From 7f662e9d3af14f7693d49eac2acba3d0c4111f03 Mon Sep 17 00:00:00 2001
From: zzz <zzz@mail.i2p>
Date: Wed, 7 Mar 2018 17:59:24 +0000
Subject: [PATCH] Clarify that tunnel IDs may not be zero

---
 i2p2www/spec/i2np.rst            |  6 ++++--
 i2p2www/spec/tunnel-creation.rst | 10 +++++-----
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/i2p2www/spec/i2np.rst b/i2p2www/spec/i2np.rst
index 06524bf0..a2b16886 100644
--- a/i2p2www/spec/i2np.rst
+++ b/i2p2www/spec/i2np.rst
@@ -3,8 +3,8 @@ I2NP Specification
 ==================
 .. meta::
     :category: Protocols
-    :lastupdated: January 2017
-    :accuratefor: 0.9.28
+    :lastupdated: March 2018
+    :accuratefor: 0.9.34
 
 .. contents::
 
@@ -308,12 +308,14 @@ Cleartext:
 
   receive_tunnel :: `TunnelId`
                     length -> 4 bytes
+                    nonzero
 
   our_ident :: `Hash`
                length -> 32 bytes
 
   next_tunnel :: `TunnelId`
                  length -> 4 bytes
+                 nonzero
 
   next_ident :: `Hash`
                 length -> 32 bytes
diff --git a/i2p2www/spec/tunnel-creation.rst b/i2p2www/spec/tunnel-creation.rst
index d17adf51..fcc5c98b 100644
--- a/i2p2www/spec/tunnel-creation.rst
+++ b/i2p2www/spec/tunnel-creation.rst
@@ -3,8 +3,8 @@ Tunnel Creation Specification
 =============================
 .. meta::
     :category: Design
-    :lastupdated: January 2016
-    :accuratefor: 0.9.24
+    :lastupdated: March 2018
+    :accuratefor: 0.9.34
 
 .. contents::
 
@@ -58,9 +58,9 @@ Also specified in the I2NP Specification [BRR]_.
 
 Cleartext of the record, visible only to the hop being asked::
 
-  bytes     0-3: tunnel ID to receive messages as
+  bytes     0-3: tunnel ID to receive messages as, nonzero
   bytes    4-35: local router identity hash
-  bytes   36-39: next tunnel ID
+  bytes   36-39: next tunnel ID, nonzero
   bytes   40-71: next router identity hash
   bytes  72-103: AES-256 tunnel layer key
   bytes 104-135: AES-256 tunnel IV key
@@ -95,7 +95,7 @@ set, the hop will be an intermediate participant.  Both cannot be set at once.
 
 Request Record Creation
 ```````````````````````
-Every hop gets a random Tunnel ID.
+Every hop gets a random Tunnel ID, nonzero.
 The current and next-hop Tunnel IDs are filled in.
 Every record gets a random tunnel IV key, reply IV, layer key, and reply key.