out;

	}

	*json_size = (size_t)ret;

	*json = buf;

	*(*json + ret) = '\0';

out:

	if (block && !quit)

		set_int_block(1);

	if (fd >= 0 && fd != STDIN_FILENO)

		close(fd);

	if (r && buf) {

		memset(buf, 0, LUKS2_MAX_MDA_SIZE);

		free(buf);

	}

	return r;

}

int tools_write_json_file(struct crypt_device *cd, const char *file, const char *json)

{

	int block, fd, r;

	size_t json_len;

	ssize_t ret;

	if (!json || !(json_len = strlen(json)) || json_len >= LUKS2_MAX_MDA_SIZE)

		return -EINVAL;

	block = tools_signals_blocked();

	if (block)

		set_int_block(0);

	if (tools_is_stdin(file)) {

		fd = STDOUT_FILENO;

		log_dbg("STDOUT descriptor JSON write requested.");

	} else {

		log_dbg("File descriptor JSON write requested.");

		fd = open(file, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR);

	}

	if (fd < 0) {

		log_err(_("Failed to open file %s in write mode."), file ?: "");

		r = -EINVAL;

		goto out;

	}

	r = 0;

	ret = write_buffer_intr(fd, json, json_len, &quit);

	check_signal(&r);

	if (r) {

		log_err(_("\nWrite interrupted."));

		goto out;

	}

	if (ret < 0 || (size_t)ret != json_len) {

		log_err(_("Failed to write JSON file."));

		r = -EIO;

		goto out;

	}

	if (isatty(fd))

		(void) write_buffer_intr(fd, "\n", 1, &quit);

out:

	if (block && !quit)

		set_int_block(1);

	if (fd >=0 && fd != STDOUT_FILENO)

		close(fd);

	return r;

}