From 6fa5ddcc675b937f94d05628e8997c07a80c6cb9 Mon Sep 17 00:00:00 2001 From: Steffen Klassert <steffen.klassert@secunet.com> Date: Mon, 9 May 2011 19:43:05 +0000 Subject: [PATCH] xfrm: Don't allow esn with disabled anti replay detection Unlike the standard case, disabled anti replay detection needs some nontrivial extra treatment on ESN. RFC 4303 states: Note: If a receiver chooses to not enable anti-replay for an SA, then the receiver SHOULD NOT negotiate ESN in an SA management protocol. Use of ESN creates a need for the receiver to manage the anti-replay window (in order to determine the correct value for the high-order bits of the ESN, which are employed in the ICV computation), which is generally contrary to the notion of disabling anti-replay for an SA. So return an error if an ESN state with disabled anti replay detection is inserted for now and add the extra treatment later if we need it. Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/xfrm/xfrm_replay.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/xfrm/xfrm_replay.c b/net/xfrm/xfrm_replay.c index e8a781422feb..47f1b8638df9 100644 --- a/net/xfrm/xfrm_replay.c +++ b/net/xfrm/xfrm_replay.c @@ -535,6 +535,9 @@ int xfrm_init_replay(struct xfrm_state *x) replay_esn->bmp_len * sizeof(__u32) * 8) return -EINVAL; + if ((x->props.flags & XFRM_STATE_ESN) && replay_esn->replay_window == 0) + return -EINVAL; + if ((x->props.flags & XFRM_STATE_ESN) && x->replay_esn) x->repl = &xfrm_replay_esn; else -- GitLab