parsembdb.m

//
//  iPhoneTracking
//
//  Created by Pete Warden on 4/15/11.
//

#import <Cocoa/Cocoa.h>

#import "parsembdb.h"

static NSNumber* getint(uint8_t* data, size_t* offset, size_t intsize);
static NSString* getstring(uint8_t* data, size_t* offset);
static NSDictionary* process_mbdb_file(NSString* filename);
static NSDictionary* process_mbdx_file(NSString* filename);

@implementation ParseMBDB

+ (NSDictionary*) getFileListForPath:(NSString*)path
{
  NSDictionary* mbdb = process_mbdb_file([path stringByAppendingPathComponent:@"Manifest.mbdb"]);
  NSDictionary* mbdx = process_mbdx_file([path stringByAppendingPathComponent:@"Manifest.mbdx"]);

  if ((mbdb==nil)||(mbdx==nil)) {
    return nil;
  }

  for (NSNumber* offset in mbdb) {
    NSMutableDictionary* fileinfo = [mbdb objectForKey:offset];
    NSString* fileID = [mbdx objectForKey:offset];
    if (fileID==nil) {
      fileID = @"<nofileID>";
    }
    [fileinfo setObject: fileID forKey:@"fileID"];
  }
  
  return mbdb;
}

@end

// Adapted from Python at
// http://stackoverflow.com/questions/3085153/how-to-parse-the-manifest-mbdb-file-in-an-ios-4-0-itunes-backup

NSNumber* getint(uint8_t* data, size_t* offset, size_t intsize){
  // Retrieve an integer (big-endian) and new offset from the current offset
  int value = 0;
  while (intsize > 0) {
    value = (value<<8) + data[*offset];
    *offset = *offset + 1;
    intsize = intsize - 1;
  }
  
  return [NSNumber numberWithInteger: value];
}

NSString* getstring(uint8_t* data, size_t* offset) {
  // Retrieve a string and new offset from the current offset into the data
  if ((data[*offset]==0xFF) && (data[*offset+1]==0xFF)) {
    // Blank string
    char* value = malloc(2);
    strcpy(value, "");
    *offset += 2;
    NSString* result = [[NSString alloc] initWithUTF8String:value];
//    NSLog(@"result=<blank>", result);
    return result;
  }

  int length = [getint(data, offset, 2) integerValue];
  size_t start = *offset;
  char* value = malloc(length+1);
  strncpy(value, (data+start), length);
  value[length] = 0;
  
  *offset += length;
  
  NSString* result = [[NSString alloc] initWithUTF8String:value];
  if (result==nil) {
    result = @"<null>";
  }
//  NSLog(@"result=%@", result);
  return result;
}

NSDictionary* process_mbdb_file(NSString* filename) {
  NSMutableDictionary* mbdb = [NSMutableDictionary dictionary]; // Map offset of info in this file => file info
  NSData* fileData = [NSData dataWithContentsOfFile: filename];
  size_t dataLength = [fileData length];
  uint8_t* data = (uint8_t*)[fileData bytes];

  if (data==NULL) {
    NSLog(@"No MBDB file found at '%@'", filename);
    return nil;
  }

  if ((data[0]!='m')||
    (data[1]!='b')||
    (data[2]!='d')||
    (data[3]!='b')) {
    fprintf(stderr, "Bad header found for mbdb file");
    return mbdb;
  }
  size_t offset = 4;
  offset = offset + 2; // value x05 x00, not sure what this is
  while (offset < dataLength) {
    NSMutableDictionary* fileinfo = [NSMutableDictionary dictionary];
    [fileinfo setObject: [NSNumber numberWithInteger: offset] forKey:@"start_offset"];
    [fileinfo setObject:getstring(data, &offset) forKey:@"domain"]; 
    [fileinfo setObject:getstring(data, &offset) forKey:@"filename"];
    [fileinfo setObject:getstring(data, &offset) forKey:@"linktarget"];
    [fileinfo setObject:getstring(data, &offset) forKey:@"datahash"];
    [fileinfo setObject:getstring(data, &offset) forKey:@"unknown1"]; 
    [fileinfo setObject:getint(data, &offset, 2) forKey:@"mode"];
    [fileinfo setObject:getint(data, &offset, 4) forKey:@"unknown2"];
    [fileinfo setObject:getint(data, &offset, 4) forKey:@"unknown3"];
    [fileinfo setObject:getint(data, &offset, 4) forKey:@"userid"];
    [fileinfo setObject:getint(data, &offset, 4) forKey:@"groupid"];
    [fileinfo setObject:getint(data, &offset, 4) forKey:@"mtime"];
    [fileinfo setObject:getint(data, &offset, 4) forKey:@"atime"];
    [fileinfo setObject:getint(data, &offset, 4) forKey:@"ctime"];
    [fileinfo setObject:getint(data, &offset, 8) forKey:@"filelen"];
    [fileinfo setObject:getint(data, &offset, 1) forKey:@"flag"];
    [fileinfo setObject:getint(data, &offset, 1) forKey:@"numprops"];

    NSMutableDictionary* properties = [NSMutableDictionary dictionary];
    const int numProps = [[fileinfo objectForKey:@"numprops"] integerValue];
    for (int ii=0; ii<numProps; ii++) {
      NSString* propname = getstring(data, &offset);
      NSString* propval = getstring(data, &offset);
      [properties setObject: propval forKey:propname];
    }
    [fileinfo setObject:properties forKey:@"properties"];

    [mbdb setObject: fileinfo forKey:[fileinfo objectForKey:@"start_offset"]];
  }
  
  return mbdb;
}

NSDictionary* process_mbdx_file(NSString* filename) {

  NSMutableDictionary* mbdx = [NSMutableDictionary dictionary]; // Map offset of info in the MBDB file => fileID string
  NSData* fileData = [NSData dataWithContentsOfFile: filename];
  size_t dataLength = [fileData length];
  uint8_t* data = (uint8_t*)[fileData bytes];

  if (data==NULL) {
    NSLog(@"No MBDX file found at '%@'", filename);
    return nil;
  }

  if ((data[0]!='m')||
    (data[1]!='b')||
    (data[2]!='d')||
    (data[3]!='x')) {
    fprintf(stderr, "Bad header found for mbdx file");
    return mbdx;
  }
  size_t offset = 4;
  offset = offset + 2; // value 0x02 0x00, not sure what this is

  char* hexArray = "0123456789abcdef";
  
  NSNumber* filecount = getint(data, &offset, 4); // 4-byte count of records 
  while (offset < dataLength) {
    // 26 byte record, made up of ...
    char* fileID_string = malloc(41);
    for (int i=0; i<20; i+=1) {
      uint8_t v = data[offset+i];
      uint8_t l = (v&0x0f);
      uint8_t h = (v&0xf0)>>4;
      fileID_string[(i*2)+0] = hexArray[h];
      fileID_string[(i*2)+1] = hexArray[l];
    }
    fileID_string[40] = 0;
    
    NSString* fileID_nsString = [[NSString alloc] initWithUTF8String:fileID_string];
    
    offset = offset + 20;
    NSNumber* mbdb_offset = getint(data, &offset, 4); // 4-byte offset field
    mbdb_offset = [NSNumber numberWithInteger: ([mbdb_offset integerValue] + 6)]; // Add 6 to get past prolog
    NSNumber* mode = getint(data, &offset, 2); // 2-byte mode field
    [mbdx setObject:fileID_nsString forKey: mbdb_offset];
  }
  
  return mbdx;
}