Arnd Bergmann <a...@arndb.de> wrote:
> Ah, I'm slowly starting to understand how this fits together. So you can add
> a key either through key_add() from local user space, or through an rxrpc
No, you can't add keys through an rxrpc socket.
There are three 'classes' of key:
(1) Client keys (type rxrpc). These must be added by add_key() by userspace
(but could also be acquired by upcalling to /sbin/request-key) and then
the kernel calls request_key() to locate them on entry through either a
kafs inode/file operation or through sendmsg() to an AF_RXRPC socket.
(2) Server keys (type rxrpc_s). These are created by userspace and are
presented to an AF_RXRPC server socket by calling setsockopt(). The
server uses these to validate/decrypt the token passed by a RESPONSE
(3) Service connection keys (type rxrpc). These are created internally by
AF_RXRPC after a successful challenge/response negotiation to hold the
security details so that we have a struct key to pass around that
corresponds to the key in (1).