Class: MailAuth::Arc::Chain

Inherits:
Object
  • Object
show all
Defined in:
lib/mailauth/arc/chain.rb

Overview

Every ARC header on a message, grouped into the sets they claim to belong to, and held to the structure RFC 8617 §5.2 step 3 requires of them.

Constant Summary collapse

KINDS = 
{
  "arc-authentication-results" => :authentication_results,
  "arc-message-signature" => :message_signature,
  "arc-seal" => :seal
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(message) ⇒ Chain

Returns a new instance of Chain.



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# File 'lib/mailauth/arc/chain.rb', line 14

def initialize(message)
  @message = message
end

Instance Method Details

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/mailauth/arc/chain.rb', line 18

def empty?
  sets.empty?
end

#newest ⇒ Object 



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# File 'lib/mailauth/arc/chain.rb', line 36

def newest
  ordered.last
end

#ordered ⇒ Object 



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# File 'lib/mailauth/arc/chain.rb', line 32

def ordered
  sets.values.sort_by(&:instance)
end

#oversized? ⇒ Boolean

Instance values run 1..50 (§4.2.1), so a chain longer than that is over the ceiling however its instances are numbered.

Returns:

  • (Boolean) 


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# File 'lib/mailauth/arc/chain.rb', line 24

def oversized?
  sets.size > MAXIMUM_SETS
end

#sets ⇒ Object 



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# File 'lib/mailauth/arc/chain.rb', line 28

def sets
  @sets ||= collect
end

#structural_error ⇒ Object 



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# File 'lib/mailauth/arc/chain.rb', line 46

def structural_error
  if incomplete = ordered.find { |set| !set.complete? }
    "ARC set i=#{incomplete.instance} does not carry exactly one of each header"
  elsif unreadable = ordered.find { |set| !set.readable? }
    "ARC set i=#{unreadable.instance} carries an invalid tag list"
  elsif ordered.map(&:instance) != (1..sets.size).to_a
    "ARC instances are not a continuous sequence"
  else
    chain_status_error
  end
end

#through(instance) ⇒ Object

Everything up to and including one instance — what that instance's seal signs (§5.1.1).



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# File 'lib/mailauth/arc/chain.rb', line 42

def through(instance)
  ordered.take_while { |set| set.instance <= instance }
end