X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=hippotat.git;a=blobdiff_plain;f=PROTOCOL;h=e18cf0e1554da169e6ffdcd8994ba3a727f8c17c;hp=4e07db163296421c402714f8858a0059a1e5725a;hb=a14782d3bb7fe3e65f19e45d913d2e5f5d8662bb;hpb=dce21e00c38132b17ec973923f4f7d0cbf47049f

diff --git a/PROTOCOL b/PROTOCOL
index 4e07db1..e18cf0e 100644
--- a/PROTOCOL
+++ b/PROTOCOL
@@ -8,7 +8,9 @@ from the queue and returns them as the POST response body payload
 Each incoming request contains up to max_batch_up bytes of payload.
 It's a multipart/form-data.
 
-Authentication: for now, plaintext secret
+Authentication: clock-based lifetime-limited bearer tokens.
+
+Encryption and integrity checking: none.  Use a real VPN over this!
 
 Routing assistance: none in hippotat; can be requested on client
  from userv-ipif via `vroutes' parameter.  Use with secnet polypath
@@ -17,12 +19,16 @@ Routing assistance: none in hippotat; can be requested on client
 Client form parameters (multipart/form-data):
  m		metadata, newline-separated list (text file) of
 			client ip address (textual)
-		       	password
+		       	token
 			target_requests_outstanding
 			http_timeout
  d              data (SLIP format, with SLIP_ESC and `-' swapped)
 
 
+Authentication token is:
+        <time_t in hex with no leading 0s> <hmac in base64>
+(separated by a single space).  The hmac is
+        HMAC(secret, <time_t in hex>)
 
 
 Possible future nonce-based authentication: