1 files changed, 38 insertions, 0 deletions
diff --git a/app/models/keyring.rb b/app/models/keyring.rb
new file mode 100644
index 0000000..6779d5d
--- /dev/null
+++ b/app/models/keyring.rb
@@ -0,0 +1,38 @@
+#
+# Keyring
+#
+# A collection of cryptographic keys.
+#
+
+class Keyring
+  class Error < RuntimeError
+  end
+
+  def initialize(storage)
+    @storage = storage
+  end
+
+  def create(type, value)
+    raise Error, "key already exists" if storage.keys[type].present?
+    storage.set_key type, {type: type, value: value, rev: new_rev}.to_json
+    storage.save
+  end
+
+  def update(type, rev:, value:)
+    old_rev = key_of_type(type)['rev']
+    raise Error, "wrong revision: #{rev}" unless old_rev == rev
+    storage.set_key type, {type: type, value: value, rev: new_rev}.to_json
+    storage.save
+  end
+
+  def key_of_type(type)
+    JSON.parse(storage.keys[type])
+  end
+
+  protected
+  attr_reader :storage
+
+  def new_rev
+    SecureRandom.urlsafe_base64(8)
+  end
+end