tools/firmware-utils: add buffalo specific fw tools

SVN-Revision: 27050

5 files changed, 1177 insertions, 0 deletions

diff --git a/tools/firmware-utils/Makefile b/tools/firmware-utils/Makefile
index ce2a15d..ebec10b 100644
--- a/tools/firmware-utils/Makefile
+++ b/tools/firmware-utils/Makefile
@@ -50,6 +50,8 @@ define Host/Compile
 	$(call cc,spw303v)
 	$(call cc,trx2edips)
 	$(call cc,xorimage)
+	$(call cc,buffalo-enc buffalo-lib, -Wall)
+	$(call cc,buffalo-tag buffalo-lib, -Wall)
 endef
 
 define Host/Install
diff --git a/tools/firmware-utils/src/buffalo-enc.c b/tools/firmware-utils/src/buffalo-enc.c
new file mode 100644
index 0000000..94de53e
--- /dev/null
+++ b/tools/firmware-utils/src/buffalo-enc.c
@@ -0,0 +1,296 @@
+/*
+ * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <libgen.h>
+#include <getopt.h>     /* for getopt() */
+#include <stdarg.h>
+
+#include "buffalo-lib.h"
+
+#define ERR(fmt, args...) do { \
+	fflush(0); \
+	fprintf(stderr, "[%s] *** error: " fmt "\n", \
+			progname, ## args ); \
+} while (0)
+
+static char *progname;
+static char *ifname;
+static char *ofname;
+static char *crypt_key = "Buffalo";
+static char *magic = "start";
+static int longstate;
+static unsigned char seed = 'O';
+
+static char *product;
+static char *version;
+static int do_decrypt;
+
+void usage(int status)
+{
+	FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
+
+	fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
+	fprintf(stream,
+"\n"
+"Options:\n"
+"  -d              decrypt instead of encrypt\n"
+"  -i <file>       read input from the file <file>\n"
+"  -o <file>       write output to the file <file>\n"
+"  -l              use longstate {en,de}cryption method\n"
+"  -k <key>        use <key> for encryption (default: Buffalo)\n"
+"  -m <magic>      set magic to <magic>\n"
+"  -p <product>    set product name to <product>\n"
+"  -v <version>    set version to <version>\n"
+"  -h              show this screen\n"
+	);
+
+	exit(status);
+}
+
+static int decrypt_file(void)
+{
+	struct enc_param ep;
+	ssize_t src_len;
+	unsigned char *buf = NULL;
+	int err;
+	int ret = -1;
+
+	src_len = get_file_size(ifname);
+	if (src_len < 0) {
+		ERR("unable to get size of '%s'", ifname);
+		goto out;
+	}
+
+	buf = malloc(src_len);
+	if (buf == NULL) {
+		ERR("no memory for the buffer");
+		goto out;
+	}
+
+	err = read_file_to_buf(ifname, buf, src_len);
+	if (err) {
+		ERR("unable to read from file '%s'", ifname);
+		goto out;
+	}
+
+	memset(&ep, '\0', sizeof(ep));
+	ep.key = (unsigned char *) crypt_key;
+
+	err = decrypt_buf(&ep, buf, src_len);
+	if (err)
+		goto out;
+
+	printf("Magic\t\t: '%s'\n", ep.magic);
+	printf("Seed\t\t: 0x%02x\n", ep.seed);
+	printf("Product\t\t: '%s'\n", ep.product);
+	printf("Version\t\t: '%s'\n", ep.version);
+	printf("Data len\t: %u\n", ep.datalen);
+	printf("Checksum\t: 0x%08x\n", ep.csum);
+
+	err = write_buf_to_file(ofname, buf, ep.datalen);
+	if (err) {
+		ERR("unable to write to file '%s'", ofname);
+		goto out;
+	}
+
+	ret = 0;
+
+out:
+	free(buf);
+	return ret;
+}
+
+static int encrypt_file(void)
+{
+	struct enc_param ep;
+	ssize_t src_len;
+	unsigned char *buf;
+	uint32_t hdrlen;
+	ssize_t totlen = 0;
+	int err;
+	int ret = -1;
+
+	src_len = get_file_size(ifname);
+	if (src_len < 0) {
+		ERR("unable to get size of '%s'", ifname);
+		goto out;
+	}
+
+	totlen = enc_compute_buf_len(product, version, src_len);
+	hdrlen = enc_compute_header_len(product, version);
+
+	buf = malloc(totlen);
+	if (buf == NULL) {
+		ERR("no memory for the buffer");
+		goto out;
+	}
+
+	err = read_file_to_buf(ifname, &buf[hdrlen], src_len);
+	if (err) {
+		ERR("unable to read from file '%s'", ofname);
+		goto free_buf;
+	}
+
+	memset(&ep, '\0', sizeof(ep));
+	ep.key = (unsigned char *) crypt_key;
+	ep.seed = seed;
+	ep.longstate = longstate;
+	ep.csum = buffalo_csum(src_len, &buf[hdrlen], src_len);
+	ep.datalen = src_len;
+	strcpy((char *) ep.magic, magic);
+	strcpy((char *) ep.product, product);
+	strcpy((char *) ep.version, version);
+
+	err = encrypt_buf(&ep, buf, &buf[hdrlen]);
+	if (err) {
+		ERR("invalid input file");
+		goto free_buf;
+	}
+
+	err = write_buf_to_file(ofname, buf, totlen);
+	if (err) {
+		ERR("unable to write to file '%s'", ofname);
+		goto free_buf;
+	}
+
+	ret = 0;
+
+free_buf:
+ 	free(buf);
+out:
+ 	return ret;
+}
+
+static int check_params(void)
+{
+	int ret = -1;
+
+	if (ifname == NULL) {
+		ERR("no input file specified");
+		goto out;
+	}
+
+	if (ofname == NULL) {
+		ERR("no output file specified");
+		goto out;
+	}
+
+	if (crypt_key == NULL) {
+		ERR("no key specified");
+		goto out;
+	} else if (strlen(crypt_key) > BCRYPT_MAX_KEYLEN) {
+		ERR("key '%s' is too long", crypt_key);
+		goto out;
+	}
+
+	if (strlen(magic) != (ENC_MAGIC_LEN - 1)) {
+		ERR("length of magic must be %d", ENC_MAGIC_LEN - 1);
+		goto out;
+	}
+
+	if (!do_decrypt) {
+		if (product == NULL) {
+			ERR("no product specified");
+			goto out;
+		}
+
+		if (version == NULL) {
+			ERR("no version specified");
+			goto out;
+		}
+
+		if (strlen(product) > (ENC_PRODUCT_LEN - 1)) {
+			ERR("product name '%s' is too long", product);
+			goto out;
+		}
+
+		if (strlen(version) > (ENC_VERSION_LEN - 1)) {
+			ERR("version '%s' is too long", version);
+			goto out;
+		}
+	}
+
+	ret = 0;
+
+out:
+	return ret;
+}
+
+int main(int argc, char *argv[])
+{
+	int res = EXIT_FAILURE;
+	int err;
+
+	progname = basename(argv[0]);
+
+	while ( 1 ) {
+		int c;
+
+		c = getopt(argc, argv, "adi:m:o:hp:v:k:r:s:");
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'd':
+			do_decrypt = 1;
+			break;
+		case 'i':
+			ifname = optarg;
+			break;
+		case 'l':
+			longstate = 1;
+			break;
+		case 'm':
+			magic = optarg;
+			break;
+		case 'o':
+			ofname = optarg;
+			break;
+		case 'p':
+			product = optarg;
+			break;
+		case 'v':
+			version = optarg;
+			break;
+		case 'k':
+			crypt_key = optarg;
+			break;
+		case 's':
+			seed = strtoul(optarg, NULL, 16);
+			break;
+		case 'h':
+			usage(EXIT_SUCCESS);
+			break;
+		default:
+			usage(EXIT_FAILURE);
+			break;
+		}
+	}
+
+	err = check_params();
+	if (err)
+		goto out;
+
+	if (do_decrypt)
+		err = decrypt_file();
+	else
+		err = encrypt_file();
+
+	if (err)
+		goto out;
+
+	res = EXIT_SUCCESS;
+
+out:
+	return res;
+}
diff --git a/tools/firmware-utils/src/buffalo-lib.c b/tools/firmware-utils/src/buffalo-lib.c
new file mode 100644
index 0000000..00ad1a5
--- /dev/null
+++ b/tools/firmware-utils/src/buffalo-lib.c
@@ -0,0 +1,480 @@
+/*
+ * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include "buffalo-lib.h"
+
+static uint32_t crc32_table[256] =
+{
+	0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9,
+	0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
+	0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61,
+	0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
+	0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9,
+	0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
+	0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011,
+	0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
+	0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
+	0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
+	0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81,
+	0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
+	0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49,
+	0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
+	0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1,
+	0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
+	0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae,
+	0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
+	0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
+	0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
+	0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde,
+	0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
+	0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066,
+	0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
+	0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e,
+	0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
+	0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6,
+	0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
+	0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
+	0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
+	0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686,
+	0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
+	0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637,
+	0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
+	0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f,
+	0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
+	0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47,
+	0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
+	0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
+	0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
+	0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7,
+	0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
+	0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f,
+	0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
+	0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7,
+	0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
+	0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f,
+	0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
+	0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
+	0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
+	0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8,
+	0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
+	0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30,
+	0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
+	0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088,
+	0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
+	0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0,
+	0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
+	0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
+	0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
+	0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0,
+	0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
+	0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668,
+	0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
+};
+
+int bcrypt_init(struct bcrypt_ctx *ctx, void *key, int keylen,
+		unsigned long state_len)
+{
+	unsigned char *state;
+	unsigned char *p = key;
+	unsigned long i, j;
+	unsigned long k = 0;
+
+	state = malloc(state_len);
+	if (state == NULL)
+		return -1;
+
+	ctx->i = 0;
+	ctx->j = 0;
+	ctx->state = state;
+	ctx->state_len = state_len;
+
+	for (i = 0; i < state_len; i++)
+		state[i] = i;
+
+	for(i = 0, j = 0; i < state_len; i++, j = (j + 1) % keylen) {
+		unsigned char t;
+
+		t = state[i];
+		k = (k + p[j] + t) % state_len;
+		state[i] = state[k];
+		state[k] = t;
+	}
+
+	return 0;
+}
+
+int bcrypt_process(struct bcrypt_ctx *ctx, unsigned char *src,
+		   unsigned char *dst, unsigned long len)
+{
+	unsigned char *state = ctx->state;
+	unsigned long state_len = ctx->state_len;
+	unsigned char i, j;
+	unsigned long k;
+
+	i = ctx->i;
+	j = ctx->j;
+
+	for (k = 0; k < len; k++) {
+		unsigned char t;
+
+		i = (i + 1) % state_len;
+		j = (j + state[i]) % state_len;
+		t = state[j];
+		state[j] = state[i];
+		state[i] = t;
+
+		dst[k] = src[k] ^ state[(state[i] + state[j]) % state_len];
+	}
+
+	ctx->i = i;
+	ctx->j = j;
+
+	return len;
+}
+
+void bcrypt_finish(struct bcrypt_ctx *ctx)
+{
+	if (ctx->state)
+		free(ctx->state);
+}
+
+int bcrypt_buf(unsigned char seed, unsigned char *key, unsigned char *src,
+	       unsigned char *dst, unsigned long len, int longstate)
+{
+	unsigned char bckey[BCRYPT_MAX_KEYLEN + 1];
+	unsigned int keylen;
+	struct bcrypt_ctx ctx;
+	int ret;
+
+	/* setup decryption key */
+	keylen = strlen((char *) key);
+	bckey[0] = seed;
+	memcpy(&bckey[1], key, keylen);
+
+	keylen++;
+
+	ret = bcrypt_init(&ctx, bckey, keylen,
+			  (longstate) ? len : BCRYPT_DEFAULT_STATE_LEN);
+	if (ret)
+		return ret;
+
+	bcrypt_process(&ctx, src, dst, len);
+	bcrypt_finish(&ctx);
+
+	return 0;
+}
+
+uint32_t buffalo_csum(uint32_t csum, void *buf, unsigned long len)
+{
+	unsigned char *p = buf;
+
+	while (len--) {
+		int i;
+
+		csum ^= *p++;
+		for (i = 0; i < 8; i++)
+			csum = (csum >> 1) ^ ((csum & 1) ? 0xedb88320ul : 0);
+	}
+
+	return csum;
+}
+
+uint32_t buffalo_crc(void *buf, unsigned long len)
+{
+	unsigned char *p = buf;
+	unsigned long t = len;
+	uint32_t crc = 0;
+
+	while (len--)
+		crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ *p++) & 0xFF];
+
+	while (t) {
+		crc = (crc << 8) ^ crc32_table[((crc >> 24) ^ t) & 0xFF];
+		t >>= 8;
+	}
+
+	return ~crc;
+}
+
+unsigned long enc_compute_header_len(char *product, char *version)
+{
+	return ENC_MAGIC_LEN + 1 + strlen(product) + 1 +
+	       strlen(version) + 1 + 3 * sizeof(uint32_t);
+}
+
+unsigned long enc_compute_buf_len(char *product, char *version,
+				  unsigned long datalen)
+{
+	unsigned long ret;
+
+	ret = enc_compute_header_len(product, version);
+	ret += datalen + sizeof(uint32_t);
+	ret += (4 - ret % 4);
+
+	return ret;
+}
+
+static void put_be32(void *data, uint32_t val)
+{
+	unsigned char *p = data;
+
+	p[0] = (val >> 24) & 0xff;
+	p[1] = (val >> 16) & 0xff;
+	p[2] = (val >> 8) & 0xff;
+	p[3] = val & 0xff;
+}
+
+static uint32_t get_be32(void *data)
+{
+	unsigned char *p = data;
+
+	return (((uint32_t)p[0]) << 24) |
+	       (((uint32_t)p[1]) << 16) |
+	       (((uint32_t)p[2]) << 8) |
+	       ((uint32_t)p[3]);
+}
+
+static int check_magic(void *magic)
+{
+	if (!memcmp("start", magic, ENC_MAGIC_LEN));
+		return 0;
+
+	if (!memcmp("asar1", magic, ENC_MAGIC_LEN));
+		return 0;
+
+	return -1;
+}
+
+int encrypt_buf(struct enc_param *ep, unsigned char *hdr,
+		unsigned char *data)
+{
+	unsigned char *p;
+	uint32_t len;
+	int err;
+	int ret = -1;
+	unsigned char s;
+
+	p = (unsigned char *) hdr;
+
+	/* setup magic */
+	len = strlen((char *) ep->magic) + 1;
+	memcpy(p, ep->magic, len);
+	p += len;
+
+	/* setup seed */
+	*p++ = ep->seed;
+
+	/* put product len */
+	len = strlen((char *) ep->product) + 1;
+	put_be32(p, len);
+	p += sizeof(uint32_t);
+
+	/* copy and crypt product name */
+	memcpy(p, ep->product, len);
+	err = bcrypt_buf(ep->seed, ep->key, p, p, len, ep->longstate);
+	if (err)
+		goto out;
+	s = *p;
+	p += len;
+
+	/* put version length */
+	len = strlen((char *) ep->version) + 1;
+	put_be32(p, len);
+	p += sizeof(uint32_t);
+
+	/* copy and crypt version */
+	memcpy(p, ep->version, len);
+	err = bcrypt_buf(s, ep->key, p, p, len, ep->longstate);
+	if (err)
+		goto out;
+	s = *p;
+	p += len;
+
+	/* put data length */
+	put_be32(p, ep->datalen);
+
+	/* encrypt data */
+	err = bcrypt_buf(s, ep->key, data, data, ep->datalen, ep->longstate);
+	if (err)
+		goto out;
+
+	/* put checksum */
+	put_be32(&data[ep->datalen], ep->csum);
+
+	ret = 0;
+
+out:
+	return ret;
+}
+
+int decrypt_buf(struct enc_param *ep, unsigned char *data,
+		unsigned long datalen)
+{
+	unsigned char *p;
+	uint32_t prod_len;
+	uint32_t ver_len;
+	uint32_t len;
+	uint32_t csum;
+	ssize_t remain;
+	int err;
+	int ret = -1;
+
+#define CHECKLEN(_l) do {		\
+	len = (_l);			\
+	if (remain < len) {		\
+		goto out;		\
+	}				\
+} while (0)
+
+#define INCP() do {			\
+	p += len;			\
+	remain -= len;			\
+} while (0)
+
+	remain = datalen;
+	p = data;
+
+	CHECKLEN(ENC_MAGIC_LEN);
+	err = check_magic(p);
+	if (err)
+		goto out;
+	memcpy(ep->magic, p, ENC_MAGIC_LEN);
+	INCP();
+
+	CHECKLEN(1);
+	ep->seed = *p;
+	INCP();
+
+	CHECKLEN(sizeof(uint32_t));
+	prod_len = get_be32(p);
+	if (prod_len > ENC_PRODUCT_LEN)
+		goto out;
+	INCP();
+
+	CHECKLEN(prod_len);
+	memcpy(ep->product, p, prod_len);
+	INCP();
+
+	CHECKLEN(sizeof(uint32_t));
+	ver_len = get_be32(p);
+	if (ver_len > ENC_VERSION_LEN)
+		goto out;
+	INCP();
+
+	CHECKLEN(ver_len);
+	memcpy(ep->version, p, ver_len);
+	INCP();
+
+	CHECKLEN(sizeof(uint32_t));
+	ep->datalen = get_be32(p);
+	INCP();
+
+	/* decrypt data */
+	CHECKLEN(ep->datalen);
+	err = bcrypt_buf(ep->version[0], ep->key, p, data, ep->datalen,
+			 ep->longstate);
+	if (err)
+		goto out;
+	INCP();
+
+	CHECKLEN(sizeof(uint32_t));
+	ep->csum = get_be32(p);
+	INCP();
+
+	csum = buffalo_csum(ep->datalen, data, ep->datalen);
+	if (csum != ep->csum)
+		goto out;
+
+	/* decrypt product name */
+	err = bcrypt_buf(ep->product[0], ep->key, ep->version, ep->version,
+			 ver_len, ep->longstate);
+	if (err)
+		goto out;
+
+	/* decrypt version */
+	err = bcrypt_buf(ep->seed, ep->key, ep->product, ep->product, prod_len,
+			 ep->longstate);
+	if (err)
+		goto out;
+
+	ret = 0;
+out:
+	return ret;
+
+#undef CHECKLEN
+#undef INCP
+}
+
+ssize_t get_file_size(char *name)
+{
+	struct stat st;
+	int err;
+
+	err = stat(name, &st);
+	if (err)
+		return -1;
+
+	return st.st_size;
+}
+
+int read_file_to_buf(char *name, void *buf, ssize_t buflen)
+{
+	FILE *f;
+	size_t done;
+	int ret = -1;
+
+	f = fopen(name, "r");
+	if (f == NULL)
+		goto out;
+
+	errno = 0;
+	done = fread(buf, buflen, 1, f);
+	if (done != 1)
+		goto close;
+
+	ret = 0;
+
+close:
+	fclose(f);
+out:
+	return ret;
+}
+
+int write_buf_to_file(char *name, void *buf, ssize_t buflen)
+{
+	FILE *f;
+	size_t done;
+	int ret = -1;
+
+	f = fopen(name, "w");
+	if (f == NULL)
+		goto out;
+
+	errno = 0;
+	done = fwrite(buf, buflen, 1, f);
+	if (done != 1)
+		goto close;
+
+	ret = 0;
+
+close:
+	fflush(f);
+	fclose(f);
+	if (ret)
+		unlink(name);
+out:
+	return ret;
+}
diff --git a/tools/firmware-utils/src/buffalo-lib.h b/tools/firmware-utils/src/buffalo-lib.h
new file mode 100644
index 0000000..614438e
--- /dev/null
+++ b/tools/firmware-utils/src/buffalo-lib.h
@@ -0,0 +1,99 @@
+/*
+ *  Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ */
+
+#ifndef _BUFFALO_LIB_H
+#define _BUFFALO_LIB_H
+
+#include <stdint.h>
+
+#define ARRAY_SIZE(_a)	(sizeof((_a)) / sizeof((_a)[0]))
+#define BIT(_x)		(1UL << (_x))
+
+#define TAG_BRAND_LEN		32
+#define TAG_PRODUCT_LEN		32
+#define TAG_VERSION_LEN		8
+#define TAG_REGION_LEN		2
+#define TAG_LANGUAGE_LEN	8
+#define TAG_PLATFORM_LEN	8
+#define TAG_HWVER_LEN		4
+#define TAG_HWVER_VAL_LEN	4
+
+struct buffalo_tag {
+	unsigned char	product[TAG_PRODUCT_LEN];
+	unsigned char	brand[TAG_BRAND_LEN];
+	unsigned char	ver_major[TAG_VERSION_LEN];
+	unsigned char	ver_minor[TAG_VERSION_LEN];
+	unsigned char	region_code[2];
+	uint32_t	region_mask;
+	unsigned char	unknown0[2];
+	unsigned char	language[TAG_LANGUAGE_LEN];
+	unsigned char	platform[TAG_PLATFORM_LEN];
+	unsigned char	hwv[TAG_HWVER_LEN];
+	unsigned char	hwv_val[TAG_HWVER_VAL_LEN];
+	uint8_t		unknown1[24];
+
+	uint32_t	len;
+	uint32_t	crc;
+	uint32_t	base1;
+	uint32_t	base2;
+	uint32_t	data_len;
+	uint8_t		flag;
+	uint8_t		unknown2[3];
+} __attribute ((packed));
+
+#define ENC_PRODUCT_LEN		32
+#define ENC_VERSION_LEN		8
+#define ENC_MAGIC_LEN		6
+
+unsigned long enc_compute_header_len(char *product, char *version);
+unsigned long enc_compute_buf_len(char *product, char *version,
+				  unsigned long datalen);
+
+struct enc_param {
+	unsigned char *key;
+	unsigned char magic[ENC_MAGIC_LEN];
+	unsigned char product[ENC_PRODUCT_LEN];
+	unsigned char version[ENC_VERSION_LEN];
+	unsigned char seed;
+	int longstate;
+	unsigned datalen;
+	uint32_t csum;
+};
+
+int encrypt_buf(struct enc_param *ep, unsigned char *hdr,
+	        unsigned char *data);
+int decrypt_buf(struct enc_param *ep, unsigned char *data,
+		unsigned long datalen);
+
+#define BCRYPT_DEFAULT_STATE_LEN	256
+#define BCRYPT_MAX_KEYLEN		254
+
+struct bcrypt_ctx {
+	unsigned long i;
+	unsigned long j;
+	unsigned char *state;
+	unsigned long state_len;
+};
+
+int bcrypt_init(struct bcrypt_ctx *ctx, void *key, int keylen,
+		unsigned long state_len);
+int bcrypt_process(struct bcrypt_ctx *ctx, unsigned char *src,
+		   unsigned char *dst, unsigned long len);
+void bcrypt_finish(struct bcrypt_ctx *ctx);
+int bcrypt_buf(unsigned char seed, unsigned char *key, unsigned char *src,
+	       unsigned char *dst, unsigned long len, int longstate);
+
+uint32_t buffalo_csum(uint32_t csum, void *buf, unsigned long len);
+uint32_t buffalo_crc(void *buf, unsigned long len);
+
+ssize_t get_file_size(char *name);
+int read_file_to_buf(char *name, void *buf, ssize_t buflen);
+int write_buf_to_file(char *name, void *buf, ssize_t buflen);
+
+#endif /* _BUFFALO_LIB_H */
diff --git a/tools/firmware-utils/src/buffalo-tag.c b/tools/firmware-utils/src/buffalo-tag.c
new file mode 100644
index 0000000..e3f7625
--- /dev/null
+++ b/tools/firmware-utils/src/buffalo-tag.c
@@ -0,0 +1,300 @@
+/*
+ *  Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <libgen.h>
+#include <getopt.h>     /* for getopt() */
+#include <netinet/in.h>
+
+#include "buffalo-lib.h"
+
+#define ERR(fmt, ...) do { \
+	fflush(0); \
+	fprintf(stderr, "[%s] *** error: " fmt "\n", \
+			progname, ## __VA_ARGS__ ); \
+} while (0)
+
+static char *region_table[] = {
+	"JP", "US", "EU", "AP", "TW", "KR"
+};
+
+static char *progname;
+static char *ifname;
+static char *ofname;
+static char *product;
+static char *brand;
+static char *language;
+static char *hwver;
+static char *platform;
+static int flag;
+static char *major;
+static char *minor = "1.01";
+static int skipcrc;
+static uint32_t base1;
+static uint32_t base2;
+static char *region_code;
+static uint32_t region_mask;
+static int num_regions;
+
+void usage(int status)
+{
+	FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
+
+	fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
+	fprintf(stream,
+"\n"
+"Options:\n"
+"  -a <platform>   set platform to <platform>\n"
+"  -b <brand>      set brand to <brand>\n"
+"  -c <base1>\n"
+"  -d <base2>\n"
+"  -f <flag>       set flag to <flag>\n"
+"  -i <file>       read input from the file <file>\n"
+"  -l <language>   set language to <language>\n"
+"  -m <version>    set minor version to <version>\n"
+"  -o <file>       write output to the file <file>\n"
+"  -p <product>    set product to <product>\n"
+"  -r <region>     set image region to <region>\n"
+"		   valid regions: JP, US, EU, AP, TW, KR, M_\n"
+"  -s              skip CRC calculation\n"
+"  -v <version>    set major version to <version>\n"
+"  -w <version>    set harwdware version to <version>\n"
+"  -h              show this screen\n"
+	);
+
+	exit(status);
+}
+
+static int check_params(void)
+{
+
+#define CHECKSTR(_var, _name, _len)	do {		\
+	if ((_var) == NULL) {				\
+		ERR("no %s specified", (_name));	\
+		return -1;				\
+	}						\
+	if ((_len) > 0 &&				\
+	    strlen((_var)) > ((_len) - 1)) {		\
+		ERR("%s is too long", (_name));		\
+		return -1;				\
+	}						\
+} while (0)
+
+	CHECKSTR(ifname, "input file", 0);
+	CHECKSTR(ofname, "output file", 0);
+	CHECKSTR(brand, "brand", TAG_BRAND_LEN);
+	CHECKSTR(product, "product", TAG_PRODUCT_LEN);
+	CHECKSTR(platform, "platform", TAG_PLATFORM_LEN);
+	CHECKSTR(major, "major version", TAG_VERSION_LEN);
+	CHECKSTR(minor, "minor version", TAG_VERSION_LEN);
+	CHECKSTR(language, "language", TAG_LANGUAGE_LEN);
+	CHECKSTR(hwver, "hardware version", 2);
+
+	if (num_regions == 0) {
+		ERR("no region code specified");
+		return -1;
+	}
+
+	return 0;
+
+#undef CHECKSTR
+}
+
+static int process_region(char *reg)
+{
+	int i;
+
+	if (strlen(reg) != 2) {
+		ERR("invalid region code '%s'", reg);
+		return -1;
+	}
+
+	if (strcmp(reg, "M_") == 0) {
+		region_code = reg;
+		region_mask |= ~0;
+		num_regions = 32;
+		return 0;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(region_table); i++)
+		if (strcmp(reg, region_table[i]) == 0) {
+			region_code = reg;
+			region_mask |= 1 << i;
+			num_regions++;
+			return 0;
+		}
+
+	ERR("unknown region code '%s'", reg);
+	return -1;
+}
+
+static void fixup_tag(unsigned char *buf, ssize_t buflen, ssize_t datalen)
+{
+	struct buffalo_tag *tag = (struct buffalo_tag *) buf;
+
+	memset(tag, '\0', sizeof(*tag));
+
+	memcpy(tag->brand, brand, strlen(brand));
+	memcpy(tag->product, product, strlen(product));
+	memcpy(tag->platform, platform, strlen(platform));
+	memcpy(tag->ver_major, major, strlen(major));
+	memcpy(tag->ver_minor, minor, strlen(minor));
+	memcpy(tag->language, language, strlen(language));
+
+	if (num_regions > 1) {
+		tag->region_code[0] = 'M';
+		tag->region_code[1] = '_';
+		tag->region_mask = htonl(region_mask);
+	} else {
+		memcpy(tag->region_code, region_code, 2);
+	}
+
+	tag->len = htonl(buflen);
+	tag->data_len = htonl(datalen);
+	tag->base1 = htonl(base1);
+	tag->base2 = htonl(base2);
+	tag->flag = flag;
+
+	if (hwver) {
+		memcpy(tag->hwv, "hwv", 3);
+		memcpy(tag->hwv_val, hwver, strlen(hwver));
+	}
+
+	if (!skipcrc)
+		tag->crc = htonl(buffalo_crc(buf, buflen));
+}
+
+static int tag_file(void)
+{
+	unsigned char *buf;
+	ssize_t fsize;
+	ssize_t buflen;
+	int err;
+	int ret = -1;
+
+	fsize = get_file_size(ifname);
+	if (fsize < 0) {
+		ERR("unable to get size of '%s'", ifname);
+		goto out;
+	}
+
+	buflen = fsize + sizeof(struct buffalo_tag);
+	buf = malloc(buflen);
+	if (!buf) {
+		ERR("no memory for buffer\n");
+		goto out;
+	}
+
+	err = read_file_to_buf(ifname, buf + sizeof(struct buffalo_tag),
+			       fsize);
+	if (err) {
+		ERR("unable to read from file '%s'", ifname);
+		goto free_buf;
+	}
+
+	fixup_tag(buf, buflen, fsize);
+
+	err = write_buf_to_file(ofname, buf, buflen);
+	if (err) {
+		ERR("unable to write to file '%s'", ofname);
+		goto free_buf;
+	}
+
+	ret = 0;
+
+free_buf:
+	free(buf);
+out:
+	return ret;
+}
+
+int main(int argc, char *argv[])
+{
+	int res = EXIT_FAILURE;
+	int err;
+
+	progname = basename(argv[0]);
+
+	while ( 1 ) {
+		int c;
+
+		c = getopt(argc, argv, "a:b:c:d:f:hi:l:m:o:p:r:sv:w:");
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'a':
+			platform = optarg;
+			break;
+		case 'b':
+			brand = optarg;
+			break;
+		case 'c':
+			base1 = strtoul(optarg, NULL, 16);
+			break;
+		case 'd':
+			base2 = strtoul(optarg, NULL, 16);
+			break;
+		case 'f':
+			flag = strtoul(optarg, NULL, 2);
+			break;
+		case 'i':
+			ifname = optarg;
+			break;
+		case 'l':
+			language = optarg;
+			break;
+		case 'm':
+			minor = optarg;
+			break;
+		case 'o':
+			ofname = optarg;
+			break;
+		case 'p':
+			product = optarg;
+			break;
+		case 'r':
+			err = process_region(optarg);
+			if (err)
+				goto out;
+			break;
+		case 's':
+			skipcrc = 1;
+			break;
+		case 'v':
+			major = optarg;
+			break;
+		case 'w':
+			hwver = optarg;
+			break;
+		case 'h':
+			usage(EXIT_SUCCESS);
+			break;
+		default:
+			usage(EXIT_FAILURE);
+			break;
+		}
+	}
+
+	err = check_params();
+	if (err)
+		goto out;
+
+	err = tag_file();
+	if (err)
+		goto out;
+
+	res = EXIT_SUCCESS;
+
+out:
+	return res;
+}