Add support for 'ftab' file format

3 files changed, 266 insertions, 1 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 1e141d1..a27f961 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -23,7 +23,7 @@ AM_LDADD = $(AC_LDADD)
 
 bin_PROGRAMS = idevicerestore
 
-idevicerestore_SOURCES = idevicerestore.c common.c tss.c fls.c mbn.c img3.c img4.c ipsw.c normal.c dfu.c recovery.c restore.c asr.c fdr.c limera1n.c download.c locking.c socket.c thread.c jsmn.c json_plist.c
+idevicerestore_SOURCES = idevicerestore.c common.c tss.c fls.c mbn.c img3.c img4.c ftab.c ipsw.c normal.c dfu.c recovery.c restore.c asr.c fdr.c limera1n.c download.c locking.c socket.c thread.c jsmn.c json_plist.c
 idevicerestore_CFLAGS = $(AM_CFLAGS)
 idevicerestore_LDFLAGS = $(AM_LDFLAGS)
 idevicerestore_LDADD = $(AM_LDADD)
diff --git a/src/ftab.c b/src/ftab.c
new file mode 100644
index 0000000..28ea40f
--- /dev/null
+++ b/src/ftab.c
@@ -0,0 +1,196 @@
+/*
+ * ftab.c
+ * Functions for handling the ftab format
+ *
+ * Copyright (c) 2019 Nikias Bassen. All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "ftab.h"
+#include "common.h"
+#include "endianness.h"
+
+int ftab_parse(unsigned char *data, unsigned int data_size, ftab_t *ftab, uint32_t *tag)
+{
+	if (!data || !data_size || !ftab) {
+		return -1;
+	}
+
+	if (data_size < sizeof(struct ftab_header)) {
+		error("ERROR: %s: Buffer too small for ftab data\n", __func__);
+		return -1;
+	}
+
+	struct ftab_header *hdr_ptr = (struct ftab_header*)data;
+	if (be32toh(hdr_ptr->magic) != 'ftab') {
+		error("ERROR: %s: Unexpected magic value 0x%08x\n", le32toh(hdr_ptr->magic));
+		return -1;
+	}
+
+	/* copy header */
+	ftab_t ftab_new = (ftab_t)calloc(1, sizeof(struct ftab_fmt));
+	memcpy(&ftab_new->header, data, sizeof(struct ftab_header));
+
+	ftab_new->header.always_01 = le32toh(ftab_new->header.always_01);
+	ftab_new->header.always_ff = le32toh(ftab_new->header.always_ff);
+	ftab_new->header.tag = be32toh(ftab_new->header.tag);
+	if (tag) {
+		*tag = ftab_new->header.tag;
+	}
+	ftab_new->header.magic = be32toh(ftab_new->header.magic);
+	ftab_new->header.num_entries = le32toh(ftab_new->header.num_entries);
+
+	/* copy entries */
+	ftab_new->entries = (struct ftab_entry*)malloc(sizeof(struct ftab_entry) * ftab_new->header.num_entries);
+	memcpy(ftab_new->entries, data + sizeof(struct ftab_header), sizeof(struct ftab_entry) * ftab_new->header.num_entries);
+
+	/* create data storage */
+	ftab_new->storage = (unsigned char**)calloc(ftab_new->header.num_entries, sizeof(unsigned char*));
+
+	/* fill data storage */
+	uint32_t i = 0;
+	for (i = 0; i < ftab_new->header.num_entries; i++) {
+		ftab_new->entries[i].tag = be32toh(ftab_new->entries[i].tag);
+		ftab_new->entries[i].offset = le32toh(ftab_new->entries[i].offset);
+		ftab_new->entries[i].size = le32toh(ftab_new->entries[i].size);
+
+		ftab_new->storage[i] = malloc(ftab_new->entries[i].size);
+		memcpy(ftab_new->storage[i], data + ftab_new->entries[i].offset, ftab_new->entries[i].size);
+	}
+
+	*ftab = ftab_new;	
+
+	return 0;
+}
+
+int ftab_get_entry_ptr(ftab_t ftab, uint32_t tag, unsigned char **data, unsigned int *data_size)
+{
+	if (!ftab || !tag || !data || !data_size) {
+		return -1;
+	}
+
+	uint32_t i;
+	int res = -1;
+	for (i = 0; i < ftab->header.num_entries; i++) {
+		if (ftab->entries[i].tag == tag) {
+			*data = ftab->storage[i];
+			*data_size = ftab->entries[i].size;
+			res = 0;
+		}
+	}
+	return res;
+}
+
+int ftab_add_entry(ftab_t ftab, uint32_t tag, unsigned char *data, unsigned int data_size)
+{
+	if (!ftab || !tag || !data || !data_size) {
+		return -1;
+	}
+
+	uint32_t new_index = ftab->header.num_entries;
+	struct ftab_entry *new_entries = realloc(ftab->entries, sizeof(struct ftab_entry) * (ftab->header.num_entries + 1));
+	if (!new_entries) {
+		error("ERROR: %s: realloc failed!\n", __func__);
+		return -1;
+	}
+	ftab->entries = new_entries;
+	unsigned char **new_storage = realloc(ftab->storage, sizeof(unsigned char*) * (ftab->header.num_entries + 1));
+	if (!new_storage) {
+		error("ERROR: %s: realloc failed!\n", __func__);
+		return -1;
+	}
+	ftab->storage = new_storage;
+
+	unsigned char *data_copy = (unsigned char*)malloc(data_size);
+	if (!data_copy) {
+		return -1;
+	}
+	memcpy(data_copy, data, data_size);
+
+	ftab->storage[new_index] = data_copy;
+	ftab->entries[new_index].tag = tag;
+	ftab->entries[new_index].size = data_size;
+	ftab->header.num_entries++;
+
+	uint32_t off = sizeof(struct ftab_header) + sizeof(struct ftab_entry) * ftab->header.num_entries;
+	uint32_t i;
+	for (i = 0; i < ftab->header.num_entries; i++) {
+		ftab->entries[i].offset = off;
+		off += ftab->entries[i].size;
+	}
+
+	return 0;
+}
+
+int ftab_write(ftab_t ftab, unsigned char **data, unsigned int *data_size)
+{
+	uint32_t i;
+	unsigned int total_size = sizeof(struct ftab_header);
+	total_size += ftab->header.num_entries * sizeof(struct ftab_entry);
+	for (i = 0; i < ftab->header.num_entries; i++) {
+		total_size += ftab->entries[i].size;
+	}
+
+	unsigned char *data_out = (unsigned char*)malloc(total_size);
+	if (!data_out) {
+		error("ERROR: %s: Out of memory?!\n", __func__);
+		return -1;
+	}
+
+	struct ftab_header *ftab_header = (struct ftab_header*)data_out;
+	memset(ftab_header, '\0', sizeof(struct ftab_header));
+	ftab_header->always_01 = htole32(ftab->header.always_01);
+	ftab_header->always_ff = htole32(ftab->header.always_ff);
+	ftab_header->tag = htobe32(ftab->header.tag);
+	ftab_header->magic = htobe32(ftab->header.magic);
+	ftab_header->num_entries = htole32(ftab->header.num_entries);
+
+	for (i = 0; i < ftab->header.num_entries; i++) {
+		struct ftab_entry* entry = (struct ftab_entry*)(data_out + sizeof(struct ftab_header) + (sizeof(struct ftab_entry) * i));
+		entry->tag = htobe32(ftab->entries[i].tag);
+		entry->offset = htole32(ftab->entries[i].offset);
+		entry->size = htole32(ftab->entries[i].size);
+		entry->pad_0x0C = 0;
+	}
+
+	unsigned char *p = data_out + sizeof(struct ftab_header) + (sizeof(struct ftab_entry) * ftab->header.num_entries);
+	for (i = 0; i < ftab->header.num_entries; i++) {
+		memcpy(p, ftab->storage[i], ftab->entries[i].size);
+		p += ftab->entries[i].size;
+	}
+
+	*data = data_out;
+	*data_size = total_size;
+
+	return 0;
+}
+
+int ftab_free(ftab_t ftab)
+{
+	if (!ftab) return -1;
+	uint32_t i = 0;
+	for (i = 0; i < ftab->header.num_entries; i++) {
+		free(ftab->storage[i]);
+	}
+	free(ftab->storage);
+	free(ftab->entries);
+	free(ftab);
+	return 0;
+}
diff --git a/src/ftab.h b/src/ftab.h
new file mode 100644
index 0000000..2efdac3
--- /dev/null
+++ b/src/ftab.h
@@ -0,0 +1,69 @@
+/*
+ * ftab.h
+ * Functions for handling the ftab format
+ *
+ * Copyright (c) 2019 Nikias Bassen. All Rights Reserved.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef IDEVICERESTORE_FTAB_H
+#define IDEVICERESTORE_FTAB_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct ftab_header {
+	uint32_t always_01; // 1
+	uint32_t always_ff; // 0xFFFFFFFF
+	uint32_t unk_0x08;  // 0
+	uint32_t unk_0x0C;  // 0
+	uint32_t unk_0x10;  // 0
+	uint32_t unk_0x14;  // 0
+	uint32_t unk_0x18;  // 0
+	uint32_t unk_0x1C;  // 0
+	uint32_t tag;       // e.g. 'rkos'
+	uint32_t magic;     // 'ftab' magic
+	uint32_t num_entries;
+	uint32_t pad_0x2C;
+};
+
+struct ftab_entry {
+	uint32_t tag;
+	uint32_t offset;
+	uint32_t size;
+	uint32_t pad_0x0C;
+};
+
+struct ftab_fmt {
+	struct ftab_header header;
+	struct ftab_entry *entries;
+	unsigned char **storage;
+};
+
+typedef struct ftab_fmt *ftab_t;
+
+int ftab_parse(unsigned char *data, unsigned int data_size, ftab_t *ftab, uint32_t *tag);
+int ftab_get_entry_ptr(ftab_t ftab, uint32_t tag, unsigned char **data, unsigned int *data_size);
+int ftab_add_entry(ftab_t ftab, uint32_t tag, unsigned char *data, unsigned int data_size);
+int ftab_write(ftab_t ftab, unsigned char **data, unsigned int *data_size);
+int ftab_free(ftab_t ftab);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif