1 files changed, 20 insertions, 3 deletions
diff --git a/app/models/keyring.rb b/app/models/keyring.rb
index 6779d5d..66f7bfd 100644
--- a/app/models/keyring.rb
+++ b/app/models/keyring.rb
@@ -8,6 +8,12 @@ class Keyring
   class Error < RuntimeError
   end
 
+  class NotFound < Error
+    def initialize(type)
+      super "no such key: #{type}"
+    end
+  end
+
   def initialize(storage)
     @storage = storage
   end
@@ -19,19 +25,30 @@ class Keyring
   end
 
   def update(type, rev:, value:)
-    old_rev = key_of_type(type)['rev']
-    raise Error, "wrong revision: #{rev}" unless old_rev == rev
+    check_rev type, rev
     storage.set_key type, {type: type, value: value, rev: new_rev}.to_json
     storage.save
   end
 
+  def delete(type, rev:)
+    check_rev type, rev
+    storage.delete_key type
+    storage.save
+  end
+
   def key_of_type(type)
-    JSON.parse(storage.keys[type])
+    JSON.parse(storage.keys[type]) if storage.keys[type]
   end
 
   protected
   attr_reader :storage
 
+  def check_rev(type, rev)
+    old = key_of_type(type)
+    raise NotFound, type unless old
+    raise Error, "wrong revision: #{rev}" unless old['rev'] == rev
+  end
+
   def new_rev
     SecureRandom.urlsafe_base64(8)
   end