Associate GgpSignature with GpgKeySubkey if comes from a subkey

Additionally we're delegating missing method calls on GpgKeySubkey to
GpgKey since most of the info required when verifying a signature is
found on GpgKey which is the parent of GpgKeySubkey

3 files changed, 31 insertions, 11 deletions

diff --git a/app/models/gpg_key.rb b/app/models/gpg_key.rb
index 6d3537b6fcf..ed09b44027c 100644
--- a/app/models/gpg_key.rb
+++ b/app/models/gpg_key.rb
@@ -40,17 +40,6 @@ class GpgKey < ActiveRecord::Base
   after_commit :update_invalid_gpg_signatures, on: :create
   after_create :generate_subkeys
 
-  def self.find_with_subkeys(fingerprint)
-    keys_table = arel_table
-    subkeys_table = GpgKeySubkey.arel_table
-
-    condition = keys_table[:primary_keyid].eq(fingerprint).or(
-      subkeys_table[:keyid].eq(fingerprint)
-    )
-
-    joins(:subkeys).where(condition).first
-  end
-
   def primary_keyid
     super&.upcase
   end
diff --git a/app/models/gpg_key_subkey.rb b/app/models/gpg_key_subkey.rb
index 4f967f1e47c..8222e5606aa 100644
--- a/app/models/gpg_key_subkey.rb
+++ b/app/models/gpg_key_subkey.rb
@@ -1,3 +1,18 @@
 class GpgKeySubkey < ActiveRecord::Base
+  include ShaAttribute
+
+  sha_attribute :keyid
+  sha_attribute :fingerprint
+
   belongs_to :gpg_key
+
+  def method_missing(m, *a, &b)
+    return super unless gpg_key.respond_to?(m)
+
+    gpg_key.public_send(m, *a, &b) # rubocop:disable GitlabSecurity/PublicSend
+  end
+
+  def respond_to_missing?(method, include_private = false)
+    gpg_key.respond_to?(method, include_private) || super
+  end
 end
diff --git a/app/models/gpg_signature.rb b/app/models/gpg_signature.rb
index 1f047a32c84..c7f75288407 100644
--- a/app/models/gpg_signature.rb
+++ b/app/models/gpg_signature.rb
@@ -15,11 +15,27 @@ class GpgSignature < ActiveRecord::Base
 
   belongs_to :project
   belongs_to :gpg_key
+  belongs_to :gpg_key_subkey
 
   validates :commit_sha, presence: true
   validates :project_id, presence: true
   validates :gpg_key_primary_keyid, presence: true
 
+  def gpg_key=(model)
+    case model
+    when GpgKey       then super
+    when GpgKeySubkey then write_attribute(:gpg_key_subkey_id, model.id)
+    end
+  end
+
+  def gpg_key
+    if gpg_key_id
+      super
+    elsif gpg_key_subkey_id
+      gpg_key_subkey
+    end
+  end
+
   def gpg_key_primary_keyid
     super&.upcase
   end