From daef1ee3798b25e8464b8eb618eaa74b8f423ac7 Mon Sep 17 00:00:00 2001 From: Tuong Lien Date: Fri, 18 Sep 2020 08:17:27 +0700 Subject: tipc: introduce encryption master key In addition to the supported cluster & per-node encryption keys for the en/decryption of TIPC messages, we now introduce one option for user to set a cluster key as 'master key', which is simply a symmetric key like the former but has a longer life cycle. It has two purposes: - Authentication of new member nodes in the cluster. New nodes, having no knowledge of current session keys in the cluster will still be able to join the cluster as long as they know the master key. This is because all neighbor discovery (LINK_CONFIG) messages must be encrypted with this key. - Encryption of session encryption keys during automatic exchange and update of those.This is a feature we will introduce in a later commit in this series. We insert the new key into the currently unused slot 0 in the key array and start using it immediately once the user has set it. After joining, a node only knowing the master key should be fully communicable to existing nodes in the cluster, although those nodes may have their own session keys activated (i.e. not the master one). To support this, we define a 'grace period', starting from the time a node itself reports having no RX keys, so the existing nodes will use the master key for encryption instead. The grace period can be extended but will automatically stop after e.g. 5 seconds without a new report. This is also the basis for later key exchanging feature as the new node will be impossible to decrypt anything without the support from master key. For user to set a master key, we define a new netlink flag - 'TIPC_NLA_NODE_KEY_MASTER', so it can be added to the current 'set key' netlink command to specify the setting key to be a master key. Above all, the traditional cluster/per-node key mechanism is guaranteed to work when user comes not to use this master key option. This is also compatible to legacy nodes without the feature supported. Even this master key can be updated without any interruption of cluster connectivity but is so is needed, this has to be coordinated and set by the user. Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller --- include/uapi/linux/tipc_netlink.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include') diff --git a/include/uapi/linux/tipc_netlink.h b/include/uapi/linux/tipc_netlink.h index dc0d23a50e69..d484baa9d365 100644 --- a/include/uapi/linux/tipc_netlink.h +++ b/include/uapi/linux/tipc_netlink.h @@ -165,6 +165,7 @@ enum { TIPC_NLA_NODE_UP, /* flag */ TIPC_NLA_NODE_ID, /* data */ TIPC_NLA_NODE_KEY, /* data */ + TIPC_NLA_NODE_KEY_MASTER, /* flag */ __TIPC_NLA_NODE_MAX, TIPC_NLA_NODE_MAX = __TIPC_NLA_NODE_MAX - 1 -- cgit v1.2.3