interface.c

/*
 * dsngctl - Control utility for DigSig-ng (digsig-ng.org)
 *
 * interface.c - functions for interfacing with the kernel module
 *
 * Copyright (c) 2013-2014, The DigSig-ng Authors
 *
 * 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.
 */

#include "interface.h"
#include "extract.h"

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>

int dsng_start(char *pkey_path)
{
	int ret = -1;
	int pkey_file, mod_file;

	pkey_file = open(pkey_path, O_RDONLY);
	if (pkey_file < 0) {
		fprintf(stderr, "dsngctl: %s: unable to open public key\n", __func__);
		goto cleanup_done;
	}

	mod_file = open("/sys/digsig/key", O_WRONLY);
	if (pkey_file < 0) {
		fprintf(stderr, "dsngctl: %s: unable to open module char device\n",
			__func__);
		goto cleanup_pkey;
	}

	if (check_pubkey(pkey_file) != 0) {
		fprintf(stderr, "dsngctl: %s: public key invalid\n", __func__);
		goto cleanup_mod;
	}

	if (get_mpi(pkey_file, mod_file, 'n') != 0) {
		fprintf(stderr, "dsngctl: %s: get_mpi(..., ..., 'n') failed\n",
			__func__);
		goto cleanup_mod;
	}

	if (get_mpi(pkey_file, mod_file, 'e') != 0) {
		fprintf(stderr, "dsngctl: %s: get_mpi(..., ..., 'e') failed\n",
			__func__);
		goto cleanup_mod;
	}

	ret = 0;

cleanup_mod:
	close(mod_file);
cleanup_pkey:
	close(pkey_file);
cleanup_done:
	return ret;
}

int digsig_is_loaded()
{
	struct stat key_stat, revoke_stat;

	if (stat("/sys/digsig/key", &key_stat) != 0) {
		fprintf(stderr, "dsngctl: %s: could not stat /sys/digsig/key\n", __func__);
		return 0;
	}

	if (stat("/sys/digsig/revoke", &revoke_stat) != 0) {
		fprintf(stderr, "dsngctl: %s: could not stat /sys/digsig/revoke\n", __func__);
		return 0;
	}

	return 1;
}

int digsig_is_initialized()
{
	int status_fd;
	int rcount;
	char status[8];

	if (!digsig_is_loaded())
		return 0;

	status_fd = open("/sys/digsig/status", O_RDONLY);
	if (status_fd < 0) {
		fprintf(stderr, "dsngctl: %s: could not open /sys/digsig/status\n", __func__);
		return 0;
	}

	rcount = read(status_fd, status, 8); /* reading 8 bytes, we won't need more */
	if (rcount < 0) {
		fprintf(stderr, "dsngctl: %s: could not read /sys/digsig/status\n", __func__);

		close(status_fd);
		return 0;
	}

	if (strncmp(status, "1", 1) == 0) {
		close(status_fd);
		return 1;
	}

	if (status_fd > 0)
		close(status_fd);

	return 0;
}