Class: Rights::KeySettings

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

Overview

The key settings determine the level of authentication needed to perform operations on the tag (DESFire) top-level, or on an application.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(hash = {}) ⇒ KeySettings

The constructor takes a hash of parameters, which correspond to the class attributes.



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# File 'lib/key_settings.rb', line 42

def initialize(hash={})
  @master_change = hash[:master_change] || 1
  @auth_get = hash[:auth_get] || 1
  @auth_create = hash[:auth_create] || 0
  @settings_change = hash[:settings_change] || 1
  @change_key = hash[:change_key] || 0x0
end

Instance Attribute Details

#auth_create ⇒ Object (readonly)

Can files/applications be created or deleted / created without application/tag master key authentication? Takes values 0 or 1.



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# File 'lib/key_settings.rb', line 26

def auth_create
  @auth_create
end

#auth_get ⇒ Object (readonly)

Can the commands (GetFileIDs, GetFileSettings, GetKeySettings) / (GetApplicationIDs, GetKeySettings) be performed without application/tag master key authentication? Takes values 0 or 1.



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# File 'lib/key_settings.rb', line 22

def auth_get
  @auth_get
end

#change_key ⇒ Object (readonly)

Only defined for application keys settings. Defines the key needed to change application keys. It can be an application key number between 0x0 and 0xE (inclusive, 0x0 being the application master key) or one of the constants CHANGED_KEY (authenticated with the key that will be changed) or IMMUTABLE (keys cannot be changed) (constants defined in the Rights module). Takes a value key such that (0x0 <= key <= 0xF).



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# File 'lib/key_settings.rb', line 38

def change_key
  @change_key
end

#master_change ⇒ Object (readonly)

Is the application/tag master key modifiable? Takes values 0 or 1.



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# File 'lib/key_settings.rb', line 17

def master_change
  @master_change
end

#settings_change ⇒ Object (readonly)

Can the key settings for this application/tag be changed again? Takes values 0 or 1.



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# File 'lib/key_settings.rb', line 30

def settings_change
  @settings_change
end

Class Method Details

.from_byte(byte) ⇒ Object

Creates a KeySettings object from a byte representing the key settings.



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# File 'lib/key_settings.rb', line 51

def self.from_byte(byte)
  KeySettings.new(
    :master_change    => (byte & 0x1) % 2,
    :auth_get         => (byte & 0x2) % 2,
    :auth_create      => (byte & 0x4) % 2,
    :settings_change  => (byte & 0x8) % 2,
    :change_key       => byte >> 4)
end

Instance Method Details

#can_change_key?(aid, changing_key, change_key) ⇒ Boolean

Can key changing_key of application aid be changed by authenticating with key change_key?

Returns:

  • (Boolean) 


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# File 'lib/key_settings.rb', line 72

def can_change_key?(aid, changing_key, change_key)
  if aid == 0
    changing_key == 0 && change_key == 0
  elsif @change_key == IMMUTABLE
    false
  elsif @change_key == CHANGED_KEY
    change_key == changing_key
  elsif @change_key == changing_key
    change_key == 0
  else
    change_key == @change_key
  end
end

#can_change_key_settings?(key_no) ⇒ Boolean

Can we change this key settings on the tag’s currently selected application if authenticated with the given key?

Returns:

  • (Boolean) 


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# File 'lib/key_settings.rb', line 118

def can_change_key_settings?(key_no)
  @settings_change and key_no == 0
end

#can_create_app?(aid, key_no) ⇒ Boolean

Can we create an application if authenticated with the given key on the given application?

Returns:

  • (Boolean) 


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# File 'lib/key_settings.rb', line 106

def can_create_app?(aid, key_no)
  aid == 0 and (@auth_create = 1 or key_no = 0)
end

#can_delete_app?(aid, key_no) ⇒ Boolean

Can we delete an application if authenticated with the given key on the given application?

Returns:

  • (Boolean) 


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# File 'lib/key_settings.rb', line 112

def can_delete_app?(aid, key_no)
  aid == 0 and key_no == 0
end

#can_edit_file?(key_no) ⇒ Boolean

Can we create or delete a file if authenticated with the given key?

Returns:

  • (Boolean) 


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# File 'lib/key_settings.rb', line 100

def can_edit_file?(key_no)
  @auth_create == 1 or key_no == 0
end

#can_get0?(aid, key_no) ⇒ Boolean

Can we perform the top-level GetApplicationIDs and GetKeySettings) commands if authenticated with the given key?

Returns:

  • (Boolean) 


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# File 'lib/key_settings.rb', line 95

def can_get0?(aid, key_no)
  aid == 0 and (@auth_get == 1 or key_no == 0)
end

#can_get?(key_no) ⇒ Boolean

Can we perform the application-level GetFileIDs, GetFileSettings and GetKeySettings commands if authenticated with the given key on the given application?

Returns:

  • (Boolean) 


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# File 'lib/key_settings.rb', line 89

def can_get?(key_no)
  @auth_get == 1 or key_no == 0
end

#to_byte ⇒ Object

Returns a byte representing the key settings, fit to be used as a command parameter.



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# File 'lib/key_settings.rb', line 62

def to_byte
  1  * @master_change +
  2  * @auth_get +
  4  * @auth_create +
  8  * @settings_change +
  16 * @change_key
end