update TODO

diff --git a/TODO b/TODO
index 88f02cda797a152ee45ff5aa642c22355ab313bc..060e3248c87de9c6c0838251e642dfe9fccc531e 100644 (file)
--- a/TODO
+++ b/TODO
@@ -119,6 +119,50 @@ Deprecations and removals:
 
 Features:
 
+* add support for asymmetric LUKS2 TPM based encryption. i.e. allow preparing
+  an encrypted image on some host given a public key belonging to a specific
+  other host, so that only hosts possessing the private key in the TPM2 chip
+  can decrypt the volume key and activate the volume. Usecase: systemd-syscfg
+  for a central orchestrator to generate syscfg images securely that can only
+  be activated on one specific host (which can be used for installing a bunch
+  of creds in /etc/credstore/ for example). Extending on this: allow binding
+  LUKS2 TPM based encryption also to the TPM2 internal clock. Net result:
+  prepare a syscfg image that can only be activated on a specific host that
+  runs a specific software in a specific time window. syscfg would be
+  automatically invalidated outside of it.
+
+* maybe add a "systemd-report" tool, that generates a TPM2-backed "report" of
+  current system state, i.e. a combination of PCR information, local system
+  time and TPM clock, running services, recent high-priority log
+  messages/coredumps, system load/PSI, signed by the local TPM chip, to form an
+  enhanced remote attestation quote. Usecase: a simple orchestrator could use
+  this: have the report tool upload thes reports every 3min somewhere. Then
+  have the orchestrator collect these reports centrally over a 3min time
+  window, and use them to determine what which node should now start/stop what,
+  and generate a small syscfg for each node, that uses Uphold= to pin services
+  on each node.  The syscfg would be encrypted using the asymmetric encryption
+  proposed above, so that it can only be activated on the specific host, if the
+  software is in a good state, and within a specific time frame. Then run a
+  loop on each node that sends report to orchestrator and then sysupdate to
+  update syscfg.  Orchestrator would be stateless, i.e. operate on desired
+  config and collected reports in the last 3min time window only, and thus can
+  be trivially scaled up since all instances of the orchestrator should come to
+  the same conclusions given the same inputs of reports/desired workload info.
+  Could also be used to deliver Wireguard secrets and thus to clients, thus
+  permitting zero-trust networking: secrets are rolled over via syscfg updates,
+  and via the time window TPM logic invalidated if node doesn't keep itself
+  updated, or becomes corrupted in some way.
+
+* Always measure the LUKS rootfs volume key into PCR 15, and derive the machine
+  ID from it securely. This would then allow us to bind secrets a specific
+  system securely.
+
+* nspawn: maybe allow TPM passthrough, backed by swtpm, and measure --image=
+  hash into its PCR 11, so that nspawn instances can be TPM enabled, and
+  partake in measurements/remote attestation and such. swtpm would run outside
+  of control of container, and ideally would itself bind its encryption keys to
+  host TPM.
+
 * tree-wide: convert as much as possible over to use sd_event_set_signal_exit(), instead
   of manually hooking into SIGINT/SIGTERM