lsd0012

commit 4d38f86a2030aecb4d4955c0a076c5c45c1fda52
parent a12631552ba92bbdb01f83e363094027aecb8138
Author: Martin Schanzenbach <schanzen@gnunet.org>
Date:   Tue, 29 Jul 2025 13:34:01 +0200

open tasks and notes

Diffstat:
M
draft-schanzen-cake.xml
 | 
29
+++++++++++++++++++----------

1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/draft-schanzen-cake.xml b/draft-schanzen-cake.xml
@@ -143,8 +143,8 @@
           <dt>RHTS:</dt> <dd>Responder Handshake Secret Key</dd>
           <dt>H(D):</dt> <dd>A 512-bit hash over D. The hash function is TBD (Blake2b or SHA-512).</dd>
           <dt>T(M):</dt> <dd>means the transcript as a concatenation of received/sent messages starting from and including the InitiatorHello pk_e until and including M. Note that the transcript refers to everything that is seen on the wire, including potentially encrypted messages or fields and metadata.</dd>
-      <dt>'{}K'</dt> <dd>indicates encryption with a handshake traffic key K and <xref target="RFC8439"/>, the ChaCha20-Poly1305 Authenticated Encryption with Associated Data (AEAD) construction.</dd>
-      <dt>'[]K'</dt> <dd>indicates encryption with an application traffic key K and <xref target="RFC8439"/>, the ChaCha20-Poly1305 Authenticated Encryption with Associated Data (AEAD) construction.</dd>
+      <dt>'{}K'</dt> <dd>indicates encryption with a handshake traffic key K and a modified <xref target="RFC8439"/>, the XChaCha20-Poly1305 Authenticated Encryption with Associated Data (AEAD) construction.</dd>
+      <dt>'[]K'</dt> <dd>indicates encryption with an application traffic key K and a modified <xref target="RFC8439"/>, the XChaCha20-Poly1305 Authenticated Encryption with Associated Data (AEAD) construction.</dd>
     </dl>
     </section>
     <section anchor="rationale" numbered="true" toc="default">
@@ -520,7 +520,7 @@ nonce = HKDF-Expand ([I,R][A,H]TS, "iv", 24)
           <li>(ss<sub>R</sub>,c<sub>R</sub>) &lt;- Encaps(pk<sub>R</sub>)</li>
         </ol>
         <t>
-          The pk<sub>I</sub> and <tt>ServiceInfo</tt> are encrypted using ChaCha20-Poly1305 <xref target="RFC8439"/>
+          The pk<sub>I</sub> and <tt>ServiceInfo</tt> are encrypted using XChaCha20-Poly1305 <xref target="RFC8439"/>
           with key and IV derived from the ETS.
           <!-- FIXME: Discuss IV. We may be able to use data from HKDF-Expand for that -->
         </t>
@@ -684,13 +684,22 @@ nonce = HKDF-Expand ([I,R][A,H]TS, "iv", 24)
         -
       </t>
     </section>
-    <!-- <section>
-         <name>Implementation and Deployment Status</name>
-         <t>
-         FIXME
-         </t>
-         </section>
-         <section>
+    <section>
+      <name>Implementation and Deployment Status</name>
+      <t>
+        The CAKE handshake is currently implemented in a branch.
+        Open tasks include:
+      </t>
+      <ol>
+        <li>Explain how XChaCha20 works (see libsodium)</li>
+        <li>Rekeying</li>
+        <li>ACK handling including retransmissions</li>
+        <li>Services info transmission (currently empty/unused)</li>
+        <li>Secrets cleanup using memset_explicit et al.</li>
+        <li>Integrate and test PILS PID changes (potentially requires in-band signalling of new PIDs in CORE, not really that much related to CAKE)</li>
+      </ol>
+    </section>
+    <!--     <section>
          <name>Acknowledgements</name>
          <t>
          FIXME