bugfix: generate 32-bit site index in packets in a sane way

[secnet.git] / NOTES

diff --git a/NOTES b/NOTES
index 2443549cb67232ce64fe9b8f127ba20a31e32019..84453dfbf12cc7abd1bb66267107dfa037b7aae9 100644 (file)
--- a/NOTES
+++ b/NOTES
@@ -60,6 +60,17 @@ explicit option. NB packets may be routed if the source OR the
 destination is marked as allowing routing [otherwise packets couldn't
 get back from eg. chiark to a laptop at greenend]).
 
+[the even newer plan]
+
+secnet sites are configured to grant access to particular IP address
+ranges to the holder of a particular public key.  The key can certify
+other keys, which will then be permitted to use a subrange of the IP
+address range of the certifying key.
+
+This means that secnet won't know in advance (i.e. at configuration
+time) how many tunnels it might be required to support, so we have to
+be able to create them (and routes, and so on) on the fly.
+
 ** VPN-level configuration
 
 At a high level we just want to be able to indicate which groups of
@@ -182,6 +193,11 @@ i? is appropriate index for receiver
 Note that 'i' may be re-used from one session to the next, whereas 'n'
 is always fresh.
 
+The protocol version selection stuff is not yet implemented: I'm not
+yet convinced it's a good idea.  Instead, the initiator could try
+using its preferred protocol (which starts with a different magic
+number) and fall back if there's no reply.
+
 Messages:
 
 1) A->B: *,iA,msg1,A,B,protorange-A,nA
@@ -231,9 +247,7 @@ retransmit or confirm reception. It is suggested that this message be
 sent when a key times out, or the tunnel is forcibly terminated for
 some reason.
 
-XXX not yet implemented.
-
-8) i?,i?,NAK/msg8
+8) i?,i?,NAK (encoded as zero)
 
 If the link-layer can't work out what to do with a packet (session has
 gone away, etc.) it can transmit a NAK back to the sender.  The sender
@@ -256,3 +270,9 @@ Keepalives are probably a good idea.
 **** Protocol sub-goal 3: send a packet
 
 9) i?,i?,msg0,(send-packet/msg9,packet)_k
+
+Some messages may take a long time to prepare (software modexp on slow
+machines); this is a "please wait" message to indicate that a message
+is in preparation.
+
+10) i?,i?,msg8,A,B,nA,nB,msg?