Class: MooTool::Models::IMG4::File

Inherits:
Object
  • Object
show all
Includes:
Helpers::IMG4
Defined in:
lib/mootool/models/img4/file.rb

Overview

An IMG4 file, or, occasionally, a file read in from another source

Constant Summary collapse

DER_PAYLOADS = 
%w[trst].freeze

Constants included from Helpers::IMG4

Helpers::IMG4::DECODE_TAGS, Helpers::IMG4::FIRMWARE_TAGS, Helpers::IMG4::HASH_LENGTHS, Helpers::IMG4::KEY_INSTANCE_TAGS, Helpers::IMG4::KVP_TAGS, Helpers::IMG4::OCTET_TAGS, Helpers::IMG4::SEQUENCE_TAGS, Helpers::IMG4::SIGNATURE_TAGS

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Helpers::IMG4

#construct, #construct_object, #decode_construct, parse_4cc

Constructor Details

#initialize(der, filename = nil) ⇒ File

Returns a new instance of File.



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# File 'lib/mootool/models/img4/file.rb', line 59

def initialize(der, filename = nil)
  MooTool::Models::FileIndex.load '/Users/rickmark/Desktop/index.json'
  @filename = filename

  raw_data = der.is_a?(MooTool::Models::Digest) ? der.value : der

  @hashes = [MooTool::Models::Digest.create(::Digest::SHA384.digest(raw_data))]
  @data = OpenSSL::ASN1.decode(raw_data)
  @type = @data.value[0].value
  @content = {}

  case @type
  when 'IM4P'
    @content[:IM4P] = MooTool::Models::IMG4::IMG4Payload.new(@data)
  when 'IM4M'
    @content[:IM4M] = MooTool::Models::IMG4::IMG4Manifest.new(@data)
  when 'IMG4'
    @content[:IM4P] = MooTool::Models::IMG4::IMG4Payload.new(@data.value[1])
    @content[:IM4M] = MooTool::Models::IMG4::IMG4Manifest.new(@data.value[2])
  when 'secb'
    @value = construct(@data)
    @content[:secb] = @value.drop(1).map do |entry|
      case entry[0]
      when 'trst', 'rssl'
        { entry[0].to_sym => File.parse_certificates(entry.drop(1)) }
      when 'rvok'
        { entry[0].to_sym => entry[1] }
      when 'trpk'
        { entry[0].to_sym => entry.drop(1).map { |e| MooTool::Models::ECCPublicKey.new e } }
      end
    end.reduce(&:merge)
  when 'comb'
    @value = construct(@data)
    @content[:comb] = @value.drop(1).map do |entry|
      { entry[0] => File.new(entry[1]) }
    end.reduce(&:merge)
  else
    @content = @value.map(&:to_h).reduce(&:merge)
  end

  # @content[:validity] = validate_signature
end

Instance Attribute Details

#file_index ⇒ Object (readonly)

Returns the value of attribute file_index.



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# File 'lib/mootool/models/img4/file.rb', line 9

def file_index
  @file_index
end

#manifest ⇒ Object (readonly)

Returns the value of attribute manifest.



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# File 'lib/mootool/models/img4/file.rb', line 9

def manifest
  @manifest
end

#payload ⇒ Object (readonly)

Returns the value of attribute payload.



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# File 'lib/mootool/models/img4/file.rb', line 9

def payload
  @payload
end

Class Method Details

.load(path) ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 15

def self.load(path)
  case path
  when FileLocation
    data = ::File.binread(path.fullname)
    new(data, path.fullname)
  when String, Pathname
    data = ::File.binread(path)
    new(data, path)
  end
end

.parse_certificates(certificates) ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 35

def self.parse_certificates(certificates)
  certificates.map do |certificate|
    certificate_data = certificate.value if certificate.is_a?(Models::Digest)
    certificate_data = certificate.to_der if certificate.respond_to?(:to_der)
    Models::Certificate.new OpenSSL::X509::Certificate.new(certificate_data)
  end
end

.parse_signature(signature) ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 26

def self.parse_signature(signature)
  signature = signature.value if signature.is_a?(OpenSSL::ASN1::OctetString)
  if signature.size > 128
    Models::Digest.create(signature, 'RSASignature')
  else
    ::MooTool::Models::ECCSignature.create(signature)
  end
end

Instance Method Details

#basename ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 179

def basename
  basename = ::File.basename(@filename)
  extension = ::File.extname(basename)
  "#{basename.chomp(extension)}.#{@type}"
end

#extract_payload ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 185

def extract_payload
  output_path = ::File.join(::File.dirname(@filename), basename)
  ::File.write(output_path, @payload)
end

#hashes ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 190

def hashes
  result = @hashes.dup

  result += @content[:comb].flat_map { |_k, v| v.hashes } if @content[:comb]

  result += @content[:IM4M].hashes if @content[:IM4M]

  result += @content[:IM4P].hashes if @content[:IM4P]

  result.map { |h| h.respond_to?(:value) ? h.value : h }.uniq.map { |h| Models::Digest.create(h) }
end

#manifest? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mootool/models/img4/file.rb', line 175

def manifest?
  !@content[:IM4M].nil?
end

#manifest_type ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 47

def manifest_type
  @content[:IM4M]&.type&.to_sym
end

#parse_element(element) ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 150

def parse_element(element)
  { element.value[0].value.to_sym => element.value[1].value }
end

#parse_pair(input) ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 154

def parse_pair(input)
  input.value.to_a.each_slice(2).to_h do |key, value|
    [key.value, value]
  end
end

#payload? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mootool/models/img4/file.rb', line 171

def payload?
  !@content[:IM4P].nil?
end

#payload_type ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 43

def payload_type
  @content[:IM4P]&.type&.to_sym
end

#print(friendly) ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 202

def print(friendly)
  output = to_h
  if friendly
    mappings = IMG4.mappings

    output.deep_transform_keys! do |key|
      new_key = mappings.dig(key.to_s, 'title') || mappings.dig(key.to_s, 'description') || key
      new_key.respond_to?(:to_sym) ? new_key.to_sym : new_key
    end
  end

  ap(output)
end

#to_h ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 51

def to_h
  content = @content.transform_values(&:inspect)

  content[:file_type] = @type
  content[:hashes] = hashes
  content
end

#types ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 160

def types
  result = [payload_type]
  result += @content[:comb].keys if @content[:comb]
  result += @content[:secb].keys if @content[:secb]
  result.compact.map(&:to_sym)
end

#validate_signature ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 106

def validate_signature
  leaf_certificate = validted_certificate_chain
  [OpenSSL::Digest.new('SHA384'), OpenSSL::Digest.new('SHA256')].flat_map do |digest|
    values = %i[IM4M IM4P].map do |kind|
      @content[kind]&.to_bytes
    end.compact

    hashes = values.map do |value|
      OpenSSL::Digest::SHA384.digest(value)
    end.compact

    signatures = %i[IM4P IM4M].map do |kind|
      signature = @content[kind]&.signature
      signature.respond_to?(:value) ? signature.value : signature
    end.compact

    signatures.flat_map do |signature|
      value_result = values.map do |value|
        { digest.hexdigest(value) => leaf_certificate.public_key.verify(digest, signature, value) }
      end

      hashes_result = hashes.map do |hash|
        { digest.hexdigest(hash) => leaf_certificate.public_key.verify(digest, signature, hash) }
      end

      hash_hashes_result = hashes.map do |hash|
        { digest.hexdigest(hash) => leaf_certificate.public_key.verify(digest, signature, digest.digest(hash)) }
      end

      join_result = [
        { digest.hexdigest(hashes.join) => leaf_certificate.public_key.verify(digest, signature, hashes.join) }
      ]

      value_result + hashes_result + hash_hashes_result + join_result
    end
  end.reduce(&:merge)
end

#validted_certificate_chain ⇒ Object 



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# File 'lib/mootool/models/img4/file.rb', line 102

def validted_certificate_chain
  @content[:IM4M].certificates.last
end