Reject GPG keys that have e-mail or names with non-valid UTF-8 encodings

These were causing 500 Errors when accessing GPG keys for some users.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/47280

lib/gitlab/gpg.rb

@@ -54,7 +54,11 @@ module Gitlab
         fingerprints = CurrentKeyChain.fingerprints_from_key(key)
 
         GPGME::Key.find(:public, fingerprints).flat_map do |raw_key|
-          raw_key.uids.map { |uid| { name: uid.name, email: uid.email.downcase } }
+          raw_key.uids.each_with_object([]) do |uid, arr|
+            name = uid.name.force_encoding('UTF-8')
+            email = uid.email.force_encoding('UTF-8')
+            arr << { name: name, email: email.downcase } if name.valid_encoding? && email.valid_encoding?
+          end
         end
       end
     end

spec/lib/gitlab/gpg_spec.rb

@@ -74,6 +74,19 @@ describe Gitlab::Gpg do
         email: 'nannie.bernhard@example.com'
       }])
     end
+
+    it 'rejects non UTF-8 names and addresses' do
+      public_key = double(:key)
+      fingerprints = double(:fingerprints)
+      email = "\xEEch@test.com".force_encoding('ASCII-8BIT')
+      uid = double(:uid, name: 'Test User', email: email)
+      raw_key = double(:raw_key, uids: [uid])
+      allow(Gitlab::Gpg::CurrentKeyChain).to receive(:fingerprints_from_key).with(public_key).and_return(fingerprints)
+      allow(GPGME::Key).to receive(:find).with(:public, anything).and_return([raw_key])
+
+      user_infos = described_class.user_infos_from_key(public_key)
+      expect(user_infos).to eq([])
+    end
   end
 
   describe '.current_home_dir' do