fwtool: add utility for appending and extracting firmware metadata/signatures

This will be used to append extra information to images which allows the
system to verify if an image is compatible with the system.

The extra data is appended to the end of the image, where it will be
ignored when upgrading from systems that do not process this data yet:

If the image is a squashfs or jffs2 image, the extra data will land
after the end-of-filesystem marker, where it will be overwritten once
the system boots for the first timee.

If the image is a sysupgrade tar file, tar will simply ignore the extra
data when unpacking.

The layout of the metadata/signature chunks is constructed in a way
that the last part contains just a magic and size information, so that
the tool can quickly check if any valid data is present without having
to do a pattern search throughout the full image.

Chunks also contain CRC32 information to detect file corruption, even
when the image is not signed.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 116 insertions, 0 deletions

diff --git a/package/system/fwtool/src/utils.h b/package/system/fwtool/src/utils.h
new file mode 100644
index 0000000000..c2e665e54a
--- /dev/null
+++ b/package/system/fwtool/src/utils.h
@@ -0,0 +1,116 @@
+/*
+ * utils - misc libubox utility functions
+ *
+ * Copyright (C) 2012 Felix Fietkau <nbd@openwrt.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef __LIBUBOX_UTILS_H
+#define __LIBUBOX_UTILS_H
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+#endif
+
+#ifdef __GNUC__
+#define _GNUC_MIN_VER(maj, min) (((__GNUC__ << 8) + __GNUC_MINOR__) >= (((maj) << 8) + (min)))
+#else
+#define _GNUC_MIN_VER(maj, min) 0
+#endif
+
+#if defined(__linux__) || defined(__CYGWIN__)
+#include <byteswap.h>
+#include <endian.h>
+
+#elif defined(__APPLE__)
+#include <machine/endian.h>
+#include <machine/byte_order.h>
+#define bswap_32(x) OSSwapInt32(x)
+#define bswap_64(x) OSSwapInt64(x)
+#elif defined(__FreeBSD__)
+#include <sys/endian.h>
+#define bswap_32(x) bswap32(x)
+#define bswap_64(x) bswap64(x)
+#else
+#include <machine/endian.h>
+#define bswap_32(x) swap32(x)
+#define bswap_64(x) swap64(x)
+#endif
+
+#ifndef __BYTE_ORDER
+#define __BYTE_ORDER BYTE_ORDER
+#endif
+#ifndef __BIG_ENDIAN
+#define __BIG_ENDIAN BIG_ENDIAN
+#endif
+#ifndef __LITTLE_ENDIAN
+#define __LITTLE_ENDIAN LITTLE_ENDIAN
+#endif
+
+static inline uint16_t __u_bswap16(uint16_t val)
+{
+	return ((val >> 8) & 0xffu) | ((val & 0xffu) << 8);
+}
+
+#if _GNUC_MIN_VER(4, 2)
+#define __u_bswap32(x) __builtin_bswap32(x)
+#define __u_bswap64(x) __builtin_bswap64(x)
+#else
+#define __u_bswap32(x) bswap_32(x)
+#define __u_bswap64(x) bswap_64(x)
+#endif
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+
+#define cpu_to_be64(x) __u_bswap64(x)
+#define cpu_to_be32(x) __u_bswap32(x)
+#define cpu_to_be16(x) __u_bswap16((uint16_t) (x))
+
+#define be64_to_cpu(x) __u_bswap64(x)
+#define be32_to_cpu(x) __u_bswap32(x)
+#define be16_to_cpu(x) __u_bswap16((uint16_t) (x))
+
+#define cpu_to_le64(x) (x)
+#define cpu_to_le32(x) (x)
+#define cpu_to_le16(x) (x)
+
+#define le64_to_cpu(x) (x)
+#define le32_to_cpu(x) (x)
+#define le16_to_cpu(x) (x)
+
+#else /* __BYTE_ORDER == __LITTLE_ENDIAN */
+
+#define cpu_to_le64(x) __u_bswap64(x)
+#define cpu_to_le32(x) __u_bswap32(x)
+#define cpu_to_le16(x) __u_bswap16((uint16_t) (x))
+
+#define le64_to_cpu(x) __u_bswap64(x)
+#define le32_to_cpu(x) __u_bswap32(x)
+#define le16_to_cpu(x) __u_bswap16((uint16_t) (x))
+
+#define cpu_to_be64(x) (x)
+#define cpu_to_be32(x) (x)
+#define cpu_to_be16(x) (x)
+
+#define be64_to_cpu(x) (x)
+#define be32_to_cpu(x) (x)
+#define be16_to_cpu(x) (x)
+
+#endif
+
+#endif