When an ActivityPub Announce is processed and the boosted toot is not known, fetch it on behalf of one of the booster's followers. This is to allow fetching self-boosts of previously-unknown private toots. If fetching on behalf of a user fails, try fetching it anonymously: the selected follower of a boosting user may be banned by the boosted toot's author.
		
			
				
	
	
		
			113 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			Ruby
		
	
	
	
	
	
			
		
		
	
	
			113 lines
		
	
	
	
		
			3.3 KiB
		
	
	
	
		
			Ruby
		
	
	
	
	
	
| # frozen_string_literal: true
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| 
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| module JsonLdHelper
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|   def equals_or_includes?(haystack, needle)
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|     haystack.is_a?(Array) ? haystack.include?(needle) : haystack == needle
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|   end
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| 
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|   def equals_or_includes_any?(haystack, needles)
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|     needles.any? { |needle| equals_or_includes?(haystack, needle) }
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|   end
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| 
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|   def first_of_value(value)
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|     value.is_a?(Array) ? value.first : value
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|   end
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| 
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|   # The url attribute can be a string, an array of strings, or an array of objects.
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|   # The objects could include a mimeType. Not-included mimeType means it's text/html.
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|   def url_to_href(value, preferred_type = nil)
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|     single_value = if value.is_a?(Array) && !value.first.is_a?(String)
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|                      value.find { |link| preferred_type.nil? || ((link['mimeType'].presence || 'text/html') == preferred_type) }
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|                    elsif value.is_a?(Array)
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|                      value.first
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|                    else
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|                      value
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|                    end
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| 
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|     if single_value.nil? || single_value.is_a?(String)
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|       single_value
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|     else
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|       single_value['href']
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|     end
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|   end
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| 
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|   def as_array(value)
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|     value.is_a?(Array) ? value : [value]
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|   end
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| 
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|   def value_or_id(value)
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|     value.is_a?(String) || value.nil? ? value : value['id']
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|   end
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| 
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|   def supported_context?(json)
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|     !json.nil? && equals_or_includes?(json['@context'], ActivityPub::TagManager::CONTEXT)
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|   end
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| 
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|   def unsupported_uri_scheme?(uri)
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|     !uri.start_with?('http://', 'https://')
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|   end
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| 
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|   def canonicalize(json)
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|     graph = RDF::Graph.new << JSON::LD::API.toRdf(json, documentLoader: method(:load_jsonld_context))
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|     graph.dump(:normalize)
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|   end
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| 
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|   def fetch_resource(uri, id, on_behalf_of = nil)
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|     unless id
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|       json = fetch_resource_without_id_validation(uri, on_behalf_of)
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|       return unless json
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|       uri = json['id']
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|     end
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| 
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|     json = fetch_resource_without_id_validation(uri, on_behalf_of)
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|     json.present? && json['id'] == uri ? json : nil
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|   end
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| 
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|   def fetch_resource_without_id_validation(uri, on_behalf_of = nil)
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|     build_request(uri, on_behalf_of).perform do |response|
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|       return body_to_json(response.body_with_limit) if response.code == 200
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|     end
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|     # If request failed, retry without doing it on behalf of a user
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|     build_request(uri).perform do |response|
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|       response.code == 200 ? body_to_json(response.body_with_limit) : nil
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|     end
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|   end
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| 
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|   def body_to_json(body)
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|     body.is_a?(String) ? Oj.load(body, mode: :strict) : body
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|   rescue Oj::ParseError
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|     nil
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|   end
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| 
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|   def merge_context(context, new_context)
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|     if context.is_a?(Array)
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|       context << new_context
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|     else
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|       [context, new_context]
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|     end
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|   end
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| 
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|   private
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| 
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|   def build_request(uri, on_behalf_of = nil)
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|     request = Request.new(:get, uri)
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|     request.on_behalf_of(on_behalf_of) if on_behalf_of
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|     request.add_headers('Accept' => 'application/activity+json, application/ld+json')
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|     request
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|   end
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| 
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|   def load_jsonld_context(url, _options = {}, &_block)
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|     json = Rails.cache.fetch("jsonld:context:#{url}", expires_in: 30.days, raw: true) do
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|       request = Request.new(:get, url)
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|       request.add_headers('Accept' => 'application/ld+json')
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| 
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|       request.perform do |res|
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|         raise JSON::LD::JsonLdError::LoadingDocumentFailed unless res.code == 200 && res.mime_type == 'application/ld+json'
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|         res.body_with_limit
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|       end
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|     end
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| 
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|     doc = JSON::LD::API::RemoteDocument.new(url, json)
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|     block_given? ? yield(doc) : doc
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|   end
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| end
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