Every signing carries a fresh random serial, so a mesh that signed per
composition composed a different declaration every time it was asked
what a machine should be. Every machine carrying a certificate then
stood eternally "waiting" — pushed seconds ago and already behind — and
the forge test, the first to wait for settledness on such a machine,
failed four runs in a row wearing three other faults' clothes.
Found live on a kept mesh, which is what settled it: two plans seconds
apart, identical to the byte but for one serial, in the certificate
file. Deduction had four theories; the diff had one line.
The keeping columns had existed since the serving key's migration —
"and what was issued for it" — and were written by nothing, the same
shape ReleasePorts was found in this morning.
Kept beside the serving key it certifies, and it stands while the name,
the key and the clock agree: a node rejoining with a new key or renamed
gets a fresh signing, exactly as if nothing were kept, and so does one
whose certificate is into its last stretch of life. The port's rule and
the secret's, applied to the third thing composed fresh each time.
08-connectivity keeps two authorities apart on purpose: a public one for
names the outside world reaches, and the mesh's own for names only the
mesh knows. Nothing implemented the second, so anything between machines
was plaintext or trust-on-first-use — which the design refuses everywhere
else.
A node now generates a fourth key at enrolment and reports the public
half. A fourth, because a key used for two purposes is one rotation away
from breaking the other: the identity key signs messages to the mesh and
would do for TLS, and reusing it would mean rotating a node's identity
every time its certificate is replaced.
**Nothing secret travels and nothing is sealed.** A certificate authority
says "this name belongs to the holder of this key", so the mesh signs a
public half it cannot use, and the certificate it issues is public. A
module asks for one and is given the certificate and, if it wants,
the mesh's own — the private key is a path to a file the machine already
has, the same arrangement the private network's key uses.
Asserted by verifying rather than inspecting, because a certificate that
parses and does not chain fails at the moment something connects:
- what the mesh issues verifies against the mesh, for the name asked for
- the name is in the subject alternative names, since a certificate
carrying it only in the common name is refused by every modern client
- it certifies the key the node generated and no other
- another mesh's certificate does not verify, which is the whole point of
two authorities being separate
- the authority cannot sign another authority — one that could is one
that can be delegated without anybody deciding to
- two control planes starting together agree on one authority, or a mesh
has certificates half its machines refuse
Certificates last ten years, which is a choice: a short life needs
something to renew it, and a renewal that fails silently is a mesh that
stops trusting itself on a date nobody wrote down. What makes one
replaceable is that the mesh reissues on demand, not that it expires.
jschoubben