1 files changed, 139 insertions, 0 deletions
diff --git a/src/utils_luks2.c b/src/utils_luks2.c
new file mode 100644
index 0000000..b8e0d6c
--- /dev/null
+++ b/src/utils_luks2.c
@@ -0,0 +1,139 @@
+/*
+ * Helper utilities for LUKS2 features
+ *
+ * Copyright (C) 2018-2021 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2018-2021 Milan Broz
+ * Copyright (C) 2018-2021 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;
+}