Class: MetasploitDataModels::Base64Serializer

Inherits:
Object
  • Object
show all
Defined in:
lib/metasploit_data_models/base64_serializer.rb

Overview

Provides ActiveRecord 3.1x-friendly serialization for descendants of ApplicationRecord. Backwards compatible with older YAML methods and will fall back to string decoding in the worst case

Examples:

Using default default of {}

serialize :foo, MetasploitDataModels::Base64Serializer.new

Overriding default to []

serialize :bar, MetasploitDataModels::Base64Serializer.new(:default => [])

Constant Summary collapse

DEFAULT =

The default for #default

{}
COERCE_DEFAULT =

The default for #coerce

false
LOADERS =

Deserializers for #load

  1. Base64 decoding and then unmarshalling the value.
  2. Parsing the value as YAML.
  3. The raw value.
[
    lambda { |serialized|
      marshaled = serialized.unpack('m').first
      # Load the unpacked Marshal object first
      Marshal.load(marshaled)
    },
    lambda { |serialized|
      # Support legacy YAML encoding for existing data
      YAML.safe_load(serialized, permitted_classes: Rails.application.config.active_record.yaml_column_permitted_classes)
    },
    lambda { |serialized|
      # Fall back to string decoding
      serialized
    }
]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(attributes = {}) ⇒ Base64Serializer

Returns a new instance of Base64Serializer.

Parameters:

  • attributes (Hash) (defaults to: {}) —

    attributes

Options Hash (attributes):

  • :default (Object) — default: {} —

    Value to use for #default.



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# File 'lib/metasploit_data_models/base64_serializer.rb', line 88

def initialize(attributes={})
  attributes.assert_valid_keys(:default, :coerce)

  @default = attributes.fetch(:default, DEFAULT)
  @coerce = attributes.fetch(:coerce, COERCE_DEFAULT)
end

Instance Attribute Details

#coerce=(value) ⇒ Object (writeonly)

Sets the attribute coerce

Parameters:

  • value —

    the value to set the attribute coerce to.



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# File 'lib/metasploit_data_models/base64_serializer.rb', line 54

def coerce=(value)
  @coerce = value
end

#default ⇒ Object

Creates a duplicate of default value

Returns:



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# File 'lib/metasploit_data_models/base64_serializer.rb', line 49

def default
  @default.dup
end

Instance Method Details

#coerce_object(value) ⇒ Object

Recursively coerce the object that has been passed in, keeping primitive types as their original type, while changing objects that cannot be serialized into a string representation of the object data.



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# File 'lib/metasploit_data_models/base64_serializer.rb', line 58

def coerce_object(value)
  case value
  when Hash
    value.transform_values { |v| coerce_object(v) }
  when Array
    value.map { |v| coerce_object(v) }
  when File, IO
    value.inspect
  when String, Integer, Float, TrueClass, FalseClass, NilClass, Symbol
    value
  else
    value.to_s
  end
end

#dump(value) ⇒ String

Serializes the value by marshalling the value and then base64 encodes the marshaled value.

Parameters:

  • value (Object) —

    value to serialize

Returns:

  • (String) 


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# File 'lib/metasploit_data_models/base64_serializer.rb', line 77

def dump(value)
  # Always store data back in the Marshal format
  to_serialize = @coerce ? coerce_object(value) : value
  marshalled = Marshal.dump(to_serialize)
  base64_encoded = [ marshalled ].pack('m')

  base64_encoded
end

#load(value) ⇒ Object

Deserializes the value by either

  1. Base64 decoding and then unmarshalling the value.
  2. Parsing the value as YAML.
  3. Returns the raw value.

Parameters:

  • value (String) —

    serialized value

Returns:

  • (Object)

See Also:



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# File 'lib/metasploit_data_models/base64_serializer.rb', line 104

def load(value)
  loaded = nil

  if value.blank?
    loaded = default
  else
    LOADERS.each do |loader|
      begin
        loaded = loader.call(value)
      rescue
        next
      else
        break
      end
    end
  end

  loaded
end