Rework the permissions model for SSH key restrictions

`allowed_key_types` is removed and the `minimum_<type>_bits` fields are
renamed to `<tech>_key_restriction`. A special sentinel value (`-1`) signifies
that the key type is disabled.

This also feeds through to the UI - checkboxes per key type are out, inline
selection of "forbidden" and "allowed" (i.e., no restrictions) are in.

As with the previous model, unknown key types are disallowed, even if the
underlying ssh daemon happens to support them. The defaults have also been
changed from the lowest known bit size to "no restriction". So if someone
does happen to have a 768-bit RSA key, it will continue to work on upgrade, at
least until the administrator restricts them.

1 files changed, 3 insertions, 2 deletions

diff --git a/spec/features/profiles/keys_spec.rb b/spec/features/profiles/keys_spec.rb
index a4ccf222b50..aa71c4dbba4 100644
--- a/spec/features/profiles/keys_spec.rb
+++ b/spec/features/profiles/keys_spec.rb
@@ -31,7 +31,8 @@ feature 'Profile > SSH Keys' do
 
     context 'when only DSA and ECDSA keys are allowed' do
       before do
-        stub_application_setting(allowed_key_types: %w[dsa ecdsa])
+        forbidden = ApplicationSetting::FORBIDDEN_KEY_VALUE
+        stub_application_setting(rsa_key_restriction: forbidden, ed25519_key_restriction: forbidden)
       end
 
       scenario 'shows a validation error' do
@@ -41,7 +42,7 @@ feature 'Profile > SSH Keys' do
         fill_in('Title', with: attrs[:title])
         click_button('Add key')
 
-        expect(page).to have_content('Key type is not allowed. Must be DSA or ECDSA')
+        expect(page).to have_content('Key type is forbidden. Must be DSA or ECDSA')
       end
     end
   end