Class: ApkResources

Inherits:
Object
  • Object
show all
Defined in:
lib/apktools/apkresources.rb

Overview

Class to parse an APK’s resources.arsc data and retrieve resource data associated with a given R.id value

Defined Under Namespace

Classes: ChunkHeader, Package, PackageHeader, ResType, ResTypeConfig, ResTypeEntry, ResTypeSpec, StringPool

Constant Summary collapse

DEBUG =

:nodoc:

false

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(apk_file) ⇒ ApkResources

Create a new ApkResources instance from the specified apk_file

This opens and parses the contents of the APK’s resources.arsc file.



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# File 'lib/apktools/apkresources.rb', line 134

def initialize(apk_file)
  data = nil
  Zip.warn_invalid_date = false

  # Get resources.arsc from the APK file
  Zip::File.foreach(apk_file) do |f|
    if f.name.match(/resources.arsc/)
      data = f.get_input_stream.read.force_encoding('BINARY')
    end
  end

  # Parse the Table Chunk
  ## Header
  header_type = read_short(data, HEADER_START)
  header_size = read_short(data, HEADER_START+2)
  header_chunk_size = read_word(data, HEADER_START+4)
  header_package_count = read_word(data, HEADER_START+8)
  puts "Resource Package Count = #{header_package_count}" if DEBUG

  # Parse the StringPool Chunk
  ## Header
  startoffset_pool = HEADER_START + header_size
  puts "Parse Main StringPool Chunk" if DEBUG
  @stringpool_main = parse_stringpool(data, startoffset_pool)
  puts "#{@stringpool_main.values.length} strings found" if DEBUG

  # Parse the Package Chunk
  ## Header
  startoffset_package = startoffset_pool + @stringpool_main.header.chunk_size
  @packages = Hash.new()
  i = 0
  while i < header_package_count
    package_element = parse_package(data, startoffset_package)
    puts "Package #{package_element.package_header.id}" if DEBUG
    startoffset_package = startoffset_package + package_element.package_header.header.chunk_size
    @packages[package_element.package_header.id] = package_element

    i += 1
  end

end

Instance Attribute Details

#package_header ⇒ Object (readonly)

PackageHeader containing information about all the type and key strings in the package



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# File 'lib/apktools/apkresources.rb', line 124

def package_header
  @package_header
end

#packages ⇒ Object (readonly)

Hash of Package chunks, keyed by package id



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# File 'lib/apktools/apkresources.rb', line 128

def packages
  @packages
end

#stringpool_main ⇒ Object (readonly)

StringPool containing all value strings in the package



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# File 'lib/apktools/apkresources.rb', line 126

def stringpool_main
  @stringpool_main
end

Instance Method Details

#get_all_keys ⇒ Object

Return hash of all the key values in the file keyed by package id



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# File 'lib/apktools/apkresources.rb', line 200

def get_all_keys
  keys = Hash.new()
  @packages.each do |key, value|
    keys[key] = value.stringpool_keystrings.values
  end

  return keys
end

#get_all_strings ⇒ Object

Return array of all string values in the file



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# File 'lib/apktools/apkresources.rb', line 179

def get_all_strings
  return @stringpool_main.values
end

#get_all_types ⇒ Object

Return hash of all the type values in the file keyed by package id



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# File 'lib/apktools/apkresources.rb', line 187

def get_all_types
  types = Hash.new()
  @packages.each do |key, value|
    types[key] = value.stringpool_typestrings.values
  end

  return types
end

#get_default_resource_value(res_id) ⇒ Object

Obtain the default value for a given resource id

res_id: ID values of a resources as a FixNum or String representation (i.e. 0x7F060001)

Returns: The default ResTypeEntry to the given id, or nil if no default exists



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# File 'lib/apktools/apkresources.rb', line 262

def get_default_resource_value(res_id)
  if res_id.is_a? String
    res_id = res_id.hex
  end

  entries = get_resource_value(res_id)
  if entries != nil
    default = ResTypeConfig.new(0, 0, 0, 0, 0, 0, 0, 0)
    default_entry = entries[default]
    return default_entry
  else
    return nil
  end
end

#get_resource_key(res_id, xml_format = false) ⇒ Object

Obtain the key value for a given resource id

res_id: ID value of a resource as a FixNum or String representation (i.e. 0x7F060001) xml_format: Optionally format return string for XML files.

If xml_format is true, return value will be @<type>/<key> If xml_format is false or missing, return value will be R.<type>.<key> If the resource id does not exist, return value will be nil



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# File 'lib/apktools/apkresources.rb', line 219

def get_resource_key(res_id, xml_format=false)
  if res_id.is_a? String
    res_id = res_id.hex
  end

  # R.id integers are a concatenation of package_id, type_id, and entry index
  res_package = (res_id >> 24) & 0xFF
  res_type = (res_id >> 16) & 0xFF
  res_index = res_id & 0xFFFF

  package_element = @packages[res_package]
  if package_element == nil
    # This is not a resource we can parse
    return nil
  end

  res_spec = package_element.type_data[res_type-1]
  if res_spec == nil
    puts "Could not find ResTypeSpec for #{res_package} #{res_type}" if DEBUG
    return nil
  end

  entry = res_spec.types.entries[res_index]
  if entry == nil
    # There is no entry in our table for this resource
    puts "Could not find #{res_spec.types.id} ResType chunk" if DEBUG
    return nil
  end

  if xml_format
    return "@#{res_spec.id}/#{entry.values[0].key}"
  else
    return "R.#{res_spec.id}.#{entry.values[0].key}"
  end
end

#get_resource_value(res_id) ⇒ Object

Obtain the value(s) for a given resource id. A default resource is one defined in an unqualified directory.

res_id: ID value of a resource as a FixNum or String representation (i.e. 0x7F060001)

Returns: Hash of all entries matching this id, keyed by their matching ResTypeConfig or nil if the resource id cannot be found.



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# File 'lib/apktools/apkresources.rb', line 286

def get_resource_value(res_id)
  if res_id.is_a? String
    res_id = res_id.hex
  end

  # R.id integers are a concatenation of package_id, type_id, and entry index
  res_package = (res_id >> 24) & 0xFF
  res_type = (res_id >> 16) & 0xFF
  res_index = res_id & 0xFFFF

  package_element = @packages[res_package]
  if package_element == nil
    # This is not a resource we can parse
    return nil
  end

  res_spec = package_element.type_data[res_type-1]
  if res_spec == nil
    puts "Could not find ResTypeSpec for #{res_package} #{res_type}" if DEBUG
    return nil
  end

  entries = res_spec.types.entries[res_index]
  if entries == nil
    puts "Could not find #{res_spec.types.id} ResType chunk" if DEBUG
    return nil
  end

  return entries
end