[tor-commits] [torspec/master] prop224: No special INTRODUCE1 cell for legacy intro points.

[nickm at torproject.org]

commit 6453c7dc4ebf7955232b6a6dd9dd0e7e726b4384
Author: George Kadianakis <desnacked at riseup.net>
Date:   Mon Sep 18 15:07:01 2017 +0300

    prop224: No special INTRODUCE1 cell for legacy intro points.
    
    Intro points don't care about the contents of the INTRO1 cell as long as
    the first 20 bytes are correctly formatted, so we don't need to have a
    special cell for legacy intros. Remove all references to it.
---
 proposals/224-rend-spec-ng.txt | 41 ++++++++---------------------------------
 1 file changed, 8 insertions(+), 33 deletions(-)

diff --git a/proposals/224-rend-spec-ng.txt b/proposals/224-rend-spec-ng.txt
index 9aeeeb7..095fd9f 100644
--- a/proposals/224-rend-spec-ng.txt
+++ b/proposals/224-rend-spec-ng.txt
@@ -54,8 +54,7 @@ Table of contents:
             3.1.3. Acknowledging establishment of introduction point [INTRO_ESTABLISHED]
         3.2. Sending an INTRODUCE1 cell to the introduction point. [SEND_INTRO1]
             3.2.1. INTRODUCE1 cell format [FMT_INTRO1]
-            3.2.2. Legacy formats [LEGACY-INTRODUCE1]
-            3.2.3. INTRODUCE_ACK cell format. [INTRO_ACK]
+            3.2.2. INTRODUCE_ACK cell format. [INTRO_ACK]
         3.3. Processing an INTRODUCE2 cell at the hidden service. [PROCESS_INTRO2]
             3.3.1. Introduction handshake encryption requirements [INTRO-HANDSHAKE-REQS]
             3.3.2. Example encryption handshake: ntor with extra data [NTOR-WITH-EXTRA-DATA]
@@ -1340,8 +1339,7 @@ Table of contents:
           [None or at most once per introduction point]
 
           The key is an ASN.1 encoded RSA public key in PEM format used for a
-          legacy introduction point as described in [LEGACY_EST_INTRO] and
-          [LEGACY-INTRODUCE1] below.
+          legacy introduction point as described in [LEGACY_EST_INTRO].
 
           This field is only present if the introduction point only supports
           legacy protocol (v2) that is <= 0.2.9 or the protocol version value
@@ -1578,14 +1576,14 @@ Table of contents:
        EXT_FIELD      [EXT_FIELD_LEN bytes]
      ENCRYPTED        [Up to end of relay payload]
 
+   AUTH_KEY_TYPE is defined as in [EST_INTRO]. Currently, the only value of
+   AUTH_KEY_TYPE for this cell is an Ed25519 public key [02].
+
    The LEGACY_KEY_ID field is used to distinguish between legacy and new style
    INTRODUCE1 cells. In new style INTRODUCE1 cells, LEGACY_KEY_ID is 20 zero
    bytes. Upon receiving an INTRODUCE1 cell, the introduction point checks the
    LEGACY_KEY_ID field. If LEGACY_KEY_ID is non-zero, the INTRODUCE1 cell
-   should be handled as specified in [LEGACY-INTRODUCE1].
-
-   AUTH_KEY_TYPE is defined as in [EST_INTRO]. Currently, the only value of
-   AUTH_KEY_TYPE for this cell is an Ed25519 public key [02].
+   should be handled as a legacy INTRODUCE1 cell by the intro point.
 
    Upon receiving a INTRODUCE1 cell, the introduction point checks
    whether AUTH_KEY matches the introduction point authentication key for an
@@ -1593,27 +1591,7 @@ Table of contents:
    INTRODUCE2 cell with exactly the same contents to the service, and sends an
    INTRODUCE_ACK response to the client.
 
-3.2.2. Legacy formats [LEGACY-INTRODUCE1]
-
-   For legacy introduction points, INTRODUCE1 cells should be of the form:
-
-     LEGACY_KEY_ID        [20 bytes]
-     N_EXTENSIONS         [1 byte]
-     N_EXTENSIONS times:
-       EXT_FIELD_TYPE     [1 byte]
-       EXT_FIELD_LEN      [1 byte]
-       EXT_FIELD          [EXT_FIELD_LEN bytes]
-     ENCRYPTED            [Up to end of relay payload]
-
-   Here, LEGACY_KEY_ID is the hash of the introduction point legacy
-   encryption key that was included in the hidden service descriptor.
-
-   Because of limitations in older versions of Tor, the relay payload size for
-   these INTRODUCE1 cells must always be at least 246 bytes, or they will be
-   rejected as invalid. The ENCRYPTED field may contain padding to reach this
-   length.
-
-3.2.3. INTRODUCE_ACK cell format. [INTRO_ACK]
+3.2.2. INTRODUCE_ACK cell format. [INTRO_ACK]
 
    An INTRODUCE_ACK cell has the following fields:
 
@@ -1780,10 +1758,7 @@ Table of contents:
 
 
    (This format is as documented in [FMT_INTRO1] above, except that here
-   we describe how to build the ENCRYPTED portion. If the introduction
-   point is running an older Tor that does not support this protocol,
-   the first field is replaced by a 20-byte AUTH_KEYID_HASH field as
-   described in [LEGACY-INTRODUCE1].)
+   we describe how to build the ENCRYPTED portion.)
 
    Here, the encryption key plays the role of B in the regular ntor
    handshake, and the AUTH_KEY field plays the role of the node ID.