Migrate parts of prop. 156 to spec section for 0.9.49

Update I2NP spec for prop. 156
Clarify prop. 154 based on subsequent decisions made in prop. 156
Add more notes common structures spec about ECIES routers
Add notes in more places that tunnel ID must not be zero

i2p2www/spec/proposals/154-ecies-lookups.rst

@@ -5,7 +5,7 @@ Database Lookups from ECIES Destinations
     :author: zzz
     :created: 2020-03-23
     :thread: http://zzz.i2p/topics/2856
-    :lastupdated: 2020-05-07
+    :lastupdated: 2021-01-08
     :status: Closed
     :target: 0.9.46
     :implementedin: 0.9.46
@@ -15,11 +15,11 @@ Database Lookups from ECIES Destinations
 
 Note
 ====
-ECIES to ElG is implemented and the proposal phase is closed.
+ECIES to ElG is implemented in 0.9.46 and the proposal phase is closed.
 See [I2NP]_ for the official specification.
 This proposal may still be referenced for background information.
-ECIES to ECIES is not fully specified or implemented at this time.
-The ECIES-to-ECIES section may be reopened or incorporated
+ECIES to ECIES with included keys is implemented as of 0.9.48.
+The ECIES-to-ECIES (derived keys) section may be reopened or incorporated
 in a future proposal.
 
 
@@ -146,14 +146,21 @@ Flag bit 4 is used in combination with bit 1 to determine the reply encryption m
 Flag bit 4 must only be set when sending to routers with version 0.9.46 or higher.
 
 
+In the table below,
+"DH n/a" means that the reply is not encrypted.
+"DH no" means that the reply keys are included in the request.
+"DH yes" means that the reply keys are derived from the DH operation.
+
+
 =============  =========  =========  ======  ===  =======
 Flag bits 4,1  From Dest  To Router  Reply   DH?  notes
 =============  =========  =========  ======  ===  =======
-0 0            Any        Any        no enc  no   current
+0 0            Any        Any        no enc  n/a  current
 0 1            ElG        ElG        AES     no   current
 0 1            ECIES      ElG        AES     no   i2pd workaround
-1 0            ECIES      ElG        AEAD    no   new, no DH
-1 1            ECIES      ECIES      AEAD    yes  future, with DH
+1 0            ECIES      ElG        AEAD    no   this proposal
+1 0            ECIES      ECIES      AEAD    no   0.9.49
+1 1            ECIES      ECIES      AEAD    yes  future
 =============  =========  =========  ======  ===  =======
 
 
@@ -262,11 +269,28 @@ tag :: 8 byte reply_tag
 
 
 
-ECIES to ECIES
---------------
+ECIES to ECIES (0.9.49)
+-----------------------------
 
-ECIES destination sends a lookup to a ECIES router.
-Supported as of 0.9.TBD.
+ECIES destination or router sends a lookup to a ECIES router, with bundled reply keys.
+Supported as of 0.9.49.
+
+ECIES routers were introduced in 0.9.48, see [Prop156]_.
+As of 0.9.49, ECIES destinations and routers may use the same format as in
+the "ECIES to ElG" section above, with reply keys included in the request.
+The lookup will use the "one time format" in [ECIES]_
+as the requester is anonymous.
+
+For a new method with derived keys, see the next section.
+
+
+
+
+ECIES to ECIES (future)
+-----------------------------
+
+ECIES destination or router sends a lookup to a ECIES router, and the reply keys are derived from the DH.
+Not fully defined or supported, implementation is TBD.
 
 The lookup will use the "one time format" in [ECIES]_
 as the requester is anonymous.
@@ -275,8 +299,6 @@ Redefine reply_key field as follows. There are no associated tags.
 The tags will be generated in the KDF below.
 
 This section is incomplete and requires further study.
-ECIES routers do not yet exist and there is no documented proposal
-for ECIES routers at this time.
 
 
 .. raw:: html
@@ -428,3 +450,5 @@ References
 .. [I2NP]
     {{ spec_url('i2np') }}
 
+.. [Prop156]
+    {{ proposal_url('156') }}

i2p2www/spec/proposals/156-ecies-routers.rst

@@ -12,6 +12,19 @@ ECIES Routers
 .. contents::
 
 
+Note
+====
+Network deployment and testing in progress.
+Subject to revision.
+Status:
+
+- ECIES Routers implemented as of 0.9.48, see [Common]_.
+- Tunnel building implemented as of 0.9.48, see [Tunnel-Creation-ECIES]_.
+- Encrypted messages to ECIES routers implemented as of 0.9.49, see [ECIES-ROUTERS]_.
+- New tunnel build message is not yet defined or implemented.
+
+
+
 
 Overview
 ========
@@ -538,6 +551,9 @@ References
 .. [ECIES]
    {{ spec_url('ecies') }}
 
+.. [ECIES-ROUTERS]
+   {{ spec_url('ecies-routers') }}
+
 .. [I2NP]
     {{ spec_url('i2np') }}