nas/app/controllers/api/fasp/base_controller.rb
2025-05-23 06:43:02 +00:00

66 lines
1.9 KiB
Ruby

# frozen_string_literal: true
class Api::Fasp::BaseController < ApplicationController
class Error < ::StandardError; end
DIGEST_PATTERN = /sha-256=:(.*?):/
KEYID_PATTERN = /keyid="(.*?)"/
attr_reader :current_provider
skip_forgery_protection
before_action :check_fasp_enabled
before_action :require_authentication
after_action :sign_response
private
def require_authentication
validate_content_digest!
validate_signature!
rescue Error, Linzer::Error, ActiveRecord::RecordNotFound => e
logger.debug("FASP Authentication error: #{e}")
authentication_error
end
def authentication_error
respond_to do |format|
format.json { head 401 }
end
end
def validate_content_digest!
content_digest_header = request.headers['content-digest']
raise Error, 'content-digest missing' if content_digest_header.blank?
digest_received = content_digest_header.match(DIGEST_PATTERN)[1]
digest_computed = OpenSSL::Digest.base64digest('sha256', request.body&.string || '')
raise Error, 'content-digest does not match' if digest_received != digest_computed
end
def validate_signature!
raise Error, 'signature-input is missing' if request.headers['signature-input'].blank?
provider = nil
Linzer.verify!(request.rack_request, no_older_than: 5.minutes) do |keyid|
provider = Fasp::Provider.find(keyid)
Linzer.new_ed25519_public_key(provider.provider_public_key_pem, keyid)
end
@current_provider = provider
end
def sign_response
response.headers['content-digest'] = "sha-256=:#{OpenSSL::Digest.base64digest('sha256', response.body || '')}:"
key = Linzer.new_ed25519_key(current_provider.server_private_key_pem)
Linzer.sign!(response, key:, components: %w(@status content-digest))
end
def check_fasp_enabled
raise ActionController::RoutingError unless Mastodon::Feature.fasp_enabled?
end
end