Merge branch 'ssh-key-linebreaks' into 'master'

Add error message for SSH key linebreaks

Solves this [request](http://feedback.gitlab.com/forums/176466-general/suggestions/5653544-check-for-linebreaks-in-ssh-key).

See merge request !672

CHANGELOG

@@ -46,6 +46,7 @@ v 7.13.0 (unreleased)
   - A fork can’t have a visibility level that is greater than the original project.
   - Faster code search in repository and wiki. Fixes search page timeout for big repositories 
   - Allow administrators to disable 2FA for a specific user
+  - Add error message for SSH key linebreaks
 
 v 7.12.2
   - Correctly show anonymous authorized applications under Profile > Applications.

app/models/key.rb

@@ -24,6 +24,7 @@ class Key < ActiveRecord::Base
 
   validates :title, presence: true, length: { within: 0..255 }
   validates :key, presence: true, length: { within: 0..5000 }, format: { with: /\A(ssh|ecdsa)-.*\Z/ }, uniqueness: true
+  validates :key, format: { without: /\n|\r/, message: 'should be a single line' }
   validates :fingerprint, uniqueness: true, presence: { message: 'cannot be generated' }
 
   delegate :name, :email, to: :user, prefix: true

spec/models/key_spec.rb

@@ -63,7 +63,7 @@ describe Key do
       key = build(:key)
 
       # Not always the middle, but close enough
-      key.key = key.key[0..100] + ' ' + key.key[100..-1]
+      key.key = key.key[0..100] + ' ' + key.key[101..-1]
 
       expect(key).not_to be_valid
     end
@@ -71,6 +71,12 @@ describe Key do
     it 'rejects the unfingerprintable key (not a key)' do
       expect(build(:key, key: 'ssh-rsa an-invalid-key==')).not_to be_valid
     end
+
+    it 'rejects the multiple line key' do
+      key = build(:key)
+      key.key.gsub!(' ', "\n")
+      expect(key).not_to be_valid
+    end
   end
 
   context 'callbacks' do