122 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			Ruby
		
	
	
	
			
		
		
	
	
			122 lines
		
	
	
		
			3.0 KiB
		
	
	
	
		
			Ruby
		
	
	
	
| # frozen_string_literal: true
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| 
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| module Gitlab
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|   class EncryptedConfiguration
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|     delegate :[], :fetch, to: :config
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|     delegate_missing_to :options
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|     attr_reader :content_path, :key, :previous_keys
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| 
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|     CIPHER = "aes-256-gcm"
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|     SALT = "GitLabEncryptedConfigSalt"
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| 
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|     class MissingKeyError < RuntimeError
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|       def initialize(msg = "Missing encryption key to encrypt/decrypt file with.")
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|         super
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|       end
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|     end
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| 
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|     class InvalidConfigError < RuntimeError
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|       def initialize(msg = "Content was not a valid yml config file")
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|         super
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|       end
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|     end
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| 
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|     def self.generate_key(base_key)
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|       # Because the salt is static, we want uniqueness to be coming from the base_key
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|       # Error if the base_key is empty or suspiciously short
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|       raise 'Base key too small' if base_key.blank? || base_key.length < 16
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| 
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|       ActiveSupport::KeyGenerator.new(base_key).generate_key(SALT, ActiveSupport::MessageEncryptor.key_len(CIPHER))
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|     end
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| 
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|     def initialize(content_path: nil, base_key: nil, previous_keys: [])
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|       @content_path = Pathname.new(content_path).yield_self { |path| path.symlink? ? path.realpath : path } if content_path
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|       @key = self.class.generate_key(base_key) if base_key
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|       @previous_keys = previous_keys
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|     end
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| 
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|     def active?
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|       content_path&.exist?
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|     end
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| 
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|     def read
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|       if active?
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|         decrypt(content_path.binread)
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|       else
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|         ""
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|       end
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|     end
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| 
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|     def write(contents)
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|       # ensure contents are valid to deserialize before write
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|       deserialize(contents)
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| 
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|       temp_file = Tempfile.new(File.basename(content_path), File.dirname(content_path))
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|       File.open(temp_file.path, 'wb') do |file|
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|         file.write(encrypt(contents))
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|       end
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|       FileUtils.mv(temp_file.path, content_path)
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|     ensure
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|       temp_file&.unlink
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|     end
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| 
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|     def config
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|       return @config if @config
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| 
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|       contents = deserialize(read)
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| 
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|       raise InvalidConfigError.new unless contents.is_a?(Hash)
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| 
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|       @config = contents.deep_symbolize_keys
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|     end
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| 
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|     def change(&block)
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|       writing(read, &block)
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|     end
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| 
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|     private
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| 
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|     def writing(contents)
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|       updated_contents = yield contents
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| 
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|       write(updated_contents) if updated_contents != contents
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|     end
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| 
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|     def encrypt(contents)
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|       handle_missing_key!
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|       encryptor.encrypt_and_sign(contents)
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|     end
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| 
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|     def decrypt(contents)
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|       handle_missing_key!
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|       encryptor.decrypt_and_verify(contents)
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|     end
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| 
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|     def encryptor
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|       return @encryptor if @encryptor
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| 
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|       @encryptor = ActiveSupport::MessageEncryptor.new(key, cipher: CIPHER)
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| 
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|       # Allow fallback to previous keys
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|       @previous_keys.each do |key|
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|         @encryptor.rotate(self.class.generate_key(key))
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|       end
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| 
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|       @encryptor
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|     end
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| 
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|     def options
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|       # Allows top level keys to be referenced using dot syntax
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|       @options ||= ActiveSupport::InheritableOptions.new(config)
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|     end
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| 
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|     def deserialize(contents)
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|       YAML.safe_load(contents, permitted_classes: [Symbol]).presence || {}
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|     end
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| 
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|     def handle_missing_key!
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|       raise MissingKeyError.new if @key.nil?
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|     end
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|   end
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| end
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