Asynchronous service request

include/libssh/priv.h

@@ -123,6 +123,7 @@ int ssh_send_banner(ssh_session session, int is_server);
 void ssh_connection_callback(ssh_session session);
 SSH_PACKET_CALLBACK(ssh_packet_dh_reply);
 SSH_PACKET_CALLBACK(ssh_packet_newkeys);
+SSH_PACKET_CALLBACK(ssh_packet_service_accept);
 
 /* config.c */
 int ssh_config_parse_file(ssh_session session, const char *filename);

include/libssh/session.h

@@ -41,6 +41,20 @@ enum ssh_session_state_e {
 	SSH_SESSION_STATE_ERROR
 };
 
+/** @internal
+ * @brief states of the authentication service request
+ */
+enum ssh_auth_service_state_e {
+	/** initial state */
+	SSH_AUTH_SERVICE_NONE=0,
+	/** Authentication service request packet sent */
+	SSH_AUTH_SERVICE_SENT,
+	/** Service accepted */
+	SSH_AUTH_SERVICE_ACCEPTED,
+	/** Access to service denied (fatal) */
+	SSH_AUTH_SERVICE_DENIED
+};
+
 struct ssh_session_struct {
     struct error_struct error;
     struct ssh_socket_struct *socket;
@@ -60,7 +74,7 @@ struct ssh_session_struct {
     /* !=0 when the user got a session handle */
     int alive;
     /* two previous are deprecated */
-    int auth_service_asked;
+//    int auth_service_asked;
 
 /* socket status */
     int blocking; // functions should block
@@ -78,6 +92,7 @@ struct ssh_session_struct {
     enum ssh_session_state_e session_state;
     int packet_state;
     int dh_handshake_state;
+    enum ssh_auth_service_state_e auth_service_state;
     ssh_string dh_server_signature; //information used by dh_handshake.
 
     KEX server_kex;

libssh/auth.c

@@ -45,19 +45,23 @@
 /** \addtogroup ssh_auth
  * @{ */
 
+/**
+ * @internal
+ * @brief ask access to the ssh-userauth service
+ * @param session SSH session handle
+ * @returns SSH_OK on success
+ * @returns SSH_ERROR on error
+ * @bug current implementation is blocking
+ */
 static int ask_userauth(ssh_session session) {
   int rc = 0;
 
   enter_function();
-
+  do {
-  if (session->auth_service_asked) {
+  	rc=ssh_service_request(session,"ssh-userauth");
-    rc = 0;
+  	if(rc==SSH_AGAIN)
-  } else if (ssh_service_request(session,"ssh-userauth")) {
+  		ssh_handle_packets(session);
-    rc = -1;
+  } while(rc==SSH_AGAIN);
-  } else {
-    session->auth_service_asked++;
-  }
-
   leave_function();
   return rc;
 }

libssh/client.c

@@ -466,6 +466,23 @@ error:
   return rc;
 }
 
+/**
+ * @internal
+ * @brief handles a SSH_SERVICE_ACCEPT packet
+ *
+ */
+SSH_PACKET_CALLBACK(ssh_packet_service_accept){
+	(void)packet;
+	(void)type;
+	(void)user;
+	enter_function();
+	session->auth_service_state=SSH_AUTH_SERVICE_ACCEPTED;
+	ssh_log(session, SSH_LOG_PACKET,
+	      "Received SSH_MSG_SERVICE_ACCEPT");
+	leave_function();
+	return SSH_PACKET_USED;
+}
+
 /**
  * @internal
  *
@@ -476,52 +493,55 @@ error:
  * @param  session      The session to use to ask for a service request.
  * @param  service      The service request.
  *
- * @return 0 on success, < 0 on error.
+ * @return SSH_OK on success
+ * @return SSH_ERROR on error
+ * @return SSH_AGAIN No response received yet
+ * @bug actually only works with ssh-userauth
  */
 int ssh_service_request(ssh_session session, const char *service) {
   ssh_string service_s = NULL;
-
+  int rc=SSH_ERROR;
   enter_function();
+  switch(session->auth_service_state){
+  	case SSH_AUTH_SERVICE_NONE:
+  		if (buffer_add_u8(session->out_buffer, SSH2_MSG_SERVICE_REQUEST) < 0) {
+  			break;
+  		}
+  		service_s = string_from_char(service);
+  		if (service_s == NULL) {
+  			break;
+  		}
 
-  if (buffer_add_u8(session->out_buffer, SSH2_MSG_SERVICE_REQUEST) < 0) {
+  		if (buffer_add_ssh_string(session->out_buffer,service_s) < 0) {
-    leave_function();
+  			string_free(service_s);
-    return -1;
+  			break;
+  		}
+  		string_free(service_s);
+
+  		if (packet_send(session) != SSH_OK) {
+  			ssh_set_error(session, SSH_FATAL,
+  					"Sending SSH2_MSG_SERVICE_REQUEST failed.");
+  			break;
+  		}
+
+  		ssh_log(session, SSH_LOG_PACKET,
+  				"Sent SSH_MSG_SERVICE_REQUEST (service %s)", service);
+  		session->auth_service_state=SSH_AUTH_SERVICE_SENT;
+  		rc=SSH_AGAIN;
+  		break;
+  	case SSH_AUTH_SERVICE_DENIED:
+  		ssh_set_error(session,SSH_FATAL,"ssh_auth_service request denied");
+  		break;
+  	case SSH_AUTH_SERVICE_ACCEPTED:
+  		rc=SSH_OK;
+  		break;
+  	case SSH_AUTH_SERVICE_SENT:
+  		rc=SSH_AGAIN;
+  		break;
   }
 
-  service_s = string_from_char(service);
-  if (service_s == NULL) {
-    leave_function();
-    return -1;
-  }
-
-  if (buffer_add_ssh_string(session->out_buffer,service_s) < 0) {
-    string_free(service_s);
-    leave_function();
-    return -1;
-  }
-  string_free(service_s);
-
-  if (packet_send(session) != SSH_OK) {
-    ssh_set_error(session, SSH_FATAL,
-        "Sending SSH2_MSG_SERVICE_REQUEST failed.");
-    leave_function();
-    return -1;
-  }
-
-  ssh_log(session, SSH_LOG_PACKET,
-      "Sent SSH_MSG_SERVICE_REQUEST (service %s)", service);
-
-  if (packet_wait(session,SSH2_MSG_SERVICE_ACCEPT,1) != SSH_OK) {
-    ssh_set_error(session, SSH_FATAL, "Did not receive SERVICE_ACCEPT");
-    leave_function();
-    return -1;
-  }
-
-  ssh_log(session, SSH_LOG_PACKET,
-      "Received SSH_MSG_SERVICE_ACCEPT (service %s)", service);
-
   leave_function();
-  return 0;
+  return rc;
 }
 
 /** \addtogroup ssh_session

libssh/packet.c

@@ -53,7 +53,7 @@ ssh_packet_callback default_packet_handlers[]= {
 	NULL, //#define SSH2_MSG_UNIMPLEMENTED 3
 	ssh_packet_ignore_callback, //#define SSH2_MSG_DEBUG	4
 	NULL, //#define SSH2_MSG_SERVICE_REQUEST	5
-	NULL, //#define SSH2_MSG_SERVICE_ACCEPT 6
+	ssh_packet_service_accept, //#define SSH2_MSG_SERVICE_ACCEPT 6
 	NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
 	NULL, NULL, NULL, // 7-19
 	ssh_packet_kexinit, //#define SSH2_MSG_KEXINIT	 20