Add a sequence diagram for channel handshake

1 files changed, 19 insertions, 1 deletions

diff --git a/spec/tor-spec/negotiating-channels.md b/spec/tor-spec/negotiating-channels.md
index c328e12..1184fd8 100644
--- a/spec/tor-spec/negotiating-channels.md
+++ b/spec/tor-spec/negotiating-channels.md
@@ -22,7 +22,7 @@ In brief:
    to establish clock skew and IP addresses.
  - The initiator checks whether the CERTS cell is correct,
    and decides whether to authenticate.
- - If the initiator does not wants to authenticate, 
+ - If the initiator does not wants to authenticate,
    it sends a [NETINFO cell](#NETINFO-cells).
  - If the initiator wants to authenticate,
    it sends a [CERTS cell](#CERTS-cells),
@@ -38,6 +38,24 @@ except for VPADDING cells.
 by scanning-resistance designs.
 It is not specified here.)
 
+```mermaid
+sequenceDiagram
+   Initiator --> Responder: TLS Handshake
+
+   Note over Initiator,Responder: The rest is encrypted
+
+   Initiator ->> Responder: VERSIONS
+   Responder ->> Initiator: VERSIONS, CERTS, AUTH_CHALLENGE, NETINFO
+
+   opt if the initiator wants to authenticate
+      Initiator ->> Responder: CERTS, AUTHENTICATE
+   end
+
+   Initiator ->> Responder: NETINFO
+```
+
+
+
 ## The TLS handshake {#tls}
 
 <span id="in-protocol">The