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/*
* img3.c
* Functions for handling with Apple's IMG3 format
*
* Copyright (c) 2010 Joshua Hill. 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 "img3.h"
#include "common.h"
#include "idevicerestore.h"
img3_file* img3_parse_file(char* data, int size) {
int data_offset = 0;
img3_header* header = (img3_header*) data;
if (header->signature != kImg3Container) {
error("ERROR: Invalid IMG3 file\n");
return NULL;
}
img3_file* image = (img3_file*) malloc(sizeof(img3_file));
if (image == NULL) {
error("ERROR: Unable to allocate memory for IMG3 file\n");
return NULL;
}
memset(image, '\0', sizeof(img3_file));
image->header = (img3_header*) malloc(sizeof(img3_header));
if (image->header == NULL) {
error("ERROR: Unable to allocate memory for IMG3 header\n");
img3_free(image);
return NULL;
}
memcpy(image->header, data, sizeof(img3_header));
data_offset += sizeof(img3_header);
img3_element_header* current = NULL;
while (data_offset < size) {
current = (img3_element_header*) &data[data_offset];
switch (current->signature) {
case kTypeElement:
image->type_element = img3_parse_element(&data[data_offset]);
if (image->type_element == NULL) {
error("ERROR: Unable to parse TYPE element\n");
img3_free(image);
return NULL;
}
debug("Parsed TYPE element\n");
break;
case kDataElement:
image->data_element = img3_parse_element(&data[data_offset]);
if (image->data_element == NULL) {
error("ERROR: Unable to parse DATA element\n");
img3_free(image);
return NULL;
}
debug("Parsed DATA element\n");
break;
case kVersElement:
image->vers_element = img3_parse_element(&data[data_offset]);
if (image->vers_element == NULL) {
error("ERROR: Unable to parse VERS element\n");
img3_free(image);
return NULL;
}
debug("Parsed VERS element\n");
break;
case kSepoElement:
image->sepo_element = img3_parse_element(&data[data_offset]);
if (image->sepo_element == NULL) {
error("ERROR: Unable to parse SEPO element\n");
img3_free(image);
return NULL;
}
debug("Parsed SEPO element\n");
break;
case kBordElement:
image->bord_element = img3_parse_element(&data[data_offset]);
if (image->bord_element == NULL) {
error("ERROR: Unable to parse BORD element\n");
img3_free(image);
return NULL;
}
debug("Parsed BORD element\n");
break;
case kKbagElement:
if (image->kbag1_element == NULL) {
image->kbag1_element = img3_parse_element(&data[data_offset]);
if (image->kbag1_element == NULL) {
error("ERROR: Unable to parse first KBAG element\n");
img3_free(image);
return NULL;
}
} else {
image->kbag2_element = img3_parse_element(&data[data_offset]);
if (image->kbag2_element == NULL) {
error("ERROR: Unable to parse second KBAG element\n");
img3_free(image);
return NULL;
}
}
debug("Parsed KBAG element\n");
break;
case kEcidElement:
image->ecid_element = img3_parse_element(&data[data_offset]);
if (image->ecid_element == NULL) {
error("ERROR: Unable to parse ECID element\n");
img3_free(image);
return NULL;
}
debug("Parsed ECID element\n");
break;
case kShshElement:
image->shsh_element = img3_parse_element(&data[data_offset]);
if (image->shsh_element == NULL) {
error("ERROR: Unable to parse SHSH element\n");
img3_free(image);
return NULL;
}
debug("Parsed SHSH element\n");
break;
case kCertElement:
image->cert_element = img3_parse_element(&data[data_offset]);
if (image->cert_element == NULL) {
error("ERROR: Unable to parse CERT element\n");
img3_free(image);
return NULL;
}
debug("Parsed CERT element\n");
break;
default:
error("ERROR: Unknown IMG3 element type\n");
img3_free(image);
return NULL;
}
data_offset += current->full_size;
}
return image;
}
img3_element* img3_parse_element(char* data) {
img3_element_header* element_header = (img3_element_header*) data;
img3_element* element = (img3_element*) malloc(sizeof(img3_element));
if (element == NULL) {
error("ERROR: Unable to allocate memory for IMG3 element\n");
return NULL;
}
memset(element, '\0', sizeof(img3_element));
element->data = (char*) malloc(element_header->full_size);
if (element->data == NULL) {
error("ERROR: Unable to allocate memory for IMG3 element data\n");
free(element);
return NULL;
}
memcpy(element->data, data, element_header->full_size);
element->header = (img3_element_header*) element->data;
element->type = (img3_element_type) element->header->signature;
return element;
}
void img3_free(img3_file* image) {
if (image != NULL) {
if (image->header != NULL) {
free(image->header);
}
if (image->type_element != NULL) {
img3_free_element(image->type_element);
image->type_element = NULL;
}
if (image->data_element != NULL) {
img3_free_element(image->data_element);
image->data_element = NULL;
}
if (image->vers_element != NULL) {
img3_free_element(image->vers_element);
image->vers_element = NULL;
}
if (image->sepo_element != NULL) {
img3_free_element(image->sepo_element);
image->sepo_element = NULL;
}
if (image->bord_element != NULL) {
img3_free_element(image->bord_element);
image->bord_element = NULL;
}
if (image->kbag1_element != NULL) {
img3_free_element(image->kbag1_element);
image->kbag1_element = NULL;
}
if (image->kbag2_element != NULL) {
img3_free_element(image->kbag2_element);
image->kbag2_element = NULL;
}
if (image->ecid_element != NULL) {
img3_free_element(image->ecid_element);
image->ecid_element = NULL;
}
if (image->shsh_element != NULL) {
img3_free_element(image->shsh_element);
image->shsh_element = NULL;
}
if (image->cert_element != NULL) {
img3_free_element(image->cert_element);
image->cert_element = NULL;
}
free(image);
image = NULL;
}
}
void img3_free_element(img3_element* element) {
if (element != NULL) {
if (element->data != NULL) {
free(element->data);
element->data = NULL;
}
free(element);
element = NULL;
}
}
int img3_replace_signature(img3_file* image, char* signature) {
int offset = 0;
img3_element* ecid = img3_parse_element(&signature[offset]);
if (ecid == NULL || ecid->type != kEcidElement) {
error("ERROR: Unable to find ECID element in signature\n");
return -1;
}
offset += ecid->header->full_size;
img3_element* shsh = img3_parse_element(&signature[offset]);
if (shsh == NULL || shsh->type != kShshElement) {
error("ERROR: Unable to find SHSH element in signature\n");
return -1;
}
offset += shsh->header->full_size;
img3_element* cert = img3_parse_element(&signature[offset]);
if (cert == NULL || cert->type != kCertElement) {
error("ERROR: Unable to find CERT element in signature\n");
return -1;
}
offset += cert->header->full_size;
if (image->ecid_element != NULL) {
img3_free_element(image->ecid_element);
}
image->ecid_element = ecid;
if (image->shsh_element != NULL) {
img3_free_element(image->shsh_element);
}
image->shsh_element = shsh;
if (image->cert_element != NULL) {
img3_free_element(image->cert_element);
}
image->cert_element = cert;
return 0;
}
int img3_get_data(img3_file* image, char** pdata, int* psize) {
int offset = 0;
int size = sizeof(img3_header);
// Add up the size of the image first so we can allocate our memory
if (image->type_element != NULL) {
size += image->type_element->header->full_size;
}
if (image->data_element != NULL) {
size += image->data_element->header->full_size;
}
if (image->vers_element != NULL) {
size += image->vers_element->header->full_size;
}
if (image->sepo_element != NULL) {
size += image->sepo_element->header->full_size;
}
if (image->bord_element != NULL) {
size += image->bord_element->header->full_size;
}
if (image->kbag1_element != NULL) {
size += image->kbag1_element->header->full_size;
}
if (image->kbag2_element != NULL) {
size += image->kbag2_element->header->full_size;
}
if (image->ecid_element != NULL) {
size += image->ecid_element->header->full_size;
}
if (image->shsh_element != NULL) {
size += image->shsh_element->header->full_size;
}
if (image->cert_element != NULL) {
size += image->cert_element->header->full_size;
}
char* data = (char*) malloc(size);
if (data == NULL) {
error("ERROR: Unable to allocate memory for IMG3 data\n");
return -1;
}
// Add data to our new header (except shsh_offset)
img3_header* header = (img3_header*) data;
header->full_size = size;
header->signature = image->header->signature;
header->data_size = size - sizeof(img3_header);
header->image_type = image->header->image_type;
offset += sizeof(img3_header);
// Copy each section over to the new buffer
if (image->type_element != NULL) {
memcpy(&data[offset], image->type_element->data, image->type_element->header->full_size);
offset += image->type_element->header->full_size;
}
if (image->data_element != NULL) {
memcpy(&data[offset], image->data_element->data, image->data_element->header->full_size);
offset += image->data_element->header->full_size;
}
if (image->vers_element != NULL) {
memcpy(&data[offset], image->vers_element->data, image->vers_element->header->full_size);
offset += image->vers_element->header->full_size;
}
if (image->sepo_element != NULL) {
memcpy(&data[offset], image->sepo_element->data, image->sepo_element->header->full_size);
offset += image->sepo_element->header->full_size;
}
if (image->bord_element != NULL) {
memcpy(&data[offset], image->bord_element->data, image->bord_element->header->full_size);
offset += image->bord_element->header->full_size;
}
if (image->kbag1_element != NULL) {
memcpy(&data[offset], image->kbag1_element->data, image->kbag1_element->header->full_size);
offset += image->kbag1_element->header->full_size;
}
if (image->kbag2_element != NULL) {
memcpy(&data[offset], image->kbag2_element->data, image->kbag2_element->header->full_size);
offset += image->kbag2_element->header->full_size;
}
if (image->ecid_element != NULL) {
memcpy(&data[offset], image->ecid_element->data, image->ecid_element->header->full_size);
offset += image->ecid_element->header->full_size;
}
if (image->shsh_element != NULL) {
memcpy(&data[offset], image->shsh_element->data, image->shsh_element->header->full_size);
header->shsh_offset = offset - sizeof(img3_header);
offset += image->shsh_element->header->full_size;
}
if (image->cert_element != NULL) {
memcpy(&data[offset], image->cert_element->data, image->cert_element->header->full_size);
offset += image->cert_element->header->full_size;
}
if (offset != size) {
error("ERROR: Incorrectly sized image data\n");
free(data);
*pdata = 0;
*psize = 0;
return -1;
}
*pdata = data;
*psize = size;
return 0;
}
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