From 944a35d200c9b22ad6a81cadd06c45ee64bd9f8f Mon Sep 17 00:00:00 2001
From: jochen <jschoubben@gmail.com>
Date: Mon, 26 Oct 2026 19:23:06 +0100
Subject: [PATCH] =?UTF-8?q?A=20node's=20record=20carries=20the=20mesh's=20?=
 =?UTF-8?q?own=20certificate=20as=20the=20machine=20holds=20it,=20and=20fr?=
 =?UTF-8?q?ombus=20composes=20with=20the=20composing=20node's=20(issue=201?=
 =?UTF-8?q?126,=20ADR=200555=20=C2=A73)?=
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---
 go/compose/frombus/frombus.go      | 14 ++++++++++++++
 go/compose/frombus/frombus_test.go |  3 ++-
 go/delivery/noderecord.go          |  3 +++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/go/compose/frombus/frombus.go b/go/compose/frombus/frombus.go
index 44cde19..67f2c1e 100644
--- a/go/compose/frombus/frombus.go
+++ b/go/compose/frombus/frombus.go
@@ -106,6 +106,20 @@ func Input(ctx context.Context, r Reader, mesh Mesh, s Scope) (compose.Input, er
 
 	in := compose.Input{OverlayCIDR: mesh.OverlayCIDR, InternalSuffix: mesh.InternalSuffix, Authority: mesh.Authority,
 		Catalogue: map[string]catalogue.Manifest{}}
+	if in.Authority == "" {
+		// The mesh's own certificate, public, as the composing node holds it; for the check of every node, as the first
+		// node holding one does.
+		if rec, ok := records[s.Node]; ok && rec.Authority != "" {
+			in.Authority = rec.Authority
+		} else {
+			for _, node := range sortedKeys(records) {
+				if a := records[node].Authority; a != "" {
+					in.Authority = a
+					break
+				}
+			}
+		}
+	}
 	read := func(module, digest string) (catalogue.Manifest, error) {
 		raw, err := r.Manifest(ctx, digest)
 		if err != nil {
diff --git a/go/compose/frombus/frombus_test.go b/go/compose/frombus/frombus_test.go
index fedc381..b8ca0ef 100644
--- a/go/compose/frombus/frombus_test.go
+++ b/go/compose/frombus/frombus_test.go
@@ -88,7 +88,7 @@ func TestInput(t *testing.T) {
 			},
 			records: map[string]delivery.NodeRecord{
 				"anchor": {Node: "anchor", TunnelKey: keys["anchor"], Capabilities: caps, Contract: 2},
-				"laptop": {Node: "laptop", TunnelKey: keys["laptop"], Capabilities: caps},
+				"laptop": {Node: "laptop", TunnelKey: keys["laptop"], Capabilities: caps, Authority: "the mesh's certificate"},
 			},
 			modules:   map[string]delivery.Module{"xterm": {Manifest: digest}, "unread": {}},
 			manifests: map[string][]byte{digest: xterm},
@@ -127,6 +127,7 @@ func TestInput(t *testing.T) {
 		Tunnels:       map[string]compose.FoundTunnel{"anchor": {Tunnel: tun}},
 		Adopted:       &compose.AdoptedTunnel{Tunnel: tun, Hub: "anchor", Adopted: true},
 		// The controller's order is by address; laptop enrolled under its peer's key, and a person named the other.
+		Authority: "the mesh's certificate",
 		CarriedPeers: []compose.CarriedPeer{{PublicKey: keys["laptop"], Address: "10.77.0.2", EnrolledAs: "laptop"},
 			{PublicKey: "peer", Address: "10.77.0.9", Named: "phone"}},
 	}
diff --git a/go/delivery/noderecord.go b/go/delivery/noderecord.go
index d7fef79..c22f8b2 100644
--- a/go/delivery/noderecord.go
+++ b/go/delivery/noderecord.go
@@ -52,6 +52,9 @@ type NodeRecord struct {
 	Networks     []catalogue.AttachedNetwork `json:"networks,omitempty"`
 	NetworksSaid bool                        `json:"networks-said,omitempty"`
 	Contract     int                         `json:"contract,omitempty"`
+	// Authority is the mesh's own certificate as this machine holds it (public): the one its declaration last wrote where
+	// a module asked for it. A node composing its own composes a certificate with it (compose.Input.Authority).
+	Authority string `json:"authority,omitempty"`
 }
 
 func (r NodeRecord) check() error {