Class: CFPropertyList::Binary

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

Overview

Binary PList parser class

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.ascii_string?(str) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rbBinaryCFPropertyList.rb', line 431

def Binary.ascii_string?(str)
  if str.respond_to?(:ascii_only?)
    str.ascii_only?
  else
    str !~ /[\x80-\xFF]/mn
  end
end

.bytes_needed(count) ⇒ Object

calculate how many bytes are needed to save count



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# File 'lib/rbBinaryCFPropertyList.rb', line 377

def Binary.bytes_needed(count)
  case
  when count < 2**8  then 1
  when count < 2**16 then 2
  when count < 2**32 then 4
  when count < 2**64 then 8
  else
    raise CFFormatError.new("Data size too large: #{count}")
  end
end

.charset_convert(str, from, to = "UTF-8") ⇒ Object

Convert the given string from one charset to another



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# File 'lib/rbBinaryCFPropertyList.rb', line 219

def Binary.charset_convert(str,from,to="UTF-8")
  return str.dup.force_encoding(from).encode(to) if str.respond_to?("encode")
  Iconv.conv(to,from,str)
end

.charset_strlen(str, charset = "UTF-8") ⇒ Object

Count characters considering character set



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# File 'lib/rbBinaryCFPropertyList.rb', line 225

def Binary.charset_strlen(str,charset="UTF-8")
  if str.respond_to?(:encode)
    size = str.length
  else
    utf8_str = Iconv.conv("UTF-8",charset,str)
    size = utf8_str.scan(/./mu).size
  end

  # UTF-16 code units in the range D800-DBFF are the beginning of
  # a surrogate pair, and count as one additional character for
  # length calculation.
  if charset =~ /^UTF-16/
    if str.respond_to?(:encode)
      str.bytes.to_a.each_slice(2) { |pair| size += 1 if (0xd8..0xdb).include?(pair[0]) }
    else
      str.split('').each_slice(2) { |pair| size += 1 if ("\xd8".."\xdb").include?(pair[0]) }
    end
  end

  size
end

.pack_int_array_with_size(nbytes, array) ⇒ Object 



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# File 'lib/rbBinaryCFPropertyList.rb', line 364

def Binary.pack_int_array_with_size(nbytes, array)
  case nbytes
  when 1 then array.pack('C*')
  when 2 then array.pack('n*')
  when 4 then array.pack('N*')
  when 8
    array.map { |int| [int >> 32, int & 0xFFFFFFFF].pack('NN') }.join
  else
    raise CFFormatError.new("Don't know how to pack #{nbytes} byte integer")
  end
end

.pack_it_with_size(nbytes, int) ⇒ Object

pack an int of nbytes with size



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# File 'lib/rbBinaryCFPropertyList.rb', line 352

def Binary.pack_it_with_size(nbytes,int)
  case nbytes
  when 1 then [int].pack('c')
  when 2 then [int].pack('n')
  when 4 then [int].pack('N')
  when 8
    [int >> 32, int & 0xFFFFFFFF].pack('NN')
  else
    raise CFFormatError.new("Don't know how to pack #{nbytes} byte integer")
  end
end

.type_bytes(type, length) ⇒ Object

Create a type byte for binary format as defined by apple



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# File 'lib/rbBinaryCFPropertyList.rb', line 389

def Binary.type_bytes(type, length)
  if length < 15
    [(type << 4) | length].pack('C')
  else
    bytes = [(type << 4) | 0xF]
    if length <= 0xFF
      bytes.push(0x10, length).pack('CCC')                              # 1 byte length
    elsif length <= 0xFFFF
      bytes.push(0x11, length).pack('CCn')                              # 2 byte length
    elsif length <= 0xFFFFFFFF
      bytes.push(0x12, length).pack('CCN')                              # 4 byte length
    elsif length <= 0x7FFFFFFFFFFFFFFF
      bytes.push(0x13, length >> 32, length & 0xFFFFFFFF).pack('CCNN')  # 8 byte length
    else
      raise CFFormatError.new("Integer too large: #{int}")
    end
  end
end

Instance Method Details

#array_to_binary(val) ⇒ Object

Convert array to binary format and add it to the object table



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# File 'lib/rbBinaryCFPropertyList.rb', line 531

def array_to_binary(val)
  saved_object_count = @written_object_count
  @written_object_count += 1
  #@object_refs += val.value.size

  values = val.value.map { |v| v.to_binary(self) }
  bdata = Binary.type_bytes(0b1010, val.value.size) <<
    Binary.pack_int_array_with_size(object_ref_size(@object_refs),
                                    values)

  @object_table[saved_object_count] = bdata
  saved_object_count
end

#bool_to_binary(val) ⇒ Object

Convert a bool value to binary and add it to the object table



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# File 'lib/rbBinaryCFPropertyList.rb', line 514

def bool_to_binary(val)

  @object_table[@written_object_count] = val ? "\x9" : "\x8" # 0x9 is 1001, type indicator for true; 0x8 is 1000, type indicator for false
  @written_object_count += 1
  @written_object_count - 1
end

#count_object_refs(object) ⇒ Object 



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# File 'lib/rbBinaryCFPropertyList.rb', line 408

def count_object_refs(object)
  case object
  when CFArray
    contained_refs = 0
    object.value.each do |element|
      if CFArray === element || CFDictionary === element
        contained_refs += count_object_refs(element)
      end
    end
    return object.value.size + contained_refs
  when CFDictionary
    contained_refs = 0
    object.value.each_value do |value|
      if CFArray === value || CFDictionary === value
        contained_refs += count_object_refs(value)
      end
    end
    return object.value.keys.size * 2 + contained_refs
  else
    return 0
  end
end

#data_to_binary(val) ⇒ Object

Convert data value to binary format and add it to the object table



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# File 'lib/rbBinaryCFPropertyList.rb', line 522

def data_to_binary(val)
  @object_table[@written_object_count] =
    (Binary.type_bytes(0b0100, val.bytesize) << val)

  @written_object_count += 1
  @written_object_count - 1
end

#date_to_binary(val) ⇒ Object

Convert date value (apple format) to binary and adds it to the object table



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# File 'lib/rbBinaryCFPropertyList.rb', line 503

def date_to_binary(val)
  val = val.getutc.to_f - CFDate::DATE_DIFF_APPLE_UNIX # CFDate is a real, number of seconds since 01/01/2001 00:00:00 GMT

  @object_table[@written_object_count] =
    (Binary.type_bytes(0b0011, 3) << [val].pack("d").reverse)

  @written_object_count += 1
  @written_object_count - 1
end

#dict_to_binary(val) ⇒ Object

Convert dictionary to binary format and add it to the object table



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# File 'lib/rbBinaryCFPropertyList.rb', line 546

def dict_to_binary(val)
  saved_object_count = @written_object_count
  @written_object_count += 1

  #@object_refs += val.value.keys.size * 2

  keys_and_values = val.value.keys.map { |k| CFString.new(k).to_binary(self) }
  keys_and_values.concat(val.value.values.map { |v| v.to_binary(self) })

  bdata = Binary.type_bytes(0b1101,val.value.size) <<
    Binary.pack_int_array_with_size(object_ref_size(@object_refs), keys_and_values)

  @object_table[saved_object_count] = bdata
  return saved_object_count
end

#int_to_binary(value) ⇒ Object

Codes an integer to binary format



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# File 'lib/rbBinaryCFPropertyList.rb', line 461

def int_to_binary(value)
  nbytes = 0
  nbytes = 1  if value > 0xFF # 1 byte integer
  nbytes += 1 if value > 0xFFFF # 4 byte integer
  nbytes += 1 if value > 0xFFFFFFFF # 8 byte integer
  nbytes = 3  if value < 0 # 8 byte integer, since signed

  Binary.type_bytes(0b0001, nbytes) <<
    if nbytes < 3
      [value].pack(
        if nbytes == 0    then "C"
        elsif nbytes == 1 then "n"
        else "N"
        end
      )
    else
      # 64 bit signed integer; we need the higher and the lower 32 bit of the value
      high_word = value >> 32
      low_word = value & 0xFFFFFFFF
      [high_word,low_word].pack("NN")
    end
end

#load(opts) ⇒ Object

Read a binary plist file

Raises:



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# File 'lib/rbBinaryCFPropertyList.rb', line 7

def load(opts)
  @unique_table = {}
  @count_objects = 0
  @object_refs = 0

  @written_object_count = 0
  @object_table = []
  @object_ref_size = 0

  @offsets = []

  fd = nil
  if(opts.has_key?(:file))
    fd = File.open(opts[:file],"rb")
    file = opts[:file]
  else
    fd = StringIO.new(opts[:data],"rb")
    file = "<string>"
  end

  # first, we read the trailer: 32 byte from the end
  fd.seek(-32,IO::SEEK_END)
  buff = fd.read(32)

  offset_size, object_ref_size, number_of_objects, top_object, table_offset = buff.unpack "x6CCx4Nx4Nx4N"

  # after that, get the offset table
  fd.seek(table_offset, IO::SEEK_SET)
  coded_offset_table = fd.read(number_of_objects * offset_size)
  raise CFFormatError.new("#{file}: Format error!") unless coded_offset_table.bytesize == number_of_objects * offset_size

  @count_objects = number_of_objects

  # decode offset table
  if(offset_size != 3)
    formats = ["","C*","n*","","N*"]
    @offsets = coded_offset_table.unpack(formats[offset_size])
  else
    @offsets = coded_offset_table.unpack("C*").each_slice(3).map {
      |x,y,z| (x << 16) | (y << 8) | z
    }
  end

  @object_ref_size = object_ref_size
  val = read_binary_object_at(file,fd,top_object)

  fd.close
  val
end

#num_to_binary(value) ⇒ Object

Converts a numeric value to binary and adds it to the object table



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# File 'lib/rbBinaryCFPropertyList.rb', line 490

def num_to_binary(value)
  @object_table[@written_object_count] =
    if value.is_a?(CFInteger)
      int_to_binary(value.value)
    else
      real_to_binary(value.value)
    end

  @written_object_count += 1
  @written_object_count - 1
end

#object_ref_size(object_refs) ⇒ Object 



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# File 'lib/rbBinaryCFPropertyList.rb', line 105

def object_ref_size object_refs
  Binary.bytes_needed(object_refs)
end

#read_fd(fd, length) ⇒ Object 



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# File 'lib/rbBinaryCFPropertyList.rb', line 206

def read_fd fd, length
  length > 0 ? fd.read(length) : ""
end

#real_to_binary(val) ⇒ Object

Codes a real value to binary format



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# File 'lib/rbBinaryCFPropertyList.rb', line 485

def real_to_binary(val)
  Binary.type_bytes(0b0010,3) << [val].pack("d").reverse
end

#string_to_binary(val) ⇒ Object

Uniques and transforms a string value to binary format and adds it to the object table



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# File 'lib/rbBinaryCFPropertyList.rb', line 440

def string_to_binary(val)
  val = val.to_s

  @unique_table[val] ||= begin
    if !Binary.ascii_string?(val)
      val = Binary.charset_convert(val,"UTF-8","UTF-16BE")
      bdata = Binary.type_bytes(0b0110, Binary.charset_strlen(val,"UTF-16BE"))

      val.force_encoding("ASCII-8BIT") if val.respond_to?("encode")
      @object_table[@written_object_count] = bdata << val
    else
      bdata = Binary.type_bytes(0b0101,val.bytesize)
      @object_table[@written_object_count] = bdata << val
    end

    @written_object_count += 1
    @written_object_count - 1
  end
end

#to_str(opts = {}) ⇒ Object

Convert CFPropertyList to binary format; since we have to count our objects we simply unique CFDictionary and CFArray



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# File 'lib/rbBinaryCFPropertyList.rb', line 59

def to_str(opts={})
  @unique_table = {}
  @count_objects = 0
  @object_refs = 0

  @written_object_count = 0
  @object_table = []

  @offsets = []

  binary_str = "bplist00"

  @object_refs = count_object_refs(opts[:root])

  opts[:root].to_binary(self)

  next_offset = 8
  offsets = @object_table.map do |object|
    offset = next_offset
    next_offset += object.bytesize
    offset
  end
  binary_str << @object_table.join

  table_offset = next_offset
  offset_size = Binary.bytes_needed(table_offset)

  if offset_size < 8
    # Fast path: encode the entire offset array at once.
    binary_str << offsets.pack((%w(C n N N)[offset_size - 1]) + '*')
  else
    # Slow path: host may be little or big endian, must pack each offset
    # separately.
    offsets.each do |offset|
      binary_str << "#{Binary.pack_it_with_size(offset_size,offset)}"
    end
  end

  binary_str << [offset_size, object_ref_size(@object_refs)].pack("x6CC")
  binary_str << [@object_table.size].pack("x4N")
  binary_str << [0].pack("x4N")
  binary_str << [table_offset].pack("x4N")

  binary_str
end