Class: RASN1::Types::Choice

Inherits:
Base
  • Object
show all
Defined in:
lib/rasn1/types/choice.rb,
lib/rasn1/tracer.rb

Overview

A ASN.1 CHOICE is a choice between different types.

Create a CHOICE

A CHOICE is defined this way:

choice = Choice.new
choice.value = [Integer.new(implicit: 0, class: :context),
                Integer.new(implicit: 1, class: :context),
                OctetString.new(implicit: 2, class: :context)]

The chosen type may be set this way:

choice.chosen = 0   # choose :int1

The chosen value may be set these ways:

choise.value[choice.chosen].value = 1
choise.set_chosen_value 1

The chosen value may be got these ways:

choise.value[choice.chosen].value # => 1
choice.chosen_value               # => 1

Encode a CHOICE

#to_der only encodes the chosen value:

choise.to_der   # => "\x80\x01\x01"

Parse a CHOICE

Parsing a CHOICE set #chosen and set value to chosen type. If parsed string does not contain a type from CHOICE, a ASN1Error is raised.

str = "\x04\x03abc"
choice.parse! str
choice.chosen        # => 2
choice.chosen_value  # => "abc"

Author:

  • Sylvain Daubert

Constant Summary

Constants inherited from Base

Base::CLASSES, Base::CLASS_MASK, Base::INDEFINITE_LENGTH, Base::MULTI_OCTETS_ID

Instance Attribute Summary collapse

Attributes inherited from Base

#asn1_class, #default, #name, #options

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Base

#==, #can_build?, constrained?, #constructed?, #do_parse_explicit, #do_parse_explicit_with_tracing, #do_parse_with_tracing, encoded_type, #explicit?, #id, #implicit?, #initialize, #initialize_copy, #optional?, parse, #primitive?, #specific_initializer, #tagged?, #type, type, #value, #value=, #value?, #value_size

Constructor Details

This class inherits a constructor from RASN1::Types::Base

Instance Attribute Details

#chosen ⇒ Integer

Chosen type

Returns:

  • (Integer) —

    index of type in choice value



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# File 'lib/rasn1/types/choice.rb', line 37

def chosen
  @chosen
end

Class Method Details

.start_tracing ⇒ Object

Patch #parse! to add tracing ability



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# File 'lib/rasn1/tracer.rb', line 103

def start_tracing
  alias_method :parse_without_tracing, :parse!
  alias_method :parse!, :parse_with_tracing
end

.stop_tracing ⇒ Object

Unpatch #parse! to remove tracing ability



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# File 'lib/rasn1/tracer.rb', line 110

def stop_tracing
  alias_method :parse!, :parse_without_tracing
end

Instance Method Details

#chosen_value ⇒ Object

Note:

#chosen MUST be set before calling this method

Get chosen value

Returns:

  • (Object) —

    value

Raises:



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# File 'lib/rasn1/types/choice.rb', line 53

def chosen_value
  check_chosen
  case @value[@chosen]
  when