Action Controller 请求伪造防护¶ ↑

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 373
def initialize(...)
  super
  @_marked_for_same_origin_verification = nil
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 383
def commit_csrf_token(request) # :doc:
  csrf_token = request.env[CSRF_TOKEN]
  csrf_token_storage_strategy.store(request, csrf_token) unless csrf_token.nil?
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 378
def reset_csrf_token(request) # :doc:
  request.env.delete(CSRF_TOKEN)
  csrf_token_storage_strategy.reset(request)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 476
def any_authenticity_token_valid? # :doc:
  request_authenticity_tokens.any? do |token|
    valid_authenticity_token?(session, token)
  end
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 557
def compare_with_global_token(token, session = nil) # :doc:
  ActiveSupport::SecurityUtils.fixed_length_secure_compare(token, global_csrf_token(session))
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 553
def compare_with_real_token(token, session = nil) # :doc:
  ActiveSupport::SecurityUtils.fixed_length_secure_compare(token, real_csrf_token(session))
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 594
def csrf_token_hmac(session, identifier) # :doc:
  OpenSSL::HMAC.digest(
    OpenSSL::Digest::SHA256.new,
    real_csrf_token(session),
    identifier
  )
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 614
def form_authenticity_param # :doc:
  params[request_forgery_protection_token]
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 488
def form_authenticity_token(form_options: {}) # :doc:
  masked_authenticity_token(form_options: form_options)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 590
def global_csrf_token(session = nil) # :doc:
  csrf_token_hmac(session, GLOBAL_CSRF_TOKEN_IDENTIFIER)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 446
def mark_for_same_origin_verification! # :doc:
  @_marked_for_same_origin_verification = request.get?
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 452
def marked_for_same_origin_verification? # :doc:
  @_marked_for_same_origin_verification ||= false
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 546
def mask_token(raw_token) # :doc:
  one_time_pad = SecureRandom.random_bytes(AUTHENTICITY_TOKEN_LENGTH)
  encrypted_csrf_token = xor_byte_strings(one_time_pad, raw_token)
  masked_token = one_time_pad + encrypted_csrf_token
  encode_csrf_token(masked_token)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 457
def non_xhr_javascript_response? # :doc:
  %r(\A(?:text|application)/javascript).match?(media_type) && !request.xhr?
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 583
def per_form_csrf_token(session, action_path, method) # :doc:
  csrf_token_hmac(session, [action_path, method.downcase].join("#"))
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 619
def protect_against_forgery? # :doc:
  allow_forgery_protection && (!session.respond_to?(:enabled?) || session.enabled?)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 575
def real_csrf_token(_session = nil) # :doc:
  csrf_token = request.env.fetch(CSRF_TOKEN) do
    request.env[CSRF_TOKEN] = csrf_token_storage_strategy.fetch(request) || generate_csrf_token
  end

  decode_csrf_token(csrf_token)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 483
def request_authenticity_tokens # :doc:
  [form_authenticity_param, request.x_csrf_token]
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 539
def unmask_token(masked_token) # :doc:
  # Split the token into the one-time pad and the encrypted value and decrypt it.
  one_time_pad = masked_token[0...AUTHENTICITY_TOKEN_LENGTH]
  encrypted_csrf_token = masked_token[AUTHENTICITY_TOKEN_LENGTH..-1]
  xor_byte_strings(one_time_pad, encrypted_csrf_token)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 509
def valid_authenticity_token?(session, encoded_masked_token) # :doc:
  if !encoded_masked_token.is_a?(String) || encoded_masked_token.empty?
    return false
  end

  begin
    masked_token = decode_csrf_token(encoded_masked_token)
  rescue ArgumentError # encoded_masked_token is invalid Base64
    return false
  end

  # See if it's actually a masked token or not. In order to deploy this code, we
  # should be able to handle any unmasked tokens that we've issued without error.

  if masked_token.length == AUTHENTICITY_TOKEN_LENGTH
    # This is actually an unmasked token. This is expected if you have just upgraded
    # to masked tokens, but should stop happening shortly after installing this gem.
    compare_with_real_token masked_token

  elsif masked_token.length == AUTHENTICITY_TOKEN_LENGTH * 2
    csrf_token = unmask_token(masked_token)

    compare_with_global_token(csrf_token) ||
      compare_with_real_token(csrf_token) ||
      valid_per_form_csrf_token?(csrf_token)
  else
    false # Token is malformed.
  end
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 561
def valid_per_form_csrf_token?(token, session = nil) # :doc:
  if per_form_csrf_tokens
    correct_token = per_form_csrf_token(
      session,
      request.path.chomp("/"),
      request.request_method
    )

    ActiveSupport::SecurityUtils.fixed_length_secure_compare(token, correct_token)
  else
    false
  end
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 635
def valid_request_origin? # :doc:
  if forgery_protection_origin_check
    # We accept blank origin headers because some user agents don't send it.
    raise InvalidAuthenticityToken, NULL_ORIGIN_MESSAGE if request.origin == "null"
    request.origin.nil? || request.origin == request.base_url
  else
    true
  end
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 470
def verified_request? # :doc:
  request.get? || request.head? || !protect_against_forgery? ||
    (valid_request_origin? && any_authenticity_token_valid?)
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 398
def verify_authenticity_token # :doc:
  mark_for_same_origin_verification!

  if !verified_request?
    logger.warn unverified_request_warning_message if logger && log_warning_on_csrf_failure

    handle_unverified_request
  end
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 436
def verify_same_origin_request # :doc:
  if marked_for_same_origin_verification? && non_xhr_javascript_response?
    if logger && log_warning_on_csrf_failure
      logger.warn CROSS_ORIGIN_JAVASCRIPT_WARNING
    end
    raise ActionController::InvalidCrossOriginRequest, CROSS_ORIGIN_JAVASCRIPT_WARNING
  end
end

# File actionpack/lib/action_controller/metal/request_forgery_protection.rb, line 602
def xor_byte_strings(s1, s2) # :doc:
  s2 = s2.dup
  size = s1.bytesize
  i = 0
  while i < size
    s2.setbyte(i, s1.getbyte(i) ^ s2.getbyte(i))
    i += 1
  end
  s2
end