+#define SSH_AGENTC_REMOVE_SMARTCARD_KEY 21
+
+/* lock/unlock the agent */
+#define SSH_AGENTC_LOCK 22
+#define SSH_AGENTC_UNLOCK 23
+
+/* add key with constraints */
+#define SSH_AGENTC_ADD_RSA_ID_CONSTRAINED 24
+#define SSH2_AGENTC_ADD_ID_CONSTRAINED 25
+#define SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED 26
+
+#define SSH_AGENT_CONSTRAIN_LIFETIME 1
+#define SSH_AGENT_CONSTRAIN_CONFIRM 2
+
+/* extended failure messages */
+#define SSH2_AGENT_FAILURE 30