rebase: vendor dependencies for Vault API

Uses github.com/libopenstorage/secrets to communicate with Vault. This
removes the need for maintaining our own limited Vault APIs.

By adding the new dependency, several other packages got updated in the
process. Unused indirect dependencies have been removed from go.mod.

Signed-off-by: Niels de Vos <ndevos@redhat.com>

vendor/golang.org/x/crypto/ssh/mux.go

@@ -240,7 +240,7 @@ func (m *mux) onePacket() error {
 	id := binary.BigEndian.Uint32(packet[1:])
 	ch := m.chanList.getChan(id)
 	if ch == nil {
-		return fmt.Errorf("ssh: invalid channel %d", id)
+		return m.handleUnknownChannelPacket(id, packet)
 	}
 
 	return ch.handlePacket(packet)
@@ -328,3 +328,24 @@ func (m *mux) openChannel(chanType string, extra []byte) (*channel, error) {
 		return nil, fmt.Errorf("ssh: unexpected packet in response to channel open: %T", msg)
 	}
 }
+
+func (m *mux) handleUnknownChannelPacket(id uint32, packet []byte) error {
+	msg, err := decode(packet)
+	if err != nil {
+		return err
+	}
+
+	switch msg := msg.(type) {
+	// RFC 4254 section 5.4 says unrecognized channel requests should
+	// receive a failure response.
+	case *channelRequestMsg:
+		if msg.WantReply {
+			return m.sendMessage(channelRequestFailureMsg{
+				PeersID: msg.PeersID,
+			})
+		}
+		return nil
+	default:
+		return fmt.Errorf("ssh: invalid channel %d", id)
+	}
+}