Fix KnownHostsKeys#keys_for to match on the entire hostlist

CHANGELOG.md

@@ -7,6 +7,8 @@ appear at the top.
 
   * Add your entries below here, remember to credit yourself however you want
     to be credited!
+  * Fix known_hosts caching to match on the entire hostlist
+    [PR #364](https://github.com/capistrano/sshkit/pull/364) @byroot
 
 ## [1.11.0][] (2016-06-14)
 

lib/sshkit/backends/netssh/known_hosts.rb

@@ -18,10 +18,12 @@ def keys_for(hostlist)
           parse_file unless keys && hashes
           keys, hashes = hosts_keys, hosts_hashes
 
-          hostlist.split(',').each do |host|
-            key_list = keys[host]
-            return key_list if key_list
+          host_names = hostlist.split(',')
 
+          keys_found = host_names.map { |h| keys[h] || [] }.compact.inject(:&)
+          return keys_found unless keys_found.empty?
+
+          host_names.each do |host|
             hashes.each do |(hmac, salt), hash_keys|
               if OpenSSL::HMAC.digest(sha1, salt, host) == hmac
                 return hash_keys

test/known_hosts/github_ip

@@ -0,0 +1 @@
+github.com,192.30.252.123 ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==

test/unit/backends/test_netssh.rb

@@ -56,23 +56,28 @@ def test_transfer_summarizer
 
       if Net::SSH::Version::CURRENT >= Net::SSH::Version[3, 1, 0]
         def test_known_hosts_for_when_all_hosts_are_recognized
-          perform_known_hosts_test("github")
+          perform_known_hosts_test('github', 'github.com')
         end
 
         def test_known_hosts_for_when_an_host_hash_is_recognized
-          perform_known_hosts_test("github_hash")
+          perform_known_hosts_test('github_hash', 'github.com')
+        end
+
+        def test_known_hosts_for_with_multiple_hosts
+          perform_known_hosts_test('github', '192.30.252.123,github.com', 0)
+          perform_known_hosts_test('github_ip', '192.30.252.123,github.com', 1)
         end
       end
 
       private
 
-      def perform_known_hosts_test(hostfile)
+      def perform_known_hosts_test(hostfile, hostlist, keys_count = 1)
         source = File.join(File.dirname(__FILE__), '../../known_hosts', hostfile)
         kh = Netssh::KnownHosts.new
-        keys = kh.search_for('github.com', user_known_hosts_file: source, global_known_hosts_file: Tempfile.new('sshkit-test').path)
+        keys = kh.search_for(hostlist, user_known_hosts_file: source, global_known_hosts_file: Tempfile.new('sshkit-test').path)
 
         assert_instance_of ::Net::SSH::HostKeys, keys
-        assert_equal(1, keys.count)
+        assert_equal(keys_count, keys.count)
         keys.each do |key|
           assert_equal("ssh-rsa", key.ssh_type)
         end