1 files changed, 73 insertions, 0 deletions
diff --git a/server.rb b/server.rb
index 13153b8..b5076f3 100644
--- a/server.rb
+++ b/server.rb
@@ -74,3 +74,76 @@ end
     ordered_collection(path).to_json
   end
 end
+
+helpers do
+
+  # https://github.com/mastodon/mastodon/blob/main/app/controllers/concerns/signature_verification.rb
+  def verify!
+    # TODO verify digest
+    begin
+      signature_params = {}
+      request.env["HTTP_SIGNATURE"].split(',').each do |pair|
+        k, v = pair.split('=')
+        signature_params[k] = v.gsub('"', '')
+      end
+
+      key_id = signature_params['keyId']
+      headers = signature_params['headers']
+      signature = Base64.decode64(signature_params['signature'])
+
+      actor = fetch key_id
+      key = OpenSSL::PKey::RSA.new(actor['publicKey']['publicKeyPem'])
+
+      comparison = headers.split(' ').map do |signed_params_name|
+        if signed_params_name == '(request-target)'
+          '(request-target): post /inbox'
+        elsif signed_params_name == 'content-type'
+          "#{signed_params_name}: #{request.env["CONTENT_TYPE"]}"
+        else
+          "#{signed_params_name}: #{request.env["HTTP_" + signed_params_name.upcase]}"
+        end
+      end.join("\n")
+
+      halt 400 unless key.verify(OpenSSL::Digest.new('SHA256'), signature, comparison)
+    rescue => e
+      p request.env["HTTP_SIGNATURE"], e
+      halt 400
+    end
+  end
+
+  def create object
+    unless object['type'] == 'Person'
+      doc = File.join("inbox", "#{Time.now.strftime('%Y-%m-%dT%H:%M:%S.%N')}.json")
+      File.open(doc, "w+") { |f| f.puts object.to_json }
+      if object['inReplyTo']
+        @dir = 'inbox'
+        items
+        if @items.select{|it| it[:id] == object['inReplyTo'] }.empty?
+           download object['inReplyTo']
+        end
+      end
+    end
+  end
+
+  def download object_url
+    create fetch(object_url)
+  end
+
+  def delete object
+    Dir["inbox/*.json"].each do |doc|
+      FileUtils.rm doc if JSON.parse(File.read(doc))["id"] == object["id"]
+    end
+  end
+
+  def ordered_collection dir
+    posts = Dir[File.join("public",dir, "*.json")].collect { |f| JSON.parse(File.read f) }.sort_by { |o| o["published"] }
+    {
+      "@context" => "https://www.w3.org/ns/activitystreams",
+      "summary" => "#{USER} #{dir}",
+      "type" => "OrderedCollection",
+      "totalItems" => posts.size,
+      "orderedItems" => posts,
+    }
+  end
+
+end