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Johnathan Corgan 6a564e26ac Prepare the v0.5.0 release content 
Everything the release needs except the version number, which stays at
0.5.0-dev until the tag.

The changelog entry covers only the work that is new on this line. The
point release's forty-six entries arrived under their own heading with the
forward merge and are left alone; the twenty that remained are regrouped by
topic and eight more added for changes no entry covered. Three of those
eight matter to someone upgrading. Five root modules and four re-exports
left the public library surface and Node::connections narrowed, none of it
recorded anywhere; the entry names what to use instead and distinguishes
the removed connection-phase enum from the Noise type of the same name,
which is a different type that still exists. Tracing targets moved, so an
existing RUST_LOG filter stops matching rather than erroring. And the
handshake resend interval key no longer governs the first resend, which is
now a constant, though it still governs later ones.

Seven more entries cover the work that landed after the first content pass
was written: the experimental native datagram API, the fipsctl probe
diagnostic, per-instance transport addressing, the app-owned UDP socket
seam, and the connect, disconnect and path-MTU fixes. The four bug fixes
among them all reach the deployed line, so the release notes no longer
claim this release carries exactly one fix for a shipped bug; it carries
four.

There is no security section, because after the split every security entry
belongs to the point release. The release notes say so plainly rather than
leaving a reader upgrading across both releases to conclude this one
carries no security work.

The notes are organized by audience, since the release spans OpenWrt
routers, embedders, FreeBSD, and the existing platforms, and a single list
serves none of them. The native datagram API is given a section of its own
rather than folded into the embedding seam: it is a client-facing API
rather than a way to host a node, and its one rule with no Berkeley-socket
counterpart, that the v1 wire carries no half-close, needs to be somewhere
a client author will read it. FreeBSD is advertised as supported on x86_64
only, stated wherever the platform appears. Android is advertised as an
embedding seam and not as a supported platform: a compile-gated library
surface with no artifact and no host application guide.

The configuration table rename is carried through every shipped file that
taught the old spelling: nine documentation files, the OpenWrt sample
config and a test generator, twenty-two sites in all. Guides written this
same cycle were among them, which is how the omission was found. The
documentation that arrived with the native API was checked for the same
omission and was already clean. The compatibility tests keep the old
spelling deliberately, since they exist to test the fold.

The changelog section is the fold of master's [Unreleased], not a snapshot
of it. An earlier version of this commit took a copy that then drifted, so
each section ended up holding a bullet the other did not and re-folding
them would have picked a winner silently. Both causes were fixed on master
instead — the NixOS module had never been recorded there, and the
pre-release batch of fixes was new — so [Unreleased] is a strict superset
and this is a copy rather than a merge. [0.5.0] carries all forty-six
bullets byte for byte, [Unreleased] is empty, and [0.4.2] is untouched,
checked by hashing it against master's copy.

The BLE work landed after the content pass and gets one summary entry in
the changelog and one section in the release notes rather than nine
bullets: the ble_available gate replacing target_os = "linux",
packet-boundary recovery for stream-oriented backends, peer recognition by
node identity instead of a rotating link address, the L2CAP PSM moving
into the backend seam and onto the advertisement, the embedder-supplied
Android radio, bounded probe retry, and inbound handshakes moved off the
accept loop.

The two release-notes copies no longer share their link paths. Relative
links resolve from one directory only, so the seven written for
docs/releases/ all 404ed from the root copy. The root copy now uses paths
from the repository root and the versioned copy keeps the ../ form; both
sets were resolved against the tree. The same two links are broken the
same way in the v0.4.0 through v0.4.2 notes, left as shipped history.

The contributor tallies are re-derived against maint..HEAD rather than
adjusted: twenty commits from outside the project and 171 from me, with
Arjen at fifteen and fr34aky at two. An earlier count of twelve and 138
was carried from a measurement taken three days before this content was
written, and the BLE branch widened the gap after it. Arjen's NixOS flake
module, the UDP sin6_scope_id fix and most of the BLE rework were
uncredited, as was fr34aky's L2CAP PSM seam. They want one last re-derive
at tag time if anything lands before the tag.

A sweep of all 99 tracked markdown files against the tree corrected
fifty-three of them. Four told the reader to run a build.sh that does not
exist; the only harness builder is testing/scripts/build.sh. The BLE build
prerequisites were described as optional on the strength of a probe that
build.rs does not perform, and bluez was named a build prerequisite when
libdbus-sys asks only for libdbus-1-dev and pkg-config and bluez is the
runtime daemon. Link cost is the primary sort key in next-hop ranking, not
reserved for future use; Ethernet runs on macOS as well as Linux; the BLE
MTU is the L2CAP CoC MTU rather than a negotiated ATT_MTU; effective
Ethernet MTU is 1497; the LAN discovery subsystem is src/mdns and eight
citations still named a src/discovery that never existed here. The
connectivity states in three tutorials were invented, and their jq filters
matched nothing including healthy peers. One command filtered on a literal
fd97: address prefix, which only the first byte of fixes, so it returned
empty for all but one reader in 256 and every later step using the
variable failed silently. transports.tor.advertise_on_nostr was
undocumented despite being validated against node.rendezvous.nostr.enabled.

The transport design document gains the BLE section it never had, written
from the source: the backend cascade and its compile_error tripwire, the
platform gate, the PSM advertisement wire layout and the byte budget that
forces a 16-bit service-data key, and the probe and admission bounds.

Three source files carried the same class of staleness and are corrected
with the documentation: the OpenWrt ipk usage line and Makefile error text
both named a packaging/openwrt that does not exist, and chaos.sh parsed
--subnet without listing it.

Folded in with the content commit, having been prepared alongside it:

The three GitHub Action pins that had gone stale. Every third-party
action is pinned to a commit SHA, nothing reports that a pin has aged,
and re-resolving all ten against their tags found dorny/test-reporter@v2,
taiki-e/install-action@v2 and vmactions/freebsd-vm@v1 had moved. The
three install-action@nextest references stay unpinned, since that action
reads the tool to install from the ref name. check-action-pins.sh passes
at 75 references and all nine workflow files parse.

The lockfile refresh, which is the mutating half of the dependency sweep.
Thirty-six packages move to their latest semver-compatible versions and
every one is transitive; nothing declared in Cargo.toml changes version.
No advisory forces any of them. It was taken before the validation
battery, because a gate run against a lockfile that later moves proves
nothing about what ships.

The sha2 0.10 to 0.11, hkdf 0.12 to 0.13 and bech32 0.11 to 0.12 majors,
three of the four deferred at v0.4.0 for change surface rather than
security. All three land with no source change. sha2 and hkdf must move
together, since both depend on digest 0.11, and neither changes an
algorithm. That matters because the chaining-key KDF in the Noise
handshake is built on Hkdf::<Sha256>, where an output change would be a
wire break rather than a compile error; no known-answer vectors exist for
that path, so the wire-compatibility gate is what covers it. secp256k1
0.31 is deliberately absent, since nostr's own requirement would leave
two copies of the ECC library in the tree.

The README support matrix, rebuilt as one feature table broken out by
Linux variety. A single Linux column hid that Debian, Ubuntu, Arch and
NixOS are one glibc build differing in packaging, that OpenWrt is musl
and drops BLE, and that Android is not a daemon platform. Transport rows
sort by how many platforms carry them. A Native API row reads its
platform set from the cfg gates. The installer row becomes a package
format row naming the artifact, and only the .deb is exercised per
release.

Four changelog and release-note gaps the BLE re-walk found: a Bluetooth
LE bullet stranded inside the released 0.4.2 section, a missing Fixed
entry for the scan and probe loop counting a pool-refused connection as
an established link, the unnamed embedder call that installs an
application-owned radio, and the fact that stopping the transport now
stops scanning as well as advertising.

Three release-document gaps found walking the unsurveyed commits: the UDP
reuse-flag fix stated in the direction opposite to the one it was made,
with the silent second-daemon bind it prevents left unsaid; the corrected
native-API socket paragraph carried into both release-note copies, which
still named SOCK_SEQPACKET on FreeBSD and two kernels where three are
handled; and the coordinate-cache hardening, which shipped with no text
anywhere despite adding four operator-visible status fields. That last
entry states plainly that the checks are mitigations and not a closure,
since the coordinate is still not authenticated.

Also folded in, the documentation pass that followed the content commit:

A stage-pipeline diagram for the probe, embedded in the fipsctl
reference under the five-stage list. It draws the five stages left to
right with each stage's failure reasons below it, and the bypass that
skips both lookup stages when the coordinates are cached or the target
is a direct peer. Its branches come from the probe state machine rather
than from the report, so the path stage is drawn as the one failure that
does not stop the probe.

A rewrite of the README's "What FIPS does" section. It now opens with
what a machine running FIPS gets, rather than with the two deployment
modes, and gives the self-organizing and permissionless property its own
paragraph since it holds for both modes.

A regrouping of the README's feature list into the mesh, getting traffic
onto it, and running a node, with a bullet added for the native datagram
API, which had none despite sitting in the support matrix. The Quick
start now leads with the released packages rather than a source build.
It also fixes a real defect: the package enables fips.service and
fips-dns.service and starts neither on a fresh install, so .fips name
resolution was silently dead until the next reboot and neither page said
to start the service.

A rewrite of the release notes. They opened with seven subsections of
upgrade caveats and reached the first feature two hundred lines in; they
now open with a summary of the release and elaborate below it in the
same order. Android is stated as supported through an embedded crate
rather than as a standalone daemon, consistently across all three
documents. The OpenWrt pair is corrected: it is 802.11s between routers
with FIPS supplying encryption, authentication and routing, plus a
convention of an open !FIPS SSID a client joins over WiFi, not meshing
over a router's own radios. The probe's path output is described as the
least-common-ancestor walk, which is the worst-case fallback route
rather than the route a packet takes. Detail that did not change what a
reader does was cut from the notes and kept in the changelog.
2026-08-30 10:42:59 +00:00

340 lines
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# Make Your Node's Identity Persistent
After completing
[join-the-test-mesh](join-the-test-mesh.md), your daemon is
connected to the public test mesh — but its identity is
ephemeral. Every restart generates a fresh Nostr keypair, so the
npub the rest of the world would use to reach you changes every
time. This tutorial walks through pinning your node to a stable
keypair, locating it on disk, and protecting it.
The whole exercise should take about ten minutes.
## What you'll build
```text
┌─────────────────────────────────────────┐
│ /etc/fips/fips.yaml │
│ node: │
│ identity: │
│ persistent: true ← this flag │
└────────────────┬────────────────────────┘
│ daemon reads on start
▼
┌─────────────────────────────────────────┐
│ /etc/fips/fips.key 0600 root:root │
│ /etc/fips/fips.pub 0644 root:root │
└─────────────────────────────────────────┘
your stable nsec / npub
```
The diagram shows the Linux layout. On macOS the same three files
live under `/usr/local/etc/fips/`; read
[Where these files live](#where-these-files-live) before running any
command below.
After this tutorial your node will have:
- A keypair on disk that the daemon reuses across restarts.
- An npub you can hand to other operators so they can add you to
their `peers:` list once and have the entry keep working.
- A clear understanding of which file holds the secret and how
to keep it that way.
## Where these files live
Every path in this tutorial is written in its Linux form. macOS and
FreeBSD install config and keys under `/usr/local/etc/fips/` instead
of `/etc/fips/`, so on those platforms substitute as you go:
| Linux / other Unix | macOS / FreeBSD |
| --- | --- |
| `/etc/fips/fips.yaml` | `/usr/local/etc/fips/fips.yaml` |
| `/etc/fips/fips.key` | `/usr/local/etc/fips/fips.key` |
| `/etc/fips/fips.pub` | `/usr/local/etc/fips/fips.pub` |
`fipsctl keygen` writes to `/usr/local/etc/fips/` by default on
macOS. The daemon still probes `/etc/fips/fips.yaml` as a fallback,
so an existing install is not broken by an upgrade, but the macOS
packaging only installs files under `/usr/local/etc/fips/`. If a
macOS host already carries key files at the old `/etc/fips/` path,
the daemon uses the old key and warns rather than minting a new
identity; the migration recipe is in the
[how-to guide](../how-to/persistent-identity.md).
## Why a stable identity matters
In FIPS your Nostr keypair *is* your node's identity in the most
literal sense. Several things derive from it:
- Your `fd97:...` mesh address — derived from the public key.
- Your `<npub>.fips` DNS name — the npub itself with `.fips`
appended.
- Every authenticated connection — Noise IK at the mesh layer,
XK at the session layer, both prove you hold the matching
secret key.
> **A keypair, briefly.** Nostr identities are secp256k1
> keypairs. The private half is the `nsec` (a bech32-encoded
> secret key); the public half is the `npub` (a bech32-encoded
> public key). The daemon needs the `nsec` to sign messages and
> complete handshakes; the rest of the world only sees the
> `npub` and uses it as your address.
The daemon supports two ways of holding that keypair:
> **Ephemeral vs. persistent.**
>
> - *Ephemeral* (the default): the daemon mints a brand-new
> keypair every time it starts, kept only in memory. No
> long-term secret is ever written to disk; nothing on your
> machine ties one run to the next; the npub your daemon
> presents to the network is fresh on every restart. This is
> the safe-by-default posture — your node has no persistent
> identity unless you explicitly ask for one.
> - *Persistent*: the daemon reads (or, on first start,
> generates and writes) a keypair stored at
> `/etc/fips/fips.key` (`/usr/local/etc/fips/fips.key` on
> macOS). The npub stays the same across
> restarts, reboots, and reinstalls as long as that file is
> preserved. You take on the cost of protecting an on-disk
> secret in exchange for being addressable by a stable name.
Persistent identity is a deliberate trade. You give up the
ephemeral default's privacy posture — once your npub is stable,
every connection your node makes is correlatable across time —
and you take on a real secret-management responsibility. In
return you get two things you can't get any other way:
1. **Other operators can reference you by npub.** In
[join-the-test-mesh](join-the-test-mesh.md) you added
`test-us01` to your `peers:` list by its npub. That entry
only works because `test-us01`'s npub doesn't change. If
anyone is going to reach you the same way, your npub has to
be just as stable.
2. **Services on your node get a fixed address.** The
[host-a-service](host-a-service.md) tutorial walks through
running an HTTP server addressable as
`<your-npub>.fips`. Clients reach the service by that
name; if your npub changes on every restart, every
client's address book breaks.
Both of these are good reasons. Neither is automatic — if your
node is purely a *client*, reaching out to others without
hosting anything itself, you may legitimately want to stay on
the ephemeral default. The rest of this tutorial assumes you've
decided you want a stable identity.
## Step 1: Note your current ephemeral npub
Before changing anything, capture the npub the daemon is using
right now so you can compare against it after the switch.
```sh
sudo fipsctl show status | grep '"npub"'
```
You'll see one line like:
```text
"npub": "npub1abc...xyz"
```
Make a note of it. We expect this to change.
## Step 2: Enable persistent identity in the config
Open `/etc/fips/fips.yaml` (`/usr/local/etc/fips/fips.yaml` on
macOS) and find the `node:` block. The shipped default has the
relevant fragment commented out; make it look like this:
```yaml
node:
identity:
persistent: true
```
Save the file. That is the only configuration change.
The daemon's behavior on the next restart:
- If `/etc/fips/fips.key` already exists, load it and use that
identity.
- If it does not exist, generate a fresh keypair, write it to
`/etc/fips/fips.{key,pub}` with the correct file modes, and
use that.
The daemon derives the key directory from whichever config file it
loaded, so on macOS both files land in `/usr/local/etc/fips/`.
## Step 3: Restart the daemon
```sh
sudo systemctl restart fips
sudo systemctl status fips
```
Status should show `active (running)` within a couple of
seconds. Confirm the new identity is in use:
```sh
sudo fipsctl show status | grep '"npub"'
```
The npub should be **different** from the one in Step 1 — the
daemon discarded the old in-memory ephemeral keypair and minted
a new one which it has now persisted to disk. From here forward
this is *your* npub.
## Step 4: Locate the keypair on disk
The daemon wrote two files:
```sh
sudo ls -l /etc/fips/fips.key /etc/fips/fips.pub
```
On macOS, list `/usr/local/etc/fips/fips.key` and
`/usr/local/etc/fips/fips.pub` instead.
Expect:
```text
-rw------- 1 root root ... fips.key
-rw-r--r-- 1 root root ... fips.pub
```
The public file is safe to share — it is your address:
```sh
sudo cat /etc/fips/fips.pub
```
This must match the `npub` reported by `sudo fipsctl show
status`. Hand this string to anyone you want to be reachable
from; they paste it into their own `peers:` block as the `npub:`
field.
The private file is the secret. **Do not** `cat` or paste its
contents anywhere — there is no reason to see it, and any line
of shell history or screen capture that contains it has captured
the secret.
## Step 5: Verify it survives a restart
Restart once more to confirm the daemon is reading `fips.key`
rather than re-generating it:
```sh
sudo systemctl restart fips
sudo fipsctl show status | grep '"npub"'
```
The npub should match Step 3 exactly. If it does not, the daemon
was unable to read `fips.key` (most likely a permission problem)
— see [Troubleshooting](#troubleshooting).
## Step 6: Protect the nsec
`fips.key` is the only thing standing between you and someone
else impersonating your node. The daemon ships it with the right
permissions; the operator's job is to keep them that way.
What that means in practice:
- **Do not loosen the file mode.** `0600` (read/write for owner
only — here `root`) is correct; `chmod 0644` to "fix" a
permission error puts the secret on display to every account
on the host.
- **Do not commit it to source control.** If you maintain
configuration in a Git repo, exclude `fips.key`; if you use
ansible-vault or a similar mechanism, encrypt it. `fips.pub`
may be checked in freely.
- **Do not paste it into chat or email.** Operators sometimes
share config snippets to demonstrate a setup; redact the
contents of `fips.key` to a placeholder before doing so.
- **Back it up the way you back up an SSH host key.** Treat the
file (or its contents) the same way you would treat
`/etc/ssh/ssh_host_ed25519_key`: encrypted, offline, available
to recover the *same* identity if the host disappears.
There is no in-protocol "key change" message in FIPS. If
`fips.key` is lost, the npub is lost — your node will come back
up with a new identity and every downstream reference to the
old one will be stale.
## What you've learned
- **Identity = keypair.** Every FIPS node is a Nostr keypair;
the npub is its address, the nsec is its credential.
- **The flag.** `node.identity.persistent: true` in
`/etc/fips/fips.yaml` is the difference between ephemeral and
persistent identity.
- **Where it lives.** `/etc/fips/fips.key` and
`/etc/fips/fips.pub`, mode `0600` and `0644`, owned
`root:root`; under `/usr/local/etc/fips/` on macOS.
- **What to share.** `fips.pub` is public; `fips.key` is not.
- **What it buys you.** A npub other operators can add to their
`peers:` list once, and that addresses the services your node
will eventually run.
## Troubleshooting
If the post-restart npub does not match `fips.pub`:
- **Check file permissions.**
`sudo ls -l /etc/fips/fips.key`, or
`sudo ls -l /usr/local/etc/fips/fips.key` on macOS. If the mode
is not `0600` or the owner is not `root:root`, the daemon may
have refused to read it. Restore with
`sudo chmod 0600 /etc/fips/fips.key && sudo chown root:root
/etc/fips/fips.key`, substituting the macOS path where it
applies.
- **Check the journal.** `sudo journalctl -u fips -n 100` after
the restart will show one of:
- `Loaded persistent identity from key file path=...` — good.
- `Generated persistent identity, saved to key file ...` —
also good, but only expected on the first start after the
flag flip.
- `Using ephemeral identity (new keypair each start)` — the
config flag was not picked up; re-check the indentation of
the `persistent: true` line.
If you see `Generated persistent identity...` on every start,
the file is being written but not read on subsequent starts;
this is almost always the same permission/path issue.
## What's next
- **Resolve peer addresses via Nostr.**
[resolve-peers-via-nostr](resolve-peers-via-nostr.md) walks
through the smallest useful step toward Nostr-mediated
discovery: keep your peer entry, drop its hard-coded address,
and let the daemon look up the current endpoint from public
Nostr relays. The first of three tutorials covering Nostr
discovery; advertising your own node and open ambient
discovery come next.
- **Reach services on other mesh nodes.**
[reach-mesh-services](reach-mesh-services.md) drives `nc`,
`traceroute6`, `curl`, and `ssh` at peers by `.fips` name and
shows that the FIPS data plane is just IPv6 from an
application's point of view.
- **Host a service of your own.**
[host-a-service](host-a-service.md) walks through bringing up
an HTTP server addressable as `<your-npub>.fips`, bound to
`fips0` so the exposure is mesh-only, behind the mesh
firewall.
For the alternative provisioning paths — minting a keypair with
`fipsctl keygen` before the daemon ever starts, or importing an
existing Nostr `nsec` — and the key-rotation procedure, see the
operator-style recipe at
[../how-to/persistent-identity.md](../how-to/persistent-identity.md).
For the full identity model:
- [../design/fips-architecture.md](../design/fips-architecture.md)
— how npubs become `NodeAddr`s and IPv6 ULAs.
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