Class: Rack::Protection::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/protection/base.rb

Constant Summary collapse

DEFAULT_OPTIONS = 
{
  reaction: :default_reaction, logging: true,
  message: 'Forbidden', encryptor: Digest::SHA1,
  session_key: 'rack.session', status: 403,
  allow_empty_referrer: true,
  report_key: 'protection.failed',
  html_types: %w[text/html application/xhtml text/xml application/xml]
}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ Base

Returns a new instance of Base.



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# File 'lib/rack/protection/base.rb', line 35

def initialize(app, options = {})
  @app = app
  @options = default_options.merge(options)
end

Instance Attribute Details

#app ⇒ Object (readonly)

Returns the value of attribute app.



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# File 'lib/rack/protection/base.rb', line 21

def app
  @app
end

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/rack/protection/base.rb', line 21

def options
  @options
end

Class Method Details

.default_options(options) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 23

def self.default_options(options)
  define_method(:default_options) { super().merge(options) }
end

.default_reaction(reaction) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 27

def self.default_reaction(reaction)
  alias_method(:default_reaction, reaction)
end

Instance Method Details

#accepts?(env) ⇒ Boolean

Returns:

  • (Boolean)

Raises:

  • (NotImplementedError) 


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# File 'lib/rack/protection/base.rb', line 44

def accepts?(env)
  raise NotImplementedError, "#{self.class} implementation pending"
end

#call(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 48

def call(env)
  unless accepts? env
    instrument env
    result = react env
  end
  result or app.call(env)
end

#default_options ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 31

def default_options
  DEFAULT_OPTIONS
end

#deny(env) ⇒ Object Also known as: default_reaction 



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# File 'lib/rack/protection/base.rb', line 75

def deny(env)
  warn env, "attack prevented by #{self.class}"
  [options[:status], { 'Content-Type' => 'text/plain' }, [options[:message]]]
end

#drop_session(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 95

def drop_session(env)
  session(env).clear if session? env
end

#encrypt(value) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 117

def encrypt(value)
  options[:encryptor].hexdigest value.to_s
end

#html?(headers) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rack/protection/base.rb', line 127

def html?(headers)
  return false unless (header = headers.detect { |k, _v| k.downcase == 'content-type' })

  options[:html_types].include? header.last[%r{^\w+/\w+}]
end

#instrument(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 68

def instrument(env)
  return unless (i = options[:instrumenter])

  env['rack.protection.attack'] = self.class.name.split('::').last.downcase
  i.instrument('rack.protection', env)
end

#origin(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 107

def origin(env)
  env['HTTP_ORIGIN'] || env['HTTP_X_ORIGIN']
end

#random_string(secure = defined? SecureRandom)) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 111

def random_string(secure = defined? SecureRandom)
  secure ? SecureRandom.hex(16) : '%032x' % rand((2**128) - 1)
rescue NotImplementedError
  random_string false
end

#react(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 56

def react(env)
  result = send(options[:reaction], env)
  result if (Array === result) && (result.size == 3)
end

#referrer(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 99

def referrer(env)
  ref = env['HTTP_REFERER'].to_s
  return if !options[:allow_empty_referrer] && ref.empty?

  URI.parse(ref).host || Request.new(env).host
rescue URI::InvalidURIError
end

#report(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 80

def report(env)
  warn env, "attack reported by #{self.class}"
  env[options[:report_key]] = true
end

#safe?(env) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rack/protection/base.rb', line 40

def safe?(env)
  %w[GET HEAD OPTIONS TRACE].include? env['REQUEST_METHOD']
end

#secure_compare(a, b) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 121

def secure_compare(a, b)
  Rack::Utils.secure_compare(a.to_s, b.to_s)
end

#session(env) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 89

def session(env)
  return env[options[:session_key]] if session? env

  raise "you need to set up a session middleware *before* #{self.class}"
end

#session?(env) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rack/protection/base.rb', line 85

def session?(env)
  env.include? options[:session_key]
end

#warn(env, message) ⇒ Object 



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# File 'lib/rack/protection/base.rb', line 61

def warn(env, message)
  return unless options[:logging]

  l = options[:logger] || env['rack.logger'] || ::Logger.new(env['rack.errors'])
  l.warn(message)
end